albertson.ch...@gmail.com said: > The "line driver" was a TTL inverter chip I was going through about 50 or > 60 feet of cat-5 wire. TTL level serial is always marginal, the specs say it > should not work but it does work most of the time.
Modern CMOS chips work much better than real TTL. Some CMOS chips have weak drivers. Cat-5 should be fine for 100 ft. Here are scope pictures from the PPS signal from a TBolt driving 100 feet of various types of wire: http://www.megapathdsl.net/~hmurray/time-nuts/coax/Coax-20ns.png http://www.megapathdsl.net/~hmurray/time-nuts/coax/TP-20ns.png The clump on the left of each graph is the input. The stuff on the right is the output. The scatter is due to the different prop times. -- These are my opinions. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.