[Elecraft] OT: PS ?s...

[John Clifford]

Greetings,

I'm trying to set up my station with battery backup and ensure that I do not
damage my Alinco DM-330MV power supply by having a powerful battery hooked
up to the station DC buss while the power supply is off.

I picked up a 20v 35A diode, and figured that rather than put this in the
line coming from the power supply to my Rigrunner, I'd open up the power
supply and put it between the output jack and the internal source of the
regulated power.  I figured I would just adjust the PS voltage up by the
amount of voltage drop (using a multimeter).  I then got more creative, and
figured that I would just adjust the meter so it showed the voltage after
the diode

So far, so good... except that now the PS won't let me adjust the voltage
using the externally available pot, and it is 'fixed' at about 13.4 volts.

Is anyone familiar with this PS?  I have a schematic, downloaded from the
Alinco website.

 - jgc

John Clifford KD7KGX

Heathkit HW-9 WARC/HFT-9/HM-9
Elecraft K2 #1678 /KSB2/KIO2/KBT2/KAT2/KNB2/KAF2/KPA100
Ten-Tec Omni VI/Opt1

email: kd7kgx@arrl.net