The indicated delay box is an unpowered device intended for timing composite video and fine-tuning for color burst phase match. As such they are analog in and out, require / expect defined source and load impedances (typically 75 Ohms), are slightly lossy, and 100% passive. I suspect they are pure LC (ignoring the fact that all real inductors have some R as well). I would expect stability in the low ns range, as more than a few degrees of color subcarrier shift shows up on NTSC.
Bob LaJeunesse ________________________________ From: Tom Van Baak <t...@leapsecond.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Thu, December 13, 2012 12:56:17 PM Subject: Re: [time-nuts] Comparing PPS from 2 GPS units "Lastly, there are cute little delay boxes (www.ebay.com/itm/150962422699) that might work. Not sure how stable they are at the ns level. But it would be fun to measure. If someone opens one of these please tell us if it's a coil of wire, some kind of LRC filter delay, or if they use those Dallas delay chips. Which is another solution for you -- google or eBay search for: silicon delay line. /tvb" _______________________________________________ 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.
