[R-390] Meters

[Barry Hauser]

Yes -- it has been covered, but nothing is ever resolved forever.  Also,
it's more humane to beat dead horses than live ones.

Anyway, as I recall, the DC resistance or is very low for the correct R-390
carrier meters -- something like 14 ohms or maybe 11?  Resistance varies for
other 1 ma meters, but is typically much higher.

To make a different meter work with reasonable deflection calls for changing
out 2 or more resistors in the IF deck (part of a bridge circuit.)  My
understanding is that Fair Radio has been doing that to get some replacement
meters working.

Also, as I recall from the thread, Dr. J. and perhaps others had cautioned
against putting an ohmmeter directly across the meter terminals.  There was
a procedure for measuring DC resistance without burning out the armature
coil.  Probably can find it in the Pearls of Wisdom on Al's R-390A FAQ site.

Barry

----- Original Message -----
From: "Scott, Barry (Clyde B)" <cbscott@ingr.com>
To: "R390 (E-mail)" <R-390@mailman.qth.net>
Sent: Wednesday, April 30, 2003 5:10 PM
Subject: [R-390] Meters


> I think this has been covered before, but I don't recall.
>
> Given the Carrier Level meter is a 1ma full scale meter, can any old 1ma
> full scale meter be used?  Same goes for the Line Level meter (not sure of
> the full scale is for that one).  Other than the scales and the physical
> size, is there something characterstic about these meters that make
> replacing them all that difficult?
>
> Thanks,
>
> Barry(II1/2) - N4BUQ
>
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