"Mike W" wrote in message
...
I have a need to produce an accurate 4Mhz 50% dutycycle
TTL squarewave to use as a timebase.

I have a 10Mhz IQD frequency standard of suitable accuracy.
How can I divide this to produce the 50% duty cycle 4Mhz
signal?. Is it even possible with logic alone?. I can
see how to mix with either 6Mhz or 14Mhz, but this then
detracts from the required accuracy.


I'd be tempted to use a PAL chip. It is possible to make a multiply by 4
and then divide by 10 in the same chip, which would make the total parts
required to get the 4 MHz 50% Sq Wave your original 10 MHz input and a
single chip.


Jim Pennell
N6BIU