[R-390] My 'new' R390

[David Wise]

A snubber attenuates or “snubs” transients. This one is 0.1uF in series with 100 ohms, across the switch contacts. Reduces the arc when the contacts open. The R-390A line filter is the module where the cord goes into the mainframe.

Dave Wise

> On Aug 16, 2025, at 11:03 AM, Barry <n4buq at knology.net> wrote:
> 
> Tube Pullers -> Jealous  :-)
> 
> Barry - N4BUQ
> 
> 
>> The line filter was bad in mine too, so, many years ago, I replaced it with
>> a IEC320 with integral filtering.
>> It just fits the hole for the original filter, mounted from the inside.
>> I cannot remember who provided the two other pictures attached, but one
>> displays a R-390 back panel that is still original, the other gives the ID
>> for the RF deck tuning slugs.
>> To any useful purpose...
>> 
>> 73, Jacques, VE2JFE in Montreal
>> 
>> The line filter can go bad. In my case, it lost connection internally and I
>> had to rebuild it which it wasn't very easy The box is soldered shut so lots
>> of heavy iron needed to get it apart and back together. Hopefully yours is
>> still okay.
>> 
>> Barry - N4BUQ
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