Mail Archive Search: <+subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*Topband\:\s+Common\s+mode\s+chokes\s*$/>

Results:

References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*Topband\:\s+Common\s+mode\s+chokes\s*$/: 34 ]

Total 34 documents matching your query.

1. TopBand: Common mode chokes (score: 1): Author: n2tk@idsi.net (Tony Kazmakites); Date: Thu, 18 Mar 1999 11:07:22 -0500; Could someone please explain to me how common mode chokes work? I see them advertised, but not sure exactly what they do and how they do it. When do you use one? Do they really help? Also, how do res; /archives//html/Topband/1999-03/msg00117.html (6,782 bytes)
2. Topband: Common mode chokes (score: 1): Author: "Carol Richards" <n2mm@comcast.net>; Date: Sun, 13 Jan 2008 11:44:01 -0500; Thank you to everyone who replied to my request. I did a lot of reading and tried to absorb the enormous wealth of knowledge available. I decided to use the binocular approach with #41 mix toroids. 8; /archives//html/Topband/2008-01/msg00094.html (6,390 bytes)
3. Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@contesting.com>; Date: Sat, 04 Jul 2009 10:16:23 -0400; I thought readers here might be interested in some crude experiments I have been doing here with a Clifton Labs active antenna and various common mode choking schemes. It's conventional wisdom that s; /archives//html/Topband/2009-07/msg00003.html (7,848 bytes)
4. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Sat, 04 Jul 2009 11:22:23 -0700; Good work! Several comments. First, since your primary interest is HF, you'll get FAR more bang for the buck with WOUND chokes, as opposed to a string of beads. The reasons why are well documented in; /archives//html/Topband/2009-07/msg00007.html (8,921 bytes)
5. Re: Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@contesting.com>; Date: Sat, 04 Jul 2009 16:33:27 -0400; These are fair points, Jim. One of the purposes if this series of tests is to see if Clifton Labs' super-duper center-tapped choke, which combines 2 different wound cores on each side of the center g; /archives//html/Topband/2009-07/msg00009.html (9,834 bytes)
6. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Sat, 04 Jul 2009 18:23:39 -0700; Good move. I haven't seen the Clifton thing, but it sounds like a good idea, for the reason noted in the previous post. Using what you have in the back room can be a useful starting point. ON4UN's de; /archives//html/Topband/2009-07/msg00010.html (9,510 bytes)
7. Re: Topband: Common mode chokes (score: 1): Author: DAVID CUTHBERT <telegrapher9@gmail.com>; Date: Sat, 4 Jul 2009 19:24:26 -0600; Very good. Another experiment would be to ground the coax shield 20' from the antenna as you did but with no ferrite beads. I suspect you will see similar results. Yes you have a 108' dipole comprise; /archives//html/Topband/2009-07/msg00011.html (10,435 bytes)
8. Re: Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@contesting.com>; Date: Sun, 05 Jul 2009 05:17:45 -0400; I wasn't aware that W2DU had developed the "center-tapped" approach, as opposed to the basic idea of the bead-type current balun. As explained on the lab notebook page, I tested with and without the; /archives//html/Topband/2009-07/msg00015.html (10,250 bytes)
9. Re: Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@contesting.com>; Date: Sun, 05 Jul 2009 05:21:38 -0400; Inteesting. Are your assumptions changed by the presence of the amplifier at the base of the whip, which is designed to match to 75-ohm cable? I will give the beadless version a try. 73, Pete N4ZR __; /archives//html/Topband/2009-07/msg00016.html (11,720 bytes)
10. Re: Topband: Common mode chokes (score: 1): Author: doktorij@bellsouth.net; Date: Mon, 06 Jul 2009 15:55:15 +0000; Hi Pete, Try a large Folger's or similar plastic coffee can to house the device Jim mentioned. You can seal it pretty easy and it will do a good job of protecting the balun. You may even be able to g; /archives//html/Topband/2009-07/msg00019.html (8,410 bytes)
11. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Tue, 07 Jul 2009 08:28:39 -0700; Caution with that, Julius. The capacitance from one end of the choke to the other is a critical component of the choke. A conductive enclosure can change that significantly by lowering the resonant f; /archives//html/Topband/2009-07/msg00026.html (9,128 bytes)
12. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Tue, 07 Jul 2009 12:01:06 -0700; not very easy. Virtually everything is plastic. There are use I can think of for the larger metal cans too. On 160M it's not critical because the wavelength is so long. Rule of thumb is within 1/20 w; /archives//html/Topband/2009-07/msg00028.html (9,225 bytes)
13. Re: Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@comcast.net>; Date: Tue, 07 Jul 2009 17:17:47 -0400; Many coffee manufacturers now make big plastic enclosures that are about 9 inches on a side. I've often thought that you could neatly mount almost any small network in one of them, so lonmg as the li; /archives//html/Topband/2009-07/msg00029.html (9,346 bytes)
14. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Tue, 07 Jul 2009 17:08:59 -0700; Yes, BUT -- when I mentioned an idea similar to that as the solution to mounting a matching network outdoors, my neighbor reminded me the UV from Old Sol attacks most plastic materials and turns them; /archives//html/Topband/2009-07/msg00030.html (9,011 bytes)
15. Re: Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@comcast.net>; Date: Wed, 08 Jul 2009 05:44:29 -0400; Or a quick spray with plastic-compatible paint. _______________________________________________ Topband mailing list Topband@contesting.com http://lists.contesting.com/mailman/listinfo/topband; /archives//html/Topband/2009-07/msg00031.html (8,927 bytes)
16. Topband: Common mode chokes (score: 1): Author: "Thomas Damboldt" <Thomas.Damboldt@T-Online.de>; Date: 08 Jul 2009 15:27 GMT; Hi, if I understand the common mode discussion correctly, a short (not necessarily active) antenna and a much longer feedline act together as kind of a dipole. If I connect my receiver with a very sh; /archives//html/Topband/2009-07/msg00032.html (8,873 bytes)
17. Re: Topband: Common mode chokes (score: 1): Author: doktorij@bellsouth.net; Date: Wed, 08 Jul 2009 18:05:59 +0000; I've been using a red Folgers Classic Roast for three years now at the base of my vertical with no signs of damage. I'd be surprised if many TopBand antenna installations, at least at my level, stay; /archives//html/Topband/2009-07/msg00033.html (10,339 bytes)
18. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Wed, 08 Jul 2009 12:34:39 -0700; For a discussion of what causes common mode current, see http://audiosystemsgroup.com/RFI-Ham.pdf It's in the discussion that leads into Coaxial Chokes. For a Power Point slides on the same topic, se; /archives//html/Topband/2009-07/msg00034.html (9,500 bytes)
19. Re: Topband: Common mode chokes (score: 1): Author: "Jim Brown" <jim@audiosystemsgroup.com>; Date: Wed, 08 Jul 2009 12:38:29 -0700; YES! That's been true of my ham shack and antenna farm for all my 54 years in ham radio. I suspect there may be two kinds of hams -- those who continually experiment and try to learn things, as we do; /archives//html/Topband/2009-07/msg00035.html (8,971 bytes)
20. Re: Topband: Common mode chokes (score: 1): Author: Pete Smith <n4zr@comcast.net>; Date: Wed, 08 Jul 2009 17:29:41 -0400; I think the problem with that is that your active antenna will then be receiving a lot of crud from various sources in your ham-shack. It's amazing how much noise I get at close range from my transce; /archives//html/Topband/2009-07/msg00036.html (9,108 bytes)

Current List: 1 - 20
Page: [1] [2]