Bob, I think you are correct. As I understand it, Rick Karlquist, a member of this list, was instrumental in the design of the E1938A. He likely would be the best resource for these data.
This topic has been discussed in the past and the archives would be a good resource as well. Joe -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Benward Sent: Sunday, June 06, 2010 10:34 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Z3816a Bob, I agree, I suspect the E1938 he was examining may have been a lemon of the lot. He did not indicate this was across the board. I am under the impression the claim to fame of the E1938 is the ultra stable double oven. Bob ----- Original Message ----- From: "Bob Camp" <li...@rtty.us> To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Saturday, June 05, 2010 11:39 PM Subject: Re: [time-nuts] Z3816a > 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" <jlt...@att.net> >> To: "'Discussion of precise time and frequency measurement'" >> <time-nuts@febo.com> >> Sent: Friday, June 04, 2010 10:56 PM >> Subject: Re: [time-nuts] Z3816a >> >> >>> Correction. Z3805A tracks 16 satellites. >>> >>> Joe >>> >>> -----Original Message----- >>> From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] >>> 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: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] >>> 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 -- 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. >>> >>> >>> _______________________________________________ >>> 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. >> > > > _______________________________________________ > 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. _______________________________________________ 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.
