[Elecraft] KX1: requesting recommended wire antenna lengths advice

[Fred Jensen]

I made mine from 24' of RG-58 with a BNC on one end, Pat.  I left about 
3 in of outer covering, and then stripped all the rest off.  If you 
spread the braid some down by the connector, you can pull a loop of the 
inner conductor through it and pull it out.  The "radiator" is just 
under 24 ft, the braid, when pulled tight is about 26 ft.  I hang the 
radiator in a tree and stretch the braid out on the ground.  Tunes fine 
on 40, 30, and 20 with the KXAT1.

40 meters is a semi-tough band for 3W, dead in the daytime and fairly 
noisy at night. 30 seems to be a much better choice.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 50th Running of the Cal QSO Party 3-4 Oct 2015
- www.cqp.org

On 4/19/2015 3:08 PM, Pat Ring wrote:
> Hello.  I researched this, eh, pretty thoroughly, but I keep running into a
> little problem with the recommended lengths for direct-fed antennas.  The
> KXATU guides recommend a 24'-28' radiator and a 1/8 wave
> ground/counterpoise, but I have seen 28' and 41' recommended as well (some
> with recommended radials and some without).  The 24' wire tuned up fine on
> 20m and 30m, around 1.2:1, but I can't get an KX1ATU lower than about 8.9
> SWR on 40.  Am I missing something obvious, or should I continue to
> experiment?  I've only tried that ATU about three times on 40M because that
> SWR seems pretty high to me and has to be tough on the kit.  I am reluctant
> to continue to try anything in this range now.  I don't really want to take
> coax on the road with me, and 20m and 30m are ok, but I would like to
> participate in the 4sQRP on 40m when I am on the road this week.  I would
> appreciate your advice.  Thanks.  Pat NQ0N