[time-nuts] HP 5370B using manual start-stop
List, I'd like to do 1000 second TIC measurements with my 5370B but I don't want to have to perchase A HP 1B prologic or similar controller for the timeing. As long as I'm interested in the TIC difference but not an absolute value is it reasonable to use the manual start/stop switches and a stop watch or similar timer? Regards, Perrier ___ 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] HP 5370 A to B conversion?
List, Is it practical to try and convert a HP 5370A to the B model. (I know that a dedicated TN could do it. Regards, Perrier ___ 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.
Re: [time-nuts] HP 5372A TIA Question
In message , Magnus D anielson writes: >Consider that you need to swap the cables to verify that it is static >with the setup and does not follow the cables. Run long series of measurements with the HP5372A OCXO free-running and with it slaved to the DUT clock. Any imperfection in the interpolator will show up as different noise characteristics in the two results. There is a test in the service manual which will give you a good indication how well tuned the interpolator is, run that before touching anything, and don't attempt to tune the interpolator unless you can follow the procedure in the manual *exactly*. PS: I do not recall it being mentioned, but the 1 MOhm input pods are horribly unstable compared to the 50 Ohm input pods, which are basically just a stripline and a BNC connector. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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.
Re: [time-nuts] HP 5372A TIA Question
Hi Adam, On 05/30/2018 12:26 AM, Adam MacDonald wrote: > Time Nuts, > I have a nice new-to-me 5372A that I'd like to use as part of a DMTD > stability analysis system. After getting a few odd glitches from a very > stable source spaced 2 ns above or below the main time interval reading, OK, so the 5372A uses a 10811A as OCXO and then synthesize a 500 MHz coarse clock which then runs in custom high-speed chips. The interpolator is a delay-chain of DFFs. So, if you jump +/- 2 ns it is that you most likely have an issue with the start/stop and coarse-counting. Could also be that the interpolator misses one way or another. Regardless I will ponder on it. > I decided to run the performance verification checkout from the service > manual. The checkout calls for a BNC-T from the rear 10 MHz timebase output > split to both A and B channels. The spec is 100 ns +/- 200 ps but I am > consistently getting either 101.6 or 101.4 ns in Time Interval mode on either > channel. So it seems to be high/off by exactly 1.4 ns. Consider that you need to swap the cables to verify that it is static with the setup and does not follow the cables. Also, there can be trigger voltage offsets which may be the cause, so that may be due to other reasons. > The standard dev is very low (typically 0-60 ps over several 100 point >runs). Curiously, in Continuous Time Interval mode, it reads dead on (100.0 >ns). I've run the sensitivity cal because I got the 160 error (dead battery), >but not the interpolator cal (I don't have the appropriate riser card and the >manual calls for a specific cable). Has anyone seen this? I suspect maybe >the interpolator board needs to be ca > librated, but maybe something else? Has anyone had experience trying to > adjust the board without a riser? Any other tests I might run to shed light > on what might be causing this? Let me ponder on this one. I don't think it is the interpolator boards, sure they might need calibration, but that should not be the issue here, you miss a cycle in the coarse counter on their the start or stop channel. That should be the focus. Cheers, Magnus ___ 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.
Re: [time-nuts] nuts about position
Hi
It’s not real clear what the magic L1 / L2 / L5 gizmo does for you right now
today. As far as I can tell,
the free processing services all only do two at a time. You can do L1 / L2 or
L1 /L5. Possibly at some
point in the future that will change.
Even with “only two” a fancy device will get you down to numbers that simply
are not believable. Any
device that thinks it’s getting into 0.000x meter precision needs to back up
and look at some of the
reference points being used.
Getting back to timing, if you guess that 0.3 m is about a nanosecond, the M8T
is off by about a nanosecond
in lat and lon. It’s off by about 2 ns in elevation. The time solution will be
some sort of RMS of this. Unless
the one and only sat you can see passes directly over you, the full 2 ns isn’t
going to come in.
Location will always be one of a list of errors in getting time data. The
bigger question will be how well the
other stuff on the list is controlled / known. Coming up with an RF delay
number that is good to < 1 ns on
any of these gizmos may be a bit tough…..
If frequency rather than time is the goal, the position error will indeed add
to the “swing” over a day. Your
antenna location / sky view will be a big part of the “how much” part of the
question. You might see a
nanosecond of swing on an hour to hour basis …. you probably would see less.
Simply put, it’s in the
3x10^-12 or less range frequency wise. Most GPSDO’s struggle below a few parts
in 10^-11 for a variety
of reasons ….
Bob
> On May 30, 2018, at 3:46 PM, Mark Sims wrote:
>
> Ok, I did the experiment. I took an 8 hour M8T RINEX file with
> GPS,SBAS,GLONASS,GALILEO data in it. I then used to TEQC to extract GPS only
> and GLONASS only data (CSRS-PPP ignores SBAS and GALILEO data). The 95%
> confidence error ellipse estimates ("rapid" orbits) were:
>
> GPS+GLONASS:lat 0.245mlon 0.219malt 0.582m
> GPS ONLY: lat 0.269mlon 0.239malt 0.616m
> GLONASS ONLY: lat 0.610mlon 0.755malt 1.835m
>
> Conclusion... if you are just interested in an accurate antenna position, a
> $25 LEA-5T should do just fine. GLONASS brings very little benefit (call it
> an inch) to the party. 24 hours of observations can reduce those numbers by
> around 50% I used one of those $70 Chinese L1/L2/GLONASS/BEIDOU antennas
> from Ebay. Note that my antenna location/environment is HORRIBLE...
>
> Things might change if you get into expensive L1+L2(or L5) receivers.
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[time-nuts] nuts about position
Ok, I did the experiment. I took an 8 hour M8T RINEX file with
GPS,SBAS,GLONASS,GALILEO data in it. I then used to TEQC to extract GPS only
and GLONASS only data (CSRS-PPP ignores SBAS and GALILEO data). The 95%
confidence error ellipse estimates ("rapid" orbits) were:
GPS+GLONASS:lat 0.245mlon 0.219malt 0.582m
GPS ONLY: lat 0.269mlon 0.239malt 0.616m
GLONASS ONLY: lat 0.610mlon 0.755malt 1.835m
Conclusion... if you are just interested in an accurate antenna position, a
$25 LEA-5T should do just fine. GLONASS brings very little benefit (call it an
inch) to the party. 24 hours of observations can reduce those numbers by
around 50% I used one of those $70 Chinese L1/L2/GLONASS/BEIDOU antennas from
Ebay. Note that my antenna location/environment is HORRIBLE...
Things might change if you get into expensive L1+L2(or L5) receivers.
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Re: [time-nuts] Free Stuffs...
Burt, who was this guy? Maybe I know him. Was he a ham? I couldn't take all the stuff but might be interested in some of the smaller items. Is there test equipment as well? I don't have a truck; I live in the SFV so it could be worth my time to drive over and cherry pick, if that's an option. Bob K6DDX On Wednesday, May 30, 2018, 8:20:39 AM PDT, Burt I. Weiner wrote: Gang, A local Southern California Broadcast Consulting Engineer buddy recently passed away. His home in Sierra Madre is going to be sold. There are 5 or 6 storage shelves, the kind with the yellow plastic bins about 6' tall, 4' wide and about 10" deep. They are loaded with the plastic bins and a lot of misc electronic and electrical parts. There is also a work bench or two. One for sure is a nice electronic type work bench. This stuff is free and must be picked up by June 9th. Obviously you will need a full size pickup truck. If interested, please contact me direct at: b...@att.net. Burt, K6OQK Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net K6OQK ___ 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. | | Virus-free. www.avast.com | ___ 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.
Re: [time-nuts] Tektronix FCA3103 ADEV measurement tau setting problem
Hi Any time I have tied a 53132 into TimeLab, I’ve used the serial port. That does a fine job of “talk only” data dump. Bob > On May 30, 2018, at 12:18 PM, Richard (Rick) Karlquist > wrote: > > > > On 5/28/2018 1:44 PM, Bob kb8tq wrote: >> Hi >> TimeLab will work with some counters and it will do most of the common >> plots. It is indeed free ….. >> Bob > > The TimeLab manual says it will support any counter that can > dump data in Talk Only mode. The Tek manual doesn't mention > Talk Only mode. The TimeLab manual also (vaguely) says it > will support the HP53132, but doesn't specify if this is > simply referring to Talk Only mode, or a more complete interface. > The Tek manual says that it has a 53132 compatibility mode > available over GPIB using SCPI commands. If the TimeLab > interface uses SCPI as well, I might be in business. Does > anyone know about that? > > Rick N6RK ___ 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.
Re: [time-nuts] Tektronix FCA3103 ADEV measurement tau setting problem
On 5/28/2018 1:44 PM, Bob kb8tq wrote: Hi TimeLab will work with some counters and it will do most of the common plots. It is indeed free ….. Bob The TimeLab manual says it will support any counter that can dump data in Talk Only mode. The Tek manual doesn't mention Talk Only mode. The TimeLab manual also (vaguely) says it will support the HP53132, but doesn't specify if this is simply referring to Talk Only mode, or a more complete interface. The Tek manual says that it has a 53132 compatibility mode available over GPIB using SCPI commands. If the TimeLab interface uses SCPI as well, I might be in business. Does anyone know about that? Rick N6RK ___ 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] Free Stuffs...
Gang, A local Southern California Broadcast Consulting Engineer buddy recently passed away. His home in Sierra Madre is going to be sold. There are 5 or 6 storage shelves, the kind with the yellow plastic bins about 6' tall, 4' wide and about 10" deep. They are loaded with the plastic bins and a lot of misc electronic and electrical parts. There is also a work bench or two. One for sure is a nice electronic type work bench. This stuff is free and must be picked up by June 9th. Obviously you will need a full size pickup truck. If interested, please contact me direct at: b...@att.net. Burt, K6OQK Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net K6OQK ___ 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.
