[R-390] meter repair

Mon, 24 Mar 2003 06:29:21 -0600

It can be done if you are lucky and careful. I was able to resurrect a dead
line level meter - one of the two little series wirewound resistors inside
was open, and I paralleled it with a 1/4W metal film unit that was very near
the same resistance, meter now works fine. Probably no longer calibrated
with any precision, but I can't tell any difference in normal use, so what
the heck. A better idea calibration-wise might have been to select another
exactly matching resistor and replace the good wirewound at the same time,
but inherent lazyness took over.
Jerry  W5KP

----- Original Message -----
From: "Mark Donaldson" <[email protected]>
To: "ronald j deeter" <[email protected]>; <[email protected]>
Sent: Monday, March 24, 2003 4:10 AM
Subject: Re: [R-390] meter repair

> Hi Ron,
>
> I have disassembled both types with success, the unit
> with the threaded collar is indeed as you described, I
> use a pair of needle nose pliers as a wrench inserting
> one nose into each of the collar slots and then twist
> on the handle of the pliers to unthread the collar,
> they are seldom torqued in very hard so it should be
> easy. On the other meter this is a tough one and has
> to be approached very carefully. I use the tip of an
> exacto knife to wedge under the meter glass and work
> my way around to loosen the glass from the surface it
> is attached to, there isn't much room to work the
> blade in and some glass chiping can be expected but
> will not show up when the bezel is back in place, the
> secret to making this work is to use a heat gun on the
> the glass to try to break down the adhesive. All the
> usual precautions apply use eye protection and don't
> inhale radioactive dust. No guaranties that you won't
> make the meter worse than when you started but I
> assume the meters are already defective so nothing
> ventured nothing gained.
>
> Mark WA1QHQ
>
> --- ronald j deeter <[email protected]> wrote:
> >  hi all-
> > the amount of knowledge this group has is
> > tremendous. best not to
> > reinvent the wheel.......
> >
> > I think someone had posted a method of getting
> > inside the metres?, I have
> > been able to repair metres when i can get into them.
> > I have two that i'm
> > unable to access.
> >
> > METRE 1. EAC - steel rear/aluminum front bezel and
> > Looks like an aluminum
> > threaded collar on the rear of metre bezel holding
> > the movement case? is
> > it, isn't it---- solutions
> >
> > METRE  2.  Simpson Bakelite case has 8 screws on
> > front of case, looks
> > like a rubber(?) gasket under the glass. the glass
> > will not pop out with
> > pressure on the glass with the loosened movement
> > from the rear. it is
> > like glued down (too many years of compression).
> > Thoughts on this one?
> >
> > thanks for any info and help
> > Ron
> >
> >
> >
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