[TowerTalk] Harmonics rectification in bearings or Pro.Sis. Tel rotors?

[Jim Brown]

On 2/8/2020 3:42 AM, SM0HRP Kari Gustafsson wrote:
> 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.

Several years ago, W3LPL alerted the ham community to the issue of 
passive intermod as a source of harmonics, identifying the junction of 
boom to mast through the rotator and switch mode power supplies as 
common culprits. As has been noted by others in this thread, the 
solution for rotators is to bond around them. The solution to SMPS is to 
search out and destroy.

73, Jim K9YC