[R-390] 390A questions

[Jim Shorney]

-----BEGIN PGP SIGNED MESSAGE-----


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

- -- 
Jim Shorney      -->.<--Put complaints in this box
jshorney@inebraska.com
nu0c@amsat.org
Ham Radio NU0C
Lincoln, NE, USA
EN10KA
http://incolor.inetnebr.com/jshorney/
-----BEGIN PGP SIGNATURE-----
Version: 2.6.2

iQCVAwUBPQ/sG0CBN4ScxcExAQHHnQP8CeZzQDHiaa8J72KzK60a8dyDdOir/x0L
xf1ZF3FQzHtW7RPWfqgAWL2qvWC04qKwWNxSDTtzO5BTP88XKQVoYdYHT7wU/P6S
QLIi3HSscLAu2N+kxSljAKDBobWELiceDVAsbBSccU/qUUhTW+GapK9I123HsoHY
ajoK0yGUjaw=
=yeuL
-----END PGP SIGNATURE-----