[Hammarlund] Oil-Filled Caps (BC-779)

[DJED1 at aol.com]

There's a couple of ways to check the capacitors.  The simplest is to  
measure the AC ripple on the B+ line, using a 600V, 0.1 mF capacitor  to isolate the 
B+ from your VTVM.   Not sure what an acceptable AC  ripple would be, but a 
couple of volts AC on 270 VDC should be OK.  Many  people measure the leakage 
current, especially on electrolytics.  To do  that, you would have to 
disconnect the capacitor from ground and insert the VTVM  in series with the cap, then 
fire up the supply and see how much current  flows.  I would expect that 
leakage in the 1 to 10 ma range would be  OK.  As always, be very careful when 
working around the high voltage- these  caps can retain a lethal voltage after the 
power supply is turned off. Good  luck
Ed