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Old April 19th 04, 04:53 PM
JLB
 
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"Michael Black" wrote in message
...

But, for some reason, when they moved to CMOS oscillators, the norm
became one gate, with a feedback resistor and a pair of capacitors, one
from input to ground, and the other from output to ground.

Oh, yes. That rang a bell.

CMOS logic is easier to get to work as an analog device than TTL. At least
for the good ol' RCA 4000 series. I am not familiar with the newer 74HC00
series to judge its performance. I would suspect that the 'bias' resistors
would have to be carefully chosen and that it would be sensitive to both the
crystal frequency and the ambient temperature.

When I was doing circuit desgin everyone most were still using TTL. The
74LS00 series was the hot item at the time.

Just from a logical viewpoint (pun not intended, by the way) I still think
he should try using two gates in a ring circuit.

Jim
N8EE