Distored SSB Audio on TX with FT747GX
 

Hi, I have a an old FT747GX, it appeared to have a burnt inductor coil on
the BPF board, and was displaying distorted audio in SSB transmission, I
wound and replaced the inductor, (L12) but Audio is still distorted, and
you can hear parts of the Tx audio thru the speaker,
it has the remote mount head kit,
would appreciate any ideas, and where to look'

rgds

Distored SSB Audio on TX with FT747GX
 

In article , "me"
wrote:

Hi, I have a an old FT747GX, it appeared to have a burnt inductor coil on
the BPF board, and was displaying distorted audio in SSB transmission, I
wound and replaced the inductor, (L12) but Audio is still distorted, and
you can hear parts of the Tx audio thru the speaker,
it has the remote mount head kit,
would appreciate any ideas, and where to look'

rgds-

It could be as simple as a high SWR, with RF in the shack.

For example, RF energy might be picked up by the speaker cable and coupled
back into the speaker audio amplifier. It could be also coupled through
the microphone cable.

RF energy can over-drive an audio amplifier so that it amplitude-detects
the signal. I can imagine that the "Donald Duck" sound of SSB would
appear as distortion in the transmitted audio.

73, Fred, K4DII

Distored SSB Audio on TX with FT747GX
 

Tnxs for reply Fred, i should have mentioned, I connected gear to a
Dummload, out put is down a little, plus a low level Motor Boat type noise
on AM and CW carrier, SSB tx is still distorted into DL, with MIC gain
increased to get meter deflection, DISTORTION increases with MIC Gain, also
tried a NEW MiC, same deal, something caused the LPF L12 to burn out

Tnxs again

rgds

"Fred McKenzie" wrote in message
...
In article , "me"
wrote:

Hi, I have a an old FT747GX, it appeared to have a burnt inductor coil on
the BPF board, and was displaying distorted audio in SSB transmission, I
wound and replaced the inductor, (L12) but Audio is still distorted, and
you can hear parts of the Tx audio thru the speaker,
it has the remote mount head kit,
would appreciate any ideas, and where to look'

rgds-

It could be as simple as a high SWR, with RF in the shack.

For example, RF energy might be picked up by the speaker cable and coupled
back into the speaker audio amplifier. It could be also coupled through
the microphone cable.

RF energy can over-drive an audio amplifier so that it amplitude-detects
the signal. I can imagine that the "Donald Duck" sound of SSB would
appear as distortion in the transmitted audio.

73, Fred, K4DII