Hi Steve, I played with such a circuit a long time ago. The slope is limited to the clocking of your circuit (one LSB digit per clock typ), which can present an issue if you cannot follow the OCXO's EFC changes fast enough. You could be chasing the OCXO voltage and this may lead to instability. Even if it is "locked", the circuit will constantly be "chasing" the OCXO, unless you implement a dead-zone where the circuit stops counting up/down when you are close enough to your target frequency. This chasing may cause the frequency to modulate up and down, and could lead to large-scale oscillations. Tough to get this to work properly, but with circuitry to add a deadzone, and to dampen the lock, and maybe to introduce gain (jump more than one LSB when far off etc) it may work. Then again implementing a standard PI controller (in a micro etc), and calculating it's stability etc is much easier than getting this to work properly. bye, Said In a message dated 12/29/2008 21:30:54 Pacific Standard Time, [email protected] writes:
As part of the current idea I have with the hockey-pucks, I'm thinking about feeding the D1 and U1 phase difference pulses out of an MC4044 out to some circuit that could clock up and down an analog output which would ultimately go to the EFC of a ocxo, IE D1 pulses when the phase of one input signal is advanced and visa versa for the U1 pin. Anyone seen a circuit like that please? Thanks & 73, Steve -- Steve Rooke - ZL3TUV & G8KVD & JAKDTTNW Omnium finis imminet _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
