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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 5 of 16 — ← Prev page 1 … 3 4 [5] 6 7 … 16 Next page →
| From | pcdhobbs@gmail.com |
|---|---|
| Date | 2017-03-18 19:11 -0700 |
| Message-ID | <b08c6497-c571-41ab-9b7e-75e11ae50c97@googlegroups.com> |
| In reply to | #452528 |
>> I've used them in instruments but never in receivers. Gilbert cells are _not_ strong mixers >>--they have many fine qualities, but good IMD performance is not one of them. >Interesting. Please educate me - when you say "strong" do you mean >"involving sharp switching"? Is is Miller effect and LO feedthrough >that limits the "strength"? Does HFA3101 not qualify as "strong"? A strong mixer is one with really good IMD performance. Antennas pick up everything at some level, so the amount of stuff that your poor little RX front end has to cope with is pretty appalling. A diode bridge with 2 or 3 series-connected Schottky diodes in each arm and a +17 dBm LO is one decent approach, and you can get one from Mini Circuits in one day if you like. A bridge made from a fast CMOS mux is another good approach, though it takes more manual work. These techniques use square wave switching (or nearly), which greatly reduces the proportion of the time when the switching devices are in their 'linear' range. In order to make an order-1 change in the behaviour of a Level 17 mixer or a FET MUX, an interfering signal has to be pretty big, i.e. a volt or two. To do the same to a Gilbert cell requires about e/kT, i.e. ~26 mV. So on a simplistic analysis, a Gilbert cell becomes nonlinear at levels a good 40 dB lower than a strong mixer. Cheers Phil Hobbs
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| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-19 13:15 +1100 |
| Message-ID | <58cde9da$0$51706$c3e8da3$f6268168@news.astraweb.com> |
| In reply to | #452533 |
On 19/03/17 13:11, pcdhobbs@gmail.com wrote: >>> I've used them in instruments but never in receivers. Gilbert cells are _not_ strong mixers >>> --they have many fine qualities, but good IMD performance is not one of > them. > >> Interesting. Please educate me - when you say "strong" do you mean >> "involving sharp switching"? Is is Miller effect and LO feedthrough >> that limits the "strength"? Does HFA3101 not qualify as "strong"? > > A strong mixer is one with really good IMD performance. Antennas pick up everything at some level, so the amount of stuff that your poor little RX front end has to cope with is pretty appalling. > > A diode bridge with 2 or 3 series-connected Schottky diodes in each arm and a +17 dBm LO is one decent approach, and you can get one from Mini Circuits in one day if you like. > > A bridge made from a fast CMOS mux is another good approach, though it takes more manual work. > > These techniques use square wave switching (or nearly), which greatly reduces the proportion of the time when the switching devices are in their 'linear' range. > > In order to make an order-1 change in the behaviour of a Level 17 mixer or a FET MUX, an interfering signal has to be pretty big, i.e. a volt or two. > > To do the same to a Gilbert cell requires about e/kT, i.e. ~26 mV. So on a simplistic analysis, a Gilbert cell becomes nonlinear at levels a good 40 dB lower than a strong mixer. Thank you. I didn't realize they used series Schottky strings. Could the need be somewhat averted with back bias instead?
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| From | pcdhobbs@gmail.com |
|---|---|
| Date | 2017-03-20 04:26 -0700 |
| Message-ID | <fcaf3619-8dfe-493b-8647-bbb85100246c@googlegroups.com> |
| In reply to | #452536 |
>Thank you. I didn't realize they used series Schottky strings. >Could the need be somewhat averted with back bias instead? Not so easy in a ring topology--the diodes are in antiparallel, not as in a bridge rectifier. The MOSFET approach was developed by the late great Ed Oxner at Siliconix in the late '70s, and published as an app note for the Si8901 monolithic quad FET. (It might have been 8601--iirc they re-used the p/n for a gate driver chip so the old one is hard to fin info on.) The idea is to put the FETs in a ring, cross-connect the gates in two pairs and put the LO there via the usual transformer. The RF and IF ports are the corners of the ring (1 and 3 for one and 2 and 4 for the other). Since the gates are high-Z, you can use a large LO swing, which is mainly what helps the IMD. The Tayloe approach uses a mux, but is the same basic idea, and aiui it came along much later. So I think it should be called the Oxner mixer. Cheers Phil Hobbs
[toc] | [prev] | [next] | [standalone]
| From | Clifford Heath <no.spam@please.net> |
|---|---|
| Date | 2017-03-21 13:17 +1100 |
| Message-ID | <58d0bb96$0$39552$b1db1813$7968482@news.astraweb.com> |
| In reply to | #452703 |
On 20/03/17 22:26, pcdhobbs@gmail.com wrote: >> Thank you. I didn't realize they used series Schottky strings. >> Could the need be somewhat averted with back bias instead? > Not so easy in a ring topology--the diodes are in antiparallel, not as in a bridge rectifier. That makes it easier - you can break the ring with a capacitor (or a pair) and bias the whole string with one bias voltage. They'll still be a ring at AC. > The MOSFET approach was developed by the late great Ed Oxner at Siliconix in the late '70s, and published as an app note for the Si8901 monolithic quad FET. (It might have been 8601--iirc they re-used the p/n for a gate driver chip so the old one is hard to fin info on.) > The idea is to put the FETs in a ring, cross-connect the gates in two pairs and put the LO there via the usual transformer. The RF and IF ports are the corners of the ring (1 and 3 for one and 2 and 4 for the other). That's just a Gilbert cell made of MOSFETs, isn't it? > Since the gates are high-Z, you can use a large LO swing, which is mainly what helps the IMD. The problem with needing large LO swing is slew rate, of course. It has to be quite substantial to get good rejection, because it's not effective while still slewing. > The Tayloe approach uses a mux, but is the same basic idea, and aiui it came along much later. So I think it should be called the Oxner mixer. Same issue. You're pushing devices to switch at substantially faster slew rates than required for the signal (large signal & rapid transition compared to the frequency of interest). Clifford Heath.
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| From | "Tim Williams" <tiwill@seventransistorlabs.com> |
|---|---|
| Date | 2017-03-21 01:32 -0500 |
| Message-ID | <oaqh84$vt9$1@dont-email.me> |
| In reply to | #452846 |
"Clifford Heath" <no.spam@please.net> wrote in message news:58d0bb96$0$39552$b1db1813$7968482@news.astraweb.com... >> Since the gates are high-Z, you can use a large LO swing, which is mainly >> what helps the IMD. > > The problem with needing large LO swing is slew rate, of course. > It has to be quite substantial to get good rejection, because > it's not effective while still slewing. > >> The Tayloe approach uses a mux, but is the same basic idea, and aiui it >> came along much later. So I think it should be called the Oxner mixer. > > Same issue. You're pushing devices to switch at substantially > faster slew rates than required for the signal (large signal & > rapid transition compared to the frequency of interest). You're ultimately limited by how much power you want to waste driving the LO port, and how much voltage the gates (and substrate) can withstand. The average gate and substrate voltages are normally biased independently, to avoid substrate diode conduction (Vss is negative so-and-so), and to get balance right. (This is in the appnote section of the aforementioned mixer IC.) I wonder what a vacuum tube design would offer. Pentodes should give fantastic dynamic range. Though THD (and by extension, IMD) probably won't be very good, because of the overall V^(3/2) characteristic. But you can do even greater things in vacuuo. The venerable 7360 is the greatest exemplar of the current-steering mixer (a half of a Gilbert cell, e.g. CA2028). It works by physically steering the electron beam itself, via electric field deflection. Look ma, no hands! (But I would guess the noise performance still isn't as good as a traditional BJT Gilbert cell, simply on account of being tube state.) Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
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| From | upsidedown@downunder.com |
|---|---|
| Date | 2017-03-21 10:38 +0200 |
| Message-ID | <c2p1dcd8le36244jstotc9q6rmlvdgrbcl@4ax.com> |
| In reply to | #452858 |
On Tue, 21 Mar 2017 01:32:19 -0500, "Tim Williams" <tiwill@seventransistorlabs.com> wrote: >"Clifford Heath" <no.spam@please.net> wrote in message >news:58d0bb96$0$39552$b1db1813$7968482@news.astraweb.com... >>> Since the gates are high-Z, you can use a large LO swing, which is mainly >>> what helps the IMD. >> >> The problem with needing large LO swing is slew rate, of course. >> It has to be quite substantial to get good rejection, because >> it's not effective while still slewing. >> >>> The Tayloe approach uses a mux, but is the same basic idea, and aiui it >>> came along much later. So I think it should be called the Oxner mixer. >> >> Same issue. You're pushing devices to switch at substantially >> faster slew rates than required for the signal (large signal & >> rapid transition compared to the frequency of interest). > >You're ultimately limited by how much power you want to waste driving the LO >port, and how much voltage the gates (and substrate) can withstand. > >The average gate and substrate voltages are normally biased independently, >to avoid substrate diode conduction (Vss is negative so-and-so), and to get >balance right. (This is in the appnote section of the aforementioned mixer >IC.) > >I wonder what a vacuum tube design would offer. Pentodes should give >fantastic dynamic range. Though THD (and by extension, IMD) probably won't >be very good, because of the overall V^(3/2) characteristic. Double tetrodes has been used as high level _transmitter_ mixers in SSB transmitters, especially when trying to avoid as many expensive VHF or UHF gain stages as possible. The QQE06/40 would be a nice high level mixer :-) I have no idea about the noise performance of small power tetrodes and hence the suitability as _receiver_ mixer. >But you can do even greater things in vacuuo. The venerable 7360 is the >greatest exemplar of the current-steering mixer (a half of a Gilbert cell, >e.g. CA2028). It works by physically steering the electron beam itself, via >electric field deflection. Look ma, no hands! (But I would guess the noise >performance still isn't as good as a traditional BJT Gilbert cell, simply on >account of being tube state.) Nice tube.
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| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Date | 2017-03-21 02:53 -0400 |
| Message-ID | <MqWdnaikwMvqUE3FnZ2dnUU7-W3NnZ2d@supernews.com> |
| In reply to | #452846 |
On 03/20/2017 10:17 PM, Clifford Heath wrote: > On 20/03/17 22:26, pcdhobbs@gmail.com wrote: >>> Thank you. I didn't realize they used series Schottky strings. >>> Could the need be somewhat averted with back bias instead? >> Not so easy in a ring topology--the diodes are in antiparallel, not as >> in a bridge rectifier. > > That makes it easier - you can break the ring with a capacitor > (or a pair) and bias the whole string with one bias voltage. > They'll still be a ring at AC. The LO switches the diodes hard, so it's tough to AC-couple them without loading down the ring and so breaking the double-balanced condition. It's probably possible, but it isn't obvious. It isn't like a sampling bridge. > >> The MOSFET approach was developed by the late great Ed Oxner at >> Siliconix in the late '70s, and published as an app note for the >> Si8901 monolithic quad FET. (It might have been 8601--iirc they >> re-used the p/n for a gate driver chip so the old one is hard to fin >> info on.) >> The idea is to put the FETs in a ring, cross-connect the gates in two >> pairs and put the LO there via the usual transformer. The RF and IF >> ports are the corners of the ring (1 and 3 for one and 2 and 4 for the >> other). > > That's just a Gilbert cell made of MOSFETs, isn't it? No, it's a bridge topology, just like a diode bridge except without mixing the control and signal currents (except via gate capacitance). > >> Since the gates are high-Z, you can use a large LO swing, which is >> mainly what helps the IMD. > > The problem with needing large LO swing is slew rate, of course. > It has to be quite substantial to get good rejection, because > it's not effective while still slewing. That's one problem. In a Gilbert cell, the RF has to go into the bases of a diff pair. It's the nonlinearity of the diff pair that causes the issue in voltage-mode Gilbert cells such as the MC1496 (The CA3102 isn't a Gilbert cell because it has only one diff pair instead of three.) A real Gilbert cell, i.e. one with current inputs instead of voltage, is somewhat better, but even with matched transistors there's still AC nonlinearity due to the Early effect. You can patch a lot of this stuff up by pouring on extra parts, but that usually leads to limitations at high frequency. > >> The Tayloe approach uses a mux, but is the same basic idea, and aiui >> it came along much later. So I think it should be called the Oxner mixer. > > Same issue. You're pushing devices to switch at substantially > faster slew rates than required for the signal (large signal & > rapid transition compared to the frequency of interest). No. The MOSFET approaches also separate the control and signal paths and reduce the ON-resistance modulation even in the fully-ON state. The biggest win is not letting the RF signals intermodulate by putting them into a nonlinear stage without feedback, such as the bases of a diff pair or a weak bipolar RF amp. (JFETs are somewhat better as RF amps because their IMD is predominantly even-order, and even-order spurs tend not to land in the IF passband the way odd-order ones often do.) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
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| From | pcdhobbs@gmail.com |
|---|---|
| Date | 2017-03-21 01:01 -0700 |
| Message-ID | <04ab28d6-0ed9-4793-9c2c-c8c17281c6bb@googlegroups.com> |
| In reply to | #452859 |
>> That's just a Gilbert cell made of MOSFETs, isn't it? >No, it's a bridge topology, just like a diode bridge except without >mixing the control and signal currents (except via gate capacitance). I was perhaps unclear--it's a ring topology, i.e. symmetrical, unlike a bridge rectifier. Both are bridges in the strict sense, of course. Cheers Phil Hobbs
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-21 12:33 +0200 |
| Message-ID | <oaqvbt$5er$3@dont-email.me> |
| In reply to | #452703 |
On 20.3.17 13:26, pcdhobbs@gmail.com wrote: > The Tayloe approach uses a mux, but is the same basic idea, and aiui it came along much later. So I think it should be called the Oxner mixer. > > Cheers > > Phil Hobbs In the same sense, we can say that the Oxner FET switch ring uses the reversing switch principle of the selenium rectifier rings of telephony SSB channels years before any FETs. -- -TV
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| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Date | 2017-03-21 09:42 -0400 |
| Message-ID | <Z-SdnQiE8r5LsEzFnZ2dnUU7-eXNnZ2d@supernews.com> |
| In reply to | #452875 |
On 03/21/2017 06:33 AM, Tauno Voipio wrote: > On 20.3.17 13:26, pcdhobbs@gmail.com wrote: > >> The Tayloe approach uses a mux, but is the same basic idea, and aiui >> it came along much later. So I think it should be called the Oxner mixer. >> >> Cheers >> >> Phil Hobbs > > > In the same sense, we can say that the Oxner FET switch > ring uses the reversing switch principle of the selenium > rectifier rings of telephony SSB channels years before > any FETs. > I don't agree. Diodes and transistors work differently in mixers (as elsewhere) because their control and signal paths are separate. The two-transformer ring DBM is also a thing of beauty, but I don't know who invented it. I think that it's a pity that in electronics we usually don't attach people's names to stuff the way it's done in science. Gilbert cells, Oxner mixers, Brokaw bandgaps, Widlar practically everythings, Eccles-Jordan flipflops, Johnson noise, Nyquist frequency....bring 'em on. ;) It helps maintain the ethos of the field, I think, and encourages people that you don't have to walk on water or be 200 years old to have a circuit named after you. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
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| From | piglet <erichpwagner@hotmail.com> |
|---|---|
| Date | 2017-03-21 19:05 +0000 |
| Message-ID | <oartd5$nfc$1@dont-email.me> |
| In reply to | #452882 |
On 21/03/2017 13:42, Phil Hobbs wrote: > > The two-transformer ring DBM is also a thing of beauty, but I don't know > who invented it. I think that it's a pity that in electronics we > usually don't attach people's names to stuff the way it's done in > science. Gilbert cells, Oxner mixers, Brokaw bandgaps, Widlar > practically everythings, Eccles-Jordan flipflops, Johnson noise, Nyquist > frequency....bring 'em on. ;) > > It helps maintain the ethos of the field, I think, and encourages people > that you don't have to walk on water or be 200 years old to have a > circuit named after you. > > Cheers > > Phil Hobbs > Hail the Hobbs Bootstrap! There is the Graetz-Pollak diode bridge but that is what we know as the full wave bridge rectifier. The Ring modulator DBM is due to Cowan-Keith. piglet
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| From | George Herold <gherold@teachspin.com> |
|---|---|
| Date | 2017-03-21 12:49 -0700 |
| Message-ID | <5da955f8-d250-4ed6-9320-2d020a9a30e8@googlegroups.com> |
| In reply to | #452922 |
On Tuesday, March 21, 2017 at 3:06:01 PM UTC-4, piglet wrote: > On 21/03/2017 13:42, Phil Hobbs wrote: > > > > The two-transformer ring DBM is also a thing of beauty, but I don't know > > who invented it. I think that it's a pity that in electronics we > > usually don't attach people's names to stuff the way it's done in > > science. Gilbert cells, Oxner mixers, Brokaw bandgaps, Widlar > > practically everythings, Eccles-Jordan flipflops, Johnson noise, Nyquist > > frequency....bring 'em on. ;) > > > > It helps maintain the ethos of the field, I think, and encourages people > > that you don't have to walk on water or be 200 years old to have a > > circuit named after you. > > > > Cheers > > > > Phil Hobbs > > > > Hail the Hobbs Bootstrap! > > There is the Graetz-Pollak diode bridge but that is what we know as the > full wave bridge rectifier. > > The Ring modulator DBM is due to Cowan-Keith. > > piglet I first say the cap multiplier in Phil's book, for about 1 year I called it a Hobbs Filter in my notebook. Short lived fame. :^) George H.
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| From | piglet <erichpwagner@hotmail.com> |
|---|---|
| Date | 2017-03-21 18:39 +0000 |
| Message-ID | <oarrsi$hpq$1@dont-email.me> |
| In reply to | #452875 |
On 21/03/2017 10:33, Tauno Voipio wrote: > In the same sense, we can say that the Oxner FET switch > ring uses the reversing switch principle of the selenium > rectifier rings of telephony SSB channels years before > any FETs. > Fascinating, thanks Tauno, I didn't know Selenium was fast enough for anything much above power line frequency, what about copper oxide? piglet
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-21 22:39 +0200 |
| Message-ID | <oas2s8$a0u$2@dont-email.me> |
| In reply to | #452917 |
On 21.3.17 20:39, piglet wrote: > On 21/03/2017 10:33, Tauno Voipio wrote: >> In the same sense, we can say that the Oxner FET switch >> ring uses the reversing switch principle of the selenium >> rectifier rings of telephony SSB channels years before >> any FETs. >> > > Fascinating, thanks Tauno, I didn't know Selenium was fast enough for > anything much above power line frequency, what about copper oxide? > > piglet > They used both. AFAIK, the technique was developed in the Bell Labs in the 1930's. -- -TV
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-21 12:30 +0200 |
| Message-ID | <oaqv7g$5er$2@dont-email.me> |
| In reply to | #452536 |
On 19.3.17 04:15, Clifford Heath wrote: >> good 40 dB lower than a strong mixer. > > Thank you. I didn't realize they used series Schottky strings. > > Could the need be somewhat averted with back bias instead? The diode ring works only because there is a forward voltage drop in the diodes. The forward drop clips the injection voltage to square wave and it limits the signal level to well below the clipping level. The series diode rings were used already in the SSB channeled telephone circuits in the 1930's to get higher levels on the modulators. -- -TV
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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
|---|---|
| Date | 2017-03-19 17:43 +0200 |
| Message-ID | <oam8ou$ta$1@dont-email.me> |
| In reply to | #452533 |
On 19.3.17 04:11, pcdhobbs@gmail.com wrote: >>> I've used them in instruments but never in receivers. Gilbert cells are _not_ strong mixers >>> --they have many fine qualities, but good IMD performance is not one of > them. > >> Interesting. Please educate me - when you say "strong" do you mean >> "involving sharp switching"? Is is Miller effect and LO feedthrough >> that limits the "strength"? Does HFA3101 not qualify as "strong"? > > A strong mixer is one with really good IMD performance. Antennas pick up everything at some level, so the amount of stuff that your poor little RX front end has to cope with is pretty appalling. > > A diode bridge with 2 or 3 series-connected Schottky diodes in each arm and a +17 dBm LO is one decent approach, and you can get one from Mini Circuits in one day if you like. > > A bridge made from a fast CMOS mux is another good approach, though it takes more manual work. > > These techniques use square wave switching (or nearly), which greatly reduces the proportion of the time when the switching devices are in their 'linear' range. > > In order to make an order-1 change in the behaviour of a Level 17 mixer or a FET MUX, an interfering signal has to be pretty big, i.e. a volt or two. > > To do the same to a Gilbert cell requires about e/kT, i.e. ~26 mV. So on a simplistic analysis, a Gilbert cell becomes nonlinear at levels a good 40 dB lower than a strong mixer. > > Cheers > > Phil Hobbs Maybe the best mixers can be built with CMOS analog switches. Google for 'Tayloe mixer'. -- -TV
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| From | upsidedown@downunder.com |
|---|---|
| Date | 2017-03-21 14:39 +0200 |
| Message-ID | <sm62dcd6jfvdgp8edvthinm5cejvhekfmt@4ax.com> |
| In reply to | #452533 |
On Sat, 18 Mar 2017 19:11:21 -0700 (PDT), pcdhobbs@gmail.com wrote: >>> I've used them in instruments but never in receivers. Gilbert cells are _not_ strong mixers >>>--they have many fine qualities, but good IMD performance is not one of >them. > >>Interesting. Please educate me - when you say "strong" do you mean >>"involving sharp switching"? Is is Miller effect and LO feedthrough >>that limits the "strength"? Does HFA3101 not qualify as "strong"? > >A strong mixer is one with really good IMD performance. Antennas pick up everything at some level, so the amount of stuff that your poor little RX front end has to cope with is pretty appalling. > >A diode bridge with 2 or 3 series-connected Schottky diodes in each arm and a +17 dBm LO is one decent approach, and you can get one from Mini Circuits in one day if you like. > >A bridge made from a fast CMOS mux is another good approach, though it takes more manual work. > >These techniques use square wave switching (or nearly), which greatly reduces the proportion of the time when the switching devices are in their 'linear' range. > >In order to make an order-1 change in the behaviour of a Level 17 mixer or a FET MUX, an interfering signal has to be pretty big, i.e. a volt or two. > >To do the same to a Gilbert cell requires about e/kT, i.e. ~26 mV. So on a simplistic analysis, a Gilbert cell becomes nonlinear at levels a good 40 dB lower than a strong mixer. > >Cheers > >Phil Hobbs The question about the pros and cons of different mixers might soon be in the past, since direct sampling ADCs perform surprisingly well. One WebSDR receiver (http://websdr.ewi.utwente.nl:8901/) samples the 0-30 MHz band and then digitally decimates the requested sub-band for individual listeners across the Internet. Unfortunately, the antenna is in the middle of a noisy campus area, thus it is hard to say something about the actual weak signal performance. However, I didn't detect any obvious spurious responses as with some ordinal receivers. For single frequency reception at one time, much slower sampling rates (fs) and hence cheaper or more accurate ADCs can be used by limiting the analog front end bandwidth well below fs/s then undersampling, thus no need for a mixer in front of the ADC.
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| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Date | 2017-03-21 09:46 -0400 |
| Message-ID | <74SdndHB0fMos0zFnZ2dnUU7-WfNnZ2d@supernews.com> |
| In reply to | #452878 |
On 03/21/2017 08:39 AM, upsidedown@downunder.com wrote: > On Sat, 18 Mar 2017 19:11:21 -0700 (PDT), pcdhobbs@gmail.com wrote: > >>>> I've used them in instruments but never in receivers. Gilbert >>>> cells are _not_ strong mixers --they have many fine qualities, >>>> but good IMD performance is not one of >> them. >> >>> Interesting. Please educate me - when you say "strong" do you >>> mean "involving sharp switching"? Is is Miller effect and LO >>> feedthrough that limits the "strength"? Does HFA3101 not qualify >>> as "strong"? >> >> A strong mixer is one with really good IMD performance. Antennas >> pick up everything at some level, so the amount of stuff that your >> poor little RX front end has to cope with is pretty appalling. >> >> A diode bridge with 2 or 3 series-connected Schottky diodes in each >> arm and a +17 dBm LO is one decent approach, and you can get one >> from Mini Circuits in one day if you like. >> >> A bridge made from a fast CMOS mux is another good approach, though >> it takes more manual work. >> >> These techniques use square wave switching (or nearly), which >> greatly reduces the proportion of the time when the switching >> devices are in their 'linear' range. >> >> In order to make an order-1 change in the behaviour of a Level 17 >> mixer or a FET MUX, an interfering signal has to be pretty big, >> i.e. a volt or two. >> >> To do the same to a Gilbert cell requires about e/kT, i.e. ~26 mV. >> So on a simplistic analysis, a Gilbert cell becomes nonlinear at >> levels a good 40 dB lower than a strong mixer. >> >> Cheers >> >> Phil Hobbs > > The question about the pros and cons of different mixers might soon > be in the past, since direct sampling ADCs perform surprisingly > well. > > One WebSDR receiver (http://websdr.ewi.utwente.nl:8901/) samples the > 0-30 MHz band and then digitally decimates the requested sub-band > for individual listeners across the Internet. Unfortunately, the > antenna is in the middle of a noisy campus area, thus it is hard to > say something about the actual weak signal performance. However, I > didn't detect any obvious spurious responses as with some ordinal > receivers. > > For single frequency reception at one time, much slower sampling > rates (fs) and hence cheaper or more accurate ADCs can be used by > limiting the analog front end bandwidth well below fs/s then > undersampling, thus no need for a mixer in front of the ADC. > > Maybe. Seems like a lot of foofaraw just for a sportscast. ;) SDR-style spectrum analyzers are pretty much entry-level junk compared with the traditional approach. Lots of bells and whistles, lots faster measurements, but in my world if you can't measure something, not-measuring it fast is no better than not-measuring it slowly. Cheers Phil "Big boat anchor fan" Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
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| From | George Herold <gherold@teachspin.com> |
|---|---|
| Date | 2017-03-17 17:31 -0700 |
| Message-ID | <32e9f24f-61b8-45f7-9bac-80ebd9439ed0@googlegroups.com> |
| In reply to | #452276 |
On Friday, March 17, 2017 at 11:38:44 AM UTC-4, Phil Hobbs wrote: > On 03/17/2017 11:28 AM, George Herold wrote: > > On Friday, March 17, 2017 at 10:30:32 AM UTC-4, John Larkin wrote: > >> On Thu, 16 Mar 2017 18:46:06 -0700 (PDT), George Herold > >> <gherold@teachspin.com> wrote: > >> > >>> On Thursday, March 16, 2017 at 8:36:16 PM UTC-4, Phil Allison wrote: > >>>> George Herold wrote: > >>>> > >>>> > >>>>>> > >>>>>>> I've got an AM radio that came with an air core antenna. > >>>>>>> (1990's vintage) > >>>>>>> ~4" (10 cm) squarish loop. Not sure how many turns. > >>>>>>> Works fine. > >>>>>>> > >>>>>> > >>>>>> ** So it's an external loop for a main powered receiver ? > >>>>>> > >>>>> Right, It's a JVC "ultra compact component system" > >>>>> FS-1000 > >>>>> > >>>> > >>>> ** So why didn't you post that info before? > >>>> > >>> 'cos I'm now at home and not at work. > >>>> It's a fucking frame antenna, already discussed here in this thread and been around since the dawn of radio. > >>>> > >>>> > >>>>> > >>>>> Knowing almost nothing about AM, (and assuming I don't care about price.) > >>>>> I figure I want the highest Q possible on the front end.. > >>>>> > >>>> > >>>> ** Nope. > >>>> > >>>> You need at least 10kHz of bandwidth at the antenna so the Q must not exceed 50 to 100 across the AM band. You will find that antenna has a fairly low Q in practice. > >>> OK I was thinking of best signal to noise, and figuring that ~1-2 kHz would > >>> be enough.. Everyones "best/ optimal" is a bit different. > >> > >> An AM antenna doesn't need to be tuned at all. An untuned coil will > >> snoop the ambient h-field. > > I guess that's right. As long as most of the noise is "in the air" it doesn't > > really matter where the band pass filter is. (Except for dynamic range issues.) > > As you say, dynamic range. An untuned input needs a stronger mixer. A > Q of 10 or 20 would help a lot. > > On the other hand, one could just use a Mini Circuits mixer with a +17 > dBm LO, or a nice analogue mux with square wave drive. It takes a lot > to screw one of those up. Hah, I made an AM radio just that way. Not with a loop, but just a length of wire. (It's probably the worlds's worst AM radio.) I had to add series L's (selected for range) to make it work. Circuit from Terman's radio electronics book. So a loop (with parallel C) into a TIA? ... (I'd rather use an opamp.) or will that wig out at the C side of the resonance? George H. > > Cheers > > Phil Hobbs > > -- > Dr Philip C D Hobbs > Principal Consultant > ElectroOptical Innovations LLC > Optics, Electro-optics, Photonics, Analog Electronics > > 160 North State Road #203 > Briarcliff Manor NY 10510 > > hobbs at electrooptical dot net > http://electrooptical.net
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| From | John Larkin <jjlarkinxyxy@highlandtechnology.com> |
|---|---|
| Date | 2017-03-17 17:46 -0700 |
| Message-ID | <9m0pcchfs69iadd62p9uun2nn39lsaq2vf@4ax.com> |
| In reply to | #452346 |
On Fri, 17 Mar 2017 17:31:46 -0700 (PDT), George Herold <gherold@teachspin.com> wrote: >On Friday, March 17, 2017 at 11:38:44 AM UTC-4, Phil Hobbs wrote: >> On 03/17/2017 11:28 AM, George Herold wrote: >> > On Friday, March 17, 2017 at 10:30:32 AM UTC-4, John Larkin wrote: >> >> On Thu, 16 Mar 2017 18:46:06 -0700 (PDT), George Herold >> >> <gherold@teachspin.com> wrote: >> >> >> >>> On Thursday, March 16, 2017 at 8:36:16 PM UTC-4, Phil Allison wrote: >> >>>> George Herold wrote: >> >>>> >> >>>> >> >>>>>> >> >>>>>>> I've got an AM radio that came with an air core antenna. >> >>>>>>> (1990's vintage) >> >>>>>>> ~4" (10 cm) squarish loop. Not sure how many turns. >> >>>>>>> Works fine. >> >>>>>>> >> >>>>>> >> >>>>>> ** So it's an external loop for a main powered receiver ? >> >>>>>> >> >>>>> Right, It's a JVC "ultra compact component system" >> >>>>> FS-1000 >> >>>>> >> >>>> >> >>>> ** So why didn't you post that info before? >> >>>> >> >>> 'cos I'm now at home and not at work. >> >>>> It's a fucking frame antenna, already discussed here in this thread and been around since the dawn of radio. >> >>>> >> >>>> >> >>>>> >> >>>>> Knowing almost nothing about AM, (and assuming I don't care about price.) >> >>>>> I figure I want the highest Q possible on the front end.. >> >>>>> >> >>>> >> >>>> ** Nope. >> >>>> >> >>>> You need at least 10kHz of bandwidth at the antenna so the Q must not exceed 50 to 100 across the AM band. You will find that antenna has a fairly low Q in practice. >> >>> OK I was thinking of best signal to noise, and figuring that ~1-2 kHz would >> >>> be enough.. Everyones "best/ optimal" is a bit different. >> >> >> >> An AM antenna doesn't need to be tuned at all. An untuned coil will >> >> snoop the ambient h-field. >> > I guess that's right. As long as most of the noise is "in the air" it doesn't >> > really matter where the band pass filter is. (Except for dynamic range issues.) >> >> As you say, dynamic range. An untuned input needs a stronger mixer. A >> Q of 10 or 20 would help a lot. >> >> On the other hand, one could just use a Mini Circuits mixer with a +17 >> dBm LO, or a nice analogue mux with square wave drive. It takes a lot >> to screw one of those up. >Hah, I made an AM radio just that way. Not with a loop, but just >a length of wire. (It's probably the worlds's worst AM radio.) >I had to add series L's (selected for range) to make it work. >Circuit from Terman's radio electronics book. > >So a loop (with parallel C) into a TIA? ... (I'd rather use an opamp.) >or will that wig out at the C side of the resonance? > A short wire antenna gets a voltage equal to the local e-field. All you need to do is drive an amp with reasonably low input capacitance, like a jfet or something. I could patent that, but it's been done for 100 years or so. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
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