Perhaps an old analog PLL would clean up the signal for further processing
in teh digital world.
Thats an interesting idea...I would need a slow moving error loop to
avoid pulling it all over the place. Unfortunately at an IF of 6kHz
and a 100baud Ive only for 60 cycles in which to lock and recognise a
particular frequency, but perhaps more like 20 cycles to allow for
reasonable edge detection between a logic 1 and zero. If i were using
a to part conversion it would be a neat solution and I'd have a higher
1st IF to minimise images.
I'm trying to resist putting a very tight filter on the front end as I
would like to be able to choose between 518kHz and 490kHz, although
practically this may be a reason why a certain commercial low end
receiver I tried (which is also dual channel) was so hit and miss.