[time-nuts] Frequency subtraction with D-flip flops
EWKehren at aol.com
EWKehren at aol.com
Tue Jun 25 08:36:50 EDT 2013
Forty years ago I did a digital mixer using three J K FF's to subtract the
IF from the LO for remote monitoring of radio stations. The output is not
symmetrical but great for a frequency counter. Shortly there after Motorola
introduced the MC12000 a D FF intended and widely used for PLL
applications, I have used it many times. More recently we are using two D FF's for
mixing in A/V applications and very high resolution frequency measurements with
up to 1 E-15 a second using output frequencies from .5 Hz to 100 Hz.
Do to attachment limitations if you want more info contact me off list and
I send you some scans.
Bert Kehren
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