[sdiy] Tempcos a NoGo

[dj hohum]

Thanks for the response.

On 6/7/07, Tom Arnold <xyzzy at sysabend.org> wrote:
> On Thu, Jun 07, 2007 at 06:20:33PM -0700, dj hohum wrote:
> > 1) Tempco resistors.
> > A pain to get, and expensive when you do.
>
> Cheap from Digikey in SMD.  Harder to work with of course, but definately
> cheap.  Manufacturer is Panasonic, if you're interested I can dig for the
> part number or I'm sure someone will volunteer it.

Are they a direct replacement, other than mechanical concerns, for the
Q81? If so, am I simply missing something obvious? Wouldn't it be
trivial to make a tiny carrier out of a piece of standard copper clad
perfboard? I'm talking about the kind that has a number of holes
connected together so you can mimic solderless breadboard layouts.
Take a small strip with fourholes connected together, xacto away the
middle trace, solder the tempco accross the gap, use the outside holes
to mount leads.

> > Why are tempcos, in particular Q81 variants no longer produced? Surely
> > there were other applications other than music synthesizers?
>
> The Q81 is actually still available if you know the correct company to order
> them from ( Vishay/Ultronix ) and are willing to buy a bunch.  The Tempco's
> I currently have ( besides the SMD ones ) are KRL's.  I think another
> supplier is Precision Resistor.   When a group purchase is done ( I'll be up
> for that in a month or so ) they get fairly inexpensive.

Can you be specific on fairly inexpensive?

Thanks,
Daryl