[R-390] mech. filters

[n4buq at knology.net]

> Barry,
> I see you  have a noisy ant trimmer.  You may get lucky and possibly save 
> yourself  from pulling the rf deck.  The ant trimmer shaft is insulated 
from 
> chassis  by a fiber washer under the nut securing it to the bracket.  The 
nut is  
> directly below the ant gear that turns the ant trim shaft.  By loosening  
the 
> nut and lifting the trimmer upwards you can get in there with a small 
brush  
> and clean crud from the washer.  Also tuner cleaner may help dislodge 
and  dirt 
> that may be there.  It's worked for me on at least one  occasion.
> 
> Regards,
> Rich WD2Q

Rich,

I'll have to try that.  I didn't know that was possible.  It sure would 
save me a lot of work.

I removed the cross-drive shaft (the one that goes to the front panel) and 
turned the trimmer by hand and I didn't notice as much noise.  I figure 
some of the problem may be in the insulating sleeves and washers for that 
assembly.

I do notice that when I turn the trimmer CW, the noise is much less than 
when turning it CCW.  A CW rotation forces the shaft against the fiber 
washer whereas a CCW rotation forces the shaft against the metal washer on 
the outside of the assembly (where the E-ring fits into the groove on the 
shaft).  This seems to indicate there is some conductivity from the gear 
through the shaft but I have all the pieces in place so not sure why that 
would be.

I wonder if I need a fiber washer between the E-ring and the frame?  I 
don't recall seeing one there but maybe I'm missing something?

Barry - N4BUQ