[Peter Wieck]

On Tuesday, September 6, 2016 at 2:32:01 PM UTC-4, Big Bad Bob wrote:
On 09/06/16 10:58, Big Bad Bob so wittily quipped:
I envision the project as having 5 or 6 simultaneous source voltages to
put on a pin (plus "no connect). So 3 bits to assign it, per 'circuit'..
repeat that circuit 12 times, one for each pin, then connect 12 wires
to a 'bus' (basically) that wires up all of the sockets.

was thinking for a moment, and the EASIEST way to implement this would
be to use a microprocessor on each board, one that either uses a simple
external clock or has an internal clock available. ok you'd have to
flash each one but so what. A $2 microprocessor would substitute for
many $ worth of components, and you could PROGRAM it to do 'whatever'.
Well, _I_ could. downside, having to FCC the board because of the CPU
clock, but getting that to pass is pretty easy [it just costs you $ to
certify it]. Tube testing equipment _MIGHT_ qualify as 'A' type gear
though... [so just use decent engineering practices, yeah].

anyway, if you use a CPU then you could put everything on an I2C bus,
and just give each board a different I2C address. That's 2 wires plus
power and ground [not including the 6 voltages] going to each board, and
since they'd all have "those wires" connected to the same things, it
would be 'busses' again and wiring would not be so difficult.

yeah. I like that. use a micro-P to control the 6 voltages. minimal
external components, using opto-isolators for the high voltage stuff,
drive directly from the output pins. nice! An ATMega 328 would do it,
and it's got a 32-pin QFP that's pretty easy to solder.

now I just need to get $ to fund it... [am I begging too hard?]

Not hardly begging too hard... But you are looking at a very small market of well-heeled tube fanatics who have the means to indulge themselves in esoteric equipment, and who are not satisfied with legacy equipment, however high-end. A small subset of a small subset at the least.

I do suggest you go to any of several Crowdfund sites and see what you might be able to arrange. You would have to have a plan, a budget and a schedule, but I expect that if this happens, it would happen there.

Writing for myself and my own needs, I have one basic emissions tester that is enough for 95% of my needs, and one very high-end legacy tester (Hickok 539B) that more than handles the other 5%. That 5% was less than 2%, but I am gradually shifting more and more to tube audio lately, so a tester that actually can test tube quality, including 6550s at proper voltages, is useful - and it does allow me to actually match properly.

But, I cannot imagine needing a curve-tracer now or in my future.

Best of luck with it!

Peter Wieck
Melrose Park, PA