Transistor Affecting Timings?

[rsocor01]

Maybe a 20 Mhz crystal oscillator with capacitors is the way to go?

"Crystals provide accurate timing to within 50 parts per million (PPM)"

If that's true, then that's better than a resonator with 0.5 % accuracy.

Actually it is a 0.005% accuracy!!!!! Yes, the external oscillator might be the way to go.

[Ramius]

If you are dealing with video and not HD video then you are dealing 29.94 frames per second, a rather low frequency. Two different crystals will never sync as each is producing a sine wave or modified square wave and the start of the pulse (leading edge) will change. You might be better off using the CCP1 and CCP2 outputs and the "HPWM" command if you are working with two different frequencies. Also, the LED in your drawing should be from the emmitter to ground, You can leave R-1 from +5v to the collector. The reasoning is that in an NPN transistor there is current flow from the base to the emmitter (notice which way the arrow points). Hope this helps. Ed