[time-nuts] Leap Second result on PST Model 1020
Hi all; I have a Precision Standard Time Model 1020 that I have been playing with for the last few weeks, BTW I'm looking for a manual for it to scan or copy I will pay round trip shipping, so here's how it behaved at the leap second. This is a clock that strips the 100 hz time code to develop time while also syncing (I think) an internal oscillator to something from the five channels of WWV it can pick up. I believe WWV gives no forewarning of leap seconds in the 100hz code so the receiver has to catch it as it happens. I have the unit set to Eastern Daylight Std time. At 8:00 p.m. local time the unit just kept going like no leap second occurred and thus was off a second. I watched it for about 5-6 minutes and didn't notice any change, so I concluded maybe at midnight local time it will correct itself, I'd stay up and watch then. At about 8:30 p.m. I looked at it again and it was on time!, so I missed it boo-hoo. So for what it's worth that's how this unit behaved. Regards; Rich ___ 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] Upcoming Loran shutdown
Loran followers; This test period is scheduled to end sometime on the 22nd, so don't panic when it disappears! Also on the X secondary a message is being sent on the 9th pulse for those with a scope attached. Regards; Rich ___ 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] Loran
Hi all; For any one interested, Loran's back up again. Sounding good in northern Indiana. Rich ___ 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] Loran again
Hi All; I hear Loran C signals back on again, I'll fire up the SRS FS-700 and check. RP ___ 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] GRI For loran signal
Hi all; I set my FS-700 to 89700 GRI, and had initial acquisition within 5 minutes here, and complete tracking and lock within 20-25 minutes. Not bad considering that the noise level here is about equal to the signal in a receiver (ICOM IC-725) with a 2.3 Khz bandwidth which is what I first tuned down to 100 khz and heard the signal earlier tonight. Rich ___ 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] Loran again
Hi all; I'm hearing Loran C signals @ 7:00 pm EST hear northern Indiana this evening. Anyone else? Rich W9ENG ___ 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] Loran
Hi all; I 'm hearing Loran C signals here in northern Indiana this evening, I guessing from New Jersey. Anyone else hearing these? Rich ___ 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] Wrist watch
The pulse that drives the stepper (in the Casio watch in this case) as Tom mentioned is detectable on an AM receiver. I have a Grundig Yacht Boy and when tuned anywhere below 300 Khz with the watch set against the top of the radio a very clear "pop" or noise burst is heard at each second. I suppose if anyone cared you could trigger one input of a time interval counter with the speaker output of the AM radio and trigger the other input from your house standard 1PPS. You might want to wrap the whole thing in aluminum to suppress external noises so as to not get false triggers. Probably not the type of experiment you'd want to try on a day when there are thunderstorms within a hundred miles though!! ;) Rich ___ 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] Re; New Wrist watch
Bob; Being this is Time-Nuts and all, shouldn't you be using UTC anyway? ;) Rich ___ 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] RE; New Wrist watch
I have a $49 Casio Wave Ceptor, white face black numerals, analog hands including second hand, date, alarm and WWVB syncing in the middle of the night. Only had to replace the battery once and it ticks are closer than I can discern when comparing to WWV @ 10or 15 Mhz. Rich, W9ENG ___ 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] Quadrifilar Helix Antenna
Hi all; Check Ebay auction # 180558168544, I have purchased a couple of these in the past for le$$, the several sellers are offering these. There is a Loran version also, so if you purchase be sure to note which one is offered. Follow the link given to view Vaisala's info rergarding the whole unit. Regards; Rich ___ 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] re;FS700 antenna
I'm usings a Burhans style (Popular Electronics ca.1983) broadband antenna with the obligatory 470 ohm resistor on my FS 700. I had no problems locking onto Wildwood NJ signals here in northern Indiana. Receiver kept lock all through the recent thunder storms right up to when they shut down again. That antenna also works with the Austron 2100s. Rich W9ENG ___ 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] Loran C back on
Hi all; Receiving Wildwood NJ GRI 8970 here in northern Indiana again today. FYI Rich - Original Message - From: To: Sent: Sunday, April 29, 2012 8:21 PM Subject: time-nuts Digest, Vol 93, Issue 152 Send time-nuts mailing list submissions to time-nuts@febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to time-nuts-requ...@febo.com You can reach the person managing the list at time-nuts-ow...@febo.com When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." Today's Topics: 1. Re: Wilkinson TDC (David) 2. Re: General Technology Corp model 304b (paul swed) 3. Re: Antique Rb Standard - Thanks, Pictures, Parts Request, Question (Magnus Danielson) 4. Re: General Technology Corp model 304b (Ed Palmer) 5. Re: Antique Rb Standard - Thanks, Pictures, Parts Request, Question (Cliff Sojourner) 6. Re: PICDIV for 1 min pulses (Bob Camp) -- Message: 1 Date: Sun, 29 Apr 2012 18:17:10 -0500 From: David To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Wilkinson TDC Message-ID: Content-Type: text/plain; charset=us-ascii On Mon, 30 Apr 2012 06:51:37 +1200, Bruce Griffiths wrote: The circuit for the Tek 2440 is in the manual. However, it isnt that well executed. I like using the 2440 as an example because the design and theory are readily available online. Its execution only had to be good enough for 40ps equivalent time sampling and less than 50 measurements per second. Unfortunately the self calibration logic is obfuscated inside of a Tektronix black box custom ASIC. Relying on the overload recovery of an unclamped jfet input opamp limits the recovery time and performance as does the unisolated input capacitance of the opamps used to control the current source transistor emitter currents, the Wavecrest interpolators which incorporate several refinements to improve the transient response of the current sources are far better in this respect. By unclamped JFET input opamps do you mean U590B and U590C which are used to adjust the ramp start to zero volts and operate open loop during the measurement? With such a slow measurement rate, that feedback loop has at least 20ms to complete settling. I notice that they attenuated the open loop gain by a factor of 6. I wonder if that was to lower the noise or to add phase margin to the control loop. The Wavecrest interpolators also have sub picosecond resolution although their noise is around 3-6ps. Is there a published schematic and theory for the Wavecrest other than the patent? The best information I have found through Google is from your own posts here. Bruce paul swed wrote: Do you have an actual circuit? It looks a lot like the old hp5360 counter interpolator. Regards Paul On Sun, Apr 29, 2012 at 3:51 AM, Bruce Griffiths wrote: The essentials of a Wikinson TDC can be simplified to the attached circuit which only requires the addition of a zero crossing comparator to monitor the voltage across the capacitor C1. A few refinements to improve the capacitor charging current switching transitions and the addition of an upper voltage clamp together with the use of faster transistors may be useful. Apart from level shifting to drive the npn and pnp longtailed pairs only a 2 bit shift register is required for the synchronisers reducing the number of external (to an FPGA or CPLD) logic packages required. The jitter of the count logic etc., isn't critical and can be implemented in an FPGA or CPLD. With a 100MHz synchroniser and counter clock a resolution of 10ps can be achieved with a 1000:1 ratio between charge and discharge currents. -- Message: 2 Date: Sun, 29 Apr 2012 19:18:13 -0400 From: paul swed To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] General Technology Corp model 304b Message-ID: Content-Type: text/plain; charset=ISO-8859-1 Curious is the manual online? Would be interesting to look at. On Sun, Apr 29, 2012 at 6:33 PM, Ed Palmer wrote: Hi Don, On 4/29/2012 2:54 PM, Donald Henderickx wrote: On 4/29/2012 1:36 PM, Ed Palmer wrote: Thank you Ed,Paul,and Marco for the reply's The foam I was referring to is or was around ceramic base were the igniter wire goes . Yes my wire also broke loose however I do not want to disassemble any more than I have to. I think that just inserting it back in to the hole and securing in some way should work. I do not know what the potential is but I have seen a spark jump at least an eight of an inch. The igniter wire has to be connected to the base of the lamp. The patent explains it quite well. Just inserting it into the hole in the ceramic is unlikely to work. I don't know what the v
[time-nuts] re;1PPS correction
Doug; You're absolutely right! I popped the lid off one I had and sure enough 10.949 Mhz, Thanks for pointing that out. Rich ___ 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] 1PPS correction
Two thoughts; First Thought,the clock in a Jupiter-T is 40Mhz, that's 4 times 10 Mhz last time I checked. Could not one of the Simple GPSDOs use the OCXO multiplied by 4 to become the receivers clock? Wouldn't that eliminate the hanging bridges? Second thought, as I was reading recent threads about reverse engineering Smart Clock and other things I was recalling that I've heard we're all just six degrees of separation from anyone on earth ie. the dear leader of north Korea etc, yet no one of us can ever find anyone who worked on a T-Bolt or at Symmetricom or Efratom or FEI or.. Just thoughts; Rich ___ 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] Loran Signals
Hi all; I exchanged an email with a gentleman from UrsaNav and he indicated that transmissions were eminating(sic) from Wilwood NJ and that they were dual rated to look like Dana and Seneca. This explains why the signals level are much lower than they were here in Indiana then when Dana was on the air. And as the article stated he also mentioned different modulation schemes that may not be able to be locked to by conventional receivers,ie. FS-700s & 2100Fs. UrsaNav does offer their SDR receivers that will recover the appropriate timing information, we shall see where this leads. Regards; Rich ___ 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] re; Who's on first
Hi all; The FS-700 locked after about 20 minutes, it's still doing third cycle search.(oops, fully locked now after another 10 minutes) Station received is 8970 X-ray, Seneca N.Y. Receiver is reporting, Rcvr Gain 72db, noise Margin 22db. I have 10 Mhz from Thunderbolt fed into the freq in and reading, 7.8 E-10 as freq offset, I'll check it in the morning(assuming everything stays on the air) and give a report then. Rich ___ 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] Who's on first?
I'm receiving a fairly strong Loran signal here in northern Indiana, and on my IC-725 at that! I'll fire up the Austrons or the FS-700, can anyone steer me toward what GRI I'm may be hearing? Thanks; Rich W9ENG ___ 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] Morion MV89A pics
That next weeks project! ___ 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] River monitor update
Hi all; I had the opportunity to drive by the Elkharrt River monitor in Goshen IN and observed this upon getting out of my car, the diamond plate equipment shelter, the crossed yagis, and solar panel. There was a GPS antenna but it was not a timing antenna in the sense of how we nutters typically think of timing antennas. On the back side of the yagi mast was u-clamped a piece of angle iron with what appeared to be a magnetic vehicle roof top GPS antenna of a few years back. It had a cable tie with electrical tape around it, the whole thing looked like an after thought. I would imagine then that at least time-stamping is occuring or maybe queueing. I would think that the close proximity of the antennas and the third harmonic of the up-link frequency would fall close to the GPS band. Next chance I get I'll check the monitor in Elkhart to see if it set the same. Regards; Rich ___ 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] OT re, Sacramento River Monitor
Fellow nutters; A comment on something posted earlier today. I know this is off topic,(except for the time-stamp-GPS anteena comment ;-)) but the web site http://water.weather. gov/ahps/ lists all the hydrologic monitors around the county. There are two near here with the crossed yagis pointing at what I would imagine is some GOES satellite. These have solar panels, but I've not noticed a GPR antenna, perhaps I shall look a little closer next time I goes by them. Rich ___ 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] "The GPS navigation is the weakest point,"
Now I've heard Lightsquared was installing a network in Iran! Just kidding, but what would happen? I would think that just jamming the L1-L2 frequencies would be enough to cause the drone to fly in circles or a straight line until it ran out of fuel and flopped to the ground, perhaps explaining the hidden undercarriage as mentioned earlier. Do you think they might turn Loran-C back on so no one here can spoof the police drones flying around!!??!! ___ 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] More Light Squared
Hi All; The 20 June issue of Aviation Week and Space Technology also has a report on interference to GPS. The tack is primarily from the aviation and FAA perspective. A quick check search on AW&STs web page shows 16 June as the lastest posting but only mentions the FCCs time extention. FYI. Rich ___ 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] Coining a new term
HI all; I believe the T-nuts have coined a new name for GPS antennas, Mushrooms! I always hated the term "pucks" any how. Regards; Rich ___ 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] Loran C sounds
Hi all; Just an aside, after hearing dual rated Lorsta Dana for the last 25 years, it is interesting to now hear a single rated chain. Rather than the syncopated clatter of Dana, now just a smooth pitter! The east coast Canadian chain is much weaker here in northern Indiana than Dana (about 125 miles air) but still quite copyable on my IC-725. As far as useability at this point, while Dana was still on I switched my 2100F over to GRI 5930 and it only took about 1/2 hour to be locked and start reading my Austron 1250 frequency numbers. I get my main frequency reference from a TAPR T-bolt, but the Austron 2100F was a fun experiment. I guess the next Loran adventure can be DXing chains. Regards; Rich ___ 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] Timex wristwatch
Hi All; Just an aside. I was just cleaning up some odd and ends today and found a Timex Expedition wristwatch I retired two Christmas' ago when I was given a Casio Wavecepter by my daughter. I looked and it "kept on tickin" while in the drawer, it was 7 seconds behind the Casio! I would always bring it into alignment with my Sharp "atomic" wall clock daily while wearing it. A little math if I did it right, about 1.1parts in 10-7! Not bad for a $20 watch. Rich ___ 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] Loran C D-Day
Hi Gang; Tomorrow is the beginning of the count down for Loran C termination, let's see how long it takes for the gov't to act on this one. I have my receivers running. That's change we can believe in! Regards; Rich ___ 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] T-Bolt MonitorDocumentation
HI All; Did I see on a post recently that there is a document for the T-Bolt Monitor program? Or was that just a figment of my imagination? Please advise/ Rich ___ 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] Loran C shut down
Hi all; I guess this is change we can believe in! Rich ___ 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] Finding out who bidders are
Hi all; It was nice back when ebay let us know who we were bidding against, if you were up a against some heavy hitter then why waste your time, etc. Now it takes a little more work to ferret out who you're up against. What I have done is to save the feedback page for a seller of an item I may have been out bid on. Usually within a short time the bidders feedback response shows up on the sellers feedback page, compare the feedback score back against the item page to check if you have the right person. Then from that you can do a bidder search in "advanced search" and look at items bid on in the last 30 days to cross check. I then save the bidder's bid page in a folder, I have done that to most of us bidding time-nuts. Creepy huh!?! Rich 1PPS ___ 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] Frequency dividers
Hi All; All this frequency divider conjecture makes me think someone ought to come up with a modern design regenerative divider! Perhaps a double balanced mixer and a couple of high speed OP amps! Regards; Rich ___ 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] French Time offset
Thanks John, yes I'm real. The 1978 date is correct, I'm looking for the article to quote. Prior to the decree, France maintained a roughly twelve and a half minute offset. I always was struck by this as the BIPM is located in France, and has been for many years. Disagreement on the location of the prime meridian perhaps? Wow, I didn't expect that much response for a trivia question. Regards to all; Rich ___ 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] Loran-C & French Clocks
Hi all; Gov't got to save that money for executive bonuses! Also, would anyone like to speculate when France finally accepted UTC? Rich ___ 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] Z3805 and Fluke.I
Hi ALL; Since Fluke.I is now advertising on our forum, perhaps he should make special deal for all us for real time-nuts, like a Z3805 for $35 or so! What do the rest of you think? Rich ___ 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] time-nuts Digest, Vol 47, Issue 72
- Original Message - From: <[EMAIL PROTECTED]> To: Sent: Sunday, June 29, 2008 2:59 PM Subject: time-nuts Digest, Vol 47, Issue 72 > Send time-nuts mailing list submissions to > time-nuts@febo.com > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > or, via email, send a message with subject or body 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of time-nuts digest..." > > > Today's Topics: > > 1. Re: Home built Ammonia cell std !! / Home built > cesiumclocks??? (John Franke) > 2. Datum 9390 (jack) > 3. Re: Home built Ammonia cell std !! / Home built > cesiumclocks??? (Magnus Danielson) > 4. Re: Datum 9390 ([EMAIL PROTECTED]) > 5. Re: Home built Ammonia cell std !! / Home built > cesiumclocks??? (John Franke) > 6. Re: Home built Ammonia cell std !! / Home built > cesiumclocks??? (Magnus Danielson) > 7. Re: Datum 9390 (jack) > 8. Re: Datum 9390 (John Miles) > 9. Re: Home built cesium clocks??? (Predrag Dukic) > > > -- > > Message: 1 > Date: Sun, 29 Jun 2008 12:20:28 -0400 > From: "John Franke" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Home built Ammonia cell std !! / Home built > cesiumclocks??? > To: "Discussion of precise time and frequency measurement" > > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > > Now that is something I am interested in doing. I finally secured use of > a > diffusion pump at a local university and expect to be making my first > sealed > all-glass absorption cells this fall. The ammonia pressure needs to be > around 8-10 microns. I will be trying for a double pass cell giving a > pass > length between 10 and 12 feet. The first ammonia atomic clock used a path > length of 33 feet. The cell was made from waveguide and did not hold a > charge due to leaks or the ammonia reacting with the gold plated > waveguide. > I believe the best ammonia based standard was only good to 10 ^ -8 in > frequency stability. > > John WA4WDL > > - Original Message - > From: "Luis Cupido" <[EMAIL PROTECTED]> > To: "Discussion of precise time and frequency measurement" > > Sent: Sunday, June 29, 2008 11:40 AM > Subject: [time-nuts] Home built Ammonia cell std !! / Home built > cesiumclocks??? > > >> We dont get much info/comments about this >> But what would an ammonia cell standard be able to do. >> I mean frequency/time wise. >> >> Maybe easier and simpler ? >> comments ? >> >> Luis Cupido. >> ct1dmk. >> >> (I understand the frequencies are much higher >> but that is not a problem, at least for me). >> >> ___ >> 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. >> > > > > > -- > > Message: 2 > Date: Sun, 29 Jun 2008 19:16:12 +0200 > From: "jack" <[EMAIL PROTECTED]> > Subject: [time-nuts] Datum 9390 > To: > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset="us-ascii" > > Do anybody have a manual for the Datum GPS synchronized Generator. > 9390-53111. ?? > > Or a manual for a model "close" to this? > > Or know where I can find one? > > > > Jack Sandum > > Norway > > [EMAIL PROTECTED] > > > > -- > > Message: 3 > Date: Sun, 29 Jun 2008 19:26:58 +0200 (CEST) > From: Magnus Danielson <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Home built Ammonia cell std !! / Home built > cesiumclocks??? > To: time-nuts@febo.com > Message-ID: <[EMAIL PROTECTED]> > Content-Type: Text/Plain; charset=us-ascii > > From: "John Franke" <[EMAIL PROTECTED]> > Subject: Re: [time-nuts] Home built Ammonia cell std !! / Home built > cesiumclocks??? > Date: Sun, 29 Jun 2008 12:20:28 -0400 > Message-ID: <[EMAIL PROTECTED]> > >> Now that is something I am interested in doing. I finally secured use of >> a >> diffusion pump at a local university and expect to be making my first >> sealed >> all-glass absorption cells this fall. The ammonia pressure needs to be >> around 8-10 microns. I will be trying for a double pass cell giving a >> pass >> length between 10 and 12 feet. The first ammonia atomic clock used a >> path >> length of 33 feet. The cell was made from waveguide and did not hold a >> charge due to leaks or the ammonia reacting with the gold plated >> waveguide. >> I believe the best ammonia based standard was only good to 10 ^ -8 in >> frequency stability. > > More like 5E-11 both in cavity pulling and collision effects. Cavity > pulling was reduced in 1961 by means of automatic cavity tuning. > > Recall that you do state-selection on the ammonia beam. An elect
[time-nuts] Thunderbolt Buy
I absolutely want to get in on this. One unit meets the need. Thanks again for the heads up. Rich ___ 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] Optical time sync
Hi All; On a different note, while at the NAB show a few weelks ago I was looking at LED based tower beacons. Now these are quite impressive but what really caught my eye was one with a Garmin hockey puck GPS antenna on top of it, I thought 'what's this?' I inquired of the sales rep lady at the booth and she informed me that beacons for wind farms are required to have sychronized beacon lights. Since ther are no wind farms near this location (northern Indiana), I wonder if anyone near one has observed these GPS sync'd lighting schemes. Would these lend themselves to common view time transfer experiments or speed of light studies. This was the first I was aware of the control of beacons this way or might this be old news and I'm just the last one to find out again! Rich ___ 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] RFTG manual?
Hi All, Did I read someone has access to manuals for Lucent RFTG models? Even if they are not for the exact model, there is likely enough infomation to get a system up and running. Please reveal yourself !! Regards; Rich ___ 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] E1938s
); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] RETRY Hi all; I was wondering who got those! Rich ___ 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] Another Time Station
Hi All; There is another time station on the AM BCB at 570Khz. It is receivable in northern Indiana on most quiet nights. It has time ticks, a longer tone at the minute mark and sends the letters R-R shortly after the top of the minute. I believe it is in the Carribean somewhere but I'm not sure, there is also another one further up the dial around 800-900Khz, but much harder for me to hear at this location. Regards; Rich ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] Re; Ebay bidding
Hi all' My three rules for Ebay, 1.) Never buy anything you can't bring your self to throw away. 2.) There will always be another one. 3.) Bid early and lose! Regards; Rich Ebay callsign:1PPS ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] Re; Audiophoolery
Hi all, Having worked for Crown International during the '70s,80s,and 90s, we received our share of audio weirdness including many who would have Crown enhance the design its products by using their particular ideas. Crown amps were/are still high end products that are still leaders in the field. That being said, one of my favorites was when Crown switched from using gray color jacketed interconnect cables to black jacketed cables. Granted we did change from spiral wound shielding wires to foil wrap with a drain wire, but oh the complaints, how we degraded the sound, how we increased the IMD, the THD and on and on. Then there was the audio specialized capacitor madness, people would remove the caps Crown installed and put the style of their choosing to enhance the signal path. Keep in mind these are direct coupled amplifiers, so they were changing caps in the feedback loops and in the compensation networks, a dangerous neighborhood to be playing around! Some blew up their amps but Crown being compassionate in those days usually repaired it if the three year warranty period was in effect. I could go on and on, but this is a time-nuts forum not an audio-nuts forum. Regards; Rich ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] yet more RFTG thoughts
Hi All; To answer a question first. I believe PLDENB likely means programmable logic device enable. Right next to that header is an Altera Max7000 series device. What we dont know is, when enabled does that mean the device just wakes up, or does it mean the device is opened to be reprogrammed. I am still interested if anyone else has measured the voltages on TP400 to see if anything is present other than +5 volts. I have not found any mode that makes my RFTG produce any voltages other than the 5volts. The DAC appears to be dormant. You can roughly follow the traces from the DAC near TP400 over to the EFC line to the oscillator. The jumpers W11-W12 is the EFC line to the osc, I measure much less than 1 volt, I would imagine with the unit working, it would be somewhere around 3-4 volts! Again I have to say I am running the RFTG-m stand alone, as I have no RFTG-RB to go with it. So as was mentioned earlier , when a 10 Mhz signal appears at the input do things start happening, I applied 10 Mhz from my HP5334, but perhaps I didn't have enough level, and thats begs a second question; if 10Mhz is present there then why would the GPS side be needed at all, unless the RFTG-m is somehow comparing the two signals and picking the one in closest agreement to GPS. Who knows? On a side note, I did a google search on RFTG and one hit was a guys resume describing how he designed RFTGs for HP. I'll let a younger and more daring person search the guy out and contact him, hi-hi! Rich ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] Estate sales
Hi all; How come every time I go to estate sales there's only old furniture and salt and pepper shakers? !! Rich ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] RFTG-m-XO experiences
Hi All; I'll give my experiences with my RFTG unit. I bought it ($$$) last fall from an ebay seller who moves a lot of time and frequency related items, it won't take much imagination to figure out who I'm speaking of. I believe he is an honest seller, and I've bought from him several times and would buy from him anytime again. On the other hand since he moves a lot of equipment I think he writes descriptions as he believes things are and not in a position to actually verify everything that's said. But that's the way ebay is, caveat emptor! I have only the RFTG-m-XO. The unit I received looks as if it were new old stock, it has '95 date codes on many of the parts, it sports a Piezo Crystal Company OCXO. When powered up and connected to an Agilent 58532 antenna, fed with 1/2" heliax, with a reasonably clear sky view, after about 10-15 minutes the no GPS and fault lights extinguish, the green on light appears. Receiver outputting 1PPS. Sounds good huh? Upon checking the oscillator I find it running about 8hz low, and after 48 hrs, 8hz low! Having tweek-itis, I adjusted the trimmer on the OCXO but could only move it a few hertz higher. Next thought, maybe if I provide 10 Mhz from another standard to the input it will lock onto that and start working, 24 hours later, 8hz low! Pondering what could be going on, I measured the EFC voltage to the OCXO and noticed it never rose above about .64v. So I broke the EFC line and the Oscillator EFC voltage (measured on the osc side of the break) floated to about 3 volts and the oscillator moved right up to 10.Mhz. What I've discovered is that my RFTG appears to be in "sleep" type mode, here's why I think this; with the unit facing you, there is a test point connector on the back left hand corner of the mezzanine board. (TP-400). The only voltage present on that connector is +5 volts. There is circuitry near TP-400 to provide the + & -15 and the 5 volt reference voltages but they are not being supplied with the required operating voltages. These voltages are likely required for the ADCs and DACs that control things. My thought is, the PLD gets some control signal from somewhere to enable all that circuitry. The "interface" connector probably figures in this also. When this happens the unit will may come to life, and do what it is intended to do! Conclusion, until we (the time-nuts) get some documentation, especially schematics and commands, we are probably wasting time, and possibly even harming the units by probing around in it , which I've done a lot of. The units were made by Efratom, which has now become part of Symmetricom, I got to think, someone around here has to know someone else who has had factory experience with these, but until such a person comes forth I think we're flying blind. Rich ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
