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References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*Topband\:\s+Efficiently\s+Matching\s+Low\-Impedance\s+Antennas\s+to\s+50ohms\s*$/: 12 ]

Total 12 documents matching your query.

1. Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: Ron Majewski <bigsky2000@sbcglobal.net>
Date: Tue, 20 Sep 2005 20:49:48 -0700 (PDT)
Hi All, I'm looking for advice about how to efficiently match my 160m inverted-L to 50 ohms. Here's what's motivating this question: My 160m inv-L is about 60ft tall with a 100ft long horizontal sect
/archives//html/Topband/2005-09/msg00065.html (8,858 bytes)

2. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Mauri" <i4jmy@iol.it>
Date: Thu, 22 Sep 2005 17:07:18 +0200
Assuming the ammeter is based on a thermocouple, your measurement has sense, even if the impedance is other than 50 Ohms and reactive. The same doesn'apply to bird wattmeter, which doesn't measure p
/archives//html/Topband/2005-09/msg00068.html (8,101 bytes)

3. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Thu, 22 Sep 2005 13:36:01 -0400
We probably know input impedance is 50 ohms or pretty close to it on the input. We don't accurately know load Z. I moved the RF ammeter to the antenna side I'm assuming the tuner was adjusted correc
/archives//html/Topband/2005-09/msg00069.html (10,547 bytes)

4. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Paul Elliot" <paab@valornet.com>
Date: Thu, 22 Sep 2005 12:45:22 -0600
I have a similar antenna, though probably not quite as long as yours (I have never measured the length). I have been under the impression, from reading the literature, that the feedpoint had an indu
/archives//html/Topband/2005-09/msg00072.html (8,698 bytes)

5. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Herb Schoenbohm" <herbs@vitelcom.net>
Date: Thu, 22 Sep 2005 18:11:44 -0700
Ron, You can get close to what you want (about 25 ohms) by tying two pieces of 50 ohm coax equal half wave lengths (in coax factoring the velocity factor) in parallel hooked shield to shield and cen
/archives//html/Topband/2005-09/msg00074.html (8,614 bytes)

6. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Tod - MN" <tod@k0to.us>
Date: Thu, 22 Sep 2005 21:07:00 -0500
Ron: I will give you my thoughts. Since the price for them is zero they may have exactly that value. If we assume your readings are correct (and they sound quite reasonable to me based upon my measur
/archives//html/Topband/2005-09/msg00075.html (9,695 bytes)

7. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Ulrich Weiss" <dj2ya@t-online.de>
Date: Fri, 23 Sep 2005 09:12:11 +0200
hello Ron, factor) Herb's suggestion will reduce your SWR to 1.6... using 75 ohm line would yield 1.4 and if you can get hold of 60 ohm line you'd be pretty close to a perfect match... after reading
/archives//html/Topband/2005-09/msg00076.html (9,091 bytes)

8. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: Barry Gross <barry.n1eu@gmail.com>
Date: Fri, 23 Sep 2005 07:16:41 -0400
Shouldn't the coax lengths be electrical quarter wavelength rather than half wavelength? 73, Barry N1EU _______________________________________________ Topband mailing list Topband@contesting.com htt
/archives//html/Topband/2005-09/msg00077.html (9,425 bytes)

9. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Fri, 23 Sep 2005 08:32:09 -0400
wavelength rather than half Indeed it would. It would be a 1/4 wl, and the impedance required would be the square root of the product of load impedance times source impedance. With a 20 ohm antenna
/archives//html/Topband/2005-09/msg00078.html (10,685 bytes)

10. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Ulrich Weiss" <dj2ya@t-online.de>
Date: Fri, 23 Sep 2005 15:35:06 +0200
half thanks for your correction, Berry, I didn't read Herb's text attentively enough, but I'm sure he wanted to say 1/4 wl.... regards Uli, DJ2YA _______________________________________________ Topb
/archives//html/Topband/2005-09/msg00079.html (9,049 bytes)

11. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: "Guy Olinger, K2AV" <olinger@bellsouth.net>
Date: Fri, 23 Sep 2005 21:05:38 -0400
"I'm looking for advice about how to efficiently match my 160m inverted-L to 50 ohms." ... " My receiver noise bridge shows that its impedance has a resistive component that's around 20 ohms," ... On
/archives//html/Topband/2005-09/msg00083.html (10,023 bytes)

12. Re: Topband: Efficiently Matching Low-Impedance Antennas to 50ohms (score: 1)
Author: Roger D Johnson <n1rj@adelphia.net>
Date: Fri, 07 Oct 2005 12:06:39 -0400
Let me throw a small monkey wrench into this. If you have an accurate set of measurements at the base of the antenna and a Smith chart program, you can achieve a wider bandwidth by NOT adjusting the
/archives//html/Topband/2005-10/msg00029.html (8,013 bytes)


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