[R-390] Lubricating RF slugs

[2002tii]

Tisha wrote:

>I would stay away from graphite as it will change the performance of the
>inductor.

That has not been my experience, at least with the small amounts I've 
used.  Out of curiosity, I just stuck a tube of graphite down the 
middle of the coil of my grid-dip meter, and there was only a small 
change in frequency.  I don't think there is any practical worry -- 
the least bit of ferrite would have pulled it WAY off frequency.

Note that both graphite and talc have been recommended by Collins 
over the years for lubricating slugs.

Best regards,

Don