On Fri, 28 May 2004 01:33:22 -0600, Dan wrote:
Richard,
thanks for the reply first "shirt drive" is because I either can not
type or cannot read what I type should be "short drive" ..
anyway , what is "common mode problems? not sure I understand ??
tnx

Hi Dan,

When the SWR changes, this is evidence of common mode currents on the
outside of the braid of the coax going to the antenna.

This is a problem because it indicates power is returning to your
transmitter and mixing with other functions (poor shielding). The
garble you describe "could" be due to this, and the test of
lengthening the coax lead to see if SWR changes would verify common
modality. It is a very simple test with a very simple result: the SWR
changes or it doesn't (it shouldn't in a well designed system).

73's
Richard Clark, KB7QHC