[Elecraft] Noise from compressor

[Robby.VY2SS]

Riddle me this!

I have strong interferance since installing an air source heat pump. It is
most annoying on 20M. It is also present on 40M and 15M. My 40M antenna is
twice as far from the compressor and the noise on that band  is reduced.  On
20M is is S3-4. It used to be S1. Here is what I have done in trying to
eliminate this problem:

1. I removed the 220VAC from the compressor at the breaker panel. The noise
is gone.

2. I turned the breaker back on and put my indoor units on fan only. The
noise is gone. I guess this proves the noise is coming from the compressor.
Also when I turn my beam toward the compressor the noise increases.

3. I disconnected my power supply and connected the K3 to a battery. The
noise is gone so It is not coming in on the house AC circuit.

4. I disonnected the antenna at the K3. The noise is gone so it seems it was
coming from the antenna.

5. I reconnect the antenna and turn the RF gain to zero. The noise is gone
from the speaker but on the waterfall it is NOT gone.

I am hearing a buzz in the speaker or headphones and can see many vertical
lines on the P3 waterfall. The wider my bandwidth setting the more noticable
problem but the lines are there for the entire width of the P3 scan. Maybe
40 lines on P3 display with a 5 khz scan width.

I have tried placing 3 capacitors across the 220VAC terminals where it
connects to the compressor. L>G, L>N, N>G with no measureable results.

I would be very happy if someone can shed a little light on this.

73,

-Robby
VY2SS


So the noise is present in the IF

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