Jamie t wrote in
:

bz wrote:

The saga continues....

Removing the plug in module DID clear the 100 ohm 'short' to ground on
the 100 volt line.

Swapping tubes did NOT fix the -150 volt supply however.
It only measures -131 volts (after several minutes of 'post hv turn on'
warm up). It drifts much more during the warm up than the -150 volt
adjustment pot will swing to voltage. In fact I see very little change
as I adjust the pot.

The 100 volt supply is putting out about 130 volts and the rest of the
supplies look about normal (have not checked the HT supply to the CRT.
I wonder if it being too high could cause all my symptoms).

Measured the current out of the -150 and 100 volt supplies (across the
5 and 10 ohm series resistors). ~.95 volts /5 ohms = 190 ma for the
-150 supply
~1.4 volts/10 ohm = 140 ma for the 100 volt supply. I am assuming that
those values are not unusual. I have not looked at ripple, etc., yet.

Looks like I am going to have to measure voltages at several points and
try to make sense of any patterns that emerge.






and to think, i through out years ago, 2 perfectly working 545 boat
anchors.

I _had_ two(with carts!). My wife "disposed" of one.

If you look at the prices on 12AX7s on the web, you will realize that you
may have thrown out thousands of dollars worth of tubes. Some vintages of
12ax7 go (to audio buffs) for unimaginable prices! Of course the russian
'knock offs' go for less than 10 bux.











--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap