Hi Hans, Yes the SN74128 will drive a 50R load to TTL levels, it does not however have a 50R output impedance. The point was made succinctly by Jeroen, that it is only strictly necessary to terminate one end of a transmission line at its characteristic impedance, as long as the other end is perfect. But what is perfect? Also this is a TTL 5V output, Brooke does not state what he wanted but, coax is usually associated with sine outputs, Logic pulses tend to be sent down balanced systems.
Regards, Robert G8RPI. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hans H. Jucker Sent: 07 April 2006 10:11 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] IC for 1 PPS Output Dear Robert You can either drive from A to B with the world finest German Maybach car or also with a British Mini Cooper. May be the SN74128 50ohms coax-cable driver is rather matched for this simple application ! Regards Hans _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Any opinions expressed in this email are those of the individual and not necessarily Genetix Ltd (Genetix) or any company associated with it. This email and any files transmitted with it are confidential and solely for the use of the intended recipient. If you are not the intended recipient or the person responsible for delivering to the intended recipient, be advised that you have received this email in error and that any use is strictly prohibited. If you have received this email in error please notify Genetix by telephone on +44 (0)1425 624600. The unauthorised use, disclosure, copying or alteration of this message is strictly forbidden. This mail and any attachments have been scanned for viruses prior to leaving the Genetix network. Genetix will not be liable for direct, special, indirect or consequential damages as a result of any virus being passed on, or arising from alteration of the contents of this message by a third party. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
