[TowerTalk] Balun for older Cushcraft 402CD
rthorne at rthorne.net
Fri Jan 19 13:55:52 EST 2018
It reminded me that my original post was for tribanders. The 1116 would
be a better choice for 40m.
Rich - N5ZC
On 1/19/2018 12:06 PM, Jim Thomson wrote:
> Date: Fri, 19 Jan 2018 06:47:25 -0600
> From: Richard Thorne <rthorne at rthorne.net>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Balun for older Cushcraft 402CD
> <Go with a a balun designs? ( balundesigns.com ) 1115d with the studs on
> <top.? Go from the balun studs to the element halves with a length of
> <wire and ring terminals crimped/soldered.
> <For mounting the balun to the boom order the BMP1 balun mounting plate.?
> <Nice and easy and clean, no tape needed other than attaching the coax to
> <the boom.
> <I just replaced a F12 balun (cal-av labs I believe) on my C31.? This was
> <the 3rd F12 balun to fail.? They short out for some reason.? JK Antennas
> <who now builds F12 antennas also uses Balun Design baluns.
> <Every one of my antennas now uses a 1115d balun and not a single problem.
> <Rich – N5ZC
> ## For his 40M MONOBAND yagi, a better choice would be the
> Balun designs 1116D. > 6300 ohms..... vs the 5200 ohms of
> the model 115D.
> ## My big problem with the balun designs CM baluns is.... their graphs
> only depict RS, XS, RP for the resonant freq only! Thats only telling folks
> a very small part of the story. Ideally you want RP to be very high in value. You also want
> RS to also be high in value, like 90-100 % of RP. In all cases, you want RS to be
> higher than XP. Since they only depict RS, XS, RP at ONE freq, they are not telling you the full story.
> Ideally, they should be graphing RS vs freq, XS vs freq, and RP vs freq. Only then do you have
> enough info to evaluate the CM choke.
> ## Their model 1115D resonates at 14.40892 mhz
> Their model 1116D resonates at 4.75734 mhz
> Jim VE7RF
> TowerTalk mailing list
> TowerTalk at contesting.com
More information about the TowerTalk