[time-nuts] WWVB teensy BPSK early experiments

[jimlux]

On 10/31/20 7:26 PM, Bob kb8tq wrote:
> Hi
> 
> 
> 
>> On Oct 31, 2020, at 9:45 PM, jimlux <jimlux at earthlink.net> wrote:
>>
>> On 10/31/20 4:46 PM, Bob kb8tq wrote:
>>> Hi
>>> Looking at the data sheet for the MCU, they really do want 24 MHz and that’s about it. I suspect you would
>>> do better to take your 10 MHz OCXO and run it into one of the frequency converter chips to get the 24.
>>> Then feed that into the board. One more chip, but you now don’t have a bunch of stuff to hack up.
>>
>>
>> Yeah.. you can spin the dial on the signal generator and move the frequency up and down, but.... Nothing is guaranteed to work right.  Who knows what sort of little DPLLs are on that chip that have narrow ranges, etc.
>>
>> This experiment was with a Teensy 3.1 - I had a lot of them, so I wasn't afraid to hack it up.
> 
> Your OCXO will have a much narrower tuning range at the extreme’s of it’s EFC than the tolerance on
> the typical crystal. The MCU PLL’s will run over the OCXO tune range ….
> 
> Bob

I was thinking if you tried to run it at 10 MHz.. yeah, if you get a 24 
MHz OCXO, no problem.

But who knows what sort of weird timing stuff might happen inside 
running at less than half the speed.