[time-nuts] ? phase comparison or other device

Dr Bruce Griffiths bruce.griffiths at xtra.co.nz
Sat Jun 30 19:50:40 EDT 2007


Try changing your input stage to the configuration depicted in the 
The input amplifier can then be something like an OP27 without affecting 
The noise spectrum at the first opamp output will actually be reduced to 
the opamp (and series resistor) input noise at frequencies outside the 
tuned circuit bandpass rather than being significantly enhanced as in 
you circuit. The first opamp will ouput also be dc stable with a zero 
signal output of around zero volts unlike your circuit.

This will do nothing for the rather large phase shift tempco, but at 
least its a more rational design.

In fact your circuit performance should improve if you just delete the 
first tuned circuit.

You still need to think about a suitable limiter that doesn't switch the 
power supply noise to the output during stauration.

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