VCO in AN-299

[jorgen.bergfors at idg.se]

MIME:pfperry at melbpc.org.au on 98-08-12 14.02.04
To:  synth-diy at mailhost.bpa.nl @ SMTP 
cc:  (bcc: Jorgen Bergfors/IDGSE)
Subject: Re: VCO in AN-299 

At 10:29 AM 12/08/98 +0100, jorgen.bergfors wrote:
>>Has anybody tried the VCO in National Semiconductor's Application Note 
299, 
>>figure 1? It is a 1 V/oct VCO that is supposed to be virtually free of 
>>temperature dependence. And it does not use tempco resistors or 
heaters. 

>....er, the CA3046 in this ckt IS the heater, at least, one of the 
>transistors
 >in it is. The circuit does work.
>Incidentally, the vca ckt also in this app note is also designed by Jim
>Williams..

>paul perry melbourne australia

Well, the text says "Figure 1 shows a circuit which eliminates all temperature 
compensation requirements".
But yes, you are right. It is the seme circuit as before, they just have 
redrawn it and removed all text about heating and temperature compensation. 
Sneaky of them. The old schematic is in Modulus 1, I just checked. 

/Jorgen