A somewhat related question - as the R component at the feedpoint of my inverted L goes down toward 25 ohms, I've begun wondering if I should do some matching at the feedpoint, rather than using my t
Yes, match at the feedpoint. You might check out Balun Designs: https://www.balundesigns.com/1-2-balun-25-to-50-ohms-3kw-1213/ Marsh, KA5M A somewhat related question - as the R component at the feed
Can someone point me toward a good way to do a 2:1 downward transformation? The very same 2.25:1 (trifilar autotransformer tapped between windings 2 and 3 for the antenna with the feedline connected
Wrong device. You want an "UNUN" not a "BALUN". A vertical antenna is unbalanced. I have an UNUN built with RG-58 coax wound around a 2.4 inch #33 ferrite core. Very easy to make. Rick N6RK You might
I stand corrected. A vertical with radials is of course unbalanced. I'm appropriately embarrassed. No more antenna advice from me. Marsh KA5M --Original Message-- From: Richard (Rick) Karlquist <rich
At my P40A station I had an inverted L, the vertical portion was ~50 feet of self supporting aluminum tubing. I never measured the impedance. I made a hairpin coil using of a piece of THHN wire, adju
How is the construction different? John KK9A Wrong device. You want an "UNUN" not a "BALUN". A vertical antenna is unbalanced. I have an UNUN built with RG-58 coax wound around a 2.4 inch #33 ferrite
I've been using the 2:1 one for 7 years at QRO for a good match at the antenna as I don't have a tuner at the amp. I can match < 1.4:1 the entire band by switching in series capacitance in 50KHz step
Grant, where is the series capacitor, before the un-un or between it and the antenna? Chuck W5PR _______________________________________________ _______________________________________________ TowerT
No problems with the match since putting it up, now at 101 confirmed on 160m :) all on this antenna. The 8 elevated aluminum electric fence wire radials are all still original. The top support (cente
Thanks for the info. I think I am going with 60 radials on the ground. I want to use the 160 vertical tower to support an 80 meter array around it. Elevated radials might make adjustments way more co
I'm not sure what your question is. Do you want to compare how an UNUN is constructed differently than a BALUN? Or are you asking about my homebrew UNUN? Any 50 to 22.2 ohm UNUN will basically consis
It's worth studying N6LF's work on elevated radials. He stresses that keeping radial currents equal reduces loss, that making them slightly shorter than resonant helps that, and so does having MORE e
If you read N6LF's work closely (see fig16 in 3/2012 QEX) you will see that radial height above 5' adds a few 10ths of a db improvement at most. (8ft =.015 wavelength above ground) Given noise and QS
That was Rudy's earlier work, on the basis of which I rigged at 4-5 ft. Their efficiency was poor. I consulted N6BT, who has also done extensive work on radials for his expeditions, who gave the advi
It is true that gain changes a few tenths of a db over the range of radial heights. Antenna efficiency matters more than gain changes for verticals near earth. The height matters a great deal below 1
Let er rip Chuck. Post pictures.73,Gary K9GS -- Original message --From: Chuck Dietz <w5prchuck@gmail.com> Date: 12/3/22 12:21 PM (GMT-06:00) To: Grant Saviers <grants2@pacbell.net> Cc: towertalk@con