View Single Post
  #6   Report Post  
Old January 20th 06, 12:06 PM posted to rec.radio.amateur.homebrew
gb
 
Posts: n/a
Default Astron Power Supply problem

"Kerry Miller" wrote in message
news:UP_zf.140961$WH.46302@dukeread01...

I can confirm that mine has a 723, not a 317. Thanks for the web sites,
looks like some great information. I hooked up that headlight tonight but
it ran fine, pulling a bit over 3 amps for an hour or so. Maybe I need
more load to make it lose regulation.

Guess I'll start digging into that regulator board, the transistors and
all the big things like the transformer seem to be fine.

Thanks,
Kerry - WD5ABC


First, test each NPN transistor with a VOM or DVM ... both methods of proper
measurement are outlined (added proper method for DVM testing to procedures)

Second, discharge electrolytic capacitors before removing or inserting the
LM 723
Most Astron regulator boards have a socket for the LM 723, IF not after
removing, install socket - observing proper placement of pin 1.

Check bridge rectifier and diodes in circuit.

The KBT site suggests substitution of a resistor value. There are also
suggestions for bypass capacitors.

Stray RF in your radio shack can cause problems in some supplies.

gb