Re: [time-nuts] Hp5061 Cesium Zeeman adjustment
Thanks Corby. Well didn't find the zeeman peaks but using a GPSDO it was very apparent what the peaks are. Its now set and the real issue is that the base unit was a option 004 now with a standard tube in it. Changing the C field resistor moved it into the correct offset range. 300 ohms down to 235 ohms for a standard tube per the manual. I did swap the synthesizer module but I do not believe thats actually an issue. Regards Paul WB8TSL On Sat, Feb 25, 2017 at 12:32 PM, wrote: > Paul, > > The Zeeman frequency you use depends on what synthesizer frequency your > unit is set for. > > Either 48.82Khz or 53.53Khz. > > See: https://www.febo.com/pipermail/time-nuts/2008-July/032378.html > > The Zeeman coil is close to a short. You set the amplitude to the spot > that gives you the best look at the peaks. > > Adjust the C-field to land on the central peak. > > Cheers, > > Corby > > ___ > 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.
Re: [time-nuts] My TICC came in the mail yesterday
FWIW, here is a quick test I ran on my TICC, assuming the attachment makes it. "TICC base" was a Trimble Thunderbolt reference and PPS. The reference for the other traces was an FE-5680A with an LTE Lite on ChA and Trimble PPS on ChB. The GPS antennas are indoors and entirely sub-optimal. The LTE Lite is in a Hammond enclosure and using the antenna supplied with the eval kit sitting on top of a metal file cabinet. The result seems to be about as expected for the LTE Lite. The Trimble typically doesn't track many satellites so I'm not expecting great results. On Fri, Feb 24, 2017 at 11:58 PM, Andrew Rodland wrote: > On Fri, Feb 24, 2017 at 7:08 PM, John Ackermann N8UR wrote: > > Hi Andrew -- > > > > There seems to be more than a little magic involved in getting sane > > three-corner measurements. I've gotten best results when the run is long > > enough to have many data points per tau, and also that results when > you're > > noise limited tend to go imaginary. Finally, I think things work best > when > > the three sources have similar noise processes, e.g., looking at 3x OCXO > or > > 3x Rb or whatever. > > > > Thanks. I'm not even complaining here, like I said, this is more > visibility than I've had in the past, and the TICC is looking pretty > good. As for more points, that was just the first 9 or so hours of a > 24-hour run, which is now completed. At the end of that, it's more > reasonable: http://i.imgur.com/7v3obqy.png — although I'm certainly > not putting much faith in anything past 1000s. And the non-hat plot: > http://i.imgur.com/xWTsqCX.png . > > Andrew > ___ > 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] Hp5061 Cesium Zeeman adjustment
Paul, The Zeeman frequency you use depends on what synthesizer frequency your unit is set for. Either 48.82Khz or 53.53Khz. See: https://www.febo.com/pipermail/time-nuts/2008-July/032378.html The Zeeman coil is close to a short. You set the amplitude to the spot that gives you the best look at the peaks. Adjust the C-field to land on the central peak. Cheers, Corby ___ 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] Hp5061 Cesium Zeeman adjustment
Working on a 5061 that I can actually see the beam current on. Looking at the manual it says to inject a frequency and there are several possible in the 50 KHz range. But it never says the drive level of the signal to use. Since this was fairly vintage equipment I might assume the coil was driven heavily. When I drive the coil at 3 or more dbm. I see the beam current go down. Is the adjustment done by actually driving the beam current down then adjusting the frequency for a slight rise? Or is it as the book says it should just be a rise from the steady state current? Just my luck the tek gen I am using has a band switch at 50 KHz splitting the possible Zeeman frequencies of interest. Lastly I stumbled into a document on C-field adjustment from HP vol 21_34 must be 1967. It suggests the better Zeeman frequency is something like 38 KHz instead of 53.53KHz. If I use 38 Khz I do see the rise. Thanks Paul WB8TSL ___ 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 5060A training manual
Frans We have it ..contact me off list Dave manu...@artekmanuals.com On 2/25/2017 7:13 AM, Electronics and Books via time-nuts wrote: is there a pdf of Hewlett Packard 5060A Cesium Beam Frequency Standard Training Manual 02127-2 Feb 1967 Met vriendelijke groeten Regards Frans i...@electronicsandbooks.com http://ElectronicsAndBooks.com Discere ne cesses ___ 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. -- Dave manu...@artekmanuals.com www.ArtekManuals.com --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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 5060A training manual
is there a pdf of Hewlett Packard 5060A Cesium Beam Frequency Standard Training Manual 02127-2 Feb 1967 Met vriendelijke groeten Regards Frans i...@electronicsandbooks.com http://ElectronicsAndBooks.com Discere ne cesses ___ 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] ``direct'' RS-232 vs. RS-232 via USB vs.PPSdecoding cards
Hi Tom, > [ USB time transfer ] > > It seems to me that if the read path and the write path are different it breaks down. > > ... But turning that into precise time requires some kind of calibration of the actual code path delays. In other words, it sounds to me like your method is valid for frequency transfer but not time transfer. Yes, but I think the same could be said of other I/O mechanisms. Even a nominally symmetric physical layer, such as Ethernet, becomes a little asymmetric once the general-purpose CPU, software, drivers, interrupts are added in to the Tx and Rx paths. Same for PCIe, although those paths are nearly all hardware. I'm sure USB is somewhat worse than PCIe. Let me dig up the old code and try a one-way calibration against a PCIe GPIO signal. The PCIe write should get out to the wire in 500 ns or so, and the Teensy (or a TIC) can measure that against the USB event that comes along later. Should allow a reasonable estimate of the fixed delay (better than measuring the round-trip total USB transaction time at the CPU and dividing by 2). The fixed delay will be system-specific, though, requiring a calibration for each unique hardware platform, unless the USB round-trip time is small enough to be ignored by the application. Certainly PCI, or better, a CPU GPIO pin, is vastly preferable to USB; but USB is very convenient and available. If USB can be coaxed into good performance, so much the better. Cheers, Peter ___ 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] My TICC came in the mail yesterday
On Fri, Feb 24, 2017 at 7:08 PM, John Ackermann N8UR wrote: > Hi Andrew -- > > There seems to be more than a little magic involved in getting sane > three-corner measurements. I've gotten best results when the run is long > enough to have many data points per tau, and also that results when you're > noise limited tend to go imaginary. Finally, I think things work best when > the three sources have similar noise processes, e.g., looking at 3x OCXO or > 3x Rb or whatever. > Thanks. I'm not even complaining here, like I said, this is more visibility than I've had in the past, and the TICC is looking pretty good. As for more points, that was just the first 9 or so hours of a 24-hour run, which is now completed. At the end of that, it's more reasonable: http://i.imgur.com/7v3obqy.png — although I'm certainly not putting much faith in anything past 1000s. And the non-hat plot: http://i.imgur.com/xWTsqCX.png . Andrew ___ 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.