Re: Topband: Topband Digest, Vol 116, Issue 49

2012-08-28 Thread wa3mej
EDDY,   IMHO you are much better using a ballanced tuner with an UNUN on the transmitter side. You will get a better match over a wider impendence AND a wider frequency range provided you choose the correct capacitor and inductors. I used this with my loop and also an openwire fed dipole wit

Re: Topband: Wideband Balun...?

2012-08-28 Thread Jim Brown
On 8/28/2012 12:28 PM, Tom W8JI wrote: > Generally a 1:1 ferrite core balun has the least problem with grossly > mismatched impedances, the widest useable frequency range, and the best > balance for a given size and cost. In this tutorial http://audiosystemsgroup.com/RFI-Ham.pdf There are gr

Re: Topband: Wideband Balun...?

2012-08-28 Thread Gary K9GS
I think what you want is an un-un...not a balun. It doesn't sound like there are any balanced elements in your system. Perhaps something like this: http://www.balundesigns.com/servlet/the-Ununs/Categories On 8/28/2012 1:29 PM, Eddy Swynar wrote: > Good Day All, > > I am thinking of incorporat

Re: Topband: Wideband Balun...?

2012-08-28 Thread Keith Jillings (G3OIT)
Yes indeed - the way it was described to me was "choke balun". I'm not a purist in such matters - if it works, I'll go with the name it was given. I was sceptical when it was suggested, but since I was having trouble matching the doublet, I decided there was little to lose. In fact, it works

Re: Topband: Wideband Balun...?

2012-08-28 Thread PaulKB8N
The Heathkit Balun is not robust at all, the coils are close-spaced and made with #18 or #20 wire. I had one as a young ham in the 60s and was quite disappointed with the physical construction. I'd not recommend going to the bother of hunting one down. Over the years, I've designed a lot o

Re: Topband: Wideband Balun...?

2012-08-28 Thread Rich Chatelain
Hi Tom, What is your recommendation (mix type and quantity) for ferrite beads on each of the 1/4 wave feed lines (RG11/U) for a 160M 4 square? I have Amidon FB-77-1024 in my inventory. Rich K7ZV -Original Message- From: topband-boun...@contesting.com [mailto:topband-boun...@contesting.

Re: Topband: Wideband Balun...?

2012-08-28 Thread Rick Karlquist
Eddy Swynar wrote: > > Is there really & truly such a thing as an air core 4:1 balun that will > cover the entire spectrum from 1.8- to 29.7-MHz...? I've looked & I've > repeatedly searched on the internet, but can not quite come up with such Basically, you are describing the old Heathkit balun.

Re: Topband: Wideband Balun...?

2012-08-28 Thread Tom W8JI
Hi Eddy, > I am thinking of incorporating a homebrewed 4:1 balun as part of a > transmatch that I have here, which was designed to feed coaxial cable-fed > antennas only... Why did you decide on a 4:1? Generally a tuner matches a much higher impedance than a 4:1 balun will safely permit, and

Re: Topband: Wideband Balun...?

2012-08-28 Thread Keith Jillings (G3OIT)
On 28/08/2012 19:29, Eddy Swynar wrote: > I am thinking of incorporating a homebrewed 4:1 balun as part of a transmatch > that I have here, which was designed to feed coaxial cable-fed antennas > only... > > Is there really & truly such a thing as an air core 4:1 balun that will cover > the ent

Topband: Wideband Balun...?

2012-08-28 Thread Eddy Swynar
Good Day All, I am thinking of incorporating a homebrewed 4:1 balun as part of a transmatch that I have here, which was designed to feed coaxial cable-fed antennas only... Is there really & truly such a thing as an air core 4:1 balun that will cover the entire spectrum from 1.8- to 29.7-MHz...?