Moog Transistor Matcher Questions

[jh.]

> >  I've noticed that the measurements aren't steady at all. Once I turn
the
> > power on, the voltage reading on the voltmeter seems to drop as I watch.
>
> :) This is very obvious illustration of all the talk about the need for
> temp compensation of expo pair. You see how it changes with temperature.
> Try to do it in constant temp room, away from open air flow (window,
> doors).
> Also be sure to use tweezers to pick and install transistors you test as
> heat from your fingers heats transistor a bit and you get some reading
> that
> quickly changes as heat is dropped. That's how sensitive it is...

Very true. It's a pain.
Last time I matched transistors, I arranged them so that I only had to touch
them with my fingers for a second or less, but I still had to wait more
than a minute or two for each transistor's measurement.

I have an idea how I will do it next time, but I have not tried it yet:

I'll stick a whole batch of transistors side by side into one of these
white, solderless prototype boards, and I'll make a cable with 3-pole
plug to contact the protoboard from the Vbe test circuit. Then the
procedure would be:

Stick in 20 transitors at once, wait 2 minutes (or even 5) until they
are all settled, and then probe them with that special plug one by one,
(hopefully) without stirring their temperature.

Anybody tried this ?

JH.