So, over the weekend I finally got my $80 eBay Calibration Special back together and working!
At some point this spring I picked up a TM 503 Power Module, PG 506 Cal Gen, TG 501 Time Mark Gen and SG 503 Leveled Sinewave Generator on eBay for $80. All the units had yearly cal stickers up to 2013. At first the units were behaving erratically, which turned out to be a power supply issue. $20 in capacitors and a new bridge rectifier in the power module solved that problem. After fully disassembling and cleaning all three units, I just needed to lube some switches, reseat all the ICs, replace some 74 Series logic and now everything works perfectly. Well, except the fast rise board in the PG 506; I broke one of the BNC connectors off the board when I over-torqued the nut. I'm trying to find a suitable pair of end launch BNC connectors to replace them with.
Anyway, it's amazing what you can find on eBay with a bit of patience and some luck. Hopefully I can get my scope calibrated this week, just waiting on some attenuators now.
Oh, I also modded the TM 503 a bit. It was a stock unit without the rear BNC/DB-50 option; but I found out the steel frame actually has the holes for the BNCs and cutout for the DB-50, they just put a cover plate on without the holes! So, I added BNC connectors, in case I need them, and also added an IEC power connector where the DB-50 would have gone. Since the built-in push-pull switch was wonky, I opted to replace it with a bog standard toggle switch in the hole that the hard-wired power cord formerly occupied. I'm really pleased with how it came out.
Sent from my Tablet