[split] Valve testers

[ppppenguin]

I don't often have the need to test valves but a couple of years ago I needed to characterise some rare triodes which had come my way and which I wished to sell for BECG funds. They were on B4 bases. The filaments were something very odd like 10V 1A. I used a bench HT supply for the anode and bench LT supplies for filament and grid. I rounded up some DMMs and lashed up a horror story with lots of croc clip leads and 4mm plugs.

The data sheet for these valves had a comprehensive set of figures so I did a series of spot checks. I could have plotted the curves if I'd had the wish and patience to do so.

The BECG benefitted by several hundred pounds. I survived without any belts

I like Rob's refinement of a lamp limiter. I suspect Rob's HT supply was, like mine, a Solartron SRS153 which is very handy but not really regulated. I have a SRS151 which is fully stabilised but so big and heavy that it only comes out when really needed. I recently bought a Farnell E350 which will probably become my usual bench HT PSU.