[TVARC] Interference help????

[Dave Alford]

Interference HELP!!!!

I have an IC7300, with rg58 feedline to remote AH-370 tuner mounted at
eaves, with a 288ft 16 ga wire loop running at 12ft Elev (eave height)
around perimeter of house.

Feedline comes in thru window to station.maybe 5ft line.  Sharing the desk
space is my PC, with external speakers.   I have tried to keep PC &
peripheral wiring and feedlines separate.  Everything is common grounded.

No problems on ssb tx.

Finally got around to setting up paddles for cw . I want to tx on 40m.  In
CW mode, on 40m, when the paddles are tx, a loud noise is heard from the ext
speakers.

Have put ferrite beads on, checked all wiring.

Again no interference heard on SSB

On CW mode

6m NO                 10m No               15m Yes interference

 
17m Yes

20m  No                                                              30m Yes

 
40m Yes

80m No               160m No 

I assume the speakers or the PC is picking up RF.  Since only 4 bands
affected, I don't think it's a harmonic issue, but a bandwidth receptivity.

 

I can unplug the speakers.symptom cured, but not the problem

 

I don't have anything handy to shield the speakers themselves to see if they
are reacting to the RF.  They, or the PC itself, could be processing RF from
the horizontal loop when I tx.  Not sure what else I can do to separate the
wires on the desk, of if the PC and wires are acting as its own antenna.

 

So HELP?????  Any ideas.tx 

 

 

KQ4VPD 

Dave Alford

 

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