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Groups > sci.electronics.design > #451909 > unrolled thread
| Started by | "billbowden" <bperryb@bowdenshobbycircuits.info> |
|---|---|
| First post | 2017-03-14 20:18 -0800 |
| Last post | 2017-03-24 21:35 +0200 |
| Articles | 20 on this page of 301 — 34 participants |
Back to article view | Back to sci.electronics.design
Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-14 20:18 -0800
Re: Antenna ferrite loopsticks verses air core? John Robertson <spam@flippers.com> - 2017-03-14 22:21 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-14 23:43 -0700
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-15 12:27 -0800
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 17:19 -0700
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-15 18:51 -0800
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 20:08 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-16 00:24 -0400
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 22:17 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-16 13:04 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-15 02:48 -0400
Re: Antenna ferrite loopsticks verses air core? makolber@yahoo.com - 2017-03-15 06:35 -0700
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-15 12:46 -0800
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 17:22 -0700
Re: Antenna ferrite loopsticks verses air core? Mike Perkins <spam@spam.com> - 2017-03-30 01:42 +0100
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-29 18:20 -0700
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-16 08:44 +0200
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 00:17 -0700
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-17 00:58 +0200
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 16:19 -0700
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-15 13:01 -0800
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-15 17:39 -0400
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 17:33 -0700
Re: Antenna ferrite loopsticks verses air core? "Dave M" <dgminala@mediacombb.net> - 2017-03-15 09:40 -0500
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 17:26 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-15 08:25 -0700
Re: Antenna ferrite loopsticks verses air core? Tim Wescott <seemywebsite@myfooter.really> - 2017-03-15 12:38 -0500
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 17:28 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-15 17:59 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-15 18:10 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-16 08:20 -0700
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-16 09:45 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-16 10:26 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 15:47 -0700
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-16 17:15 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 17:36 -0700
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-16 18:46 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 23:45 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-17 07:30 -0700
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-17 08:28 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-17 11:38 -0400
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-17 12:21 -0700
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-17 13:08 -0800
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-18 10:32 +1100
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-17 17:10 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-17 22:31 -0400
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-18 14:53 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-18 20:38 -0400
Re: Antenna ferrite loopsticks verses air core? Jeff Liebermann <jeffl@cruzio.com> - 2017-03-18 18:10 -0700
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-18 18:39 -0700
Re: Antenna ferrite loopsticks verses air core? Jeff Liebermann <jeffl@cruzio.com> - 2017-03-19 09:53 -0700
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-19 12:27 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-18 22:11 -0400
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-19 10:41 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-17 17:13 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-17 17:28 -0700
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-18 12:21 +0200
Re: Antenna ferrite loopsticks verses air core? Allan Herriman <allanherriman@hotmail.com> - 2017-03-18 12:15 +0000
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-17 17:36 -0700
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-17 18:09 -0700
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-17 18:21 -0700
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-18 10:49 +0200
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-18 08:30 -0700
Re: Antenna ferrite loopsticks verses air core? mkolber1@gmail.com - 2017-03-18 12:49 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-18 12:57 -0700
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-18 23:48 +0200
Re: Antenna ferrite loopsticks verses air core? krw@notreal.com - 2017-03-18 20:08 -0400
Re: Antenna ferrite loopsticks verses air core? kevin93 <kevin@whitedigs.com> - 2017-03-18 13:09 -0700
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-18 04:08 -0500
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-19 12:32 +1100
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-19 10:45 -0500
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-20 11:08 +1100
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-19 22:31 -0500
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-20 16:31 +1100
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-21 01:19 -0500
Re: Antenna ferrite loopsticks verses air core? Jasen Betts <jasen@xnet.co.nz> - 2017-03-22 19:15 +0000
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-18 10:41 +1100
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-18 14:47 -0700
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-19 00:22 +0200
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-19 12:39 +1100
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-18 19:11 -0700
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-19 13:15 +1100
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-20 04:26 -0700
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-21 13:17 +1100
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-21 01:32 -0500
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-21 10:38 +0200
Re: Antenna ferrite loopsticks verses air core? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-21 02:53 -0400
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-21 01:01 -0700
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-21 12:33 +0200
Re: Antenna ferrite loopsticks verses air core? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-21 09:42 -0400
Re: Antenna ferrite loopsticks verses air core? piglet <erichpwagner@hotmail.com> - 2017-03-21 19:05 +0000
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-21 12:49 -0700
Re: Antenna ferrite loopsticks verses air core? piglet <erichpwagner@hotmail.com> - 2017-03-21 18:39 +0000
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-21 22:39 +0200
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-21 12:30 +0200
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-19 17:43 +0200
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-21 14:39 +0200
Re: Antenna ferrite loopsticks verses air core? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-21 09:46 -0400
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-17 17:31 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-17 17:46 -0700
Re: Antenna ferrite loopsticks verses air core? George Herold <gherold@teachspin.com> - 2017-03-17 18:18 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-21 09:55 -0400
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-17 07:27 -0700
Re: Antenna ferrite loopsticks verses air core? DemonicTubes <tlackie@gmail.com> - 2017-03-17 09:11 -0700
Re: Antenna ferrite loopsticks verses air core? pcdhobbs@gmail.com - 2017-03-17 11:40 -0700
Re: Antenna ferrite loopsticks verses air core? bitrex <bitrex@de.lete.earthlink.net> - 2017-03-17 12:29 -0400
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-17 12:25 -0700
Re: Antenna ferrite loopsticks verses air core? bitrex <bitrex@de.lete.earthlink.net> - 2017-03-18 16:20 -0400
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 15:41 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-16 16:14 -0700
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 16:25 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-19 11:22 -0500
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-15 21:20 -0500
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-15 23:02 -0500
Re: Antenna ferrite loopsticks verses air core? whit3rd <whit3rd@gmail.com> - 2017-03-15 22:52 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-16 02:48 -0400
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 00:10 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-16 08:21 -0500
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-16 16:10 -0700
Re: Antenna ferrite loopsticks verses air core? Bill Beaty <billb@eskimo.com> - 2017-03-16 12:12 -0700
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-03-16 13:06 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-16 15:39 -0500
Re: Antenna ferrite loopsticks verses air core? John Larkin <jjlarkin@highlandtechnology.com> - 2017-03-16 19:57 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-18 21:26 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-17 09:44 -0700
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-17 17:35 -0700
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-17 18:35 -0800
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-20 09:01 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-19 08:20 -0500
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-19 15:31 -0800
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-19 19:42 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-19 19:20 -0500
Re: Antenna ferrite loopsticks verses air core? Phil Allison <pallison49@gmail.com> - 2017-03-19 17:49 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-19 20:19 -0500
Re: Antenna ferrite loopsticks verses air core? Robert Baer <robertbaer@localnet.com> - 2017-03-19 19:44 -0800
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 00:00 -0400
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-19 23:56 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 08:36 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-20 09:29 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 12:54 -0500
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 13:16 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-20 12:31 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 16:46 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 17:17 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-20 18:25 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 17:15 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 18:25 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 17:56 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-20 18:49 -0700
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-21 00:19 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-21 07:27 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-21 07:28 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-21 11:24 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-21 13:39 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-23 13:52 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-23 16:48 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-23 23:58 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-24 01:13 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-24 07:00 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-24 12:47 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-24 15:13 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-24 17:05 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-24 08:44 -0500
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-24 09:13 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-24 09:40 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-24 13:08 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-24 13:42 -0700
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-24 14:20 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-24 22:46 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-24 22:13 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 09:29 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-25 11:33 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 15:20 -0400
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-25 15:25 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 19:17 -0400
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-25 17:02 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 21:25 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 20:10 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 21:32 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 22:42 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-26 00:00 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-26 04:00 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-26 05:36 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-26 09:34 -0500
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-26 10:23 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-26 13:10 -0400
Re: Antenna ferrite loopsticks verses air core? Jasen Betts <jasen@xnet.co.nz> - 2017-03-27 09:32 +0000
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 14:44 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 16:34 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 16:12 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 17:44 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 17:08 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-25 16:00 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 18:27 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 19:31 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-25 21:21 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 23:42 -0400
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-25 17:34 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 16:34 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 17:21 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 18:27 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 17:54 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 20:55 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 20:09 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 21:28 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 21:23 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 23:25 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-21 07:54 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-21 07:57 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-21 11:54 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-21 12:21 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-21 21:40 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-21 13:27 -0400
Re: Antenna ferrite loopsticks verses air core? "billbowden" <bperryb@bowdenshobbycircuits.info> - 2017-03-20 15:41 -0800
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-20 19:13 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-20 21:18 -0400
Re: Antenna ferrite loopsticks verses air core? "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-03-21 04:35 -0500
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-20 11:06 +0200
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-24 10:14 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-24 13:59 -0400
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-24 13:36 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 13:49 -0400
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-25 12:30 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-25 21:39 -0400
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-26 07:35 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-26 13:15 -0400
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-27 07:46 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-27 10:59 -0400
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-27 09:22 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-27 23:47 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-28 18:15 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-28 03:42 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-28 19:07 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-28 04:35 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-28 21:58 +1100
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-28 09:42 -0500
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-28 12:51 +0300
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-28 07:23 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 13:28 -0400
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-30 00:37 +0300
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 21:02 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-28 09:57 -0500
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-28 09:05 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-28 11:27 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 13:29 -0400
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-27 14:57 +0300
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-27 07:25 -0500
Re: Antenna ferrite loopsticks verses air core? Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-03-27 09:47 -0700
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-27 19:51 +0300
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-27 12:21 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-27 18:54 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-28 10:16 +1100
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-27 16:58 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-27 23:33 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-28 18:18 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-28 03:48 -0400
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-28 07:28 -0700
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-28 13:41 +0300
Re: Antenna ferrite loopsticks verses air core? Jasen Betts <jasen@xnet.co.nz> - 2017-03-28 07:44 +0000
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-27 21:18 -0500
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-28 18:22 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-28 04:01 -0400
Re: Antenna ferrite loopsticks verses air core? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-03-28 11:04 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-28 10:58 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-28 11:13 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-28 10:12 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 13:47 -0400
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-29 14:18 -0500
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-30 00:47 +0300
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-29 19:15 -0500
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 21:40 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-29 14:26 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 23:47 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-29 10:18 +1100
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-03-29 19:12 -0500
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-29 11:49 +1100
Re: Antenna ferrite loopsticks verses air core? Jeff Liebermann <jeffl@cruzio.com> - 2017-03-29 18:21 -0700
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-29 14:19 +1100
Re: Antenna ferrite loopsticks verses air core? Jeff Liebermann <jeffl@cruzio.com> - 2017-03-29 18:01 -0700
Re: Antenna ferrite loopsticks verses air core? Ralph Barone <ralph@invalid.com> - 2017-03-30 02:35 +0000
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-03-29 14:23 +1100
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-29 23:46 -0400
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-03-30 21:40 -0700
Re: Antenna ferrite loopsticks verses air core? krw@notreal.com - 2017-03-31 20:08 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-04-02 12:59 +1000
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-04-01 23:55 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-04-02 14:36 +1000
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-04-02 01:56 -0400
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-04-02 18:11 +1000
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-04-02 07:35 -0500
Re: Antenna ferrite loopsticks verses air core? mkolber1@gmail.com - 2017-04-02 06:16 -0700
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-04-03 07:40 +1000
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-04-02 08:12 -0700
Re: Antenna ferrite loopsticks verses air core? Clifford Heath <no.spam@please.net> - 2017-04-03 08:47 +1000
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-04-02 18:39 -0700
Re: Antenna ferrite loopsticks verses air core? amdx <nojunk@knology.net> - 2017-04-02 21:22 -0500
Re: Antenna ferrite loopsticks verses air core? dagmargoodboat@yahoo.com - 2017-04-03 14:12 -0700
Re: Antenna ferrite loopsticks verses air core? rickman <gnuarm@gmail.com> - 2017-03-27 23:25 -0400
Re: Antenna ferrite loopsticks verses air core? upsidedown@downunder.com - 2017-03-28 12:58 +0300
Re: Antenna ferrite loopsticks verses air core? Joerg <news@analogconsultants.com> - 2017-03-27 07:52 -0700
Re: Antenna ferrite loopsticks verses air core? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-03-24 21:35 +0200
Page 12 of 16 — ← Prev page 1 … 10 11 [12] 13 14 … 16 Next page →
| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-24 13:36 -0700 |
| Message-ID | <ejleajFr79kU1@mid.individual.net> |
| In reply to | #453422 |
On 2017-03-24 10:59, rickman wrote: > On 3/24/2017 1:14 PM, Joerg wrote: >> On 2017-03-20 02:06, Tauno Voipio wrote: [...] >>> Please do not use PVC as RF insulation or support pieces. >>> It is lossy to extremely lossy at RF. >>> >> >> Plasticized PVC ain't stellar but not horrid. >> >> http://g3ynh.info/zdocs/comps/part_6.html >> >> Or do they add a lot of vispipuuro into the mix in Finland? :-) > > Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 > MHz. That is in no way acceptable for the sort of high Q circuits that > are being discussed. That's comparable to wood, 0.059. > > This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ 0.01. > The losses in ferrite rods are nothing to sneeze at in comparison. I have used both in ham radio a lot when I was young. I built kilowatt level RF power amps, impedance matching boxes and similar gear. Ferrite rods in transmitters sometimes became so hot that you could barely touch them while inductors wound on some random piece of PVC pipe remained cool. I don't remember the PVC type other than that it was remnants they sold for pennies in the plumbing department so that was very likely well plasticized. My comeuppance happened when I made a wideband and thus tapered-wound inductor on PVC pipe that was very long and I was concerned that it might snap off during transport. Fielddays, contests and such often required transport. So I took some allthread all the way to the top, big washer, cinched it down good and called it a day. HUGE mistake. It started to glow and melt the PVC. Luckily next to an open window as this stuff can potentially kill. -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-25 13:49 -0400 |
| Message-ID | <ob6ae3$5sr$1@dont-email.me> |
| In reply to | #453440 |
On 3/24/2017 4:36 PM, Joerg wrote: > On 2017-03-24 10:59, rickman wrote: >> On 3/24/2017 1:14 PM, Joerg wrote: >>> On 2017-03-20 02:06, Tauno Voipio wrote: > > [...] > >>>> Please do not use PVC as RF insulation or support pieces. >>>> It is lossy to extremely lossy at RF. >>>> >>> >>> Plasticized PVC ain't stellar but not horrid. >>> >>> http://g3ynh.info/zdocs/comps/part_6.html >>> >>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >> >> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 >> MHz. That is in no way acceptable for the sort of high Q circuits that >> are being discussed. That's comparable to wood, 0.059. >> >> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ 0.01. >> > > The losses in ferrite rods are nothing to sneeze at in comparison. I > have used both in ham radio a lot when I was young. I built kilowatt > level RF power amps, impedance matching boxes and similar gear. Ferrite > rods in transmitters sometimes became so hot that you could barely touch > them while inductors wound on some random piece of PVC pipe remained > cool. I don't remember the PVC type other than that it was remnants they > sold for pennies in the plumbing department so that was very likely well > plasticized. Maybe I don't recall the context of the ferrite, but the receiving antennas in much of this thread and described in detail at Kleijer's web site showed measurable losses with better plastics than PVC. Even cardboard was a poor support relatively speaking. Seems he would use a foam type plastic to get some rigidity with a minimum of loss. Foam PVC was not bad, but his Q measurements increased significantly with foam polypropylene. Obviously foam is better because there is less actual material. Solid PVC would show more pronounced losses. He does some amazingly detailed work. You might find it interesting. The LC experiments were reported in a series of web pages. Page 10 doesn't have a link to page 11, but otherwise they are all chained. http://www.crystal-radio.eu/enlctest.htm I found it very illuminating his tests with the variable capacitors. Even parts like bushings were found to make a difference. -- Rick C
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-25 12:30 -0700 |
| Message-ID | <ejnupqFbqtjU1@mid.individual.net> |
| In reply to | #453578 |
On 2017-03-25 10:49, rickman wrote: > On 3/24/2017 4:36 PM, Joerg wrote: >> On 2017-03-24 10:59, rickman wrote: >>> On 3/24/2017 1:14 PM, Joerg wrote: >>>> On 2017-03-20 02:06, Tauno Voipio wrote: >> >> [...] >> >>>>> Please do not use PVC as RF insulation or support pieces. >>>>> It is lossy to extremely lossy at RF. >>>>> >>>> >>>> Plasticized PVC ain't stellar but not horrid. >>>> >>>> http://g3ynh.info/zdocs/comps/part_6.html >>>> >>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>> >>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 >>> MHz. That is in no way acceptable for the sort of high Q circuits that >>> are being discussed. That's comparable to wood, 0.059. >>> >>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ 0.01. >>> >> >> The losses in ferrite rods are nothing to sneeze at in comparison. I >> have used both in ham radio a lot when I was young. I built kilowatt >> level RF power amps, impedance matching boxes and similar gear. Ferrite >> rods in transmitters sometimes became so hot that you could barely touch >> them while inductors wound on some random piece of PVC pipe remained >> cool. I don't remember the PVC type other than that it was remnants they >> sold for pennies in the plumbing department so that was very likely well >> plasticized. > > Maybe I don't recall the context of the ferrite, but the receiving > antennas in much of this thread and described in detail at Kleijer's web > site showed measurable losses with better plastics than PVC. Even > cardboard was a poor support relatively speaking. Seems he would use a > foam type plastic to get some rigidity with a minimum of loss. Foam PVC > was not bad, but his Q measurements increased significantly with foam > polypropylene. Obviously foam is better because there is less actual > material. Solid PVC would show more pronounced losses. > > He does some amazingly detailed work. You might find it interesting. > The LC experiments were reported in a series of web pages. Page 10 > doesn't have a link to page 11, but otherwise they are all chained. > Looks like there isn't a page 11. > http://www.crystal-radio.eu/enlctest.htm > He gets good Q with PVC. Worse with cardboard but who knows what kind of stuff he used. It looks like carton material. That is often post-consumer recycled and you never know what's in it. Water content is another factor, got to bake it out and then lacquer it immediately afterwards. The huge jump in Q in part 3 shows that he used the wrong measurement setup until then. You can't do this sort of stuff with a 100:1 scope probe, it has to be at least a high-end FET probe. However, hat off, he achieved amazing Q values in his experiments. Look at the Q values he gets in part 7. Those are all regular plumbing PVC pipes. L16 has lower Q but that PVC tube isn't even particularly clean. It is important to keep or make them pristine when building high-Q stuff. > I found it very illuminating his tests with the variable capacitors. > Even parts like bushings were found to make a difference. > I remember that from my ham radio days. Dirty or oxidized rotor contacts ... phssssst ... PHUT ... *BANG* and worst case that could take the tubes into the abyss along with it. I also spent part of a Wenol polishing paste tube keeping the final Pi-filter inductor shiny so it wouldn't heat up too badly and unsolder a connection to it (which could also result in a loud bang). BTW, while such high Q isn't all that useful in practice if you ever needed that there are simpler means to achieve it. An old method is the "Q-multiplier". In essence the resonance circuit sits inside an amplifier stage that is deliberately pulled very close to oscillation. That shrinks the bandwidth big time. -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-25 21:39 -0400 |
| Message-ID | <ob75u8$jae$1@dont-email.me> |
| In reply to | #453597 |
On 3/25/2017 3:30 PM, Joerg wrote: > On 2017-03-25 10:49, rickman wrote: >> On 3/24/2017 4:36 PM, Joerg wrote: >>> On 2017-03-24 10:59, rickman wrote: >>>> On 3/24/2017 1:14 PM, Joerg wrote: >>>>> On 2017-03-20 02:06, Tauno Voipio wrote: >>> >>> [...] >>> >>>>>> Please do not use PVC as RF insulation or support pieces. >>>>>> It is lossy to extremely lossy at RF. >>>>>> >>>>> >>>>> Plasticized PVC ain't stellar but not horrid. >>>>> >>>>> http://g3ynh.info/zdocs/comps/part_6.html >>>>> >>>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>>> >>>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 >>>> MHz. That is in no way acceptable for the sort of high Q circuits that >>>> are being discussed. That's comparable to wood, 0.059. >>>> >>>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ >>>> 0.01. >>>> >>> >>> The losses in ferrite rods are nothing to sneeze at in comparison. I >>> have used both in ham radio a lot when I was young. I built kilowatt >>> level RF power amps, impedance matching boxes and similar gear. Ferrite >>> rods in transmitters sometimes became so hot that you could barely touch >>> them while inductors wound on some random piece of PVC pipe remained >>> cool. I don't remember the PVC type other than that it was remnants they >>> sold for pennies in the plumbing department so that was very likely well >>> plasticized. >> >> Maybe I don't recall the context of the ferrite, but the receiving >> antennas in much of this thread and described in detail at Kleijer's web >> site showed measurable losses with better plastics than PVC. Even >> cardboard was a poor support relatively speaking. Seems he would use a >> foam type plastic to get some rigidity with a minimum of loss. Foam PVC >> was not bad, but his Q measurements increased significantly with foam >> polypropylene. Obviously foam is better because there is less actual >> material. Solid PVC would show more pronounced losses. >> >> He does some amazingly detailed work. You might find it interesting. >> The LC experiments were reported in a series of web pages. Page 10 >> doesn't have a link to page 11, but otherwise they are all chained. >> > > Looks like there isn't a page 11. That's what I was saying. There *is* a page 11, page 10 just doesn't have a link to it. Go back to the index. >> http://www.crystal-radio.eu/enlctest.htm >> > > He gets good Q with PVC. Worse with cardboard but who knows what kind of > stuff he used. It looks like carton material. That is often > post-consumer recycled and you never know what's in it. Water content is > another factor, got to bake it out and then lacquer it immediately > afterwards. He gets good Q with FOAM PVC. Totally different from solid PVC, much less of it and a lot more air. The point is foam anything else worked even better. > The huge jump in Q in part 3 shows that he used the wrong measurement > setup until then. You can't do this sort of stuff with a 100:1 scope > probe, it has to be at least a high-end FET probe. However, hat off, he > achieved amazing Q values in his experiments. > > Look at the Q values he gets in part 7. Those are all regular plumbing > PVC pipes. L16 has lower Q but that PVC tube isn't even particularly > clean. It is important to keep or make them pristine when building > high-Q stuff. > > >> I found it very illuminating his tests with the variable capacitors. >> Even parts like bushings were found to make a difference. >> > > I remember that from my ham radio days. Dirty or oxidized rotor contacts > .... phssssst ... PHUT ... *BANG* and worst case that could take the > tubes into the abyss along with it. I also spent part of a Wenol > polishing paste tube keeping the final Pi-filter inductor shiny so it > wouldn't heat up too badly and unsolder a connection to it (which could > also result in a loud bang). > > BTW, while such high Q isn't all that useful in practice if you ever > needed that there are simpler means to achieve it. An old method is the > "Q-multiplier". In essence the resonance circuit sits inside an > amplifier stage that is deliberately pulled very close to oscillation. > That shrinks the bandwidth big time. How do you accomplish that without an amplifier? You did notice the site is all about *crystal* radios, right? -- Rick C
[toc] | [prev] | [next] | [standalone]
| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-26 07:35 -0700 |
| Message-ID | <ejq1tfFo702U1@mid.individual.net> |
| In reply to | #453661 |
On 2017-03-25 18:39, rickman wrote: > On 3/25/2017 3:30 PM, Joerg wrote: >> On 2017-03-25 10:49, rickman wrote: >>> On 3/24/2017 4:36 PM, Joerg wrote: >>>> On 2017-03-24 10:59, rickman wrote: >>>>> On 3/24/2017 1:14 PM, Joerg wrote: >>>>>> On 2017-03-20 02:06, Tauno Voipio wrote: >>>> >>>> [...] >>>> >>>>>>> Please do not use PVC as RF insulation or support pieces. >>>>>>> It is lossy to extremely lossy at RF. >>>>>>> >>>>>> >>>>>> Plasticized PVC ain't stellar but not horrid. >>>>>> >>>>>> http://g3ynh.info/zdocs/comps/part_6.html >>>>>> >>>>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>>>> >>>>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 >>>>> MHz. That is in no way acceptable for the sort of high Q circuits >>>>> that >>>>> are being discussed. That's comparable to wood, 0.059. >>>>> >>>>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ >>>>> 0.01. >>>>> >>>> >>>> The losses in ferrite rods are nothing to sneeze at in comparison. I >>>> have used both in ham radio a lot when I was young. I built kilowatt >>>> level RF power amps, impedance matching boxes and similar gear. Ferrite >>>> rods in transmitters sometimes became so hot that you could barely >>>> touch >>>> them while inductors wound on some random piece of PVC pipe remained >>>> cool. I don't remember the PVC type other than that it was remnants >>>> they >>>> sold for pennies in the plumbing department so that was very likely >>>> well >>>> plasticized. >>> >>> Maybe I don't recall the context of the ferrite, but the receiving >>> antennas in much of this thread and described in detail at Kleijer's web >>> site showed measurable losses with better plastics than PVC. Even >>> cardboard was a poor support relatively speaking. Seems he would use a >>> foam type plastic to get some rigidity with a minimum of loss. Foam PVC >>> was not bad, but his Q measurements increased significantly with foam >>> polypropylene. Obviously foam is better because there is less actual >>> material. Solid PVC would show more pronounced losses. >>> >>> He does some amazingly detailed work. You might find it interesting. >>> The LC experiments were reported in a series of web pages. Page 10 >>> doesn't have a link to page 11, but otherwise they are all chained. >>> >> >> Looks like there isn't a page 11. > > That's what I was saying. There *is* a page 11, page 10 just doesn't > have a link to it. Go back to the index. > Indeed. I change the number in the URL by hand by starting with page 11 he change the URL structure. Well, I am not complaining, my web site design skills aren't that great either. > >>> http://www.crystal-radio.eu/enlctest.htm >>> >> >> He gets good Q with PVC. Worse with cardboard but who knows what kind of >> stuff he used. It looks like carton material. That is often >> post-consumer recycled and you never know what's in it. Water content is >> another factor, got to bake it out and then lacquer it immediately >> afterwards. > > He gets good Q with FOAM PVC. Totally different from solid PVC, much > less of it and a lot more air. The point is foam anything else worked > even better. > Look at page 7. Very nice Q values except for the dirty pipe yet this is all on regular PVC pipe. > >> The huge jump in Q in part 3 shows that he used the wrong measurement >> setup until then. You can't do this sort of stuff with a 100:1 scope >> probe, it has to be at least a high-end FET probe. However, hat off, he >> achieved amazing Q values in his experiments. >> >> Look at the Q values he gets in part 7. Those are all regular plumbing >> PVC pipes. L16 has lower Q but that PVC tube isn't even particularly >> clean. It is important to keep or make them pristine when building >> high-Q stuff. >> >> >>> I found it very illuminating his tests with the variable capacitors. >>> Even parts like bushings were found to make a difference. >>> >> >> I remember that from my ham radio days. Dirty or oxidized rotor contacts >> .... phssssst ... PHUT ... *BANG* and worst case that could take the >> tubes into the abyss along with it. I also spent part of a Wenol >> polishing paste tube keeping the final Pi-filter inductor shiny so it >> wouldn't heat up too badly and unsolder a connection to it (which could >> also result in a loud bang). >> >> BTW, while such high Q isn't all that useful in practice if you ever >> needed that there are simpler means to achieve it. An old method is the >> "Q-multiplier". In essence the resonance circuit sits inside an >> amplifier stage that is deliberately pulled very close to oscillation. >> That shrinks the bandwidth big time. > > How do you accomplish that without an amplifier? You did notice the > site is all about *crystal* radios, right? > You need an amplifier for that. If you want to you can make an energy-harvesting one, sans battery. I mentioned this method purely as a hint, in case anyone ever needs high Q without making fancy large coils and babying them. -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-26 13:15 -0400 |
| Message-ID | <ob8sqg$4bp$1@dont-email.me> |
| In reply to | #453752 |
On 3/26/2017 10:35 AM, Joerg wrote: > On 2017-03-25 18:39, rickman wrote: >> On 3/25/2017 3:30 PM, Joerg wrote: >>> On 2017-03-25 10:49, rickman wrote: >>>> On 3/24/2017 4:36 PM, Joerg wrote: >>>>> On 2017-03-24 10:59, rickman wrote: >>>>>> On 3/24/2017 1:14 PM, Joerg wrote: >>>>>>> On 2017-03-20 02:06, Tauno Voipio wrote: >>>>> >>>>> [...] >>>>> >>>>>>>> Please do not use PVC as RF insulation or support pieces. >>>>>>>> It is lossy to extremely lossy at RF. >>>>>>>> >>>>>>> >>>>>>> Plasticized PVC ain't stellar but not horrid. >>>>>>> >>>>>>> http://g3ynh.info/zdocs/comps/part_6.html >>>>>>> >>>>>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>>>>> >>>>>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 >>>>>> MHz. That is in no way acceptable for the sort of high Q circuits >>>>>> that >>>>>> are being discussed. That's comparable to wood, 0.059. >>>>>> >>>>>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ >>>>>> 0.01. >>>>>> >>>>> >>>>> The losses in ferrite rods are nothing to sneeze at in comparison. I >>>>> have used both in ham radio a lot when I was young. I built kilowatt >>>>> level RF power amps, impedance matching boxes and similar gear. >>>>> Ferrite >>>>> rods in transmitters sometimes became so hot that you could barely >>>>> touch >>>>> them while inductors wound on some random piece of PVC pipe remained >>>>> cool. I don't remember the PVC type other than that it was remnants >>>>> they >>>>> sold for pennies in the plumbing department so that was very likely >>>>> well >>>>> plasticized. >>>> >>>> Maybe I don't recall the context of the ferrite, but the receiving >>>> antennas in much of this thread and described in detail at Kleijer's >>>> web >>>> site showed measurable losses with better plastics than PVC. Even >>>> cardboard was a poor support relatively speaking. Seems he would use a >>>> foam type plastic to get some rigidity with a minimum of loss. Foam >>>> PVC >>>> was not bad, but his Q measurements increased significantly with foam >>>> polypropylene. Obviously foam is better because there is less actual >>>> material. Solid PVC would show more pronounced losses. >>>> >>>> He does some amazingly detailed work. You might find it interesting. >>>> The LC experiments were reported in a series of web pages. Page 10 >>>> doesn't have a link to page 11, but otherwise they are all chained. >>>> >>> >>> Looks like there isn't a page 11. >> >> That's what I was saying. There *is* a page 11, page 10 just doesn't >> have a link to it. Go back to the index. >> > > Indeed. I change the number in the URL by hand by starting with page 11 > he change the URL structure. Well, I am not complaining, my web site > design skills aren't that great either. > >> >>>> http://www.crystal-radio.eu/enlctest.htm >>>> >>> >>> He gets good Q with PVC. Worse with cardboard but who knows what kind of >>> stuff he used. It looks like carton material. That is often >>> post-consumer recycled and you never know what's in it. Water content is >>> another factor, got to bake it out and then lacquer it immediately >>> afterwards. >> >> He gets good Q with FOAM PVC. Totally different from solid PVC, much >> less of it and a lot more air. The point is foam anything else worked >> even better. >> > > Look at page 7. Very nice Q values except for the dirty pipe yet this is > all on regular PVC pipe. Compared to what? He is comparing coil winding methods. What would the Q be with other supports? >>> The huge jump in Q in part 3 shows that he used the wrong measurement >>> setup until then. You can't do this sort of stuff with a 100:1 scope >>> probe, it has to be at least a high-end FET probe. However, hat off, he >>> achieved amazing Q values in his experiments. >>> >>> Look at the Q values he gets in part 7. Those are all regular plumbing >>> PVC pipes. L16 has lower Q but that PVC tube isn't even particularly >>> clean. It is important to keep or make them pristine when building >>> high-Q stuff. >>> >>> >>>> I found it very illuminating his tests with the variable capacitors. >>>> Even parts like bushings were found to make a difference. >>>> >>> >>> I remember that from my ham radio days. Dirty or oxidized rotor contacts >>> .... phssssst ... PHUT ... *BANG* and worst case that could take the >>> tubes into the abyss along with it. I also spent part of a Wenol >>> polishing paste tube keeping the final Pi-filter inductor shiny so it >>> wouldn't heat up too badly and unsolder a connection to it (which could >>> also result in a loud bang). >>> >>> BTW, while such high Q isn't all that useful in practice if you ever >>> needed that there are simpler means to achieve it. An old method is the >>> "Q-multiplier". In essence the resonance circuit sits inside an >>> amplifier stage that is deliberately pulled very close to oscillation. >>> That shrinks the bandwidth big time. >> >> How do you accomplish that without an amplifier? You did notice the >> site is all about *crystal* radios, right? >> > > You need an amplifier for that. If you want to you can make an > energy-harvesting one, sans battery. I mentioned this method purely as a > hint, in case anyone ever needs high Q without making fancy large coils > and babying them. What energy will be harvested? -- Rick C
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-27 07:46 -0700 |
| Message-ID | <ejsmu8F9p23U1@mid.individual.net> |
| In reply to | #453773 |
On 2017-03-26 10:15, rickman wrote: > On 3/26/2017 10:35 AM, Joerg wrote: >> On 2017-03-25 18:39, rickman wrote: >>> On 3/25/2017 3:30 PM, Joerg wrote: >>>> On 2017-03-25 10:49, rickman wrote: >>>>> On 3/24/2017 4:36 PM, Joerg wrote: >>>>>> On 2017-03-24 10:59, rickman wrote: >>>>>>> On 3/24/2017 1:14 PM, Joerg wrote: >>>>>>>> On 2017-03-20 02:06, Tauno Voipio wrote: >>>>>> >>>>>> [...] >>>>>> >>>>>>>>> Please do not use PVC as RF insulation or support pieces. >>>>>>>>> It is lossy to extremely lossy at RF. >>>>>>>>> >>>>>>>> >>>>>>>> Plasticized PVC ain't stellar but not horrid. >>>>>>>> >>>>>>>> http://g3ynh.info/zdocs/comps/part_6.html >>>>>>>> >>>>>>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>>>>>> >>>>>>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 at 1 >>>>>>> MHz. That is in no way acceptable for the sort of high Q circuits >>>>>>> that >>>>>>> are being discussed. That's comparable to wood, 0.059. >>>>>>> >>>>>>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ >>>>>>> 0.01. >>>>>>> >>>>>> >>>>>> The losses in ferrite rods are nothing to sneeze at in comparison. I >>>>>> have used both in ham radio a lot when I was young. I built kilowatt >>>>>> level RF power amps, impedance matching boxes and similar gear. >>>>>> Ferrite >>>>>> rods in transmitters sometimes became so hot that you could barely >>>>>> touch >>>>>> them while inductors wound on some random piece of PVC pipe remained >>>>>> cool. I don't remember the PVC type other than that it was remnants >>>>>> they >>>>>> sold for pennies in the plumbing department so that was very likely >>>>>> well >>>>>> plasticized. >>>>> >>>>> Maybe I don't recall the context of the ferrite, but the receiving >>>>> antennas in much of this thread and described in detail at Kleijer's >>>>> web >>>>> site showed measurable losses with better plastics than PVC. Even >>>>> cardboard was a poor support relatively speaking. Seems he would >>>>> use a >>>>> foam type plastic to get some rigidity with a minimum of loss. Foam >>>>> PVC >>>>> was not bad, but his Q measurements increased significantly with foam >>>>> polypropylene. Obviously foam is better because there is less actual >>>>> material. Solid PVC would show more pronounced losses. >>>>> >>>>> He does some amazingly detailed work. You might find it interesting. >>>>> The LC experiments were reported in a series of web pages. Page 10 >>>>> doesn't have a link to page 11, but otherwise they are all chained. >>>>> >>>> >>>> Looks like there isn't a page 11. >>> >>> That's what I was saying. There *is* a page 11, page 10 just doesn't >>> have a link to it. Go back to the index. >>> >> >> Indeed. I change the number in the URL by hand by starting with page 11 >> he change the URL structure. Well, I am not complaining, my web site >> design skills aren't that great either. >> >>> >>>>> http://www.crystal-radio.eu/enlctest.htm >>>>> >>>> >>>> He gets good Q with PVC. Worse with cardboard but who knows what >>>> kind of >>>> stuff he used. It looks like carton material. That is often >>>> post-consumer recycled and you never know what's in it. Water >>>> content is >>>> another factor, got to bake it out and then lacquer it immediately >>>> afterwards. >>> >>> He gets good Q with FOAM PVC. Totally different from solid PVC, much >>> less of it and a lot more air. The point is foam anything else worked >>> even better. >>> >> >> Look at page 7. Very nice Q values except for the dirty pipe yet this is >> all on regular PVC pipe. > > Compared to what? He is comparing coil winding methods. What would the > Q be with other supports? > The Q is over 500. It was claimed in this thread that PVC is not suitable as coil winding material and this proves that it is quite suitable. Which I already knew because I've used it in RF power amps decades ago. > >>>> The huge jump in Q in part 3 shows that he used the wrong measurement >>>> setup until then. You can't do this sort of stuff with a 100:1 scope >>>> probe, it has to be at least a high-end FET probe. However, hat off, he >>>> achieved amazing Q values in his experiments. >>>> >>>> Look at the Q values he gets in part 7. Those are all regular plumbing >>>> PVC pipes. L16 has lower Q but that PVC tube isn't even particularly >>>> clean. It is important to keep or make them pristine when building >>>> high-Q stuff. >>>> >>>> >>>>> I found it very illuminating his tests with the variable capacitors. >>>>> Even parts like bushings were found to make a difference. >>>>> >>>> >>>> I remember that from my ham radio days. Dirty or oxidized rotor >>>> contacts >>>> .... phssssst ... PHUT ... *BANG* and worst case that could take the >>>> tubes into the abyss along with it. I also spent part of a Wenol >>>> polishing paste tube keeping the final Pi-filter inductor shiny so it >>>> wouldn't heat up too badly and unsolder a connection to it (which could >>>> also result in a loud bang). >>>> >>>> BTW, while such high Q isn't all that useful in practice if you ever >>>> needed that there are simpler means to achieve it. An old method is the >>>> "Q-multiplier". In essence the resonance circuit sits inside an >>>> amplifier stage that is deliberately pulled very close to oscillation. >>>> That shrinks the bandwidth big time. >>> >>> How do you accomplish that without an amplifier? You did notice the >>> site is all about *crystal* radios, right? >>> >> >> You need an amplifier for that. If you want to you can make an >> energy-harvesting one, sans battery. I mentioned this method purely as a >> hint, in case anyone ever needs high Q without making fancy large coils >> and babying them. > > What energy will be harvested? > The energy present in the environment, for example energy from the local radio transmitters. You can then use that to demodulate the signals of others. http://mwrf.com/systems/harvesting-energy-rf-sources -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-27 10:59 -0400 |
| Message-ID | <obb96t$1ff$1@dont-email.me> |
| In reply to | #453876 |
On 3/27/2017 10:46 AM, Joerg wrote: > On 2017-03-26 10:15, rickman wrote: >> On 3/26/2017 10:35 AM, Joerg wrote: >>> On 2017-03-25 18:39, rickman wrote: >>>> On 3/25/2017 3:30 PM, Joerg wrote: >>>>> On 2017-03-25 10:49, rickman wrote: >>>>>> On 3/24/2017 4:36 PM, Joerg wrote: >>>>>>> On 2017-03-24 10:59, rickman wrote: >>>>>>>> On 3/24/2017 1:14 PM, Joerg wrote: >>>>>>>>> On 2017-03-20 02:06, Tauno Voipio wrote: >>>>>>> >>>>>>> [...] >>>>>>> >>>>>>>>>> Please do not use PVC as RF insulation or support pieces. >>>>>>>>>> It is lossy to extremely lossy at RF. >>>>>>>>>> >>>>>>>>> >>>>>>>>> Plasticized PVC ain't stellar but not horrid. >>>>>>>>> >>>>>>>>> http://g3ynh.info/zdocs/comps/part_6.html >>>>>>>>> >>>>>>>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>>>>>>> >>>>>>>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 >>>>>>>> at 1 >>>>>>>> MHz. That is in no way acceptable for the sort of high Q circuits >>>>>>>> that >>>>>>>> are being discussed. That's comparable to wood, 0.059. >>>>>>>> >>>>>>>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ >>>>>>>> 0.01. >>>>>>>> >>>>>>> >>>>>>> The losses in ferrite rods are nothing to sneeze at in comparison. I >>>>>>> have used both in ham radio a lot when I was young. I built kilowatt >>>>>>> level RF power amps, impedance matching boxes and similar gear. >>>>>>> Ferrite >>>>>>> rods in transmitters sometimes became so hot that you could barely >>>>>>> touch >>>>>>> them while inductors wound on some random piece of PVC pipe remained >>>>>>> cool. I don't remember the PVC type other than that it was remnants >>>>>>> they >>>>>>> sold for pennies in the plumbing department so that was very likely >>>>>>> well >>>>>>> plasticized. >>>>>> >>>>>> Maybe I don't recall the context of the ferrite, but the receiving >>>>>> antennas in much of this thread and described in detail at Kleijer's >>>>>> web >>>>>> site showed measurable losses with better plastics than PVC. Even >>>>>> cardboard was a poor support relatively speaking. Seems he would >>>>>> use a >>>>>> foam type plastic to get some rigidity with a minimum of loss. Foam >>>>>> PVC >>>>>> was not bad, but his Q measurements increased significantly with foam >>>>>> polypropylene. Obviously foam is better because there is less actual >>>>>> material. Solid PVC would show more pronounced losses. >>>>>> >>>>>> He does some amazingly detailed work. You might find it interesting. >>>>>> The LC experiments were reported in a series of web pages. Page 10 >>>>>> doesn't have a link to page 11, but otherwise they are all chained. >>>>>> >>>>> >>>>> Looks like there isn't a page 11. >>>> >>>> That's what I was saying. There *is* a page 11, page 10 just doesn't >>>> have a link to it. Go back to the index. >>>> >>> >>> Indeed. I change the number in the URL by hand by starting with page 11 >>> he change the URL structure. Well, I am not complaining, my web site >>> design skills aren't that great either. >>> >>>> >>>>>> http://www.crystal-radio.eu/enlctest.htm >>>>>> >>>>> >>>>> He gets good Q with PVC. Worse with cardboard but who knows what >>>>> kind of >>>>> stuff he used. It looks like carton material. That is often >>>>> post-consumer recycled and you never know what's in it. Water >>>>> content is >>>>> another factor, got to bake it out and then lacquer it immediately >>>>> afterwards. >>>> >>>> He gets good Q with FOAM PVC. Totally different from solid PVC, much >>>> less of it and a lot more air. The point is foam anything else worked >>>> even better. >>>> >>> >>> Look at page 7. Very nice Q values except for the dirty pipe yet this is >>> all on regular PVC pipe. >> >> Compared to what? He is comparing coil winding methods. What would the >> Q be with other supports? >> > > The Q is over 500. It was claimed in this thread that PVC is not > suitable as coil winding material and this proves that it is quite > suitable. Which I already knew because I've used it in RF power amps > decades ago. Again, context. You are living in a different world. PVC is *not* suitable in the crystal radio world because there are *much* better materials. If PVC was the only material available it would be a *great* coil support. If mud was the only material available it would be a *great* coil support. >>>>> The huge jump in Q in part 3 shows that he used the wrong measurement >>>>> setup until then. You can't do this sort of stuff with a 100:1 scope >>>>> probe, it has to be at least a high-end FET probe. However, hat >>>>> off, he >>>>> achieved amazing Q values in his experiments. >>>>> >>>>> Look at the Q values he gets in part 7. Those are all regular plumbing >>>>> PVC pipes. L16 has lower Q but that PVC tube isn't even particularly >>>>> clean. It is important to keep or make them pristine when building >>>>> high-Q stuff. >>>>> >>>>> >>>>>> I found it very illuminating his tests with the variable capacitors. >>>>>> Even parts like bushings were found to make a difference. >>>>>> >>>>> >>>>> I remember that from my ham radio days. Dirty or oxidized rotor >>>>> contacts >>>>> .... phssssst ... PHUT ... *BANG* and worst case that could take the >>>>> tubes into the abyss along with it. I also spent part of a Wenol >>>>> polishing paste tube keeping the final Pi-filter inductor shiny so it >>>>> wouldn't heat up too badly and unsolder a connection to it (which >>>>> could >>>>> also result in a loud bang). >>>>> >>>>> BTW, while such high Q isn't all that useful in practice if you ever >>>>> needed that there are simpler means to achieve it. An old method is >>>>> the >>>>> "Q-multiplier". In essence the resonance circuit sits inside an >>>>> amplifier stage that is deliberately pulled very close to oscillation. >>>>> That shrinks the bandwidth big time. >>>> >>>> How do you accomplish that without an amplifier? You did notice the >>>> site is all about *crystal* radios, right? >>>> >>> >>> You need an amplifier for that. If you want to you can make an >>> energy-harvesting one, sans battery. I mentioned this method purely as a >>> hint, in case anyone ever needs high Q without making fancy large coils >>> and babying them. >> >> What energy will be harvested? >> > > The energy present in the environment, for example energy from the local > radio transmitters. You can then use that to demodulate the signals of > others. > > http://mwrf.com/systems/harvesting-energy-rf-sources I understand the concept, I'm asking specifically. Have you built anything like this? -- Rick C
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-27 09:22 -0700 |
| Message-ID | <ejsshiFat27U1@mid.individual.net> |
| In reply to | #453880 |
On 2017-03-27 07:59, rickman wrote: > On 3/27/2017 10:46 AM, Joerg wrote: >> On 2017-03-26 10:15, rickman wrote: >>> On 3/26/2017 10:35 AM, Joerg wrote: >>>> On 2017-03-25 18:39, rickman wrote: >>>>> On 3/25/2017 3:30 PM, Joerg wrote: >>>>>> On 2017-03-25 10:49, rickman wrote: >>>>>>> On 3/24/2017 4:36 PM, Joerg wrote: >>>>>>>> On 2017-03-24 10:59, rickman wrote: >>>>>>>>> On 3/24/2017 1:14 PM, Joerg wrote: >>>>>>>>>> On 2017-03-20 02:06, Tauno Voipio wrote: >>>>>>>> >>>>>>>> [...] >>>>>>>> >>>>>>>>>>> Please do not use PVC as RF insulation or support pieces. >>>>>>>>>>> It is lossy to extremely lossy at RF. >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Plasticized PVC ain't stellar but not horrid. >>>>>>>>>> >>>>>>>>>> http://g3ynh.info/zdocs/comps/part_6.html >>>>>>>>>> >>>>>>>>>> Or do they add a lot of vispipuuro into the mix in Finland? :-) >>>>>>>>> >>>>>>>>> Are you reading the same page? It says PVC Tanδ is 0.04 - 0.14 >>>>>>>>> at 1 >>>>>>>>> MHz. That is in no way acceptable for the sort of high Q circuits >>>>>>>>> that >>>>>>>>> are being discussed. That's comparable to wood, 0.059. >>>>>>>>> >>>>>>>>> This page even lists PVC in the "Lossy" group as defined by Tanδ ≥ >>>>>>>>> 0.01. >>>>>>>>> >>>>>>>> >>>>>>>> The losses in ferrite rods are nothing to sneeze at in >>>>>>>> comparison. I >>>>>>>> have used both in ham radio a lot when I was young. I built >>>>>>>> kilowatt >>>>>>>> level RF power amps, impedance matching boxes and similar gear. >>>>>>>> Ferrite >>>>>>>> rods in transmitters sometimes became so hot that you could barely >>>>>>>> touch >>>>>>>> them while inductors wound on some random piece of PVC pipe >>>>>>>> remained >>>>>>>> cool. I don't remember the PVC type other than that it was remnants >>>>>>>> they >>>>>>>> sold for pennies in the plumbing department so that was very likely >>>>>>>> well >>>>>>>> plasticized. >>>>>>> >>>>>>> Maybe I don't recall the context of the ferrite, but the receiving >>>>>>> antennas in much of this thread and described in detail at Kleijer's >>>>>>> web >>>>>>> site showed measurable losses with better plastics than PVC. Even >>>>>>> cardboard was a poor support relatively speaking. Seems he would >>>>>>> use a >>>>>>> foam type plastic to get some rigidity with a minimum of loss. Foam >>>>>>> PVC >>>>>>> was not bad, but his Q measurements increased significantly with >>>>>>> foam >>>>>>> polypropylene. Obviously foam is better because there is less >>>>>>> actual >>>>>>> material. Solid PVC would show more pronounced losses. >>>>>>> >>>>>>> He does some amazingly detailed work. You might find it >>>>>>> interesting. >>>>>>> The LC experiments were reported in a series of web pages. Page 10 >>>>>>> doesn't have a link to page 11, but otherwise they are all chained. >>>>>>> >>>>>> >>>>>> Looks like there isn't a page 11. >>>>> >>>>> That's what I was saying. There *is* a page 11, page 10 just doesn't >>>>> have a link to it. Go back to the index. >>>>> >>>> >>>> Indeed. I change the number in the URL by hand by starting with page 11 >>>> he change the URL structure. Well, I am not complaining, my web site >>>> design skills aren't that great either. >>>> >>>>> >>>>>>> http://www.crystal-radio.eu/enlctest.htm >>>>>>> >>>>>> >>>>>> He gets good Q with PVC. Worse with cardboard but who knows what >>>>>> kind of >>>>>> stuff he used. It looks like carton material. That is often >>>>>> post-consumer recycled and you never know what's in it. Water >>>>>> content is >>>>>> another factor, got to bake it out and then lacquer it immediately >>>>>> afterwards. >>>>> >>>>> He gets good Q with FOAM PVC. Totally different from solid PVC, much >>>>> less of it and a lot more air. The point is foam anything else worked >>>>> even better. >>>>> >>>> >>>> Look at page 7. Very nice Q values except for the dirty pipe yet >>>> this is >>>> all on regular PVC pipe. >>> >>> Compared to what? He is comparing coil winding methods. What would the >>> Q be with other supports? >>> >> >> The Q is over 500. It was claimed in this thread that PVC is not >> suitable as coil winding material and this proves that it is quite >> suitable. Which I already knew because I've used it in RF power amps >> decades ago. > > Again, context. You are living in a different world. PVC is *not* > suitable in the crystal radio world because there are *much* better > materials. If PVC was the only material available it would be a *great* > coil support. If mud was the only material available it would be a > *great* coil support. > Can you explain why one even want a Q in excess of 500 in the AM band? > >>>>>> The huge jump in Q in part 3 shows that he used the wrong measurement >>>>>> setup until then. You can't do this sort of stuff with a 100:1 scope >>>>>> probe, it has to be at least a high-end FET probe. However, hat >>>>>> off, he >>>>>> achieved amazing Q values in his experiments. >>>>>> >>>>>> Look at the Q values he gets in part 7. Those are all regular >>>>>> plumbing >>>>>> PVC pipes. L16 has lower Q but that PVC tube isn't even particularly >>>>>> clean. It is important to keep or make them pristine when building >>>>>> high-Q stuff. >>>>>> >>>>>> >>>>>>> I found it very illuminating his tests with the variable capacitors. >>>>>>> Even parts like bushings were found to make a difference. >>>>>>> >>>>>> >>>>>> I remember that from my ham radio days. Dirty or oxidized rotor >>>>>> contacts >>>>>> .... phssssst ... PHUT ... *BANG* and worst case that could take the >>>>>> tubes into the abyss along with it. I also spent part of a Wenol >>>>>> polishing paste tube keeping the final Pi-filter inductor shiny so it >>>>>> wouldn't heat up too badly and unsolder a connection to it (which >>>>>> could >>>>>> also result in a loud bang). >>>>>> >>>>>> BTW, while such high Q isn't all that useful in practice if you ever >>>>>> needed that there are simpler means to achieve it. An old method is >>>>>> the >>>>>> "Q-multiplier". In essence the resonance circuit sits inside an >>>>>> amplifier stage that is deliberately pulled very close to >>>>>> oscillation. >>>>>> That shrinks the bandwidth big time. >>>>> >>>>> How do you accomplish that without an amplifier? You did notice the >>>>> site is all about *crystal* radios, right? >>>>> >>>> >>>> You need an amplifier for that. If you want to you can make an >>>> energy-harvesting one, sans battery. I mentioned this method purely >>>> as a >>>> hint, in case anyone ever needs high Q without making fancy large coils >>>> and babying them. >>> >>> What energy will be harvested? >>> >> >> The energy present in the environment, for example energy from the local >> radio transmitters. You can then use that to demodulate the signals of >> others. >> >> http://mwrf.com/systems/harvesting-energy-rf-sources > > I understand the concept, I'm asking specifically. Have you built > anything like this? > Yes, similar but not at liberty to reveal details as this was paid client work. -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-27 23:47 -0400 |
| Message-ID | <obcm64$e0c$1@dont-email.me> |
| In reply to | #453886 |
On 3/27/2017 12:22 PM, Joerg wrote: > On 2017-03-27 07:59, rickman wrote: >> On 3/27/2017 10:46 AM, Joerg wrote: >>> >>> The Q is over 500. It was claimed in this thread that PVC is not >>> suitable as coil winding material and this proves that it is quite >>> suitable. Which I already knew because I've used it in RF power amps >>> decades ago. >> >> Again, context. You are living in a different world. PVC is *not* >> suitable in the crystal radio world because there are *much* better >> materials. If PVC was the only material available it would be a *great* >> coil support. If mud was the only material available it would be a >> *great* coil support. >> > > Can you explain why one even want a Q in excess of 500 in the AM band? Q is a measure of the losses. Having a high Q in the coil means the coil has lower losses. Having a higher Q in the tuning capacitor means it has lower losses. The lower the losses the more power that ends up in the headphones. The Q of the radio won't be the same as the Q of the components because you are sucking off power to drive the headphones. Besides, the number you came up with (10 kHz) would be perfect for AM radio if you can get that, that is the channel spacing. Great selectivity. -- Rick C
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| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-28 18:15 +1100 |
| Message-ID | <58da0d81$0$39527$b1db1813$7968482@news.astraweb.com> |
| In reply to | #453950 |
On 28/03/17 14:47, rickman wrote: > On 3/27/2017 12:22 PM, Joerg wrote: >> On 2017-03-27 07:59, rickman wrote: >>> On 3/27/2017 10:46 AM, Joerg wrote: >>>> >>>> The Q is over 500. It was claimed in this thread that PVC is not >>>> suitable as coil winding material and this proves that it is quite >>>> suitable. Which I already knew because I've used it in RF power amps >>>> decades ago. >>> >>> Again, context. You are living in a different world. PVC is *not* >>> suitable in the crystal radio world because there are *much* better >>> materials. If PVC was the only material available it would be a *great* >>> coil support. If mud was the only material available it would be a >>> *great* coil support. >>> >> >> Can you explain why one even want a Q in excess of 500 in the AM band? > > Q is a measure of the losses. Having a high Q in the coil means the > coil has lower losses. Having a higher Q in the tuning capacitor means > it has lower losses. The lower the losses the more power that ends up > in the headphones. You have this quite wrong. A Q of 500 is a loss of 0.2%, and 1500 is a loss of only 0.067%. Increase your coil area by 0.13% (a fraction of a millimeter of diameter) and you recover the power you lost by "only" having a Q of 500, by gathering more power to start with. Furthermore, because the signal of interest spreads +-5Khz or so, when you use a super high Q, you *reject* the parts of the signal that are outside the passband. So yeah, you get more voltage for for the low audio frequencies, but *less power overall*. Duh. Doesn't sound like such a good deal now, does it? Clifford Heath.
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-28 03:42 -0400 |
| Message-ID | <obd3vj$fgu$1@dont-email.me> |
| In reply to | #453961 |
On 3/28/2017 3:15 AM, Clifford Heath wrote: > On 28/03/17 14:47, rickman wrote: >> On 3/27/2017 12:22 PM, Joerg wrote: >>> On 2017-03-27 07:59, rickman wrote: >>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>> >>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>> suitable as coil winding material and this proves that it is quite >>>>> suitable. Which I already knew because I've used it in RF power amps >>>>> decades ago. >>>> >>>> Again, context. You are living in a different world. PVC is *not* >>>> suitable in the crystal radio world because there are *much* better >>>> materials. If PVC was the only material available it would be a >>>> *great* >>>> coil support. If mud was the only material available it would be a >>>> *great* coil support. >>>> >>> >>> Can you explain why one even want a Q in excess of 500 in the AM band? >> >> Q is a measure of the losses. Having a high Q in the coil means the >> coil has lower losses. Having a higher Q in the tuning capacitor means >> it has lower losses. The lower the losses the more power that ends up >> in the headphones. > > You have this quite wrong. A Q of 500 is a loss of 0.2%, and > 1500 is a loss of only 0.067%. Increase your coil area by 0.13% > (a fraction of a millimeter of diameter) and you recover the > power you lost by "only" having a Q of 500, by gathering more > power to start with. > > Furthermore, because the signal of interest spreads +-5Khz or so, > when you use a super high Q, you *reject* the parts of the signal > that are outside the passband. So yeah, you get more voltage for > for the low audio frequencies, but *less power overall*. > > Duh. Doesn't sound like such a good deal now, does it? You trimmed the part of my post that dealt with the bandwidth issue. Why don't you read that again? Just like Joerg you are applying knowledge of electronics to part of a receiver without understanding how it all works together. Oh, and these receivers typically use a long wire antenna, not the coil, to collect the signal. -- Rick C
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| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-28 19:07 +1100 |
| Message-ID | <58da19c4$0$60300$c3e8da3$66d3cc2f@news.astraweb.com> |
| In reply to | #453965 |
On 28/03/17 18:42, rickman wrote: > On 3/28/2017 3:15 AM, Clifford Heath wrote: >> On 28/03/17 14:47, rickman wrote: >>> On 3/27/2017 12:22 PM, Joerg wrote: >>>> On 2017-03-27 07:59, rickman wrote: >>>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>>> >>>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>>> suitable as coil winding material and this proves that it is quite >>>>>> suitable. Which I already knew because I've used it in RF power amps >>>>>> decades ago. >>>>> >>>>> Again, context. You are living in a different world. PVC is *not* >>>>> suitable in the crystal radio world because there are *much* better >>>>> materials. If PVC was the only material available it would be a >>>>> *great* >>>>> coil support. If mud was the only material available it would be a >>>>> *great* coil support. >>>>> >>>> >>>> Can you explain why one even want a Q in excess of 500 in the AM band? >>> >>> Q is a measure of the losses. Having a high Q in the coil means the >>> coil has lower losses. Having a higher Q in the tuning capacitor means >>> it has lower losses. The lower the losses the more power that ends up >>> in the headphones. >> >> You have this quite wrong. A Q of 500 is a loss of 0.2%, and >> 1500 is a loss of only 0.067%. Increase your coil area by 0.13% >> (a fraction of a millimeter of diameter) and you recover the >> power you lost by "only" having a Q of 500, by gathering more >> power to start with. >> >> Furthermore, because the signal of interest spreads +-5Khz or so, >> when you use a super high Q, you *reject* the parts of the signal >> that are outside the passband. So yeah, you get more voltage for >> for the low audio frequencies, but *less power overall*. >> >> Duh. Doesn't sound like such a good deal now, does it? > > You trimmed the part of my post that dealt with the bandwidth issue. Why > don't you read that again? Because you said 10KHz, when your bandwidth is nothing like that. I just couldn't be bothered to call you on all your lie^H^H^Halternative facts
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-28 04:35 -0400 |
| Message-ID | <obd73k$o6s$1@dont-email.me> |
| In reply to | #453969 |
On 3/28/2017 4:07 AM, Clifford Heath wrote: > On 28/03/17 18:42, rickman wrote: >> On 3/28/2017 3:15 AM, Clifford Heath wrote: >>> On 28/03/17 14:47, rickman wrote: >>>> On 3/27/2017 12:22 PM, Joerg wrote: >>>>> On 2017-03-27 07:59, rickman wrote: >>>>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>>>> >>>>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>>>> suitable as coil winding material and this proves that it is quite >>>>>>> suitable. Which I already knew because I've used it in RF power amps >>>>>>> decades ago. >>>>>> >>>>>> Again, context. You are living in a different world. PVC is *not* >>>>>> suitable in the crystal radio world because there are *much* better >>>>>> materials. If PVC was the only material available it would be a >>>>>> *great* >>>>>> coil support. If mud was the only material available it would be a >>>>>> *great* coil support. >>>>>> >>>>> >>>>> Can you explain why one even want a Q in excess of 500 in the AM band? >>>> >>>> Q is a measure of the losses. Having a high Q in the coil means the >>>> coil has lower losses. Having a higher Q in the tuning capacitor means >>>> it has lower losses. The lower the losses the more power that ends up >>>> in the headphones. >>> >>> You have this quite wrong. A Q of 500 is a loss of 0.2%, and >>> 1500 is a loss of only 0.067%. Increase your coil area by 0.13% >>> (a fraction of a millimeter of diameter) and you recover the >>> power you lost by "only" having a Q of 500, by gathering more >>> power to start with. >>> >>> Furthermore, because the signal of interest spreads +-5Khz or so, >>> when you use a super high Q, you *reject* the parts of the signal >>> that are outside the passband. So yeah, you get more voltage for >>> for the low audio frequencies, but *less power overall*. >>> >>> Duh. Doesn't sound like such a good deal now, does it? >> >> You trimmed the part of my post that dealt with the bandwidth issue. Why >> don't you read that again? > > Because you said 10KHz, when your bandwidth is nothing like that. > I just couldn't be bothered to call you on all your > lie^H^H^Halternative facts Why are you here? You aren't interested in discussing anything. You just want to make drama. -- Rick C
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| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-28 21:58 +1100 |
| Message-ID | <58da41ea$0$39513$b1db1813$7968482@news.astraweb.com> |
| In reply to | #453972 |
On 28/03/17 19:35, rickman wrote: > On 3/28/2017 4:07 AM, Clifford Heath wrote: >> On 28/03/17 18:42, rickman wrote: >>> On 3/28/2017 3:15 AM, Clifford Heath wrote: >>>> On 28/03/17 14:47, rickman wrote: >>>>> On 3/27/2017 12:22 PM, Joerg wrote: >>>>>> On 2017-03-27 07:59, rickman wrote: >>>>>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>>>>> >>>>>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>>>>> suitable as coil winding material and this proves that it is quite >>>>>>>> suitable. Which I already knew because I've used it in RF power >>>>>>>> amps >>>>>>>> decades ago. >>>>>>> >>>>>>> Again, context. You are living in a different world. PVC is *not* >>>>>>> suitable in the crystal radio world because there are *much* better >>>>>>> materials. If PVC was the only material available it would be a >>>>>>> *great* >>>>>>> coil support. If mud was the only material available it would be a >>>>>>> *great* coil support. >>>>>>> >>>>>> >>>>>> Can you explain why one even want a Q in excess of 500 in the AM >>>>>> band? >>>>> >>>>> Q is a measure of the losses. Having a high Q in the coil means the >>>>> coil has lower losses. Having a higher Q in the tuning capacitor >>>>> means >>>>> it has lower losses. The lower the losses the more power that ends up >>>>> in the headphones. >>>> >>>> You have this quite wrong. A Q of 500 is a loss of 0.2%, and >>>> 1500 is a loss of only 0.067%. Increase your coil area by 0.13% >>>> (a fraction of a millimeter of diameter) and you recover the >>>> power you lost by "only" having a Q of 500, by gathering more >>>> power to start with. >>>> >>>> Furthermore, because the signal of interest spreads +-5Khz or so, >>>> when you use a super high Q, you *reject* the parts of the signal >>>> that are outside the passband. So yeah, you get more voltage for >>>> for the low audio frequencies, but *less power overall*. >>>> >>>> Duh. Doesn't sound like such a good deal now, does it? >>> >>> You trimmed the part of my post that dealt with the bandwidth issue. Why >>> don't you read that again? >> >> Because you said 10KHz, when your bandwidth is nothing like that. >> I just couldn't be bothered to call you on all your >> lie^H^H^Halternative facts > > Why are you here? You aren't interested in discussing anything. You > just want to make drama. I'm sorry you're so confused by facts, but I'm not responsible for fixing your innumeracy. I'll just get the popcorn and watch while you chase unicorns.
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| From | amdx <nojunk@knology.net> |
|---|---|
| Date | 2017-03-28 09:42 -0500 |
| Message-ID | <obdsjt$10h$1@dont-email.me> |
| In reply to | #453978 |
On 3/28/2017 5:58 AM, Clifford Heath wrote:
> On 28/03/17 19:35, rickman wrote:
>> On 3/28/2017 4:07 AM, Clifford Heath wrote:
>>> On 28/03/17 18:42, rickman wrote:
>>>> On 3/28/2017 3:15 AM, Clifford Heath wrote:
>>>>> On 28/03/17 14:47, rickman wrote:
>>>>>> On 3/27/2017 12:22 PM, Joerg wrote:
>>>>>>> On 2017-03-27 07:59, rickman wrote:
>>>>>>>> On 3/27/2017 10:46 AM, Joerg wrote:
>>>>>>>>>
>>>>>>>>> The Q is over 500. It was claimed in this thread that PVC is not
>>>>>>>>> suitable as coil winding material and this proves that it is quite
>>>>>>>>> suitable. Which I already knew because I've used it in RF power
>>>>>>>>> amps
>>>>>>>>> decades ago.
>>>>>>>>
>>>>>>>> Again, context. You are living in a different world. PVC is *not*
>>>>>>>> suitable in the crystal radio world because there are *much* better
>>>>>>>> materials. If PVC was the only material available it would be a
>>>>>>>> *great*
>>>>>>>> coil support. If mud was the only material available it would be a
>>>>>>>> *great* coil support.
>>>>>>>>
>>>>>>>
>>>>>>> Can you explain why one even want a Q in excess of 500 in the AM
>>>>>>> band?
>>>>>>
>>>>>> Q is a measure of the losses. Having a high Q in the coil means the
>>>>>> coil has lower losses. Having a higher Q in the tuning capacitor
>>>>>> means
>>>>>> it has lower losses. The lower the losses the more power that
>>>>>> ends up
>>>>>> in the headphones.
>>>>>
>>>>> You have this quite wrong. A Q of 500 is a loss of 0.2%, and
>>>>> 1500 is a loss of only 0.067%. Increase your coil area by 0.13%
>>>>> (a fraction of a millimeter of diameter) and you recover the
>>>>> power you lost by "only" having a Q of 500, by gathering more
>>>>> power to start with.
>>>>>
>>>>> Furthermore, because the signal of interest spreads +-5Khz or so,
>>>>> when you use a super high Q, you *reject* the parts of the signal
>>>>> that are outside the passband. So yeah, you get more voltage for
>>>>> for the low audio frequencies, but *less power overall*.
>>>>>
>>>>> Duh. Doesn't sound like such a good deal now, does it?
>>>>
>>>> You trimmed the part of my post that dealt with the bandwidth issue.
>>>> Why
>>>> don't you read that again?
>>>
>>> Because you said 10KHz, when your bandwidth is nothing like that.
>>> I just couldn't be bothered to call you on all your
>>> lie^H^H^Halternative facts
>>
>> Why are you here? You aren't interested in discussing anything. You
>> just want to make drama.
>
> I'm sorry you're so confused by facts, but I'm not responsible for
> fixing your innumeracy. I'll just get the popcorn and watch while you
> chase unicorns.
>
I'm afraid you are missing some facts on crystal radio crystal
optimization. Here's research by one of the real gurus of crystal radio
optimization, Ben Tongue of Blonder Tongue fame.
> http://www.bentongue.com/xtalset/xtalset.html
There is a lot here so A quick look says article 22 and 24 may help,
but others have relevant information.
Mikek
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
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| From | upsidedown@downunder.com |
|---|---|
| Date | 2017-03-28 12:51 +0300 |
| Message-ID | <01bkdc1m41nsfhifilicoj1q2f5npppesg@4ax.com> |
| In reply to | #453950 |
On Mon, 27 Mar 2017 23:47:00 -0400, rickman <gnuarm@gmail.com> wrote: >On 3/27/2017 12:22 PM, Joerg wrote: >> On 2017-03-27 07:59, rickman wrote: >>> On 3/27/2017 10:46 AM, Joerg wrote: >>>> >>>> The Q is over 500. It was claimed in this thread that PVC is not >>>> suitable as coil winding material and this proves that it is quite >>>> suitable. Which I already knew because I've used it in RF power amps >>>> decades ago. >>> >>> Again, context. You are living in a different world. PVC is *not* >>> suitable in the crystal radio world because there are *much* better >>> materials. If PVC was the only material available it would be a *great* >>> coil support. If mud was the only material available it would be a >>> *great* coil support. >>> >> >> Can you explain why one even want a Q in excess of 500 in the AM band? That is the _unloaded_ Qu. Still 500 sounds excessive high for ordinary LC circuits or loop antennas. At higher frequencies a silver coated cavity resonator would easily ac hive that. >Q is a measure of the losses. Having a high Q in the coil means the >coil has lower losses. Having a higher Q in the tuning capacitor means >it has lower losses. The lower the losses the more power that ends up >in the headphones. When you connect the load you get the _loaded_ Ql. This Ql determines the actual receiver bandwidth. For AM reception a 10 kHz bandwidth would be desirable, so at 1 MHz the loaded Ql=100 would be suitable. The Qu/Ql ratio determines the signal losses. a Qu/Ql=10:1 gives less than 1 dB losses, a 2:1 ratio and the loss is a few decibels. A 500/100 ratio gives about 2 dB losses. In receivers with amplification, this loss is directly added to the noise figure. For this reason, it is undesirable to have too high loaded Ql in front of the first amplifier stage. On the other hand, a wide front end can easily overload the first amplifier or mixer. A high Ql filter between the first amplifier and mixer helps a lot. This is an issue on VHF and above. >The Q of the radio won't be the same as the Q of the components because >you are sucking off power to drive the headphones. Besides, the number >you came up with (10 kHz) would be perfect for AM radio if you can get >that, that is the channel spacing. Great selectivity. It should be noted that BW = f / Q only gives the -3 dB point of the response curve. There might be a 40-60 dB signal on the adjacent channel, which will effectively kill the reception of the wanted signal.
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-28 07:23 -0700 |
| Message-ID | <ejv9ukFplm0U1@mid.individual.net> |
| In reply to | #453974 |
On 2017-03-28 02:51, upsidedown@downunder.com wrote: > On Mon, 27 Mar 2017 23:47:00 -0400, rickman <gnuarm@gmail.com> wrote: > >> On 3/27/2017 12:22 PM, Joerg wrote: >>> On 2017-03-27 07:59, rickman wrote: >>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>> >>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>> suitable as coil winding material and this proves that it is quite >>>>> suitable. Which I already knew because I've used it in RF power amps >>>>> decades ago. >>>> >>>> Again, context. You are living in a different world. PVC is *not* >>>> suitable in the crystal radio world because there are *much* better >>>> materials. If PVC was the only material available it would be a *great* >>>> coil support. If mud was the only material available it would be a >>>> *great* coil support. >>>> >>> >>> Can you explain why one even want a Q in excess of 500 in the AM band? > > That is the _unloaded_ Qu. Still 500 sounds excessive high for > ordinary LC circuits or loop antennas. At higher frequencies a silver > coated cavity resonator would easily ac hive that. > >> Q is a measure of the losses. Having a high Q in the coil means the >> coil has lower losses. Having a higher Q in the tuning capacitor means >> it has lower losses. The lower the losses the more power that ends up >> in the headphones. > > When you connect the load you get the _loaded_ Ql. This Ql determines > the actual receiver bandwidth. For AM reception a 10 kHz bandwidth > would be desirable, so at 1 MHz the loaded Ql=100 would be suitable. > Exactly, not 500 or 1000. Still, even with a somewhat matching loaded Q the audio quality is mediocre because a simple tuned circuit has a poor shape factor. This results in higher audio frequencies being muffled, speech to be less easy to understand and as you said further below a strong station on the next AM channel will spoil the whole experience by swamping the signal. > The Qu/Ql ratio determines the signal losses. a Qu/Ql=10:1 gives less > than 1 dB losses, a 2:1 ratio and the loss is a few decibels. A > 500/100 ratio gives about 2 dB losses. Which is close to impossible to even hear. > ... In receivers with > amplification, this loss is directly added to the noise figure. For > this reason, it is undesirable to have too high loaded Ql in front of > the first amplifier stage. On the other hand, a wide front end can > easily overload the first amplifier or mixer. A high Ql filter between > the first amplifier and mixer helps a lot. This is an issue on VHF and > above. > > >> The Q of the radio won't be the same as the Q of the components because >> you are sucking off power to drive the headphones. Besides, the number >> you came up with (10 kHz) would be perfect for AM radio if you can get >> that, that is the channel spacing. Great selectivity. > It should be noted that BW = f / Q only gives the -3 dB point of the > response curve. There might be a 40-60 dB signal on the adjacent > channel, which will effectively kill the reception of the wanted > signal. > There is probably some sort of sports ambition where the guy with the highest Q wins a trophy or at least a free beer :-) -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-29 13:28 -0400 |
| Message-ID | <obgqlj$t0d$1@dont-email.me> |
| In reply to | #453985 |
On 3/28/2017 10:23 AM, Joerg wrote: > On 2017-03-28 02:51, upsidedown@downunder.com wrote: >> On Mon, 27 Mar 2017 23:47:00 -0400, rickman <gnuarm@gmail.com> wrote: >> >>> On 3/27/2017 12:22 PM, Joerg wrote: >>>> On 2017-03-27 07:59, rickman wrote: >>>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>>> >>>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>>> suitable as coil winding material and this proves that it is quite >>>>>> suitable. Which I already knew because I've used it in RF power amps >>>>>> decades ago. >>>>> >>>>> Again, context. You are living in a different world. PVC is *not* >>>>> suitable in the crystal radio world because there are *much* better >>>>> materials. If PVC was the only material available it would be a >>>>> *great* >>>>> coil support. If mud was the only material available it would be a >>>>> *great* coil support. >>>>> >>>> >>>> Can you explain why one even want a Q in excess of 500 in the AM band? >> >> That is the _unloaded_ Qu. Still 500 sounds excessive high for >> ordinary LC circuits or loop antennas. At higher frequencies a silver >> coated cavity resonator would easily ac hive that. >> >>> Q is a measure of the losses. Having a high Q in the coil means the >>> coil has lower losses. Having a higher Q in the tuning capacitor means >>> it has lower losses. The lower the losses the more power that ends up >>> in the headphones. >> >> When you connect the load you get the _loaded_ Ql. This Ql determines >> the actual receiver bandwidth. For AM reception a 10 kHz bandwidth >> would be desirable, so at 1 MHz the loaded Ql=100 would be suitable. >> > > Exactly, not 500 or 1000. Still, even with a somewhat matching loaded Q > the audio quality is mediocre because a simple tuned circuit has a poor > shape factor. This results in higher audio frequencies being muffled, > speech to be less easy to understand and as you said further below a > strong station on the next AM channel will spoil the whole experience by > swamping the signal. > > >> The Qu/Ql ratio determines the signal losses. a Qu/Ql=10:1 gives less >> than 1 dB losses, a 2:1 ratio and the loss is a few decibels. A >> 500/100 ratio gives about 2 dB losses. > > > Which is close to impossible to even hear. > > >> ... In receivers with >> amplification, this loss is directly added to the noise figure. For >> this reason, it is undesirable to have too high loaded Ql in front of >> the first amplifier stage. On the other hand, a wide front end can >> easily overload the first amplifier or mixer. A high Ql filter between >> the first amplifier and mixer helps a lot. This is an issue on VHF and >> above. >> >> >>> The Q of the radio won't be the same as the Q of the components because >>> you are sucking off power to drive the headphones. Besides, the number >>> you came up with (10 kHz) would be perfect for AM radio if you can get >>> that, that is the channel spacing. Great selectivity. >> It should be noted that BW = f / Q only gives the -3 dB point of the >> response curve. There might be a 40-60 dB signal on the adjacent >> channel, which will effectively kill the reception of the wanted >> signal. >> > > There is probably some sort of sports ambition where the guy with the > highest Q wins a trophy or at least a free beer :-) It *is* a hobby. No one builds a crystal radio set because he wants to listen to talk radio. You comments indicate you neither understand the hobby nor do you really understand the technology, but I believe the latter is a choice on your part. You seem to be deliberately refusing to try to understand what is being said. Your comment above about not being able to hear a few dB is a good example of your mindset. Rather than trying to understand why anyone would care if tweaking the core material for a coil adds a few dB, you make a comment showing your disdain. Open your mind. Look at the bigger picture. You tell me why anyone cares about the few dB from optimizing this one feature? Someone could just as easily point to the many things you are involved in an nitpick any one action. But that would in no way diminish the activity as a whole. -- Rick C
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| From | upsidedown@downunder.com |
|---|---|
| Date | 2017-03-30 00:37 +0300 |
| Message-ID | <m29odclmicn0cum9keo4gnghjsfi8so5qp@4ax.com> |
| In reply to | #454130 |
On Wed, 29 Mar 2017 13:28:05 -0400, rickman <gnuarm@gmail.com> wrote: >On 3/28/2017 10:23 AM, Joerg wrote: >> On 2017-03-28 02:51, upsidedown@downunder.com wrote: >>> On Mon, 27 Mar 2017 23:47:00 -0400, rickman <gnuarm@gmail.com> wrote: >>> >>>> On 3/27/2017 12:22 PM, Joerg wrote: >>>>> On 2017-03-27 07:59, rickman wrote: >>>>>> On 3/27/2017 10:46 AM, Joerg wrote: >>>>>>> >>>>>>> The Q is over 500. It was claimed in this thread that PVC is not >>>>>>> suitable as coil winding material and this proves that it is quite >>>>>>> suitable. Which I already knew because I've used it in RF power amps >>>>>>> decades ago. >>>>>> >>>>>> Again, context. You are living in a different world. PVC is *not* >>>>>> suitable in the crystal radio world because there are *much* better >>>>>> materials. If PVC was the only material available it would be a >>>>>> *great* >>>>>> coil support. If mud was the only material available it would be a >>>>>> *great* coil support. >>>>>> >>>>> >>>>> Can you explain why one even want a Q in excess of 500 in the AM band? >>> >>> That is the _unloaded_ Qu. Still 500 sounds excessive high for >>> ordinary LC circuits or loop antennas. At higher frequencies a silver >>> coated cavity resonator would easily ac hive that. >>> >>>> Q is a measure of the losses. Having a high Q in the coil means the >>>> coil has lower losses. Having a higher Q in the tuning capacitor means >>>> it has lower losses. The lower the losses the more power that ends up >>>> in the headphones. >>> >>> When you connect the load you get the _loaded_ Ql. This Ql determines >>> the actual receiver bandwidth. For AM reception a 10 kHz bandwidth >>> would be desirable, so at 1 MHz the loaded Ql=100 would be suitable. >>> >> >> Exactly, not 500 or 1000. Still, even with a somewhat matching loaded Q >> the audio quality is mediocre because a simple tuned circuit has a poor >> shape factor. This results in higher audio frequencies being muffled, >> speech to be less easy to understand and as you said further below a >> strong station on the next AM channel will spoil the whole experience by >> swamping the signal. >> >> >>> The Qu/Ql ratio determines the signal losses. a Qu/Ql=10:1 gives less >>> than 1 dB losses, a 2:1 ratio and the loss is a few decibels. A >>> 500/100 ratio gives about 2 dB losses. >> >> >> Which is close to impossible to even hear. >> >> >>> ... In receivers with >>> amplification, this loss is directly added to the noise figure. For >>> this reason, it is undesirable to have too high loaded Ql in front of >>> the first amplifier stage. On the other hand, a wide front end can >>> easily overload the first amplifier or mixer. A high Ql filter between >>> the first amplifier and mixer helps a lot. This is an issue on VHF and >>> above. >>> >>> >>>> The Q of the radio won't be the same as the Q of the components because >>>> you are sucking off power to drive the headphones. Besides, the number >>>> you came up with (10 kHz) would be perfect for AM radio if you can get >>>> that, that is the channel spacing. Great selectivity. >>> It should be noted that BW = f / Q only gives the -3 dB point of the >>> response curve. There might be a 40-60 dB signal on the adjacent >>> channel, which will effectively kill the reception of the wanted >>> signal. >>> >> >> There is probably some sort of sports ambition where the guy with the >> highest Q wins a trophy or at least a free beer :-) > >It *is* a hobby. No one builds a crystal radio set because he wants to >listen to talk radio. This seems to be a US specific thing. In Europe, there are not much local MF broadcasts any more. The situation was different 50 years ago, but now it is hard to find a local LF/MF/HF transmitter within 1000 km, thus a simple crystal radio is more or less useless. >You comments indicate you neither understand the hobby That is US country specific. >nor do you really >understand the technology, but I believe the latter is a choice on your >part. You seem to be deliberately refusing to try to understand what is >being said. Why should I deliberately bang my head against the wall ? >Your comment above about not being able to hear a few dB is a good >example of your mindset. 1-2 dB of extra loss is significant in UHF EME (moonbounce) communication, in which the amplifier itself has a noise figure in the order of 1 dB (i.e. 100 K noise temperature). For any MF communication circuits, the band noise is huge from location to location, from day to day or from hour to hour, so a 1-2 dB variation doesn't really cause problems. > Rather than trying to understand why anyone >would care if tweaking the core material for a coil adds a few dB, you >make a comment showing your disdain. Open your mind. Look at the >bigger picture. You tell me why anyone cares about the few dB from >optimizing this one feature? I really do not understand why you make such fuss about LF, MF and lower HF. However, those few decibels are of great concern in UHF/SHF bands.
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