If you like the 752, you should see/try the 580 - it was the replacement for 752 (which in turn supposedly replaced 539c), and has all the 752 features and more. plus fully transistorized so no calibration problems or tubes to wear out internally.
Cardmatics are ok, but I would opt not to get one (had an option on USM118 for $450 but passed) for a couple reasons: high maintenance - have to clean pins from time to time, some finicky mechanical parts in the card reader. Also, settings are set in stone (plastic) with the cards- no option to set your own parameters and no way to really even tell what parameters are set by the card. Also, finding a full set of cards is getting to be tough. Blank cards are even harder to find.
AVO- tend to be expensive but not really any more versatile than the better hickoks. Still limited to 300-400 plate volts or so, maybe not even that much (depends on AVO.).
TV7 is a good choice and if found at reasonable price, probably best choice. Eico/BK - not bad for what they are, esp. the transistorized BKs. no tube tester will really do more than rudimentary matching at best, btw.
-Ed
Cardmatics are ok, but I would opt not to get one (had an option on USM118 for $450 but passed) for a couple reasons: high maintenance - have to clean pins from time to time, some finicky mechanical parts in the card reader. Also, settings are set in stone (plastic) with the cards- no option to set your own parameters and no way to really even tell what parameters are set by the card. Also, finding a full set of cards is getting to be tough. Blank cards are even harder to find.
AVO- tend to be expensive but not really any more versatile than the better hickoks. Still limited to 300-400 plate volts or so, maybe not even that much (depends on AVO.).
TV7 is a good choice and if found at reasonable price, probably best choice. Eico/BK - not bad for what they are, esp. the transistorized BKs. no tube tester will really do more than rudimentary matching at best, btw.
-Ed