wind your own tempcos

[Martin Czech]

:::Umm... depending on where the tempco was placed in the expo converter 
:::circuit, isn't it possible that the inductance of the coil might have some 
:::adverse effect on incoming control voltages that are being FM'd at audio 
:::rates?  Would the 63mH value be high enough that its effect would be out of 
:::the usable VCO range?  Of course, the additional copper wire you might add to 
:::it would surely change its overall inductance (to a larger value), wouldn't 
:::it?  (I hope I am making myself clear enough here, I'm not quite sure how to 
:::articulate this)

I'm thinking of a resistive divider.

I think that FM would use the linear control input, which doesn't require
a voltage change at the resistive divider with tempco.

You are right, a 700 Ohm series resistance Rl and a L of 63mH and an
upper leg R of 1Meg means a pole at -(Rl+R)/L and a zero at -Rl/L.
A kind of lead/lag. The attenuation of this divider changes from 63dB @
0Hz to 0 db @10MHz, the knee is at 1500 Hz, which is in the audio range.

Of course, at such high frequencys the winding capacitance would
become important, I guess this device will have many ups and downs
of phase...

I didn't mean to make additional windings, simply replace the pain 
of WYO (wind your own) with a simple, cheap device. These guys come
plastic encapsulated, I guess it would be a good idea to see them naked.

Eg. to drown them into heat grease.

(Oh my god, did you see the word "naked". Now this mail won't make it
to Australia and other puritanic places in the world.)

m.c.

(from the land of relative sexual enlightment)