[Elecraft] High SWR problem

Sun Aug 17 17:56:00 2003

CW mode makes it easier to tune up <G> - the output is more stable while =
you
twist the ATU controls. You can switch to SSB to ID if you don't want to =
use
CW, but it's perfectly legal to use CW in any part of the bands.=20

A quick check is to try to load up on 40. As you go down in frequency =
the
antenna becomes electrically shorter, less efficient and generally =
easier to
"tune up" with an ATU.=20

If you can adjust for low SWR on 40 or 80, at least you know your coax
connections are OK and the ATU/SWR Meter combo works.=20

If so, then I'd change the length of the antenna. A half wave end fed is =
a
very efficient combination - if you get the wire up high enough - but =
can be
very hard to match. The adjustments, as others pointed out, become very
touchy. Many (most?) commercial ATU's cannot handle antennas whose =
length is
very close to an electrical wavelength or even two wavelengths long in =
many
cases. The impedance at the feedpoint climbs to a value too high for the =
ATU
to handle. Changing the length of the wire only a few feet on 20 meters =
will
make a big change in the impedance and should bring it within the range =
of
the ATU.

Ron AC7AC

-----Original Message-----
From: [email protected] =
[mailto:[email protected]]
On Behalf Of Edward Kenworthy
Sent: Sunday, August 17, 2003 1:45 PM
To: [email protected]
Subject: Re: [Elecraft] High SWR problem

On a related note, I'm using SSB and saying a long "aaaaaahhhhhh" down =
the
mike when trying to adjust my ATU (even if no-one's listening it's still
embarrassing to have to append one's call sign after that ;-) Would I be
better off using AM for a continuous carrier ?

Edward