Re: K3 and end fed wire

Michael Kopec

I know I will probably get a lot of what the heck feedback on this set-up, but it works for me using both my kX3 and K2 with internal tuners, I use a bnc test connector with two test poles connected directly to the radio. I directly connect a 27ft wire, usually strung at a 30 to 45 degree upward angle, to the red pole and a 27ft counterpoise/radial to the other black pole, usually laid on the ground. The xcvr tunes fine on 10 thru 40m with the internal tuner. When I am done operating, I just roll up the #20 stranded wire on a old fishing line spool. It is easy and works for me.

On Tuesday, May 18, 2021, 04:42:51 PM EDT, K9MA <k9ma@...> wrote:

I know they're not popular, but I recommend an external tuner located at the end of the wire. The only exception might be if the coax is short and the wire is NOT a multiple of a half wave. In either case, the counterpoise connects near the end of the antenna.  If you can, the simplest arrangement is to bring the end of the wire right to the tuner near the radio. 

That said, the half wave multiple wire can work very well, if you can match it with an external tuner. (Some use a 9:1 transformer, but I don't.) The big advantage is that only a minimal counterpoise is required, because the antenna impedance is very high. Also, the part of the wire near the feedpoint doesn't radiate much, so bringing the wire right to the radio doesn't hurt performance much.  I have long been using an end fed 40 meter half wave for portable operation on 40, 20, and 15 meters. For 80 meters, I add two 20 meter long radials, bypass the external tuner, and use the internal ATU. On 80, an isolation choke cuts down on RF in the shack, though I don't use it for QRP operation.

Scott K9MA

On 5/18/2021 11:11 AM, JOHN MCBRIDE wrote:
I am considering using my K3 on Field Day with an end fed wire. I have studied the information from Wayne N6KR as well as looked at other information on this topic on line. I am wondering about a transmission line from the ATU (RG8 or other) on the K3 to connect to the end fed wire several feet away. But the recommendation is for the counterpoise to be connected to the ground on the K3. Do I need to run a separate counterpoise wire from the K3 or can the counterpoise be connected to the braid/shield of the transmission line? Any and all responses will be helpful. Thanks!
John N0UQC

-- Scott  K9MAk9ma@...

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