[R-390] Olson ME-185 meters

[David Wise]

Tom,

I couldn't find documentation.

If the movement full scale current is 1mA or less and the "burden" is 18mV or less (unlikely), it's an electrical drop-in for the CARRIER function with at most a trivial mod consisting of series and shunt resistors.

If it's 1mA or less and 100mV or less (usually true), you can do a simple IF deck mod that Gary Gitzen and I cooked up.  It's backward compatible, and in my opinion, it's the "right" way, the way a seasoned engineer at Collins would have done it.  Read my article in the Pearls.

And there's always Jan Skirrow's op-amp circuit, which is more complicated but goes on the "outside" without touching the receiver design.

Couldn't say about the LEVEL function.

FWIW,
Dave Wise
________________________________________
From: r-390-bounces at mailman.qth.net <r-390-bounces at mailman.qth.net> on behalf of Thomas Chirhart <k4ncgva at gmail.com>
Sent: Wednesday, July 05, 2017 9:49 AM
To: R-390
Subject: [R-390] Olson ME-185 meters

Has anyone used these meters in the R-390? I've been looking for my spare R-390 parts and stumbled upon this NIB pair.
73
Tom K4NCG