On Jun 27, 11:40 am, wrote:
How old is the compressor ? apparently at some point they were
supposed to improve this. ...

They're Veco electronics on Danfoss compressors ca 2000. They put out
a horrible radio belch when they switch on and then chirp all over the
hf bands when running. I don't hear them at all on FM. Still, I
don't find it too tedious to just switch them off when using the SSB.

-- Tom.