On 2019/10/12 10:35 a.m., wrote:
On Fri, 11 Oct 2019 18:10:53 -0700, John Robertson
wrote:

On 2019/10/11 5:37 p.m., wrote:
I am just getting into tube, AKA valve, stuff. At this point I am
learning about them, how they work, how they are used, etc. I
surprised myself a little when I identified an audio amp just by
looking at it. This amp was a component for a larger radio and did not
have any type controls on it. And no labels or anything either. It was
just a chassis with screw terminals.
Anyway, time to get to the point. How valuable is a tube tester for
someone who is only, or mainly, going to be messing with audio gear
and the gear for testing audio gear. Maybe what I really need is a
gear tester? Ahem. So, this would just be for hobby use, at least for
now, and I am not gonna spend a lot of money on it. Can a simple
tube tester be of much use? I say simple because I imagine a not so
simple tester will have a not so low price.
I suppose I could always get a more sophisticated tester that needs
repair but then I would need to learn how to repair it and calibrate
it. Are they hard to calibrate? What sorts of test equipment would be
needed to calibrate one?
I'm a machinist and I know how I would approach this type of
problem if it was a mechanical assembly. I have built pretty
sophisticated and accurate inspection equipment using less
sophisticated machines and tools. But I would be lost trying to repair
a tube tester without help.
Thanks,
Eric


Well, having easily half a dozen tube testers in my shop may suggest
that I am biased, but really, how can you NOT have a tube tester if you
are using tube equipment? Short of having only a few tube devices, and
knowing what the parameters should be for each tube in those circuits if
working properly (resistors good too!) so that you could use a volt
meter only, a tube tester can take a lot of the guesswork out.

Mutual conductance testing is ideal (and most expensive type of tester)
and the drug-store go/no go testers are at the bottom. The decision is
driven by your budget and how often you are likely to need the thing.

If you are frustrated when trying to fix an amp or radio because you
don't' know if the tube(s) are the cause, then you need to spend the money.

Tube testers are quite robust, so they rarely need service. Usually just
a switch or tube test socket goes bad so pretty easy to deal with.

Get schematics for whatever tester you choose!

Oh, and get a scope at the same time. And a signal generator. And a cap
tester...

John :-#)#
I already have a Tek 465B and a BK 4MHz function generator. No cap
tester yet.
Eric


If you can find an old EICO or Heathkit component tester
(Resistors/Caps/Inductors - using a Wheatstone Bridge) with the "Magic
Eye". They are great for reforming caps (they go up to 600V if I am not
mistaken) and the Magic Eye is a nice touch.

John :-#)#



--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."