Brooke Clarke wrote: >Hi: > >I've got the TVB 1 PPS PIC circuit working and would like to add an >output IC to drive 50 a couple of Ohm cables. >Need two outputs, the normal 1 PPS and also the 10 kHz output since I >think it would work with the SRS app note for making 1,000 TI >measurements in one second to better see small offsets. > >I seem to remember that there may be an internal resistance already in >some chips so putting a 47 or 50 Ohm resistor in series may result in an >impedance above 50 Ohms. Any thoughts? > >Thanks, > >Brooke Clarke > > > Why do you need to drive the cable with a 50 Ohm source. You need a 50 Ohm load on the receiving end to reduce reflections. But that is not a problem for the drivers. I would use a low impedance driver to minimize losses in the driver.
Just my approach. Bill K7NOM _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts