[sdiy] my VCO not oscillating :(

[Michael Ruberto]

I have finally built the prototype of my SEM VCO clone. Unfortunately, it 
will not oscillate. I have removed all components involved with the linear 
detune mod and jumpered the circuit so it is the same as the original SEM 
schematic. This was just to rule out that mod as the problem. Here's what 
I've found so far. Q7 is conducting and is resulting in R22 getting hot (not 
too hot). Q2 has 15 volts on it's gate. This doesn't seem right to me - it 
seems Q2 should be conducting which in turn would hold Q7 off. I'm thinking 
Q2 is the culprit but I'm not ruling out the possibility that I have been 
going by the wrong pinout for the device.

Any help with this is very much appreciated.


http://frankentron.freezope.org/source/REV4-2.gif

M. A. Ruberto