[ICOM] Audio Problem

[Tony Lord]

Hi all,

Can any one advise about an intermittent audio problem on my 756Pro II. Let
me give station setup first:

Rig:   Icom IC 756 Pro II 

Amp: SGS Smart Power Cube

Ant:  Cushcraft A3S, Cushcraft R8 and G5RV Long wire.

Comp. controlled, DX4WIN, ARSWIN and ON4AOI (band decoder)

Ant Switcher: Amertron

Rig selector:       Multi Switch NCS 3240



The logging software selects antenna according to the band in use. When
operating 20m it selects the A3S. 95 times out of a 100 I am complemented on
the quality of the audio. However every now and then someone says audio
doesn't sound so good, a bit raspy but understandable. This only ever
happens on 20m using the A3S (tower mounted @ 75 feet some 50 feet from the
shack). Further sometimes I can be operating for some time (checking the
quality on the monitor function) then it goes wrong.

If I use the monitor control on the rig I can hear this, if I change antenna
or use the dummy load (or use different band) then it sounds 100% OK.



Any one got any ideas as to what may be causing this? SWR on 20m varies from
1.2 to 1.5. Sounds like an RF problem to me??



Thanks 73's de Tony G8DQZ