Re: [time-nuts] Anybody have suggestions for time related science fair projects?

David.vanhorn wrote: > Measuring the speed of light (Fizeau or Michelson method? Other ways) > > > I saw a great demo of this at the Exploratorium in SF. They had a long spool > of fiber optic, a disc with holes, and a light source. When static, if the > light shines through the hole in the

Re: [time-nuts] Help Identifying this surplus Timing Module

Thank you bob and Gary for your investigations! I appreciate it! Here are a couple more views: https://imgur.com/a/auWdXvq "This is the picture with sticker removed. The large IC at the back has its label scratched off. ... that was intentional, but he has a note saying it is a member of

Re: [time-nuts] Anybody have suggestions for time related science fair projects?

On 5/11/18 7:07 AM, Philip Gladstone wrote: On 11/05/2018 07:23, jimlux wrote: On 5/10/18 9:55 PM, Hal Murray wrote: A few months ago, I was a judge for the county level middle school science fair.  (I'm not very good at what they wanted, but that's a different problem.) What sort of

Re: [time-nuts] TruePosition GPSDO Holdover Issues

What antenna are you using and where is it located? I have the TruePosition with a Motorola PCTEL 8508851k66 antenna on a windowsill with a ground plane under the antenna and it generally sees 4-7 sats. I have seen some holdovers but it has been better after running for a while and doing a

Re: [time-nuts] TruePosition GPSDO Holdover Issues

It definitely works better on a windowsill than under the roof. It also did not work at all with a patch antenna. I can compare it to another GPSDO used as a reference and I see ADEV in the range of 2.5E-10 for low Tau 10-1000s, heading down for larger Tau. I see phase noise of -102 dBc/Hz at 10

Re: [time-nuts] Ublox Galileo/Beidou PRNs

Mark! On Fri, 11 May 2018 21:02:59 + Mark Sims wrote: > Does anybody know how Ublox maps their reported PRNs for Galileo and > Beidou satellites to the true satellite PRNs. What little there is > on the web appears on the web is rather incorrect. Depends a LOT on

Re: [time-nuts] Help Identifying this surplus Timing Module

A little Googling found a two page datasheet. It doesn't tell you much more than what you already found out, but does have specifications. I can't figure out the correct link to include here, but a Google search with the string "ATiMe-s 38.88" (don't include the quotes) should bring up the

[time-nuts] Ashtech Z12 question.

The "new" Z12 from Ebay came in today. Works fine (except bad memory backup batteries). So antenna, power supply, cables are OK. Replacing the memory backup batteries is fairly easy, except for the gazillion and three screw to open it up. A pair of memory batteries costs around $15. I

[time-nuts] Datametrics SP-100 Time Code Generator

Hello, I'm looking for a schematic and/or service manual for a Datametrics SP-100, a 1970s-era rack-mount IRIG time code generator.  According to the Time Nuts archives, Dave Brown (ZL3FJ) was looking for this information back in 2005 but as far as I can see received no reply.  I have found

Re: [time-nuts] Help Identifying this surplus Timing Module

Hi The big chip with the sticker on it is an Altera FPGA. A picture of the back side might help a little (if there is anything on the back side …). Simple answer - it’s a nice source of parts …. Bob > On May 11, 2018, at 7:16 PM, CubeCentral wrote: > > Hello All! > >

Re: [time-nuts] Help Identifying this surplus Timing Module

Hi Given the frequency of the oscillator, it’s some sort of sync module for a telecom system. What data rate and what sort of coding …. who knows … Bob > On May 11, 2018, at 7:16 PM, CubeCentral wrote: > > Hello All! > > > > I would like to enlist your help in

[time-nuts] Help Identifying this surplus Timing Module

Hello All! I would like to enlist your help in identifying this "surplus Timing Module": https://imgur.com/a/Psw8gP7 All the hints I've been given are: - Purchased about a decade ago - Might use a Motorola DSP as the processor A quick google search lead me to a possible

[time-nuts] Ublox Galileo/Beidou PRNs

Does anybody know how Ublox maps their reported PRNs for Galileo and Beidou satellites to the true satellite PRNs. What little there is on the web appears on the web is rather incorrect. For Galileo I have seen Ublox PRNs from 212 to 240. That seems to imply it might be ACTUAL =

Re: [time-nuts] Question about frequency counter testing

Hi, On 05/11/2018 05:35 PM, Bob kb8tq wrote: > Hi > > If you do the weighted average as indicated in the paper *and* compare it to > a “single sample” computation, > the results are different for that time interval. To me that’s a problem. To > the authors, the fact that the rest of > the

Re: [time-nuts] HP 5372A

HI > On May 11, 2018, at 3:12 PM, Magnus Danielson > wrote: > > Hi Don, > > On 05/10/2018 02:59 PM, Don Murray via time-nuts wrote: >> Hi Magnus... >> >> >> Appreciate any help! >> >> I participate in the ARRL Frequency Measuring Test, >> and I would like to

Re: [time-nuts] HP 5372A

Hi Don, On 05/10/2018 02:59 PM, Don Murray via time-nuts wrote: > Hi Magnus... >   >   > Appreciate any help! >   > I participate in the ARRL Frequency Measuring Test, > and I would like to automate the measuring process. >   > I have two frequencies, A and B... >   > A is a GPS locked HP 3336B

Re: [time-nuts] HP 5372A

If want to exploit what the 5372A can do in FMT-context, you should feed it the amplified and band-pass filtered RF (rather than some down-converted and otherwise mangled version of the signal) and capture timing of the actual zero-crossings and post-process that. -- Poul-Henning Kamp

Re: [time-nuts] Question about frequency counter testing

Oleg, On 05/11/2018 04:42 PM, Oleg Skydan wrote: > Hi > > -- > From: "Bob kb8tq" >> The most accurate answer is always “that depends”. The simple answer >> is no. > > I have spent the yesterday evening and quite a bit of the night

Re: [time-nuts] HP 5372A

When I was working at the Arecibo Observatory and we were running the ionospheric heater at 5.1 MHz (think Mini-HAARP), I'd sometimes go home (about 3 miles away) and listen to the signal there.There was frequently substantial random fading of the signal, suggesting that I was hearing the

Re: [time-nuts] HP 5372A

Hi Well, having actually run FMT virtually “in the back yard” of the transmitting station …. it’s surprising what 70 miles will do. In this case, back yard really does mean on the premises. There is a lot that gets into even fairly sort distance propagation. Bob > On May 11, 2018, at 1:52

Re: [time-nuts] HP 5372A

By the way, if you would like some data captured during the last run, let me know. I have an excel sheet of the peak data from spectrum lab centered on 1850hz as I use the 3586B receiver. Regards, Jerry Jerry Hancock je...@hanler.com (415) 215-3779 > On May 11, 2018, at 10:52 AM, Jerry

[time-nuts] TruePosition GPSDO Holdover Issues

I've had one of the cheap TruePosition GPSDOs running here for the past week, this is the earlier version with the Bliley oscillator, and as Mark reported have been seeing what I consider to be excessive holdover reports from Lady Heather. At 55 degrees north the number of Sats visible can be

Re: [time-nuts] HP 5372A

If you were in Connie’s back yard or had a very stable ground wave, then yes, you could automate the testing. There are a number of challenges with this method as looking at the data with a simple graph will tell. You might have large fluctuations on the high frequency side only, for

Re: [time-nuts] (UK) NPL open house

On Fri, May 11, 2018 at 12:57 PM, Adrian Godwin wrote: > Next thursday : > > https://www.eventbrite.co.uk/e/national-physical-laboratory-open-house-2018-prepare-to-be-amazed-tickets-42330306085 If any other Time Nuts are going, it might be amusing to meet up. Cheers

Re: [time-nuts] Ashtech Z12 question.

Hi Mark: I've found there are two main reasons older equipment stops working. 1. A metal to metal joint that's supposed to be conductive is not. See Hints & Tips: What Goes Wrong: http://www.prc68.com/I/HaT.shtml#Wgw The fix is simply to disassemble, cycle all joints a few times and reassemble.

Re: [time-nuts] Z3816A RS-232 interface

Check TWO things. 1.) Has the RS-232 level converter (1488/1489, MAX232, etc.) failed? 2.) What MODE is your Z3816A, SCPI? The GPSCon software places Z3816A into SCPI. This is discussed in K8CU’s notes, below: K8CU Notes - HP Z3816A GPS Frequency Standard Receiver

Re: [time-nuts] Question about frequency counter testing

Hi Dana, On 05/10/2018 06:17 PM, Dana Whitlow wrote: > I'm a bit fuzzy, then, on the definition of ADEV. I was under the > impression that one measured a series of > "phase samples" at the desired spacing, then took the RMS value of that > series, not just a single sample, > as the ADEV value.

Re: [time-nuts] Question about frequency counter testing

Oleg, On 05/10/2018 10:46 AM, Oleg Skydan wrote: > Hi > > Now I have some questions. As you know I am experimenting with the > counter that uses LR calculations to improve its resolution. The LR data > for each measurement is collected during the gate time only, also > measurements are

[time-nuts] Ashtech Z12 question.

Antenna is good... it is feeding an HP amplified splitter which goes to 7 other receivers. And yes, it died in the middle of a run. I have another Z12 coming from Ebay... -- > Rats. Is the antenna known to be good? Is the Z12 providing bias on the antenna cable? Did the Z12

Re: [time-nuts] Question about frequency counter testing

Hi If you do the weighted average as indicated in the paper *and* compare it to a “single sample” computation, the results are different for that time interval. To me that’s a problem. To the authors, the fact that the rest of the curve is the same is proof that it works. I certainly agree

Re: [time-nuts] Anybody have suggestions for time related science fair projects?

How about measuring variations in propagation delay for WWV on various frequencies, or WWVB, using GPS ticks as a reference. DanaK8YUM On Fri, May 11, 2018 at 9:41 AM, Van Horn, David < david.vanh...@backcountryaccess.com> wrote: > > Measuring the speed of light (Fizeau or Michelson

Re: [time-nuts] Question about frequency counter testing

Hi -- From: "Bob kb8tq" The most accurate answer is always “that depends”. The simple answer is no. I have spent the yesterday evening and quite a bit of the night :) reading many interesting papers and several related

Re: [time-nuts] Anybody have suggestions for time related science fair projects?

Measuring the speed of light (Fizeau or Michelson method? Other ways) I saw a great demo of this at the Exploratorium in SF. They had a long spool of fiber optic, a disc with holes, and a light source. When static, if the light shines through the hole in the disc into the fiber, then you

Re: [time-nuts] Anybody have suggestions for time related science fair projects?

On 11/05/2018 07:23, jimlux wrote: On 5/10/18 9:55 PM, Hal Murray wrote: A few months ago, I was a judge for the county level middle school science fair.  (I'm not very good at what they wanted, but that's a different problem.) What sort of interesting time related experiments can a middle

Re: [time-nuts] Anybody have suggestions for time related science fair projects?

Hi NTP time offsets through various phases of the distribution process ….. Bob > On May 11, 2018, at 12:55 AM, Hal Murray wrote: > > > A few months ago, I was a judge for the county level middle school science > fair. (I'm not very good at what they wanted, but

Re: [time-nuts] Anybody have suggestions for time related sciencefairprojects?

Hi how about frequency difference /temperature of a oved'ed Xtal oscillator -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bill Hawkins Sent: 11 May 2018 06:40 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Anybody

[time-nuts] Z3816A rs-232 interface

I am getting some very peculiar behavior with the serial interface on my GPS rcvr (Z3816A). I have tried several computers and several different GPS utilities (GPS-DOS2, Sat Stat, GpsCon, etc.). To date, the only thing that works is Sat Stat on a windows 2000 computer. I am using a Null modem

[time-nuts] (UK) NPL open house

Next thursday : https://www.eventbrite.co.uk/e/national-physical-laboratory-open-house-2018-prepare-to-be-amazed-tickets-42330306085 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to

Re: [time-nuts] Anybody have suggestions for time related science fair projects?

On 5/10/18 9:55 PM, Hal Murray wrote: A few months ago, I was a judge for the county level middle school science fair. (I'm not very good at what they wanted, but that's a different problem.) What sort of interesting time related experiments can a middle school geek do? Borrowing serious