View Single Post
  #1   Report Post  
Old September 18th 13, 04:01 PM posted to rec.radio.amateur.antenna
J.B. Wood[_2_] J.B. Wood[_2_] is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2013
Posts: 62
Default Does anyone have plans for a 4:1 air core balun that actuallyworks?

On 09/17/2013 09:16 AM, Michael wrote:

This post is for anyone who finds this thread, and wants to know what my working solution is.

I purchased several 4:1 five killowatt baluns from Universal-Radio.com. The brand name and model number is "Hy Power GU4-HF-5KWS". When I tested these baluns with a 200 ohm resistor they showed a 1:1 match. I adjusted the length of the 450 ladder line coming from the Lazy H antennas to find the point where the tuner required the least amount of inductance to bring the system to resonance. The balun stayed much cooler this way. In retrospect I probably could have used a 1:1 balun as well. The length of the ladder line makes a huge difference in how hot the balun gets for a certain amount of power at the design frequency.

The Hy-Power 4:1 balun is Guanella Current HF Balun. It works well and the Lazy H antennas have been performing beautifully.

Thanks for all the replies.

Michael

Hello, and what is the bandwidth (in terms of a ratio) in which the
balun is expected to operate? Transmission-line baluns not
incorporating ferromagnetic materials have been around for a long time
but they're relatively narrow band devices. (Baluns using tapered
transmission lines and providing bandwidths approaching 1000:1 can be
constructed but aren't generally off-the-shelf available). Sincerely,
and 73s from N4GGO,

--
J. B. Wood e-mail: