Tri VCO core

[Ian Fritz]

Hi folks --

There have been some recent questions about the novel triangle VCO core I
published in EN #111 some years ago, including statements that it can't work
and a suggestion that I didn't really build it.

For clarification, I have attached a brief analysis of how the circuit
works. For those not interested, I appologize for the bandwidth.

As implemented, the VCO has a somewhat restricted range because of the use
of passive load resistors. Replacing these with the more usual active
transistor loads should improve performance. I hope to try this soon.

Best regards.

  Ian