[Elecraft] Power Supply Questions

[Jim Wiley]

For those of you who might be interested, no matter what power supply 
you are using, I have a nifty little circuit that converts a standard 1 
mA DC milliampere meter to an expanded scale voltmeter reading 11 to 16 
volts, with 13.5 volts at top center of the meter scale. Linear readout 
too, no compressed readings at one end of the scale.  I have converted 
the Astron RM-60 that I use for my ham shack to this method, and I can 
tell you that the expanded scale sure makes setting the DC power bus to 
the correct value a lot easier.


I also show a simple method for converting another 1 mA meter to an 
ammeter (or you could use a switch select amps or volts using just one 
meter).


If there are no meters in your supply, then you can use this circuit to 
build up a set.  Surplus milliammeters are reasonably easy to find. 


Send me an e-mail off list and I will respond with the details.  The 
conversion costs about $10 in parts (not including meters), and you will 
need to recalibrate the scale of whatever meter you end up using (change 
the markings) - a not too difficult process.   Note that I will have to 
finish creating a write-up of this, and I am right now swamped with 
creating new Extra class exams for our VEC, but when that's done, I will 
be able to put some time on this.


- Jim,  KL7CC