[sdiy] Tempco question

[Michael Schulze]

www.synthtech.com has 'em for 6 bucks each

> From: Gene Stopp <gene at ixiacom.com>
> Date: Tue, 21 May 2002 11:25:24 -0700
> To: synth-diy at dropmix.xs4all.nl
> Subject: RE: [sdiy] Tempco question
> 
> Yeah sure - the v/oct trimmer should take up the slack, as long as the
> tempco has the right "co".
> 
> Brings me to a related question - anybody got a handful of tempco's for
> sale? I've seen the occasional email on the list, but I've never acted, and
> now I forget who it could have been. Either that, or a pointer to a
> distributor known to have them. Thanks all!
> 
> Best Regards,
> 
> - Gene
> 
> 
> -----Original Message-----
> From: Michael Schulze [mailto:michael.schulze at oberlin.edu]
> Sent: Tuesday, May 21, 2002 10:47 AM
> To: synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] Tempco question
> 
> 
> Thanks to all who have been answering my questions!
> 
> I have found the tempco resistors I need, and I can get 5% ones for free.
> These will be used to build a BERGFOTRON quad VCO board.  Will the 5%
> tolerance be tight enough for the circuit?
> 
> The Bergfotron vco is a modification of the ASM1 VCO.  The tempco resistor
> is the bottom resistor in a voltage divider between the output of the CV
> summing amp and the input of the expo converter npn pair.  So we are talking
> a +/- 50 ohm tolerance between a 56k and a 1k.   Geez, at 50/57000 I guess
> that's 0.08% of the voltage divider.  Should be ok, no???