[R-390] First time R-390 Owner

[Renee K6FSB]

Jim-
I obtained a failed R390A deck where the plate cap was extremely leaky 
and 2 of the filters plate side were open. I do not recall all the 
history other than I replaced the cap and the filters....I tossed the 
bad ones...put the deck in a "build". I saved the cap for years as it 
was a proof that some caps do go bad...It is long gone now. wish I had 
kept the filters......

the only other caps in a r390 that had issues were last IF audio filter 
red postage stamp, either a 100 or 180 was shorted.
Oh wow that brings back memories....I do recall another poor R390 was in 
sad sad shape as well, it had spent more than a few summers and winters 
out doors- no covers, mice nests, bug nests, and mud in everything, 
weeds growing..... thank goodness for soap and a hose! it was like it 
had been stored in a flood plain/ middle of a field. In the end it 
played, that was a lot of work! oh yea the big problem besides filthy 
dirty - cables- RF and one or two of the audio cables were bad too. I do 
not recall any caps tho..geee this goes way back. I was a kid did not 
know much then! I learned a lot...especially what that silly green gear 
did! HiHi
Renée

On 8/12/25 9:43 AM, Jim Whartenby via R-390 wrote:
> Speaking of which, does anyone have first hand knowledge of loosing a mechanical filter due to a leaky or shorted C553?  I know Henry Rogers mentions having some bad R-390A mechanical filters but the failure was on the grid side of the filter, not the plate side.  I think that it has more to do with the reliability of those early mechanical filters then to a leaky C553.
> I have repaired a few of the mechanical filters used in the R-390A.  The problem is usually a broken transducer wire connected to the internal solder terminal.  This is sometimes caused by the rubber isolator turning into goo and allowing the internals to slide down inside the tube and stress the transducer wires.  It also could be due to a hard drop of the R-390A since those mechanical filters are mounted vertically.  It is a little tricky unsoldering the end bells and replacing the isolator rubber but it is not that difficult.  This is my experience but YMMV.Jim
> Logic: Method used to arrive at the wrong conclusion, with confidence.  Murphy
>
>      On Tuesday, August 12, 2025 at 10:58:17 AM CDT, Adam Morehouse <morehouse90 at gmail.com> wrote:
>
>   Hey Barry,
>
> I have not yet - I wanted to check in and make sure there aren't any
> components that should be changed before a test, like the filter killer cap
> in the A model.
>
> Adam
>
> On Tue, Aug 12, 2025 at 11:46 AM Barry <n4buq at knology.net> wrote:
>
>> Hi Adam,
>>
>> While I only have a sample size of one R390, I think you may find the
>> components in these are much more likely to still be good and there may not
>> be that many "replace on sight" components as might be in other radios.
>>
>> Have you powered it up to see how it behaves?
>>
>> 73,
>> Barry - N4BUQ
>>
>>> Hey guys,
>>>
>>> Long time lurker here. You fellas helped me through my R-390A restoration
>>> (which just got back from Bill Riches for his finishing touches). This
>>> weekend I purchased an R-390, and another R-390A. Both them are are
>> pretty
>>> pristine - faces are great, extremely clean inside. The R390A has some
>>> weirds to the IF deck and Audio deck, which I haven't figured out....the
>>> R390 looks untouched.
>>>
>>> I am not very smart with electronics - I'm a young man, and typically
>>> restore old Philcos, Zeniths, etc as a hobby. Replacing caps and
>> resistors
>>> I can do. Everything else confuses me, but I am trying to learn,
>> especially
>>> since I've got a growing collection of communication receivers.
>>>
>>> Supposedly, the R390 went to Rick Mish around 2004 - I think the owner
>>> might be confused with the R-390A, as it's cleaner than new inside. The
>>> R390 looks untouched. I am sad that there doesn't seem to be as many
>>> articles, etc for the non-A...I do some original TM's on the way.
>>>
>>> In order to test thing, what are the bare minimum caps/resistors to
>>> replace? I haven't torn it down yet - I see a 10uF can behind the front
>>> cover, and what looks like an oil filled cap near the P/S. Hopefully
>>> nothing under the RF deck needs to be looked at, as that seems like a
>> bear
>>> compared to the R390A.
>>>
>>>
>>> Thanks for any help, or advice. I really appreciate it!
>>>
>>> Adam K2AAM
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