Hi,
I have discovered what it seems like rectification in my HD Alu Tower where
on the top there is antenna ball bearing thrust (SKF) below a 61D Prosistel
rotor. I used various techniques to pin poin to the tower.
The harmonics is growl sounding on 20 m (TX on 40 m) and is some -120 dB
below the fundamental (40 m) after double low- and high as filters (giving
some 100 dB of combined out of band suppression) in TX and RX chain.
I have read that some have encountered harmonics rectification in thrust
bearings. Anyone has any experience from ball bearings and rectification? Or
rectification in Prosistel rotors (in the potentiometer?).
Being a physicist I wonder how the mechanism is with this kind of
rectification in bearings and grease which I assume is isolating. Or?
I am close to getting a skylift and do the shortening of the bearing with a
jumper and see if it helps bit it is winter her. Brr.cold.
73s Kari SM0HRP
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