[email protected] said: > carbon composition 5% -550 ppm/deg C > cheap 5 % metal film -240 ppm/deg C > 1% metal film axial lead <-1 ppm/deg C > 1% thick film surface mount <-1 ppm/deg C ... > Also the carbon composition resistor drifted with time at elevated > temperature.
I assume the drift is slow enough so that any any control loop will easily track it. What is the drift like at non-elevated temperatures? What is the drift like for good resistors? If I'm using 2 resistors as a divider, how well do they track? Does it matter if they have same or different values? The problem I see with resistors (or voltage reference or ???) drifting is that it gets tangled up with the crystal drifting. If you are expecting the crystal to drift and trying to measure it by something like set the DAC controling the EFC to some constant (say half range) and then measure the frequency, it will be easy to overlook the drift from non-crystal sources and get a bogus answer. It might even be too good or the wrong sign if the resistors and such are drifting in the other direction. -- These are my opinions. I hate spam. _______________________________________________ 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.
