[R-390] 390A questions

[blw]

Jim,

Welcome to the list....even if you own a Drake. (g)

The nametag problem is fairly common. Tags were swapped for inventory
control or at depot. Hank Arney did make repro tags that were supposed to be
of good quality. Maybe he will contact you if more are available.

I guess you could check the back of the chassis and see what manufacturer
and contract number you find. You can check the AF deck and power supply
easily for manufacturers. That will give you some idea of what components
are there for starters. It was common to throw in whatever component was on
the shelve at depot, so don't be surprised to find a mix of manufacturers.

I think the cap you are curious about is C553 in the IF deck. Go to
http://www.r390a.com/ProbCaps.html and you will see this with a good pic of
the location. This is Chuck Rippel's page. He did the videos on the R-390A
and SP-600. You will find a lot of good info on his website.

Glad you joined the list. Let us know how this radio comes along.


Barry


> If you guys will let a Drake man in here... :-)
> 
> I just picked up a well-used R390A that hasn't been powered in 10+
> years (yes, I have a variac).  I've been reading a lot of stuff on the
> web, and noticed several notes about the cap that shorts and destroys
> the mechanical filter(s).  How prevalent is this?  I plan to replace
> the cap anyway with a higher voltage rating, but I was wondering if
> anyone has looked into methods of protecting the filters.  I was
> thinking, maybe a small-value pico-fuse in series with the cap?  It
> seems at that frequency, it would have negligible effect on circuit
> operation.  I've seen them as small as 1/8 amp, would that be small
> enough to blow if the cap shorted?  I have no idea at this point of
> potential current involved, just idle speculation.
> 
> Is there an easy way to tell manufacturer and approx. age if the
> nameplate has been removed?  Who's the guy that sells replacement
> nameplates?
> 
> How many Jims do you have in here?
> 
> 73
> 
> Jim