[time-nuts] The VE2ZAZ GPSDO

SAIDJACK at aol.com SAIDJACK at aol.com
Sat Oct 21 02:29:35 EDT 2006

Hello Bruce,
I agree. The DAC reference is an LM7805CT regulator with 0.8mV/C  (typ.) 
temperature coefficient. Considering that typical Oscillators  (MTI units for 
example) have about +-20Hz deviation per 5V - this alone  - excluding the Opamps 
tempco, would lead to a temperature drift  of 0.32Hz over a 50 Deg C temp 
range. That's about 3.2E-08, quite  a bit worse than a good surplus oscillator.
And the 7805 does not have a maximum tempco rating, so it could be 10x  worse 
than that...

More information about the time-nuts mailing list