CTC-4 Director 21

[SwizzyMan]

Originally Posted by old_tv_nut

What size cap across the crystal? It's probably too big if it pulls it 545 Hz too low. It needs to free run close to correct so the reactance tube and coil can pull it either way.

I seem to be mixing up my results here. What I get with the crystal across the cap is 3.5760. The target is 3.57545. I am not putting the right results here. Let me start over now. The closest I can get the oscillator to run at is 3.5766 without a cap across crystal. With a cap across the crystal I pull about 3.5762 or thereabouts. the capacitor across the crystal does not pull down the frequency much at all. I would venture to guess the cap was maybe 5pf.