[ARC5] Crummy Grounds

[Richard Knoppow]

    Checking grounds has become a standard practice with many 
boat anchor radios. For instance, the Drake list suggestions 
include working all the screws used for mounting circuit boards 
and terminals because grounds are made through many of them. The 
screws become slightly corroded with time and cause many strange 
problems. We are dealing with gear that is considered new if only 
about fifty years old and can be eighty years old.
    An example: when I got my Collins R-388 it had a persistent 
hum in the audio. 60Hz, was there with the rectifier tube pulled 
out. I found a heater string went to ground through the frame of 
the headphone jack. The filaments still lit up but a current was 
introduced into the audio. Took the jack off and scraped the 
paint off the hole in the panel. That fixed it. Who knows how 
long it was that way.

On 3/18/2019 11:16 AM, David Stinson wrote:
> An example of what, in my experience, is becoming
> as
> big a problem for Boatanchor and Mil-Radio folks
> as are old capacitors: Hi-Z Grounds.

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL