On Sun, Nov 15, 2020 at 01:43 PM, Arv Evans wrote:
Since H&P only corrects HF frequency during each cycle of the LF clock
there is a possibility of overshoot if the delta-C is too large.?
Hi Arv,
This is good information you supplied while I was slowly working on my last message. So, the Huff and Puff method may introduce a constantly varying low frequency phase shift. That makes sense.
In Hans' design he refers to using Huff and Puff in his xtal oven frequency adjustment method. But, because it uses a full microprocessor to generate the up and down voltage pulses, it may really be more of a sample and hold arrangement as a DAC. Not limited to correcting only when the phase delta reaches a certain point. I'll need to see what he did in his software.
Tom, wb6b
