[R-390] R-390A Restoration Progress (at last)

[Glenn Little WB4UIV]

Be careful with the switch cleaners.
Use it very sparingly.
Excess can be absorbed into the switch.
When this happens, the switch might swell and misalign the wiper to 
the contacts.
You may have to soak the switch in alcohol to get the cleaner out of 
the switch.
The cleaner should be applied to the contacts only.

YMMV

73
Glenn
WB4UIV


At 08:30 PM 12/15/2008, Richard W. Solomon wrote:
>I rewire the AC input to eliminate the RF Filter. Radio turns on
>and makes noise. AF Gain control scratchiness eliminated by just
>running pot back and forth several times.
>
>I can hear WWV on 10 Mc (yeah !!) with a short wire, but as I
>cycle through the B/W positions I notice the 4 Kc position has
>a marked reduction in level (audio out). I removed the module
>and gave the switch a shot of De-Oxit and I'll try it again tomorrow.
>
>Hopefully the Mechanical Filter is OK, but what are the odds that
>one or both Silver Micas are bad ? Would you recommend I just replace
>both of them ? I suppose if I replace them both and still have the
>lower level then the Filter must be kaput. I don't see any need for
>4 Kc anyway !! Too narrow for AM.
>
>Comments ...
>
>73, Dick, W1KSZ
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