> Thus one cannot arbitrarily increase Vcc without considering the consequences > ...
True, but with the AC voltages as low as they are, I do think it is safe to think that the crystal current should be higher. I was not suggesting to arbitrarily rise the Vcc, I was asking any chance it is at the wrong voltage??? Even though 2.49 volts is plenty of Vcc to design an osc circuit to run on, It seems like a low, funny voltage to design for, on what I assume is an old product. ws ******************* ----- Original Message ----- From: "Bruce Griffiths" <[email protected]> To: "Discussion of precise time and frequency measurement" <[email protected]> Sent: Friday, July 03, 2009 8:36 PM Subject: Re: [time-nuts] Broken Ovenaire OSC 85-50 > WB6BNQ wrote: >> I agree with Warren. The VCC seems way too low. Interestingly, noone else >> seems to think so, >> or did not notice it. >> >> Bill....WB6BNQ >> >> >> > It was noticed, but it is consistent with the resistor values used in > the circuit. > The crystal current is determined by the dc emitter current of the > oscillator transistor. > Thus one cannot arbitrarily increase Vcc without considering the > consequences for the crystal current etc. > > Bruce >> WarrenS wrote: >> >> >>> Here is my two cents worth >>> 20 mv output, sure sounds like something is broken. >>> It should be fixed before it is modified. >>> The 2.49 volts on the Red input voltage seem LOW, More Vcc maybe. >>> The "Grn" labeled wire, FreqCtrl input should be about 1/2 VCC for >>> testing. >>> If you do 'need' to modify the gain, >>> It would seem better to bypass the 470 ohm resistor with a cap in series >>> with the 47 ohms. >>> >>> ws >>> >> >> >> _______________________________________________ >> 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.
