Well, to check my tubes, of course.
no really. I am just getting into electronics/vacuum
tubes(ive used tubes
for a long time, but I mean getting involved in the deeper
aspects like
design, theory, whatnot) and as such, I am trying to
assemble a tool kit
for my garage(currently where I woodwork and lift
weights/box)...
something that will allow me access to all the functions a
serious
hobbyist/future builder(
) will use..
I am in North Carolina.
Hmm. There is an issue here at the heart of what folk might
mean by "hobby".
The vast majority of audio enthusiasts who have used valve
equipment have never needed a valve tester. Similarly, more
or less, consumers of light bulbs don't need light bulb
testers. I doubt even light bulb fetishists need testers.
You buy from a reliable source and plug it in. If it's still
dark you wonder if it's the fault of the fitting or the
bulb, so you swap for a known good'n. On the very rare
occasion you end up flummoxed, you might call for help.
If you design an amp and build it, then arguably you should
do so with average valve characteristics in mind, and ensure
that your design is able to accept the likely range of
real-valve approximations to that average. Datasheets are
the best guide to average characteristics. If you buy tested
valves from a reputable dealer you shouldn't need a tester.
If you have a basic set of equipment, as suggested by Peter,
and you are building an amp to your own design, then it may
be more instructive and useful to test your valves in situ.
You can change circuit parameters and observe valve
behaviour as you build, and refine your design at the same
time. A tester is unlikely to be any real help.
I've got a good portable AVO. It is a beautifully crafted
machine with cute knobs and switches, telephone dial and
meter...lots of bakelite and alloy. Luckily it was a very
good investment because it was only useful when I had a
passing interest in strange valves. I'm going to sell it and
will make a huge profit, if I haven't missed the boat. It
will go to someone who will hardly ever use it, and who
hopes to make another profit someday. Some day some part of
it will fail and it won't be worth fixing because it
contains a million miles of tightly bunched cotton-insulated
wire connections which, due in part perhaps to its Navy
history, have corroded to such a fragile and brittle state
that disturbance will force a total rewire which will take
millions of hours of suicidally tedious work. Every other
part is unobtainable, and even good quality multipole,
multiposition switches have limited mileage. Meters have
accidents. The telephone dial may last forever, but is of
little use on its own, these days.
All the same, I can quite correctly sell it as "in perfect
working order".
So it depends what kind of hobby you want. If your interest
is only in valves rather than the equipment that uses them,
then a tester could be all you need, but reliable accuracy
will cost a fortune. If you're interested in equipment such
as valve amplifiers, it's unlikely you would ever need a
tester. Patrick hasn't got a tester, and he's a proper
professional, in the commercial sense.
If you still want a tester, Peter is knowledgeable, seems
willing to advise you and, importantly considering carriage
costs, American, although I gather America is quite big,
geographically speaking, so he may not be very close, I
suppose.
A few modern testers may be in production, perhaps intended
for use with a PC. I doubt producers last long because there
is no real market, but it may be worth a search. For those
who actually need to measure transconductance accurately,
this could be the way to go because it should be much
cheaper. Serious commercial valve resellers make their own
rigs, I think.
Finally, consider making friends with someone close by who
has a decent, calibrated Hickok or full-size AVO.
cheers,
Ian, a million miles away in Yorkshire.