Why not use a dummy load and get the antenna and interface cables out of the
equation?
If the problem persists, may be a power supply problem -- filtering or
inadequate current handling.
Check the DX power supply with an Oscilloscope - Turn down the power and
test again.

--
Keyboard In The Noise

Opinions are the cheapest commodities in the world. Author unknown but
"right on"

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"Dan" wrote in message
...
I am hoping someone here can guide me to what the heck is wrong with
my antenna system. Here is what is going on. Frist, I know neight of
trhese antennas are very good phtsically or functionally BUT they both
can be tuned down to a very accepatble SWR. However, using eithe my
Icom 706 G OR my old Kenwood 440 AT even with a good SWR 1.5 or
better I get a terrible audio report. I have monitored the audio using
the other radio and it sounds like a warble variable picth sounds as I
speak. sounds like very high over driving but I have that all turned
down. I have used an MFJ 949e tuner and even let the Kenwood with
auto tuner tune the antenna same results .. good SWR but terrible
audio. At first I assumed it was the icom 706 but the kenwood sounds
exactly the same. BUT when I do tune on the Kenwood auto tuners it
does seem better... at times...
The radioas are between two computers and I also have a echostation
interface very close with the serial cable connected to the Icom.. I
have tried all combos I can thik of removing and or changing all
connection scables etc.. .. do you think even though the antennas tune
ok and I know they are not the best (that i could be getting some
type of werid resonating? One antenna is a ground mounted vertical the
other is a mulit band trapped diploes I kinds suspect both (since they
are very old) have bed traps etc BUT I still go back to they seem to
tune down in SWR.. help.. it is driving me nuts,, (shirt drive)

thanks any and all ideas are appreciated...