22-06-2015, 09:40 PM
Honestly, I think you're being a bit hard on yourself 
Starting with a lamp limiter and a variac is absolutely the right thing. The non-contact voltage detector is also useful (not just for old radios). And of course, you've got your new DMM with good test leads. So I think you're doing good.
Isolation transformers are more debatable. Sometimes they are essential; other times they do more harm than good. Perhaps put off the purchase until after the move, and use the time between now and then to get your head around all the issues that have come up in this thread (and countless threads before).
My aim was to explain that the issue is not "black and white", and that if very experienced engineers can be confused by isolation transformers, then you mustn't feel bad if you don't immediately get it. Please don't be intimidated by this - it's just a case of starting from first principles... Please ask for clarification if needed.
If/when you do get one, it's probably best to make it a "portable" unit. In quotes because it'll be heavy! Very useful for secondary purposes, like gluing things together and holding doors open
Unless you get into TV work, 100VA would probably be plenty. The ones I have here are 500VA (just over 2 amps) - and are fine for everything I've needed to do. As suggested earlier, two connected back-to-back might do the job, but whatever you do, please make it safe. You did such a good job with your lamp limiter and variac that I'm sure you'll have no problems - but if in doubt, please ask.
Starting with a lamp limiter and a variac is absolutely the right thing. The non-contact voltage detector is also useful (not just for old radios). And of course, you've got your new DMM with good test leads. So I think you're doing good.
Isolation transformers are more debatable. Sometimes they are essential; other times they do more harm than good. Perhaps put off the purchase until after the move, and use the time between now and then to get your head around all the issues that have come up in this thread (and countless threads before).
My aim was to explain that the issue is not "black and white", and that if very experienced engineers can be confused by isolation transformers, then you mustn't feel bad if you don't immediately get it. Please don't be intimidated by this - it's just a case of starting from first principles... Please ask for clarification if needed.
If/when you do get one, it's probably best to make it a "portable" unit. In quotes because it'll be heavy! Very useful for secondary purposes, like gluing things together and holding doors open
Unless you get into TV work, 100VA would probably be plenty. The ones I have here are 500VA (just over 2 amps) - and are fine for everything I've needed to do. As suggested earlier, two connected back-to-back might do the job, but whatever you do, please make it safe. You did such a good job with your lamp limiter and variac that I'm sure you'll have no problems - but if in doubt, please ask.
