[R-390] Testing old original meters for the R-390A

[Larry H]

Bob,  You can hook the meter up to a 600 ohm output with a 600 ohm resistor across it and measure the ac voltage.  It should be about .78vac at 0 db or 0 vu while hearing a 1kc tone.  Or it should be @ .98 vac for 2 db.

Regards, Larry


On Monday, August 4, 2014 8:50 PM, Larry H <dinlarh at att.net> wrote:
 


Bob,  The carrier level is pretty easy - it's a 17.5 ohm 1 ma dc full scale meter.  You can easily measure the resistance of it.  The deflection is easiest measured with a vom in series with it connected to a battery and pot to adjust current.  About 1.5v and 5k pot.

Regards, Larry


On Monday, August 4, 2014 5:36 PM, rbethman <rbethman at comcast.net> wrote:



I would like to know the best method of using a VTVM to test the 
functionality of said meters.

I need to figure out if they are functional, or I have to pursue another 
pair.

The corner screws are green and will be getting replaced with ones from 
my vast good clean steel hardware collection.

Bob - N0DGN
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