Magnus Danielson wrote: > Hi! > > I have a HP G-69B-2 Z-235 Crystal Oven 100 kHz lying around. I'm considering > heating it up and run it (just for fun). Operating temperature is 65 C. > > Anyone care to share any information on this device? I have no clue which box > it ever was in or anything. Also, thoughts of suitable oscillator setups? > > I should probably have a run-by the network analyzer. > > Cheers, > Magnus > > _______________________________________________ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > Magnus
Typical face shear 100kHz crystals have a maximum drive level of 2 milliwatts and a max ESR of 5kohms. This implies a maximum crystal drive current of 630uA rms. You may wish to restrict the crystal dissipation to less than 100uW or less corresponding to a crystal current of 140uA rms or less for a crystal ESR of 5kohm. At such low frequencies an opamp with a shunt feedback resistor becomes a viable option for the buffer amplifier. Just connect the one end of the crystal directly to the opamp summing junction. If an OPA134 opamp with a 140 uA crystal current and a 14K shunt feedback resistor were employed to drive 2V rms into a 1K load the distortion products will be 80dB below the carrier and the output will have relatively low phase noise. An additional buffer stage is required to drive a 50 ohm load. Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts