Said, I agree. I intended to complete the page by doing more tests, but the interesting point of the demonstration is that it is sufficient to match the cable at the far end, and in doing so, you preserve the full amplitude of the pulse. If you put 45 ohms in series and terminate in 50 ohms at the other end, you end up with half the signal. However you do not need to do that.
That was the reason why I wrote the page in the first place. I will try to clarify that when I get a chance. Didier Sent from my Droid Razr 4G LTE wireless tracker. -----Original Message----- From: saidj...@aol.com To: time-nuts@febo.com Sent: Mon, 26 Nov 2012 2:36 PM Subject: Re: [time-nuts] pulse height Didier, Oh, ok that makes sense, but that is a non-standard output, so not sure that you want to use such an output as a sample case for generic applications. Alternatively maybe rename the page to "Trimble CMOS-output Coax Cable Impedance Matching" to make that clear. It would be better to put a 45 Ohms series resistor in that system to give you a 50 Ohms standard output, and redo the tests. BTW: we have had to put up with that (in my opinion) stupid output impedance, on our Mini-JLT boards we are also driving the 1PPS with very low impedance to be compatible to the discontinued Mini-T. I wish Trimble had heard of incident-wave switching when they designed all of their units, and used a proper 50 Ohms output impedance. bye, Said In a message dated 11/26/2012 11:12:32 Pacific Standard Time, shali...@gmail.com writes: Said, in the text I indicated the source was not a 50 ohm terminated signal generator, but the 1 pps output of a Thunderbolt with about 5 ohm impedance, hence the ringing. Didier _______________________________________________ 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. _______________________________________________ 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.
