[time-nuts] Simulating LORAN-A GRI Timing Generator

asmagal at fc.up.pt asmagal at fc.up.pt
Sat Jan 8 17:25:13 UTC 2011


Quoting "J. Forster" <jfor at quik.com>:

> The GRI and Delay counters need to be 5 decimal digits. My current
> thinking is manual entry of the numbers via BCD coded thumbwheel switches.

More than thirty years ago, I built a Rate Generator for LORAN-C
excatly according to the above principle. It is still wandering
at my junk box and is a three digit preset counter (3XSN7490)
a quad input decoding gate (SN7420) and the thumbwheel switches.

Using more or less the same principle there is also a six digit
delay resolving one microsecond.

They are very ancient designs but they work pretty well.

Best regards

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