Enlighten a total novice

[Rene Schmitz]

At 12:40 02.07.99 +0200, Haible Juergen wrote:
>	>If anyone wants to see an example of this: 
>> http://titan.cs.uni-bonn.de/~schmitz/vco3.html
>> 
>	>A VCO with that will sweep from 0.001 Hz(~15 Minutes) to 50kHz.
>
>
>I like this trick with the two FETs in series !
>
>JH.
>

Yes, I like it too, its freely after Horrowitz and Hill 2nd ed. p224.
And largely inspired by the "VCO hacks and tweaks" thread here.
It also uses the 2SC1583 in the expo convertor, as in your korg-style-VCO.
The device is not as bad as one thinks at first. 
Infact I've measured the Vbe matching to 1-2mV (on two devices).
The beta is much higher, and r(be) seems to be lower. 
At least the high frequency performance is acceptable even without an
HF-trimpot.

Bye
 René

             ,   : (uzs159 at uni-bonn.de)
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