[time-nuts] C-Max Receiver Experiment

Chuck Forsberg WA7KGX N2469R caf at omen.com
Mon Oct 31 03:06:26 EDT 2011


In the late 70s I took a 6800 based micro I designed for
Sidereal and developed "CTU - Chuck's Terminal Unit",
a program that ran an autostart responder on 80 meters.

The computer ran 1000 non maskable interrupts per second.
This powered Baudot send, receive, and distortion measurements.
It also powered a software phase locked loop that synced to and
decoded the WWVB signal.

A loopstick with lots of turns and a trimmer fed into a FET gate
makes for a very selective antenna.  I also happened to have a
60 KHz crystal filter on hand.  There weren't many switching
power supplies back then and reception was passable.  Today I
have a Radio Shack clock that has great difficulty synching and
two Oregon Scientific weather consoles that can't sync at all.

-- 
Chuck Forsberg WA7KGX N2469R     caf at omen.com   www.omen.com
Developer of Industrial ZMODEM(Tm) for Embedded Applications
   Omen Technology Inc      "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231   503-614-0430





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