[Elecraft] [KX3] Portable Antenna question

[Ron D'Eau Claire]

Actually making an end-fed wire 1/2 wavelength long is ideal, from an
antenna efficiency standpoint, because such an antenna does not need a good
ground return (it needs something to keep the rig from floating up to a high
RF potential that causes the tuning to shift as one touches the rig or moves
wires, but that has little effect on the efficiency of the antenna itself). 

The problem is that very large RF voltage are developed at the end of such a
wire - well beyond what any compact or semi-compact tuner that doesn't use
big air variable caps can handle. So we compromise. 

It's tough to specify an impedance range for a tuner. I'm not surprised it's
not obvious in the manuals. Basically, throw up what you can and see if it
works. Most wires will work. And, if needed, you can consider adjusting the
length a bit if it doesn't . 

73 Ron AC7AC



-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Lynn W. Taylor,
WB6UUT
Sent: Friday, March 08, 2013 8:52 PM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] [KX3] Portable Antenna question

Of course -- and experimenting is half the fun.  I expect to go through a
lot of wire playing.

I'm pretty good with the theory -- and as everyone has said, it makes sense
to avoid feeding the end of a half-wave wire.

I haven't yet found the impedance range for the tuner in the manuals.  
I'm still reading.

I also moved not too long ago, and a lot of things (like my antenna
book) are in a box somewhere.  I'm still searching.  I think my Par
EF-20 is in one of those boxes, as is a nice chunk of coax with a BNC on one
end, and a PL-259 on the other.  I did find my straight key, but I haven't
been on CW this millenium.

... and I've got 100' of Wireman #534 due to arrive tomorrow.  I can always
buy more.

-- Lynn