The Racal 9839 UHF frequency meter/counter arrived earlier, packaging very poor as usual, thankfully no further damage other than what it already has. The 9839 has a pre-scaler for up to 560MHz & eight
number readout bulbs in quite a compact size case and no fan.
It appears a previous owner has done quite a bit of work before giving up (possibly why an IC is missing).
I like how they thoughtfully sleeved the fuse holder & mains socket, but then fitted a filter board with exposed connections above these, the transformer connections are right above the +5V adjustment pot too.
I've no idea why the track from the +200V fuseholder has been cut (dotted green line) and a link added between R60 & the electrolytic capacitor.
The 60mA fuse for the +200V rail is OK.
The display only has a few digits working, I should be able to work through the faulty sections using the 9835/7 manual as the display boards are similar (no manuals exist for the 9839), some IC's have been replaced & a number of tracks repaired by a previous owner, I can see at least one broken track that got missed.
I've already adjusted the +5V rail as it was around +5.2V.
David