[Elecraft] K3, noise from com cable on SSB?

[Mike Smith VE9AA]

A new to me low SN# K3..no problems on CW.  Noise blanker now works!

 

I "think" all the SSB settings are ok.

I run SO2R with a YCCC SO2R+ box, so audio gets routed through a laptop,
then out to the so2r box, then to one of 2 rigs.

 

When on SSB I hear a moderately loud feedback-ISB noise w/ an added pulsing
noise in my earphones (monitor) (and also outgoing on the air).

It's probably equal to about 25w or 25% of my outgoing sound.  No good.

 

I initially thought it was my cheapie antique unshielded FTDI based serial
to USB adapter, as it had LED's which flashed to the exact pulse I was
hearing, so I replaced it with a brand new FTDI based cable.

 

Same sound.

 

If I plug a mic directly into the radio, no problems.

 

Another radio on my same (SO2R) setup has no noise on the audio, so do I
have something not set right in the rig, or what's going on with my com
port?

 

Thanks for any insight.

 

Mike VE9AA

 

Mike, Coreen & Corey

Keswick Ridge, NB