[Elecraft] K3 TVI on 40 meters only

[Mike Pilgrim]

Recently replaced my ic-7600 with a new to me K3.  I don't recall this issue
when using the ic7600, but I now have TVI in my u-Verse TVs when using the
K3 on 40 meters, primarily on CW, with diminishing evidence on SSB up to
7.2.50 but okay above that.  The symptom is pixilation on the screen, then
audio blanks out, and finally the set top box will completely lose signal.
This occurs on two TV operating on wireless set top boxes, and two hardwired
with CAT-5 cabling.  I have tried on three separate end-fed long wires fed
by coax through a 9:1 UNUN, two with feedline length of 100' and the third
approximately 60 feet.  I can operate satisfactorily on all bands from160 to
10 Meters with exception of 40 Meters on all three antennas.  The K3 auto
tuner indicates 1 bar of SWR with output power anywhere from 10 to 100
Watts.  I have also used an external ATU with same results.  I have looked
at everything I can think of, including terminating each antenna port with a
dummy load, but to no avail.  I've traced out all grounds and coax
connections.  Nothing helps.  What might I be overlooking?  Is there an
inherent issue in the K3 which might attribute to this symptom?  That seems
likely since I don't recall this problem when using the same antennas with
the IC-7600.  I welcome any ideas or suggestions for where to look next.

Thanks,

Mike, K5MP

mpilgrim at bellsouth.net