[R-390] R-390 Rookie Questions

[Barry Hauser]

Hi Joe

They're standard glass fuses.  Values should be marked near the fuseholders 
on the back panel.

I'm not sure if the 3 amp is supposed to be slow/blow or not.  You should be 
running with ovens off -- screwdriver switch on the back panel.  If so, I 
think you can try a lower amperage fuse -- 2 or 2 1/2 amp.  If they blow, 
stick with the 3 amp.  You can make-do with fuses from Radio Shack in a 
pinch, though probably not the highest quality.  They still stock 2, 2.5 and 
3 amp of that size (1 1/4" X 1/4").   The 3/8 amp fuse is not as easy to 
find.  In a pinch you can use a 1/2 amp.  Mouser lists all the exact values 
including the 3/8th amp.  The 20 amp DC fuse (28 v.) is not needed.

When you turn the bandwidth switch, do you feel the six detents, i.e. does 
it click into place?  If not, first thing to check is if the shaft clamp is 
slipping.  The knob is on a short shaft extension that attaches to the 
actual switch shaft with a clamp.  That clamp might be loose or split.  You 
need a bristol (spline) wrench for it.  If it's just slipping, you may also 
need to pull the IF deck to lube and free up the switch shaft if it's stuck 
with old lube that has turned to glue.

If that's not the case, you've got some other problem there, maybe a short.

Sounds like the speaker hookup you've got is pretty good.  The speaker setup 
that was used with some of these was that single or double driver on rack 
panel affair with matching transformers.  Both originals and repro's are 
kind of pricey.

hope this helps,
Barry





----- Original Message ----- 
From: "carolew" <carolew at bellatlantic.net>
To: <r-390 at mailman.qth.net>
Sent: Friday, April 21, 2006 9:59 PM
Subject: [R-390] R-390 Rookie Questions


>     I just picked up my first R-390 (not an A). It's a very impressive
> receiver. Undoubtedly, I will be peppering you guys with quite a few
> questions in the coming weeks. Some will be dumb rookie questions but
> please bear with me.
>
>    Here are my first:
>
>    1.  Where can I get a spare set of fuses? What values would you
> recommend?
>
>    2.  The bandwidth does not appear to work. The set sounds the same
> regardless of the position of the bandwidth switch. Any obvious things
> to check out?
>
>    3. What speaker did the military use with the R-390? Currently, I'm
> using a generic boatanchor speaker coupled to the set with a Hammond
> matching transformer. It sounds pretty good.
>
>    Thanks.
>
>                            Joe Connor
>
>
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