Hi The 1938 and 10811 share the same basic crystal. The difference between a "very good" and a "acceptable" crystal can be an order of magnitude or more on ADEV at tau >= 1 second. In a very stable environment the rare 10811 with the 5x10^-13 at 1 second crystal will beat most of the production 10811's or 1938's. It's sort of luck of the draw in that respect.
Bob On Jun 5, 2010, at 11:31 PM, Robert Benward wrote: > Joe, > Thank you for your inputs! The Z3815A I suspect is low voltage, it has a > large PC card/motherboard type of connector with a large molex/amphenol power > connector. There appears to be a pair of DC-DC modules inside. You would > need to make some internal taps to get the 10MHz out to a BNC. I also read > somewhere an author's disappointment on the performance of the (his?) E1938A > compare to the 10811. I have one that is stand alone, running continuously. > > I was under the impression that the maximum number of satellites in view is > about 12 (24 active in a constellation hemisphere view), the other channels I > think are used for WAAS and other data channels. > > Bob > > > > ----- Original Message ----- From: "J. L. Trantham" <[email protected]> > To: "'Discussion of precise time and frequency measurement'" > <[email protected]> > Sent: Friday, June 04, 2010 10:56 PM > Subject: Re: [time-nuts] Z3816a > > >> Correction. Z3805A tracks 16 satellites. >> >> Joe >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of J. L. Trantham >> Sent: Friday, June 04, 2010 9:51 PM >> To: 'Discussion of precise time and frequency measurement' >> Subject: Re: [time-nuts] Z3816a >> >> I have Z3816A's and TBolt's. Both do a great job. For the TBolt, I use >> TBoltMon.exe to monitor and for the Z3816A, I use SatStat. The Z3816A >> requires a 'null modem' adapter or an appropriately wired serial cable to >> connect to the serial port of the computer where as the TBolt uses a >> straight serial cable. >> >> The only potential advantage of the Z3815A that I know of is the fact that >> it uses the E1938A oscillator. I have a couple of these oscillators and >> they are superior in performance. However, I have no firsthand knowledge of >> performance of the Z3816A versus the Z3815A. >> >> The Z3816A and the TBolt tracks up to 8 satellites. The Z3816A also tells >> you what other satellites are under consideration but are not being tracked, >> perhaps up to 8 other non-used satellites. I have at most seen the Z3816A >> refer to a total of 11 satellites (8 tracked and 3 not tracked) but my >> antenna is not in an ideal location. I do not know about the Z3815A. The >> Z3805A tracks up to 12 satellites, if I recall correctly, and probably >> should also be included in the comparison list if you are looking for a >> GPSDO. >> >> The Z3816A comes in at least two variants, one powered by a DC supply (I use >> 30 VDC for mine) and the other powered by 120 VAC. I don't know about the >> Z3815A. >> >> Good luck, >> >> Joe >> >> >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of Robert Benward >> Sent: Friday, June 04, 2010 7:13 PM >> To: time-nuts >> Subject: [time-nuts] Z3816a >> >> Hi All, >> Is there any downside to a model Z3816A? I also see a Z3815A on Ebay, but >> the connector arrangement is not attractive. Does anyone have a link to a >> comparison chart between all these models? >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
