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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 13 of 16 — ← Prev page 1 … 11 12 [13] 14 15 16 Next page →
| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-29 21:02 -0400 |
| Message-ID | <obhl9m$ldf$1@dont-email.me> |
| In reply to | #454149 |
On 3/29/2017 5:37 PM, upsidedown@downunder.com wrote: > 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. Nearly everything you wrote is not relevant to the conversation I have been having. Why did you choose me to reply to? I was not addressing you. -- Rick C
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| From | amdx <nojunk@knology.net> |
|---|---|
| Date | 2017-03-28 09:57 -0500 |
| Message-ID | <obdtg5$4b6$1@dont-email.me> |
| In reply to | #453974 |
On 3/28/2017 4:51 AM, 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. Bell labs reported a bandwidth of 300Hz to 3000Hz is range required for intelligible speech. When you slip your headphones on, all you need is to identify the call letters of a distant station. No one complains of excessive Q, it is so easy to spoil. I have a coil on my Q meter now, adding a 10M resistor across a coil with Q=1300 lowers it to Q=1100. > > 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. > > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-28 09:05 -0700 |
| Message-ID | <ejvfv0FqruoU1@mid.individual.net> |
| In reply to | #453990 |
On 2017-03-28 07:57, amdx wrote: > On 3/28/2017 4:51 AM, 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. > > > Bell labs reported a bandwidth of 300Hz to 3000Hz is range required > for intelligible speech. When you slip your headphones on, all you need > is to identify the call letters of a distant station. > No one complains of excessive Q, it is so easy to spoil. Here is a high-Q sound :-) https://www.youtube.com/watch?v=q_BU5hR9gXE [...] -- Regards, Joerg http://www.analogconsultants.com/
[toc] | [prev] | [next] | [standalone]
| From | amdx <nojunk@knology.net> |
|---|---|
| Date | 2017-03-28 11:27 -0500 |
| Message-ID | <obe2o2$mv9$1@dont-email.me> |
| In reply to | #454000 |
On 3/28/2017 11:05 AM, Joerg wrote:
> On 2017-03-28 07:57, amdx wrote:
>> On 3/28/2017 4:51 AM, 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.
>>
>>
>> Bell labs reported a bandwidth of 300Hz to 3000Hz is range required
>> for intelligible speech. When you slip your headphones on, all you need
>> is to identify the call letters of a distant station.
>> No one complains of excessive Q, it is so easy to spoil.
>
>
> Here is a high-Q sound :-)
>
> https://www.youtube.com/watch?v=q_BU5hR9gXE
>
> [...]
>
Yes, needs a Q spoiler!
Mikek
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-29 13:29 -0400 |
| Message-ID | <obgqo3$t0d$2@dont-email.me> |
| In reply to | #454000 |
On 3/28/2017 12:05 PM, Joerg wrote: > On 2017-03-28 07:57, amdx wrote: >> On 3/28/2017 4:51 AM, 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. >> >> >> Bell labs reported a bandwidth of 300Hz to 3000Hz is range required >> for intelligible speech. When you slip your headphones on, all you need >> is to identify the call letters of a distant station. >> No one complains of excessive Q, it is so easy to spoil. > > > Here is a high-Q sound :-) > > https://www.youtube.com/watch?v=q_BU5hR9gXE You have eyes, yet you can not see. -- Rick C
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-27 14:57 +0300 |
| Message-ID | <obauhu$q3u$1@dont-email.me> |
| In reply to | #453752 |
On 26.3.17 17:35, 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. > >> >>> 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. Joerg, you seem not understand the innermost sense of the crystal- radio people. They are closely related to audiophools, and it is quite impossible to use sensible technical argumentation here. The question of best MF band coils has been solved already in the 1930's: A honeycomb coil wound with Litz wire (gloves on). The canonical fixing / insulating material is beeswax. -- -TV
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| From | amdx <nojunk@knology.net> |
|---|---|
| Date | 2017-03-27 07:25 -0500 |
| Message-ID | <obb05c$vn8$1@dont-email.me> |
| In reply to | #453859 |
On 3/27/2017 6:57 AM, Tauno Voipio wrote:
> On 26.3.17 17:35, 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.
>>
>>>
>>>> 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.
>
>
> Joerg, you seem not understand the innermost sense of the crystal-
> radio people. They are closely related to audiophools, and it is
> quite impossible to use sensible technical argumentation here.
I don't get that at all, can you back that up with any facts?
>
> The question of best MF band coils has been solved already in the
> 1930's: A honeycomb coil wound with Litz wire (gloves on). The
> canonical fixing / insulating material is beeswax.
>
I don't know have you tried a 6" polystyrene tube with 0.0625 wall
thickness, wound with 660/46 litz wire with 12 turns per inch?
If anyone has an interest, here's a pdf of multiple honeycomb coils
and data. I think it is from the 30's or 40's. I can't seem to get
it to download properly. But what I could see doesn't give Q directly,
so needs to be calculated.
> http://nvlpubs.nist.gov/nistpubs/nbstechnologic/nbstechnologicpapert298.pdf
Mikek
Mikek
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| From | Lasse Langwadt Christensen <langwadt@fonz.dk> |
|---|---|
| Date | 2017-03-27 09:47 -0700 |
| Message-ID | <6e4b1031-64a0-4f4c-94c9-2c31429bfbc4@googlegroups.com> |
| In reply to | #453864 |
Den mandag den 27. marts 2017 kl. 14.25.07 UTC+2 skrev amdx: > On 3/27/2017 6:57 AM, Tauno Voipio wrote: > > On 26.3.17 17:35, 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. > >> > >>> > >>>> 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. > > > > > > Joerg, you seem not understand the innermost sense of the crystal- > > radio people. They are closely related to audiophools, and it is > > quite impossible to use sensible technical argumentation here. > > I don't get that at all, can you back that up with any facts? > > > > > The question of best MF band coils has been solved already in the > > 1930's: A honeycomb coil wound with Litz wire (gloves on). The > > canonical fixing / insulating material is beeswax. > > > I don't know have you tried a 6" polystyrene tube with 0.0625 wall > thickness, wound with 660/46 litz wire with 12 turns per inch? > sound like it needs more unicorn tears and maturing under a full moon ;)
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-27 19:51 +0300 |
| Message-ID | <obbfob$op5$3@dont-email.me> |
| In reply to | #453864 |
On 27.3.17 15:25, amdx wrote: >> >> The question of best MF band coils has been solved already in the >> 1930's: A honeycomb coil wound with Litz wire (gloves on). The >> canonical fixing / insulating material is beeswax. >> > I don't know have you tried a 6" polystyrene tube with 0.0625 wall > thickness, wound with 660/46 litz wire with 12 turns per inch? The point with a multilayer coil is better magnetic coupling between the turns. Honeycomb winding keeps distributed capacitances better controlled. -- -TV
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| From | amdx <nojunk@knology.net> |
|---|---|
| Date | 2017-03-27 12:21 -0500 |
| Message-ID | <obbhhr$2mb$1@dont-email.me> |
| In reply to | #453864 |
On 3/27/2017 7:25 AM, amdx wrote:
> On 3/27/2017 6:57 AM, Tauno Voipio wrote:
>> On 26.3.17 17:35, 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.
>>>
>>>>
>>>>> 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.
>>
>>
>> Joerg, you seem not understand the innermost sense of the crystal-
>> radio people. They are closely related to audiophools, and it is
>> quite impossible to use sensible technical argumentation here.
>
> I don't get that at all, can you back that up with any facts?
>
>>
>> The question of best MF band coils has been solved already in the
>> 1930's: A honeycomb coil wound with Litz wire (gloves on). The
>> canonical fixing / insulating material is beeswax.
>>
> I don't know have you tried a 6" polystyrene tube with 0.0625 wall
> thickness, wound with 660/46 litz wire with 12 turns per inch?
>
> If anyone has an interest, here's a pdf of multiple honeycomb coils and
> data. I think it is from the 30's or 40's. I can't seem to get
> it to download properly. But what I could see doesn't give Q directly,
> so needs to be calculated.
>> http://nvlpubs.nist.gov/nistpubs/nbstechnologic/nbstechnologicpapert298.pdf
>>
>
> Mikek
>
Anyone get that pdf to load properly, the graphs I want see are only
half there, left side or right side.
Mikek
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-27 18:54 -0400 |
| Message-ID | <obc50r$b47$1@dont-email.me> |
| In reply to | #453898 |
On 3/27/2017 1:21 PM, amdx wrote: > On 3/27/2017 7:25 AM, amdx wrote: >> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>> On 26.3.17 17:35, 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. >>>> >>>>> >>>>>> 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. >>> >>> >>> Joerg, you seem not understand the innermost sense of the crystal- >>> radio people. They are closely related to audiophools, and it is >>> quite impossible to use sensible technical argumentation here. >> >> I don't get that at all, can you back that up with any facts? >> >>> >>> The question of best MF band coils has been solved already in the >>> 1930's: A honeycomb coil wound with Litz wire (gloves on). The >>> canonical fixing / insulating material is beeswax. >>> >> I don't know have you tried a 6" polystyrene tube with 0.0625 wall >> thickness, wound with 660/46 litz wire with 12 turns per inch? >> >> If anyone has an interest, here's a pdf of multiple honeycomb coils and >> data. I think it is from the 30's or 40's. I can't seem to get >> it to download properly. But what I could see doesn't give Q directly, >> so needs to be calculated. >>> http://nvlpubs.nist.gov/nistpubs/nbstechnologic/nbstechnologicpapert298.pdf >>> >>> >> >> Mikek >> > Anyone get that pdf to load properly, the graphs I want see are only > half there, left side or right side. If you are talking about the graph on page 10, that isn't loading correctly for me either. But it appears to be the same graph on page 12. Likewise the bad image on page 14 is the same as the image on page 16, etc. Even in a PDF viewer not in the browser the pages render *very* slowly. Even just scrolling back a couple of pages makes it start all over again. Very hard to view. I think this document needs to be recovered by re-imaging it and turning it into a new PDF file. -- Rick C
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| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-28 10:16 +1100 |
| Message-ID | <58d99d61$0$4499$c3e8da3$b280bf18@news.astraweb.com> |
| In reply to | #453864 |
On 27/03/17 23:25, amdx wrote: > On 3/27/2017 6:57 AM, Tauno Voipio wrote: >> Joerg, you seem not understand the innermost sense of the crystal- >> radio people. They are closely related to audiophools, and it is >> quite impossible to use sensible technical argumentation here. > > I don't get that at all, can you back that up with any facts? ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? More voltage does not create better audio.
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-27 16:58 -0700 |
| Message-ID | <ejtn8iFg6qmU1@mid.individual.net> |
| In reply to | #453929 |
On 2017-03-27 16:16, Clifford Heath wrote: > On 27/03/17 23:25, amdx wrote: >> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>> Joerg, you seem not understand the innermost sense of the crystal- >>> radio people. They are closely related to audiophools, and it is >>> quite impossible to use sensible technical argumentation here. >> >> I don't get that at all, can you back that up with any facts? > > ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? > More voltage does not create better audio. That's what I was wondering all the time. In the ranges tested there are largely just AM stations, no CW or morse code. Even at 10kHz BW the audio experience will not be very pleasing, it'll sound more like on a telephone. Then there is the tempco. Someone opens a window and whoops the resonant frequency goes somewhere else. However, the crystal radio guys I've met were more down-to-earth and unlike audiophools did not spend $199.98 for a few feet of gold-plated cable with individual electron spin control and all that. -- Regards, Joerg http://www.analogconsultants.com/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-27 23:33 -0400 |
| Message-ID | <obcldm$c91$1@dont-email.me> |
| In reply to | #453934 |
On 3/27/2017 7:58 PM, Joerg wrote: > On 2017-03-27 16:16, Clifford Heath wrote: >> On 27/03/17 23:25, amdx wrote: >>> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>>> Joerg, you seem not understand the innermost sense of the crystal- >>>> radio people. They are closely related to audiophools, and it is >>>> quite impossible to use sensible technical argumentation here. >>> >>> I don't get that at all, can you back that up with any facts? >> >> ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? >> More voltage does not create better audio. > > > That's what I was wondering all the time. In the ranges tested there are > largely just AM stations, no CW or morse code. Even at 10kHz BW the > audio experience will not be very pleasing, it'll sound more like on a > telephone. How much bandwidth is available on an AM radio station??? Do you actually know much about crystal radios? > Then there is the tempco. Someone opens a window and whoops the resonant > frequency goes somewhere else. Again, you are not speaking from knowledge. There are ham radio antennas with exactly this sort of high Q and they manage to maintain tuning during 100 watt transmissions. Why are you guys trying to discuss a topic you actually know little about. -- Rick C
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| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-28 18:18 +1100 |
| Message-ID | <58da0e2a$0$39527$b1db1813$7968482@news.astraweb.com> |
| In reply to | #453948 |
On 28/03/17 14:33, rickman wrote: > On 3/27/2017 7:58 PM, Joerg wrote: >> On 2017-03-27 16:16, Clifford Heath wrote: >>> On 27/03/17 23:25, amdx wrote: >>>> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>>>> Joerg, you seem not understand the innermost sense of the crystal- >>>>> radio people. They are closely related to audiophools, and it is >>>>> quite impossible to use sensible technical argumentation here. >>>> >>>> I don't get that at all, can you back that up with any facts? >>> >>> ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? >>> More voltage does not create better audio. >> >> >> That's what I was wondering all the time. In the ranges tested there are >> largely just AM stations, no CW or morse code. Even at 10kHz BW the >> audio experience will not be very pleasing, it'll sound more like on a >> telephone. > > How much bandwidth is available on an AM radio station??? Do you > actually know much about crystal radios? The carrier, and the sidebands, which spread either side by the bandwidth of the audio being broadcast - perhaps 5 or 8KHz. That means as soon as your Q exceeds 200 (@1MHz), you start to reject some of the transmitted power. >> Then there is the tempco. Someone opens a window and whoops the resonant >> frequency goes somewhere else. > > Again, you are not speaking from knowledge. There are ham radio > antennas with exactly this sort of high Q and they manage to maintain > tuning during 100 watt transmissions. > > Why are you guys trying to discuss a topic you actually know little about You really know so little that you can't even conceive of how little you know.
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2017-03-28 03:48 -0400 |
| Message-ID | <obd4bm$gl9$1@dont-email.me> |
| In reply to | #453962 |
On 3/28/2017 3:18 AM, Clifford Heath wrote: > On 28/03/17 14:33, rickman wrote: >> On 3/27/2017 7:58 PM, Joerg wrote: >>> On 2017-03-27 16:16, Clifford Heath wrote: >>>> On 27/03/17 23:25, amdx wrote: >>>>> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>>>>> Joerg, you seem not understand the innermost sense of the crystal- >>>>>> radio people. They are closely related to audiophools, and it is >>>>>> quite impossible to use sensible technical argumentation here. >>>>> >>>>> I don't get that at all, can you back that up with any facts? >>>> >>>> ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? >>>> More voltage does not create better audio. >>> >>> >>> That's what I was wondering all the time. In the ranges tested there are >>> largely just AM stations, no CW or morse code. Even at 10kHz BW the >>> audio experience will not be very pleasing, it'll sound more like on a >>> telephone. >> >> How much bandwidth is available on an AM radio station??? Do you >> actually know much about crystal radios? > > The carrier, and the sidebands, which spread either side by the > bandwidth of the audio being broadcast - perhaps 5 or 8KHz. > That means as soon as your Q exceeds 200 (@1MHz), you start to > reject some of the transmitted power. Determined by the Q of the resonant circuit in the radio, not the Q of the coil. >>> Then there is the tempco. Someone opens a window and whoops the resonant >>> frequency goes somewhere else. >> >> Again, you are not speaking from knowledge. There are ham radio >> antennas with exactly this sort of high Q and they manage to maintain >> tuning during 100 watt transmissions. >> >> Why are you guys trying to discuss a topic you actually know little about > > You really know so little that you can't even conceive of how little you > know. I can clearly see what you don't understand. Why are you being rude about it? -- Rick C
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| From | Joerg <news@analogconsultants.com> |
|---|---|
| Date | 2017-03-28 07:28 -0700 |
| Message-ID | <ejva8hFpntoU1@mid.individual.net> |
| In reply to | #453967 |
On 2017-03-28 00:48, rickman wrote: > On 3/28/2017 3:18 AM, Clifford Heath wrote: >> On 28/03/17 14:33, rickman wrote: >>> On 3/27/2017 7:58 PM, Joerg wrote: >>>> On 2017-03-27 16:16, Clifford Heath wrote: >>>>> On 27/03/17 23:25, amdx wrote: >>>>>> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>>>>>> Joerg, you seem not understand the innermost sense of the crystal- >>>>>>> radio people. They are closely related to audiophools, and it is >>>>>>> quite impossible to use sensible technical argumentation here. >>>>>> >>>>>> I don't get that at all, can you back that up with any facts? >>>>> >>>>> ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? >>>>> More voltage does not create better audio. >>>> >>>> >>>> That's what I was wondering all the time. In the ranges tested there >>>> are >>>> largely just AM stations, no CW or morse code. Even at 10kHz BW the >>>> audio experience will not be very pleasing, it'll sound more like on a >>>> telephone. >>> >>> How much bandwidth is available on an AM radio station??? Do you >>> actually know much about crystal radios? >> >> The carrier, and the sidebands, which spread either side by the >> bandwidth of the audio being broadcast - perhaps 5 or 8KHz. >> That means as soon as your Q exceeds 200 (@1MHz), you start to >> reject some of the transmitted power. > Most of all it muffles higher audio frequencies in the sidebands which makes the listening experience less than pleasant. This is why good receivers like the ones in my lab have 6- or 8-pole crystal filters. > Determined by the Q of the resonant circuit in the radio, not the Q of > the coil. > > >>>> Then there is the tempco. Someone opens a window and whoops the >>>> resonant >>>> frequency goes somewhere else. >>> >>> Again, you are not speaking from knowledge. There are ham radio >>> antennas with exactly this sort of high Q and they manage to maintain >>> tuning during 100 watt transmissions. As the old Romans said, hic Rhodus, hic salta. Give us an example of such an antenna with a Q of 500 or more. Just one. And yes, I have a ham radio license and decades of RF experience. My clients pay me for that. >>> >>> Why are you guys trying to discuss a topic you actually know little >>> about >> >> You really know so little that you can't even conceive of how little you >> know. > > I can clearly see what you don't understand. Why are you being rude > about it? > <holds up mirror> See? :-) -- Regards, Joerg http://www.analogconsultants.com/
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-28 13:41 +0300 |
| Message-ID | <obdefs$gct$1@dont-email.me> |
| In reply to | #453948 |
On 28.3.17 06:33, rickman wrote: > > Again, you are not speaking from knowledge. There are ham radio > antennas with exactly this sort of high Q and they manage to maintain > tuning during 100 watt transmissions. > > Why are you guys trying to discuss a topic you actually know little about. > There are cases where the Q of the tuner and antenna combination restricted the way the transmission can be modulated. In aviation, there are non-directional beacons (NDB) working in the MF range. Due to obvious mechanical restrictions, the vertical antennas are very short compared to the wavelength (70 ft compared to 4000 ft). We had to limit the frequency of the AM modulated identifier Morse code from the standard 1050 Hz to 400 Hz to pass the bandwidth of the antenna system. And yes, there was some power, typically 500W into the antenna and a couple of W into the air. -- -TV
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| From | Jasen Betts <jasen@xnet.co.nz> |
|---|---|
| Date | 2017-03-28 07:44 +0000 |
| Message-ID | <obd483$kgl$1@gonzo.alcatraz> |
| In reply to | #453934 |
On 2017-03-27, Joerg <news@analogconsultants.com> wrote: > On 2017-03-27 16:16, Clifford Heath wrote: >> On 27/03/17 23:25, amdx wrote: >>> On 3/27/2017 6:57 AM, Tauno Voipio wrote: >>>> Joerg, you seem not understand the innermost sense of the crystal- >>>> radio people. They are closely related to audiophools, and it is >>>> quite impossible to use sensible technical argumentation here. >>> >>> I don't get that at all, can you back that up with any facts? >> >> ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500? >> More voltage does not create better audio. > > > That's what I was wondering all the time. In the ranges tested there are > largely just AM stations, no CW or morse code. Even at 10kHz BW the > audio experience will not be very pleasing, it'll sound more like on a > telephone. in a crystal radio the tank is fairly heavily loaded that reduces the effective Q, every picowatt that isn't lost in the tank parts is a picowatt you can send to the earpiece. -- This email has not been checked by half-arsed antivirus software
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| From | amdx <nojunk@knology.net> |
|---|---|
| Date | 2017-03-27 21:18 -0500 |
| Message-ID | <obch11$1d9$1@dont-email.me> |
| In reply to | #453929 |
On 3/27/2017 6:16 PM, Clifford Heath wrote:
> On 27/03/17 23:25, amdx wrote:
>> On 3/27/2017 6:57 AM, Tauno Voipio wrote:
>>> Joerg, you seem not understand the innermost sense of the crystal-
>>> radio people. They are closely related to audiophools, and it is
>>> quite impossible to use sensible technical argumentation here.
>>
>> I don't get that at all, can you back that up with any facts?
>
> ~1MHz, Q=500, bandwidth ~ 2KHz. Remind me why you need Q>1500?
You haven't connected an antenna, and tried to drive a headset yet.
> More voltage does not create better audio.
But if it is a very weak signal on the antenna, you don't want to
waste any signal in loss resistances.
Mikek
---
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