PL700B's...White Oak or Pine Box

[mlucitt]

Attached is SOA curve(s) for an MJ15024

I have attached the datasheet for the ON Semi MJ21195/96. Look at Fig. 13 for the SOA data. I think the MJ21196 transistors are the least of your worries.

 

[Peter S]

Hi Guys; My bridging experiments are on pause for the moment. Latest issue is a little hiccup with one of the recently WOPL'ed 700 II's. Both LED meter channels are reading a few notches above minimum with no signal. I imagined a high frequency oscillation but scope found nothing. Searching this forum, I see there is a capacitor (guessing a filter for the meter board power supply?) on one of the meters that causes this issue.
Just wondering if anyone has experienced this, and is it a matter of replacing this electrolytic? Only asking because it is a bit of a PITA to get these monsters in and out of the rack!
Thanks, and hope you're all staying well!

 

[WOPL Sniffer]

My first 700B has a non functioning left VU meter. It is the coiled spring with jewel bearing type rather than the torsional ribbon. One of the coils broke, years ago. I was actually able to reattach it, the outer end of the coil was the issue. It held for 20 years but now the inner end of the coil has broken from the armature connection. This time it's down for the count, I'm afraid.
Anyone have a spare meter kicking around?? Bet this is not the first time someone has asked!

Have you ever tried to change a needle (the pointer) on one of those movements? I have one of those movements but the needle isn't perfect. They are delicate and can be a challenge to get them perfect again.