[sdiy] parts supplier for tempco rersistors/mat-02

[Neil Johnson]

Hi Mike,

> I am having trouble finding tempco resistors, the MAT-02 transistor pair,
> and small value polystyrene caps for my vco project.

Ok, firstly are you sure you _need_ a MAT-02?  I'm using a 2SC1583
npn-pair and it seems ok for my little VCO board.

Tempco resistors are funny things.  The original transistor-specific
tempcos are getting harder to find, so I'm using a standard tempco with a
slightly higher coefficient, and bulking it out to the desired coeff with
an ordinary metal-film resistor.  The particular device I'm using is
3,900ppm/'C, and being surface-mount is glued directly to the case of the
tranny-pair.

Polystyrene caps are supposedly going to become rarer and rarer, as the
company that _made_ the polystyrene film has stopped production.  *Gulp*.
Polycarbonate is still available, but doesn't quite have the same
performance :-(  Close, but no cigar...

Sadly, I don't know about US suppliers, but hopefully you might be able to
widen your search to more accessible parts.

Cheers,
Neil

--
Neil Johnson :: Computer Laboratory :: University of Cambridge ::
http://www.njohnson.co.uk          http://www.cl.cam.ac.uk/~nej22
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