[Elecraft] [OT] Astron Power Supply Current Meter

[Ron D'Eau Claire]

I serviced mountain top communications repeaters for General Communications Engineering in Oakland in the 1990's. Our repeaters were scattered on mountain tops all over the metropolitan area. I never had to replace one of the many Astron 20 power supplies even though they were loaded close to the full 16 amps while the repeater was transmitting, which often was nearly continuously in busy periods. AFAIK, those power supplies had been in that service for years. 

Note the 20A is rated for 16 amps CONTINUOUS so we weren't overloading them at all. The ICS (intermittent duty) rating is 20 amps. I don't know if they define ICS differently than the industry as that web site claims but, since Astron is a BIG supplier of commercial power supplies in critical applications, I'm surprised to hear that claim.

I can say that I use a 10+ year old Astron 20A to power my K3 plus some accessories. Key down at 100 watts, I'm pulling a bit over 20 amps on some bands, and the Astron has never complained. 

METER CALIBRATION

The meters in the 20M have calibration pots. Adjust R103 to calibrate the current meter and adjust R104 to calibrate the voltmeter. I wouldn't be surprised if the 50M had similar calibration pots. 

I have no connection with Astron except having used them professionally and in the Ham shack with excellent results for many years. 

73, 

Ron AC7AC



-----Original Message-----

I just bought a used RM-50M and found this thread looking up meter
troubleshooting.  On mine, the voltmeter reads really low even though I have
13.8V at output terminals.  Please consider the following:

http://www.repeater-builder.com/astron/astron-intro-stuff.html Introductory
Information on Astron™ power supplies 

and, specific to meters:

http://astron.w4zt.com/ Astron Power Supply Meter Modification 

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