Re: [time-nuts] Question for the cesium nuts.
Perhaps the future of timing is the newly developed (and not yet commercialized) Mercury ion frequency standard. Also, some high end rubidium (such as Perkin-Elmer) manufacturers are able to develope 133Rb clocks having 450 000 hours MTBF! That'a a lot of nanoseconds! 73 de Normand VE2UM --- Jack Hudler [EMAIL PROTECTED] wrote: It seems to me that like all good things they must come to and end. If all CBTs have a life expectancy that varies depending on the manufacturer. What are we going to do when all the CBTs owned by amateurs start to end of life? I for one am certainly not going to buy one, not at those prices! (Unless I'm retired then that's another story) You only have calculate the time value of money for that CBT purchase over the remaining time to retirement; If that doesn't stop you dead in your tracks then this group really is aptly named! :) From my perspective, that of wanting to own a Cesium Standard; I don't really want to layout the monies for something that's going to end of life on me shortly (few years) afterwards. I know that handling (Caesium) Cesium-133 is tricky at best. It's a heavy alkali metal and contact with moisture is right out! Other than that it's not terribly difficult to create a safe environment to work with it. So there must be something else that's considerably more difficult than opening the tube, recharging the ampoule, resealing it, pulling an ultra high vacuum and baking it out. I've not seen any pictures of a naked CBT, still I'm not too worried about cracking the tube open if its Pyrex, unless resealing it caused the cesium beam collimation to be lost. Are there if any getters to worry about? If so, how would one ablate the contaminates of the surface? Anyone care to start a discussion on the merits of restoring a CBT to life? Jack ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Delay through GPS antenna splitter/amplifier -- an answer, and a question
One is much better to take the filter's delay in account rather than NOT USING a filter!!! i can hardly imagine a GPS receiver/antenna without any form of preselection, and, unfortunately, they're many of those filterless units on the market! 73 de Normand VE2UM Montreal, Qc. Canada --- John Ackermann N8UR [EMAIL PROTECTED] wrote: I had a chance recently to look at the performance of the two-port and eight-port HP GPS antenna splitters on a super-duper network analyzer. Screenshots of the results are at http://www.febo.com/time-freq/pages/gps-splitter. In short, the minimum delay (at the center of the passband) from antenna port to output port is around 15 nanoseconds for the eight way unit, and about 22 nanoseconds for the two way one. The delay seems consistent on all the ports, with less than 1 nanosecond variation. However, there is also a hump in the delay near the edges of the passband, about 12 MHz above and below the center. The delay at the edges increases by perhaps 5 nanoseconds, though depending on the port, it's not always symmetrical. So, an interesting question for any of you *real* GPS experts is what effect a variation in group delay of the RF input has on the timing solution? Is the true length of the amp/splitter some average of the delay across the passband, or, given the spread spectrum nature of the signal, does it not really matter? In fact, is the length of the splitter even related to the measured group delay? This also raises the issue that any GPS antenna that has RF filtering is likely to have similar delays; I've never seen that sort of data published. John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Get your own web address. Have a HUGE year through Yahoo! Small Business. http://smallbusiness.yahoo.com/domains/?p=BESTDEAL ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] CHU 7.335MHz saved or lost?
Hi... I've just got this message (in french) about CHU Canada @ 7.335 MHz: - - - - - - - - - - - - - - - - - - - - - - - - - - - Bonjour Normand, Merci pour votre support de CHU. Nous avons eu la permission du CRTC de renouveler notre licence sans aucun change à la fréquence ou le mode d'opération. Alors les opérations sur les trois fréquences continuerons comme avant. Raymond Pelletier Fréquence et temps Institut des étalons nationaux de mesure Conseil national de recherches Canada M-36, salle 1026 1200 chemin Montréal Ottawa, Canada K1A 0R6 Tél: (613) 993-3430 Télécopieur: (613) 952-1394 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] Gouvernment du Canada - - - - - - - - - - - - - - - - - - - - - - - - - - - In clear, it says that the CNRC (The Canadian NIST) has the prmission from the CRTC to renew the CHU licence on 7.335 MHz without any frequency change. Long life CHU! 73 de Normnad VE2UM Montreal, Qc. Canada The fish are biting. Get more visitors on your site using Yahoo! Search Marketing. http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] 3325A attenuators
Do you hear the relays working when you change the signal level? If yes, and that's probably the case, i definitely suspect burned-out attenuator resistors/modules (HIGHLY probably due to excessive reverse power (Signal generator directly plugged to a transceiver which has been accidently keyed)). If your attenuators use resistors, you may try to substitute nearest 1% precision resistors. Theorical values for a 50 ohm system: 10dB attenuator: Pi attenuator: Series resistor: 71.151246 ohm Parallel resistors: 96.247531 ohm T attenuator: Parallel resistor: 35.136419 ohm Series resistors: 25.974692 ohm 20dB attenuator: Pi attenuator: Series resistor: 247.5 ohm Parallel resistors: 61.11 ohm T attenuator: Parallel resistor: 10.10101 ohm Series resistors: 40.909091 ohm 40dB attenuator: Pi attenuator: Series resistor: 2499.75 ohm Parallel resistors: 51.010101 ohm T attenuator: Parallel resistor: 1.001 ohm Series resistors: 49.0099 ohm For 40dB, i suggest to use two cascaded 20dB units instead of a single 40dB unit (values much closer to 50 ohms for the single resistor) 73 de Normand VE2UM Montreal, Qc. Canada --- Paul S. Linsay [EMAIL PROTECTED] wrote: Hi, I have a 3325A and the amplitude attenuators are not working. I opened it up and it has sealed black relays, not the unsealed ones mentioned in the maintenance manual. When I run the front panel self- test everything passes. Any suggestions on what to do next? Thanks for your help, Paul-- ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Never Miss an Email Stay connected with Yahoo! Mail on your mobile. Get started! http://mobile.yahoo.com/services?promote=mail ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Thunderbolt specs
On the Thunderbolt's spex, Allan deviation is shown between 1 and 1000 seconds Does anyone have the AD for longer time periods? 73 de Normand VE2UM (Who already has his Thunderboltmon software, and now waits for the hardware!!!) Need Mail bonding? Go to the Yahoo! Mail QA for great tips from Yahoo! Answers users. http://answers.yahoo.com/dir/?link=listsid=396546091 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Thunderbolt Purchase Person's list
Add me to the list for ONE unit (if it is under 250$) 73 de Normand VE2UM Montreal, Qc. Canada [EMAIL PROTECTED] --- Colin Bradley [EMAIL PROTECTED] wrote: Here is the latest Thunderbolt purchase list. It is now near 40 units. Bored stiff? Loosen up... Download and play hundreds of games for free on Yahoo! Games. http://games.yahoo.com/games/front ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Rockland 5100 Synthesizer manual?
Wow!! I got one too and i have a problem with it... It's resolution below th hertz doesn't work... I've opened the unit, and it's highly complex... It comprises a 10 bit DAC and and a passive output anti-aliasing filter. But, me too, i miss the manual! 73 de Normand VE2UM Montreal, Qc. Canada --- John Ackermann N8UR [EMAIL PROTECTED] wrote: Anyone have a manual for (or any information about) a Rockland 5100 synthesizer? It appears to be 0-2 MHz with 0.001 Hz resolution, and I got it cheap... Thanks, John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Now that's room service! Choose from over 150,000 hotels in 45,000 destinations on Yahoo! Travel to find your fit. http://farechase.yahoo.com/promo-generic-14795097 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Odd request
...And i forgot one thing... The Telechron solenoid assembly is symmetric and reversible. That allowed some manufacturers to sell Bar clocks that had their hands run backwards!! 73 de Normnad VE2UM --- Normand Martel [EMAIL PROTECTED] wrote: Hi Tom... Not only Telechron were very popular electric clock movements, they were BY FAR the very best mechanical movements ever made. When young, i've opened A LOT of used electro-mechanical clock movements, and most of them showed evident traces of wear. Worn-out gear pinions, dried-out and seized brass/steel bushings, dried-out and cracked nylon pinions (Nylon tends to harden and shrink with time and heat, so Nylon parts shall NEVER be put on a traction stress when manufactured) were frequent on old clock movements, but NEVER on Telechrons, except very rare cases of pinion wear on the output shaft (3.6 RPM) Telechron movements were very unique. The motors were two-pole shaded pole synchronous motors with an external solenoid and a completly sealed rotor stuck within the poles pieces. The self-starting rotor, composed of three spring steel disks forced in place on a smooth shaft and spinning at 3600 RPM (60 Hz) was inside a sealed cylindrical aluminum gearbox (older gearboxes were in a copper sealed box) containing not only the rotor shaft, but also a 1000:1 reduction geartrain. Pinions were made of stacked thin steel pinion disks forced on the shaft to form single solid pinions. The faster rotating gears plates were made of some kind of red-orange colored fiber material and the slower rotating (higher torque) plates, of soft brass. The gear holding plates were made of thick alunimum with a thinner aluminum subplate that prevented the gears from sliding longitudinally, but far more important, the thin space between the plates and subplates had a capital role: Keeping a fine capillary oil film between the plate and subplate, that film kept the gear shafts permanently lubricated, thus eliminating all trace of wear. Even the gears themselves (the rotor was spinning at 3600 RPM and the second gear, at 864 RPM) didn't show any trace of wear, even under a magnifying glass. I even remember the gear ratios of a Telechron: Rotor: 12 toothed pinion (3600 RPM) Second gear: 50 tooth fiber plate coupled to a 12 tooth pinion R:r: 4.167:1 Third gear: 54 tooth fiber plate coupled to a 18 tooth pinion R:r: 4.5:1 Fourth gear: 60 tooth fiber plate coupled to a 12 tooth pinion R:r: 3.333:1 Fifth gear: 60 tooth brass plate coupled to a 12 tooth pinion R:r: 4:1 Output gear: 60 tooth brass plate coupled to an external 10 tooth pinion R:r: 4:1 4.16667*4.5*3.33*4*4=1000 Definitely a fine movement! I still use an ld Telechron at my shop. 73 de Normand VE2UM --- Tom Van Baak (mobile) [EMAIL PROTECTED] wrote: See Mitchell's SWCC page at: http://www.telechron.com/ /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Need Mail bonding? Go to the Yahoo! Mail QA for great tips from Yahoo! Answers users. http://answers.yahoo.com/dir/?link=listsid=396546091 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Get your own web address. Have a HUGE year through Yahoo! Small Business. http://smallbusiness.yahoo.com/domains/?p=BESTDEAL ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] 10811 warmup
It's bizarre.. The oscillator is some kind of Colpitts but with coils instead of capacitors in the feedback path. (i don't call it a Hartley, bcause Hartley's use a SINGLE tapped inductor.) 73 de Normand VE2UM --- Dr Bruce Griffiths [EMAIL PROTECTED] wrote: Hal Murray wrote: Is it okay to power up the main assembly once it is removed from the outer shell / insulation? Lots of info here: http://www.hparchive.com/Manuals/HP-10811AB-Manual.pdf I think I saw a warning about that, but maybe it was something else. It is OK to power up the oscillator and output amplifier, but the oven circuit should not be powered up. Bruce ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Now that's room service! Choose from over 150,000 hotels in 45,000 destinations on Yahoo! Travel to find your fit. http://farechase.yahoo.com/promo-generic-14795097 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Z3801A - notes on the hp58533a GPSDO
Nice building (I couldn't resist... When i see coordinates, I HAVE TO go to maps.google.com to see whetre it is!!! Is it officially recognized as being an addiction??) ;-=) Have a good day! 73 de Normand VE2UM Saint-Hubert (near Montreal), Qc. Canada ($GPGGA,005712,4528.8200,N,07325.8200,W,...) ,--- [EMAIL PROTECTED] [EMAIL PROTECTED] wrote: $GPGGA,135308,4656.5706,N,00723.4843,E,0,04,00.50,000562.6,M,0049.4,M,, Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Announcing the TAPR FatPPS Pulse Stretcher
I've made a such pulse stretcher to render the 1ms pulse from a CMC Superstar and the 10µS pulse from a Trimble Lassen SK8 visible via an L.E.D. by using a simple 555 timer configured in a monostable fashion. Sure it is not nanosecond precise and i'm not sure AT ALL it will react to a 20ns pulse, but for a visual monitoring, it is perfect (pulse stretched to about 30ms). 73 de Normand VE2UM Montreal, QC Canada --- John Ackermann N8UR [EMAIL PROTECTED] wrote: Is your PPS signal too short to trigger your serial port? Is that what's troubling you, Bunkie? If so, the new TAPR FatPPS is the answer you've been looking for... The FatPPS is a DB-9 dongle that implements a pulse stretcher. Input signals as short as 20 nanoseconds produce an output pulse about 30 milliseconds wide (the width can be changed by changing a few component values). It can be powered from the host computer's serial port, and so requires no external connections at all. It works with either TTL or RS-232 level input pulses (the output is always TTL level), and can invert input or output pulse polarity if needed. I designed the FatPPS because the ~20 microsecond wide PPS signals from several of my time sources (like the Z3801A GPSDO, and HP frequency standards) was too short to reliably work with the serial ports on my NTP servers. Hopefully, it will be of use to some of you as well. The FatPPS is available only as a fully assembled and tested unit, and is shipping now. The price is $44 for TAPR members, and $49 for non-members. There are more details, and you can place an order, at http://www.tapr.org/kits_fatpps.html. You can view the installation and operations manual (which is still a work in progress) at http://www.tapr.org/~n8ur/FatPPS_Manual.pdf. Thanks for the interruption. John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] TrueTime A-60FS antenna Data Needed
Oops!.. I tought it was a GPS antenna... For WWVB reception, you better wait at nighttime... I have here a Radio Shack Atomic radio controlled clock and during daytime, i have zero reception, but at night i'd say, 4 days out of 5, my clock syncs. I live in Montreal, Canada, so quite far away from Boulder, CO and my antenna is nailed on an inside wall in a bungalow. You probably live closer from WWVB than me, and your antenna looks like an outdoor unit. So good luck! 73 de Normand VE2UM Montreal, Qc. Canada --- Doug Millar [EMAIL PROTECTED] wrote: Hi Norman, Thanks for you very complete check out information. It worked! The antenna is an active type with a preamp. I also hooked it up to a VLF receiver and found it receives very well from near DC to 100khz. No obvious peak at 60khz. Thanks again, Doug K6JEY At 03:08 PM 1/5/2007, Normand Martel wrote: You could do a simple test: With an ohmmeter, on Diode test and with reversed polarity (Red on shield, black on center pin), measure the DC resistance on the RF connector. If it's a short ( 1 ohm) DO NOT APPLY ANY VOLTAGE ON IT! Your antenna is passive and conducting. If the ohmmeter indicates a diode reading (about 0.7V) the antenna is active and some bias will be required to have the antenna work. If the reading is infinite, it is either a passive (open) or active antenna. To further determine the type of antenna, i suggest you to use some length of coax (20-50ft) cable to put the antenna away from you, and, using a regulated 5 volts power supply with a 1000 ohms SERIES resistor, apply power (forward polarity, e.g. positive on center pin) to the antenna and measure the voltage across the 1000 ohm resistor. If you have some voltage across the resistor, this indicates that the antenna preamplifier draws some current and, obviously, the antenna is active. If no voltage is present across the 1000 ohms resistor, your antenna is passive. Why the 20-50 foot coax? Simply to put some isolation between you and the antenna. If the preamplifier is turned on by the 1000 ohms bias and the antenna is too close from you, the whole thing will start to oscillate. 73 de Normand VE2UM --- Doug Millar [EMAIL PROTECTED] wrote: Hello, Hope the New Year is going well. I recently got the above antenna to use on another receiver, but no data. Does anyone have a description of the interface? Is it just a simple ferrite antenna, or does it have a preamp and need bias, or other ? Any info would be very helpful. Thanks, Doug K6JEY ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] TrueTime A-60FS antenna Data Needed
You could do a simple test: With an ohmmeter, on Diode test and with reversed polarity (Red on shield, black on center pin), measure the DC resistance on the RF connector. If it's a short ( 1 ohm) DO NOT APPLY ANY VOLTAGE ON IT! Your antenna is passive and conducting. If the ohmmeter indicates a diode reading (about 0.7V) the antenna is active and some bias will be required to have the antenna work. If the reading is infinite, it is either a passive (open) or active antenna. To further determine the type of antenna, i suggest you to use some length of coax (20-50ft) cable to put the antenna away from you, and, using a regulated 5 volts power supply with a 1000 ohms SERIES resistor, apply power (forward polarity, e.g. positive on center pin) to the antenna and measure the voltage across the 1000 ohm resistor. If you have some voltage across the resistor, this indicates that the antenna preamplifier draws some current and, obviously, the antenna is active. If no voltage is present across the 1000 ohms resistor, your antenna is passive. Why the 20-50 foot coax? Simply to put some isolation between you and the antenna. If the preamplifier is turned on by the 1000 ohms bias and the antenna is too close from you, the whole thing will start to oscillate. 73 de Normand VE2UM --- Doug Millar [EMAIL PROTECTED] wrote: Hello, Hope the New Year is going well. I recently got the above antenna to use on another receiver, but no data. Does anyone have a description of the interface? Is it just a simple ferrite antenna, or does it have a preamp and need bias, or other ? Any info would be very helpful. Thanks, Doug K6JEY ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Locking gunn diode
While talking about microwave prescalers, here's a 12 GHz prescaler project for the HP5328A frequency counter by Bert VE2ZAZ. Thje prescaler is based on the Hittite HMC363S8G div. by 8 12 GHz prescaler http://www3.sympatico.ca/b.zauhar/hp5328a/hp5328a_prescaler.htm The page not only shows the construction of the prescaler itself, but also it's integration inside the 5328 counter and the rquired modifications of the HP counter. 73 de Normand Martel VE2UM Montreal, Qc. Canada --- Didier Juges [EMAIL PROTECTED] wrote: Hittite has dividers (prescalers) that go to 18 GHz: http://www.hittite.com/ I have a couple of samples of the :8 that goes to 12 GHz, precisely to try and phase lock a Gunn, which I have not used yet (another long winter project that won't happen as long as I am in Florida :-) Didier Normand Martel wrote: Some time ago, i've found documentation on microwave prescalers, (from Hewlett-Packard/Agilent) that could count up to 18 GHz. Tonight, i've found those SiGe prescalers from NEC: µPB1510GV .5-3 GHz div. by 4 prescaler: http://www.ncsd.necel.com/microwave/english/pdf/PU10311EJ01V0DS.pdf µPB1512TU 5-13 GHz div. by 8 prescaler: http://www.ncsd.necel.com/microwave/english/pdf/PU10537EJ02V0DS.pdf µPB1514TU 8-16 GHz div. by 8 prescaler: http://www.ncsd.necel.com/microwave/english/pdf/PU10541EJ02V0DS.pdf Bizarre that no prescalers have been developed to work on the 3-5 GHz band... ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Locking gunn diode
Some time ago, i've found documentation on microwave prescalers, (from Hewlett-Packard/Agilent) that could count up to 18 GHz. Tonight, i've found those SiGe prescalers from NEC: µPB1510GV .5-3 GHz div. by 4 prescaler: http://www.ncsd.necel.com/microwave/english/pdf/PU10311EJ01V0DS.pdf µPB1512TU 5-13 GHz div. by 8 prescaler: http://www.ncsd.necel.com/microwave/english/pdf/PU10537EJ02V0DS.pdf µPB1514TU 8-16 GHz div. by 8 prescaler: http://www.ncsd.necel.com/microwave/english/pdf/PU10541EJ02V0DS.pdf Bizarre that no prescalers have been developed to work on the 3-5 GHz band... From Agilent, i've found the following differential in/out 16 GHz prescalers (based on the HMMC-31xx /2 /4 and /8 12/16GHz prescalers): www.avagotech.com/assets/downloadDocument.do?id=528 Nothing indicates a minimum working frequency, if it can go down to the sub-GHz, that could be an interesting product. On another site, i saw that the HMMC-3102 3104 and 3108 prescalers cover from 500 MHz up to 16 GHz. Link: http://www.datasheetcatalog.com/catalog/p382200.shtml 73 de Normand VE2UM Montreal, Qc. Canada --- David Forbes [EMAIL PROTECTED] wrote: At 5:11 PM + 12/18/06, [EMAIL PROTECTED] wrote: 12-18-06 Is it possible to lock a 10ghz gunn diode transceiver (supply voltage 10.00 vdc) to a 10 mhz standard? Signal applied to either gunn diode or varactor supply voltages. Rick Rick, Sure it's possible. I work on radiotelescopes that use 100 GHz gunn diode oscillators, phase-locked using a box called the STS XL-800. Unfotunately, those boxes cost several thousand dollars and aren't readily available on ebay. The basic method is the same as any voltage-controlled oscilator, but you have to supply a good bit of current to the diode and you need to have a well-controlled driver so that you don't burn it out. The usual method of sampling the Gunn frequency is to mix it down using a harmonic mixer to produce an IF frequency that's usable in a generic PLL, some tens of megahertz. All of the above is a rather complicated piece of hardware by the time you're done. It's not a task for the timid. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] GPS new L2C civil signal -- timing uses?
...On a totally different (e.g. positoning) topic, does anyone know if any major GPS equipment manufacturer will commercialize dual frequency (L1/L2C) GPS recivers? ...In timing, the interesting point i see is the possibility to have a two-tier redudancy GPS timesource (and eventually a three-tier redudancy with the upcoming og Galileo). For now, i will watch the sky for that guy with a big white beard, a sleigh and eight reindeer... for that brand new L2C time machine!! 73 de Normand Martel VE2UM Montreal, Qc. Canada --- Magnus Danielson [EMAIL PROTECTED] wrote: From: Christopher Hoover [EMAIL PROTECTED] Subject: RE: [time-nuts] GPS new L2C civil signal -- timing uses? Date: Thu, 16 Nov 2006 15:40:57 -0800 Message-ID: [EMAIL PROTECTED] Anyone know of the timing uses and properties of this new L2C civil signal vis a vis the existing civil signal? Do you mean beyond that of ICD-GPS-200C? I don't know. I am unclear of the relationship between that and the new L2C civil signal referred to in the article. Are you saying both refer to the same thing? If so, what are the implications for timing apps? (I'm happy to go back through the archives if this has already been discussed.) OK. The new GPS IIR-M sats (third going up UTC 18:12 tomorrow) transmitts both the old L1 C/A signal as well as the new L2C signals. This is totally covered in the ICD-GPS-200D [1] (which is the one to use, not the ICD-GPS-200C, which I incorrectly directed you to). These three signals is unencrypted and when visible they allow for two-frequency measures on capable receivers with suitable two-frequency antennas. Based on traditional GPS theory, this allows the receiver to shift from a modelled delay of the ionsphere to a measure based model ionspheric delay and the implications on time measures is much reduced systematic error. Requirements for augmentation through reference stations is lowered if not eliminated. Naturally, hardware cost goes up since you now have two frequencies to deal with. If you are a teeny weeny serious you look ahead towards the L5 and Galilleo signal structures which certainly would require additional frequencies. [1] http://www.navcen.uscg.gov/gps/modernization/IS-GPS-200D_w_IRN_1_7Mar06%20NS.pdf If we get our durty hands on the propper receivers (and we will) we, as fellow time-nuts, will have a much improved state. With Glonass in the rising on top of this, things looks good. Oh, and to be clear, L2C is actually three different signals, C/A on L2, L2CM and L2CL. where you either have C/A on L2 or both L2CM and L2CL (at the same time). Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts The all-new Yahoo! Mail beta Fire up a more powerful email and get things done faster. http://new.mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] FMT
--- John Ackermann N8UR [EMAIL PROTECTED] wrote: Hi Normand -- Your method is similar to mine, except that I use a much closer beat note (usually less than 100 Hz) and use spectrum analyzer software and a sound card to measure the beat note (in the form of the delta between two traces on the waterfall display). Well, you use long term DIGITAL techniques to track probably to the µHz.. i simply use an ANALOG technique to get down to a +/- 10 mHz resolution, and using a higher beat frequency is simply more comfortable to the eye (X-Y scope display). Also, my generator has a 100 Hz resolution, so i can only use 100 Hz multiple beat notes. I think one of the reasons this method works so well is that the FFT effectively averages the signal over some time, and I use a tool in the software to derive an average across all the FFT results. That smooths out the instantaneous variations that make real-time measurement such a challenge. John Maybe some day!! 73 de Normand VE2UM Cheap talk? Check out Yahoo! Messenger's low PC-to-Phone call rates. http://voice.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] FMT
Personnaly, i use a self-developed technique to remotely measure a station's frequency: I use a precision OXCO controlled RF signal generator to inject an unmodulated (CW) signal (via a directional coupler) signal 1000 Hz below the actual station's frequency (example, to monitor CHU at 7335 kHz, i inject a 7334 kHz signal into the coupler). I then adjust the generator's level to obtain a comfortable 1000 Hz from my receiver (in AM mode preferably, but it even works in FM... do not use SSB or CW modes, since the receiver's BFO will interfere). Finally, i measure the 1 kHz beat's frequency with precision (for that, i use an synthesized audio generator with a ramp (sawtooth) output on an o'scope in a X-Y function (X = ramp, Y = beat). I prefer to use a ramp rather than a sine signal, since the ramp closely resembles a classic temporal sweep in a scope. This way, it becomes very easy to see if the generator's frequency is above or below the beat's frequency, which is much harder with a sine X input. One other way is to use the scope in classic mode with the audio synthetizer (preferably in square wave, but sine would also do the job) feeding the scope's external trigger. However, on distant HF signals, it becomes very hard to precisely measure the station's frequency due to the signal's fading which has important effects on the signal's phase. This phase unstability originates from the constantly changing RF signal's path due to the naturally unstable ionosphere's condition. The receiver does NOT need to be a precision unit (you could even use a VFO controlled radio), since the beat comes from the heterodyning between the station's and the generator's signals. 73 de Normand Martel VE2UM Montreal, Qc. Canada. --- John Ackermann N8UR [EMAIL PROTECTED] wrote: Hi Colin -- Actually, the transmitters used for the FMT seem to be very stable and as far as I've been able to observe (during each of the 4 FMTs since they restarted the event) don't drift by a noticeable amount during the test. I'm actually more concerned about the ARRL's measurement setup than I am about the transmitter stability. At least through last year, they measured the frequency off-air by hooking the counter to an outside antenna through a bandpass filter, rather than tapping off the output of the transmitters. With multiple KW signals floating around the vicinity, there's lots of opportunity for counter confusion. Some of us believe that ARRL's frequency measurement of the 160M signal last year was about 0.4 Hz off, and I suspect the measurement setup caused that. John Colin Bradley wrote: I just finished several email exchanges with Joe Carcia, station manager for W1AW, about the operation of the station. I had hoped that the regular daily bulletins broadcast by W1AW would be tightly controlled in frequency, which would allow me to get some practice measuring them. He informed me that they use two IC-756Pro II¢s and one Orion I for the transmissions. These radios do not permit the use of external standards for frequency control. Neither do the Harris 3200¢s. All of these radios use TCXO¢s for frequency control. This setup will be the same used for the FMT on the 15th. They will monitor frequency with a counter hooked to their Z3801. It¢s hard to believe, with a 100-watt amplifier in the same case, that these radios don¢t drift several cycles during a long transmission. For that reason I would encourage persons making measurements to do so during the specified time for each frequency in question. I think it would be very hard to measure the frequency to 1 cycle or less with the frequency control they use. The West Coast station that will broadcast a 40-meter test signal which will, most likely, be more accurate. That station will be using a Heathkit DX-60 into a 400-watt amp. Frequency control is from a HP-107BR into a HP-5100 synthesizer. While old, this equipment will probably be up to the job. The oscillator is set against GPS and the whole setup will be independently monitored by another station a mile away with a Cesium standard. Colin Bradley ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Blackout in Europe and power line frequency jump
--- Tom Van Baak [EMAIL PROTECTED] wrote: Your report, though, inspires me to look into more reliable and precise ways to measure the frequency of one's local grid. I had not actually considered monitoring electric fields off the air before, but it seems like this might be fairly practical. One very simple method that I have used is plug in a AC wall wart transformer with the 6 VAC secondary going directly into a HP53131A frequency counter. The serial data you get then looks like this: 53747.845696 59.996,154,495,1 Hz 53747.846854 59.999,588,387,2 Hz 53747.848012 60.001,434,856,1 Hz 53747.849172 60.001,288,258,8 Hz 53747.850330 60.002,697,145,5 Hz 53747.850330 N : 36 53747.850330 STD DEV: 0.004,660,852,51 Hz 53747.850330 MEAN : 60.004,606,291,05 Hz 53747.850330 MAX: 60.020,723,348,6 Hz 53747.850330 MIN: 59.996,154,495,1 Hz 53747.851489 60.006,143,055,9 Hz 53747.852646 60.001,106,173,4 Hz 53747.853805 60.003,317,733,6 Hz 53747.854963 60.000,519,248,1 Hz 53747.856122 59.997,117,006,6 Hz which you can run as long as you like and process the data as you see fit. In this particular example the gate time was 100 s and so the statistics were hourly. Another way is to use a surplus TrueTime TFDM: http://www.leapsecond.com/pages/mains/ /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts I've always been interested in the AC mains frequency precison... I've even imagined a mechanical phase accumulator, but never made it... However, my interested was in the actual AC mains PHASE instead of frequency, since electrical clock lead/lag is more dependant of the actual phase (compared to a 60 Hz Cs/Rb/GPS standard) of the hydro line (a lead/lag of 21600 degrees would correspond to a one second L/L) than the actual frequency. Also because phase is the integral of frequency, it is far easier to monitor errors in phase rather than in frequency on a long term basis. Have a good day! Normand Martel VE2UM Montreal, Qc. Canada Want to start your own business? Learn how on Yahoo! Small Business. http://smallbusiness.yahoo.com/r-index ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Blackout in Europe and power line frequency jump
--- Poul-Henning Kamp [EMAIL PROTECTED] wrote: A big cruise-boat needed to pass under a 400 kV line on the river Ems and to avoid trouble the turned it off during the passage. That resulted in overloads elsewhere and all the cards came crashing down. Something tells me that the next cruise ship will have to wait until 2:00 AM before passing below this line Normand Martel Sponsored Link Degrees online in as fast as 1 Yr - MBA, Bachelor's, Master's, Associate Click now to apply http://yahoo.degrees.info ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Frequency processing scheme of HP5065 vapourrubidium standard
Seems very interesing!!! If i'm right, That could lead to rubidium based primary standards... Normand Martel --- Rob Kimberley [EMAIL PROTECTED] wrote: What about the Rubidium Fountain? See first article in the Autumn 2005 report at link below. http://www.npl.co.uk/publications/news/time/ Rob Kimberley Want to start your own business? Learn how on Yahoo! Small Business. http://smallbusiness.yahoo.com/r-index ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Frequency processing scheme of HP5065 vapour rubidium standard
--- Ulrich Bangert [EMAIL PROTECTED] wrote: John, offset that changed annually. IIRC, it was typically something like 300x10e-10. Agreed! And that is what the manual says its good for! However, the question remains why different physics packages need DIFFERENT thumbwheel settings in order to achieve the SAME time scale. 73 de Ulrich, DF6JB I've read the answer last week on the forum... (sorry i don't remember who gave the answer...) It's simple: The technology used on cesiums CAN NOT be applioed on Rubidiums. With Cesium, high end techniologies like fountains or beans can be used, and if i understand well, with these technologies, PURE CESIUM is used, so there is NOTHING that can affect or pull the resonance of cesium from it's natural resonance. (9 192 631 770 Hz). With rubidium, buffer gases must be used, and these gasses pull away the resonance away from Rubidium's natural resonance. And that is the source of all our problems with rubidium: Buffer gas/rubidium evaporation/absorption will affect the frequency pulling, thus the drift in Rubidiums. This also explins why two rubidiums clocks wiill have different settings (Rb/buffer mixture tolerances). With Cesium, no pulling, with rubidium, some pulling. That's why Rubidiums aren't primary standards. If we could build a Rb (or ANY OTHER element) atomic clock with the same technology that we use with Cs (total element purity), there wouldn't be any pulling over time and Rb's would be considered primary standards. Hope this explanation will help! 73 de Normand Martel VE2UM Sponsored Link $200,000 mortgage for $660/mo - 30/15 yr fixed, reduce debt, home equity - Click now for info http://yahoo.ratemarketplace.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Frequency processing scheme of HP5065 vapourrubidium standard
--- Bill Hawkins [EMAIL PROTECTED] wrote: Normand Martel VE2UM wrote, With Cesium, high end techniologies like fountains or beans can be used Yes, I know it's a typo and I mean no harm to Normand, but it gives new meaning to the term bean counter. (Normally, a bean counter is an accountant.) Regards, Bill Hawkins ...Oops, Beams!!! BTW, beans make me fart, and farts are bad timekeepers (frequency is unstable, poor S/N ratio, very high jitter and drifts way too much. Sorry, no Allan deviation!) Have a good day! 73 de Normand Martel VE2UM Want to start your own business? Learn how on Yahoo! Small Business. http://smallbusiness.yahoo.com/r-index ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Health of GPS constellation questioned -- recently there have been more satellite outages than ever before
in effect until further notice. Civil users will receive Standard Positioning Service (SPS) accuracy as specified in the Federal Radionavigation Plan (FRP). POC for policy: CDR Jackson at DSN 692-2634 or (719) 554-2634. (NANU 121-91182/DTG 011354Z JUL 91) b. According to the 2nd Satellite Operations Squadron (2SOPS) Operational Advisory Bulletin: SA was implemented on November 15, 1991 to the SPS level. For information concerning: BLOCK II see file . . . . . GPSB2 GPS SYSTEM see file . . . . . GPSSY TIME TRANSFER see file . . . . . GPSTT -- File GPSTD last updated Tue Sep 5 11:35:09 UTC 2006 SUMMARY PRN 03 (Unusable 24 Aug 1502 UT and will remain unusable until further notice) PRN 12 non orbiting PRN 15 (Unusable 21 Aug 1358 UT and will remain unusable until further notice) PRN 29 (Unusable 26 Aug 0147 UT and will remain unusable until further notice) PRN's 31 32 non orbiting 6 out of 32 birds being KO, it is nor critical (the constellation is supposed to have at least 24 live sats), but when you look ar PRN's 15, 03 29, (all three being shut down within a week) no, it is not normal... BTW, on all the 26 live stellites, only six (01, 08, 10, 24, 27 and 30) run on Cesium standards, all other rely on Rubidium. 73 de Normand Martel VE2UM Montreal, Qc. Canada. --- Christopher Hoover [EMAIL PROTECTED] wrote: [ the story seems overblown to me, but still worth sharing. follow the last link for some real data. - ch ] GPS World: Current GPS constellation Aug 30, 2006 http://sidt.gpsworld.com/gpssidt/article/articleDetail.jsp?id=368448 The current GPS constellation - its health and viability - continues in question and under scrutiny, despite reassurances from the Air Force. Last month's GPS World Survey Construction e-newsletter relayed user plaints that there aren't enough healthy GPS satellites. Surveyors say they can't use RTK a full day with the current constellation even with every satellite healthy - and that recently there have been more satellite outages than ever before. They've resorted to filling GPS gaps with GLONASS. The online story drew immediate affirmation. While most of the time we get good coverage, for the last couple months we have had a 4 to 6-hour gap where we 'float' a lot and our precision goes down. Unfortunately this gap is usually between 10 am and 2 pm, which creates some interesting scheduling problems. For years only three companies offered combined GPS/GLONASS receivers; that number recently doubled and now includes all major survey manufacturers. The market speaks. It would be ironic if GPS troubles helped revive GLONASS, just as perceived GPS shortcomings helped launch Galileo. Others have written to ask what the JPO has been doing that has kept them occupied and unable to carry on GPS modernization or effective sustainment. In our September print issue of GPS World, We invited the GPS Joint Program Office to give their view http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=368240 , and we asked an independent consultant for his perspective http://www.gpsworld.com/gpsworld/article/articleDetail.jsp?id=367591 as well. ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Falling Edge Error
If i'm not wrong, virtually ALL GPS modules have their timing standardized on the RISING edge and do NOT guarantee anything about the falling edge. Glenn's measurements confirm that fact... Ideally, to get sure the users will use the rising edge, that signal shall be a sawtooth!!! (or simpler: a random falling edge.) 73 de Normand VE2UM Montreal, Qc. Canada --- Glenn [EMAIL PROTECTED] wrote: I just tried a quick test with my HP 5334A, with a LPRO to TVB divider on channel A and an Oncore UT+ on channel B. frequency difference: measured on the falling edge: 37E-9 Hz measured on the leading edge: 6.7E-9 Hz Both measurements are from the rising or falling edge of the 1 PPS of the GPS, 100 sample average. cheers, glenn ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Ugly Frequency Dividers
This morning, i've just remembered another weird frequency divider i say on a chronorecorder (a device used to adjust mechanical watches) a few years ago... The frequency dividers stages (three or four, i'm not sure) were unijunction transistor based staircase generators using the charge pump/reservoir principle to divide the input frequency by an integer N factor. Interinstignly, the N factor was adjustable using a potentiometer. Again here, just as with the ring counter, no glitch problem here, as with the binary dividers, but the pot had to be carefully adjusted so it is in the middle of the correct N range, this way, the counter can resist aging. Interinstignly, since it uses the charge pump/reservoir principle instead of the well hnown gated monostable, this counter is relativey (within a reasonable measure) frequency independant. Again, just as the all-transistor ring counter, i do not have the schematic, but i know the owner of the chronorecorder, and next time i'll see him, i'll ask for a look inside the device to sketch a schematic. BTW, i do not know the jitter response of such a counter, but i can eassilly imagine that it is very poor (slow transitions), but since it smells analog, i like it!! ;-) 73 de Normand VE2UM Montreal, Qc, anada __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Ugly Frequency Dividers
That remembers me the ugliest (or most exotic?) frequency divider i ever saw: It was part of a Marconi (damn, i don't remember the model number, but it was an OLD model), more precisely the 600 MHz divide by ten prescaler. The input divider was based on two tunnel diodes that acted as a div. by two divider followed by the really most bizarre divide by five unit i ever saw: Fifteen discrete NPN transistors arranged in a star (or pentagon (Hell Echelon!! ) ) topology with the input placed at the center of the star. The 15 transistor were in a symmetrical loop of 5 three transistor units working in a closed loop. Years later, i've made searches to find the schematic of this prescaler, but without the model number, this is quasi-impossible. If one of this forum's members has this schematic, i would be pleased to ask for a copy! Damn! That strange star all-transistor divider could count up to 300 MHz after all!!! Have a good day gang and keep this forum running!! 73 de Normand Martel VE2UM Montreal, Quebec, Canada --- Randy Warner [EMAIL PROTECTED] wrote: Tom, Attached is my entry in the butt-ugly PPS divider contest. A whole lot of 74HC192's and 74HC74's. I think this is circa 1999 or so. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tom Van Baak Sent: Tuesday, August 08, 2006 2:16 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Frequency Dividers Let me add this photo - I found in a box my first attempt to make a PPS divider as well as an early breadboard prototype of the much simpler, PIC-based, divider. http://www.leapsecond.com/pages/ppsdiv/ver1.jpg /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Discussion of precise time and frequency measurement
To get sure your Tektronix triggers correctly, use the Manual trigger mode. This way, you won't seee any trace on the screen without a trigger source (in auto mode, the scope will show a trace regardless it's triggered or not). Also, many Tek scopes have a trig view mode which i find very useful to view the actual trigger source. It's especially useful to adjust the trig threshold. On digital signals, stay away from the HI and LOW rails (noise). One other thing, get sure that the trig source input is DC coupled. AC coupling (especially if the PPS pulse is wide) will show RC time constant curves, which you do not want. Finally, get sure your scope trigs on the UTC edge of the PPS pulse (which is usually the LOW to HIGH transition). The return transition is absolutely NOT standardized to nothing and is useless. Also, i do not know if your scope is digital (memory) or analog, but it becomes VERY hard to precisely time pulse time differences with high resolution (µs/cm) on an analog scope with a 1PPS signal (the trace becomes extremely faint. You'll have to shut off all surrounding lights to be able to view the trace). Hope that it will help. 73 de Normand Martel VE2UM. Montreal, Qc. Canada --- Phaysal Khan [EMAIL PROTECTED] wrote: John, At the momet I m trying to do some similar stuff. I want to compare PPS output from two different rcvrs, the reference being Leica MC500 and the subject recvr being M12. but I am having problem with my oscilloscope which is a Tektronix one with 300 MHZ range. It is not locking on to the signal and the signal keeps on sliding sideways (seems to be a triggring problem). by the way, could you let me know what scenario have you build for comparing your signals and what instrument are u using to check the offset between the two. Regards Faisal [EMAIL PROTECTED] wrote: 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: time-nuts Digest, Vol 24, Issue 47 ([EMAIL PROTECTED]) 2. CDMA time synch problem in Salt Lake City, UT (Dave Andersen) 3. Leap second letters (Bill Hawkins) 4. Re: HP 5370A manual (John Day) 5. Re: GPS jamming (Robert Atkinson) 6. Loran timing experiment (John Ackermann N8UR) 7. Re: Leap second letters (Glenn) 8. Re: Leap second letters (Tom Van Baak) -- Message: 1 Date: Wed, 26 Jul 2006 21:12:12 EDT From: [EMAIL PROTECTED] Subject: Re: [time-nuts] time-nuts Digest, Vol 24, Issue 47 To: time-nuts@febo.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=US-ASCII Hello Faisal, a small annecdote about GPS jamming from the design of our FireFox GPS Disciplined synthesizers: We have a broadband synthesizer driven by a GPSDO on the same PCB. This synthesizer would completely swamp out the GPS receiption if you set it to 1574MHz CW output, the on-board noise was so powerfull (the output of the unit can be set from DC to 1640MHz). Our output can go up to +18dBm, millions of times more power than the GPS signal itself... The effect was that the M12+ receiver would just loose lock within a +-5 - 10MHz bandwidth around the GPS carrier. The receiver would show 0 sattelites being received. As soon as you set the frequency outside of this band, everything was fine. We improved this by putting the GPS board into a metal shield. So the effect of noise generated inside the enclosure was greatly mitigated. But the CW power radiated by the BNC connector itself on the unit is still enough to find its way to the antenna 10 meters away and about 3m above it, and swamp the signal! Putting a small paperclip into the BNC RF output connector at +18dBm at 1574MHz would probably cause a couple of blocks in our neighbourhood to loose GPS lock :) Never tried this and never will of course. bye, Said -- Message: 2 Date: Wed, 26 Jul 2006 21:14:34 -0400 From: Dave Andersen Subject: [time-nuts] CDMA time synch problem in Salt Lake City, UT To: Discussion of precise time and frequency measurement Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=ISO-8859-1; format=flowed I've sent this to EndRun tech support, but since they're not around at the moment, figured I'd run a quick check with people on the list. I don't really expect an oh, here's your problem, but I'd love one if someone happens to know! I have a somewhat older Praecis Ct (CDMA cellular time receiver) that seems to be having
Re: [time-nuts] Discussion of precise time and frequency measurement
The other method i use is a homebrew programmable (thumbwheels) pulse generator (1µs resolution) to compare my DUT (an Oscilloquartz B540 OCXO) against a GPS receiver. The pulse generator divides the B540's 5MHz by 5 million to get an arbitrary 1PPS. The arb. 1PPS is then used as the START signal for the programmable pulse and the end of the pulse is compared (using a 4046) against the GPS 1PPS. The 4046 wil then drive (via a pulse stretcher) a LED. If the pulse is too short (Thumbwheel setting too low) the LED will blink, if it's too long, (setting too high), the LED will stay off. I adjust the thumbwheels to the highest setting that allow LED blinking. The actual thumbwheel setting is totally arbitrary and means nothing. However, successive recordings over time (using nothing more than paper and pen) show me the actual progression (lead/lag) of my B540 against the GPS. I also wrote C code to create a simple DOS program that will calculate the actual frequency error (using thumbwheel setting progression against elapsed time) and necessary vernier adjust on the B540. All manual, old-fashioned, but working! But, the John's method (interval counter) is far better (better resolution, easy interval reading). 73 de Normand Martel VE2UM Montreal, Qc. Canada --- John Ackermann N8UR [EMAIL PROTECTED] wrote: Hi Faisal -- I use a time interval counter to compare 1pps signals -- the DUT goes to the start input, and the reference (here, GPS) to the stop input. You measure the time interval between the two, and use the change in interval to determine noise and offset. For the LORAN experiment, I used my HP 5370B though this application could do with a much simpler counter. I use homebrew logging programs under Linux using GPIB to log and process the data. John Phaysal Khan said the following on 07/27/2006 08:28 PM: John, At the momet I m trying to do some similar stuff. I want to compare PPS output from two different rcvrs, the reference being Leica MC500 and the subject recvr being M12. but I am having problem with my oscilloscope which is a Tektronix one with 300 MHZ range. It is not locking on to the signal and the signal keeps on sliding sideways (seems to be a triggring problem). by the way, could you let me know what scenario have you build for comparing your signals and what instrument are u using to check the offset between the two. Regards Faisal [EMAIL PROTECTED] wrote: 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: time-nuts Digest, Vol 24, Issue 47 ([EMAIL PROTECTED]) 2. CDMA time synch problem in Salt Lake City, UT (Dave Andersen) 3. Leap second letters (Bill Hawkins) 4. Re: HP 5370A manual (John Day) 5. Re: GPS jamming (Robert Atkinson) 6. Loran timing experiment (John Ackermann N8UR) 7. Re: Leap second letters (Glenn) 8. Re: Leap second letters (Tom Van Baak) -- Message: 1 Date: Wed, 26 Jul 2006 21:12:12 EDT From: [EMAIL PROTECTED] Subject: Re: [time-nuts] time-nuts Digest, Vol 24, Issue 47 To: time-nuts@febo.com Message-ID: [EMAIL PROTECTED] Content-Type: text/plain; charset=US-ASCII Hello Faisal, a small annecdote about GPS jamming from the design of our FireFox GPS Disciplined synthesizers: We have a broadband synthesizer driven by a GPSDO on the same PCB. This synthesizer would completely swamp out the GPS receiption if you set it to 1574MHz CW output, the on-board noise was so powerfull (the output of the unit can be set from DC to 1640MHz). Our output can go up to +18dBm, millions of times more power than the GPS signal itself... The effect was that the M12+ receiver would just loose lock within a +-5 - 10MHz bandwidth around the GPS carrier. The receiver would show 0 sattelites being received. As soon as you set the frequency outside of this band, everything was fine. We improved this by putting the GPS board into a metal shield. So the effect of noise generated inside the enclosure was greatly mitigated. But the CW power radiated by the BNC connector itself on the unit is still enough to find its way to the antenna 10 meters away and about 3m above it, and swamp the signal! Putting a small paperclip into the BNC RF output connector at +18dBm at 1574MHz would probably cause a couple of blocks in our neighbourhood to loose GPS lock :) Never tried this and never
Re: [time-nuts] No Leap Second Dec 2006
Thanks! That was news for me! I just hope that Tom won't be sad... ;-) 73 de Normand Martel VE2UM Montreal, Qc. Canada --- karl strauss [EMAIL PROTECTED] wrote: Just saw this posting, sorry if it is old news: INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS) SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE SERVICE DE LA ROTATION TERRESTRE OBSERVATOIRE DE PARIS 61, Av. de l'Observatoire 75014 PARIS (France) Tel. : 33 (0) 1 40 51 22 26 FAX : 33 (0) 1 40 51 22 91 Internet : mailto:[EMAIL PROTECTED][EMAIL PROTECTED] Paris, 19 July 2006 Bulletin C 32 To authorities responsible for the measurement and distribution of time INFORMATION ON UTC - TAI NO positive leap second will be introduced at the end of December 2006. The difference between Coordinated Universal Time UTC and the International Atomic Time TAI is : from 2006 January 1, 0h UTC, until further notice : UTC-TAI = -33 s Leap seconds can be introduced in UTC at the end of the months of December or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every six months, either to announce a time step in UTC, or to confirm that there will be no time step at the next possible date. Daniel GAMBIS Director Earth Orientation Center of IERS Observatoire de Paris, France ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] GPS Timing in Interference Environment
First of all, welcome in our little group of timing enthusiasts Faisal! You'll see that we often find the best jams in small pots!!! My toughts are more on Rob's interference problems rater on your problem, (since i have no idea of CW interference effects on timing CPS receivers)... But my personal tought is that you must take great care on the type of antenna you'll use on your system. As Rob said, the important thing to care about is the INPUT filter (the one right behind the antenna element and BEFORE any preamplifier). Using a GPS (or ANY) receiver in presence of strong RF fields requires high quality (passive) filtering! And for Rob's problem, that's a patent case of the importance of GOOD filtering, not only for the GPS receiver, but also for the transmitter. Rob's DAB transmitter has a 500kW ERP, that's +87dBm! On the other side, GPS signals are in the -130dBm range, that's an over 217 dB of difference!!! I'm even surprised that the system worked considering that 1575.42MHz 2nd sumharmonic (787.71MHz) is INSIDE the TV channel's bandwidth! (783.25-789.25). So don't hesitate to invest in a high quality antenna! Good luck in your project and don't hesitate to give us some news about it! 73 de Normand VE2UM Montreal, Qc. Canada --- Rob Kimberley [EMAIL PROTECTED] wrote: Faisal, There is probably some documented evidence available by Googling, but from my own personal experience, I can tell you about an instance which happened about 10 years ago while selling Datum GPS timing products in the UK. The customer, Crown Castle, was running all of the BBC TV and Radio transmitter network in the UK, and had a problem at a site near Oxford with GPS reception. They had bought equipment from another supplier for a new DAB network which was not working reliably on that site. GPS reception was intermittent, and was insufficient to provide good disciplining of the internal OCXO in the unit, and therefore the DAB installation was not being synchronised properly. I brought in one of the new Datum units to try (9390-6000), which like the competitor used a Trimble engine and matching antenna. We had the same problems. On further investigation one of the TV transmitter frequencies being used (actually the second harmonic) was very close to the 1575 MHz of the GPS L1. We discussed ways of maybe shielding the antenna in some way (not really practical), but eventually after discussing with Datum we managed to fix the problem by upgrading the antennae to then new Bullet II (HE?) antenna which had a three pole filter rather than the single pole filter that was in the original antennae. Both the competitors and the Datum product worked fine after the upgrade. For the record, the transmitter ERP was 500KW, the centre frequency of the channel in question was 786MHz (Vision at 783.25 and Sound at 789.25), and the control cabins and GPS installation were probably about 50 - 100 yards away from the base of the TV antenna tower. GPS antenna were mounted on the roof (single storey) of the control cabins Hope this of interest. Regards Rob Kimberley - Original Message - From: Phaysal Khan [EMAIL PROTECTED] To: time-nuts@febo.com Sent: Tuesday, July 25, 2006 4:33 AM Subject: [time-nuts] GPS Timing in Interference Environment Hi, I am new in this group, and wanted to discuss something abt GPS timing. I am working on GPS system signals from timing point of view. I want to see Effects of Interference(CW) on GPS timing receivers. At this stage I am mainly interested on what will happen to the timing receiver itself when effected by CW interference and the next stage will be to find out how this effect could be mitigated. What I intend to do now, is to compare the 1 PPS pulse from two different rcvrs ( I will be using Motorola M12+ Oncore as the subject rcvr and Leica CRS1000 as the reference. Do you ppl have any suggestions? Regards Faisal __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Quick Allan deviation measures
Hi... Talking about Allan deniation, is it possible to find somewhere the Allan deviation data for the all-new Synergy Timing M12M? and, for Tom (or anyone else...), Did you have time to get a unit and do some tests (Allan deviation/sawtooth data/glitch behavior)? Thanks and 73 de Normand Martel VE2UM __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] New frequency standard, Mercury better than Cesium?
They should be able the standard uses a single mercury atom!! ;-) --- Jack Hudler [EMAIL PROTECTED] wrote: Now if they can just make that fit inside a soup can and cost less than $300; we'd all have our own Mercury Standard. :) ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Administrivia: Message Sizes
I agree!!! I already ordered a PDF file from a user (i don't remember who) on this forum and we exchanged the file directly without passing through the forum. 73 de Normand VE2UM Montreal, Qc. Canada __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Interesting Patent
Hi... I remember having seen an interesting analog counter/frequency divider using charge pumps and unijunction transistors in a watchmaker's mechanical watch adjusting machine. ( i don't remember the machine's name, but it is used to adjust the oscillator's (balance wheel/hairspring) frequency. The interesting part was that the unijunctions worked in a charge pump fashion rather than an RC time constant fashion. This way, at least theorically (i never tried it), the counter could be used with a variable frequency source. The principle is simple: The unijunction transistor is used in it's traditional relaxation oscillator circuit, except that there's no pullup resistor between the unijunction's emitter and supply line. The Emitter-ground capacitor is charged by another (smaller) capacitor through a series diode an a calibrated voltage pulse. This way, at each input pulse, the capacitor is charged with a fixed (predetermined) voltage increment. After 'n' pulses, when the emitter reaches the discharge voltage, the UJT fires and sends an output pulse. (If one watches the emitter voltage with a scope, he will see a staircase waveform). The interesting part is that the voltage increment remains fixed, regardless of the pulse's duration or frequency (up to a certain extent...). I know, it's hard to describe the circuit with words, but if i find the schematic, i'll find a way to send it here. Have a good day! Normand Martel Montreal, Qc. Canada __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP 5061A on Ebay
On the eBay listing it is written: Because of the nature of this item (or the quantity we have in stock) we have made the decision not to individually test each item. Well... I could understand on Beta VCR's, but TO NOT TEST a HP5061 Cesium beam frequency standard for functionality, (a known good standard will sell for MUCH MORE $) George is right, we shall have BIG questions about the seller's reputation Normand Martel VE2UM Guys, There is a 5061A on Ebay! it is item # 7617020608. STAY AS FAR AWAY FROM THIS UNIT AS POSSIBLE I bought it at a Dovebid auction and it was damaged in shipping..look at the handle on the right side. The unit took a hit hard enough to break a 1/2 inch AL casting. LV is ok. 3.5KV supply is inopThe tube is anybody's guess. I got a full refund for the item and shipping. __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] M12+ Temp sensitivity
I may be the 259th to ask you, but do you have a date when the new M12M will be officially available? I almost have bought a Resolution T a few weeks ago when i heard about the M12+ and it's successor, the M12M. Now i'm waiting! Well... I know... this is a forum about time... ;-) Have a good day! 73 de Normand Martel VE2UM Montreal, Canada ...Too bad! The Habs have lost against Canes! Said, Hey! Whaddya mean CHEAP? The marketing guys call it feature laden and cost effective! Anyway, you're right. The M12+ is extremely sensitive to environmental stimuli. On our receiver/adapter board assemblies I actually include a piece of foam tape between the two boards that gives the crystal (crystal, not TCXO) some isolation from the outside world. The old original M12's actually worked better in this respect because they were in a normal crystal can which lengthened the thermal time constant enough that temperature perturbations weren't a problem. The SMD Rakon crystal used by current M12+'s just doesn't have any sense of humor when it comes to temperature changes. The new M12M's DO HAVE a Rakon TCXO and are a lot more insensitive than the M12+'s. Randy __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Old DOS Oncore Program for 6-12 channel receivers
Hi... I'm also interested... I have an old 486 that runs on DOS, ant it would be happy to run this program!! 73 de Normand VE2UM __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Oncore GPS models
Hi... F.O.Q. (Full of questions!!!) First, is the Oncore UT+ the same unit as the M12+? And if not, are there significant differences between both units? Briefly, would you suggest me to spend more on a M12+ than a UT+ ?? (or let me wait until july for the allnew M12M...) Also, Randy Warner suggests only versions 2.2 or 3.2. What happened between versions 2.2 and 3.0 ? (it looks like that there have been major hardware changes...) And... Is it easy to reflash one of those units? (do we need special hardware, and are reflashing software / firmware easily available on the Net?) FinallyOn R5122U1112 (version 2.2), how is the 100 PPS behavior? (if i refer to the PDF file uploaded by Randy, a significant correction has been brought to the 100 PPS only on the version 3.2 firmware...) Thanks and 73 de Normand VE2UM. P.S.: Are transactions accepted on this forum? (for example, asking anyone if they have GPS boards for sale..) __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] How Rubidiums make their frequency
Hi.. In his message, Paul-Henning Kamp writes that a drift-free standard has not been yet designed... But Isn't Cesium drift-free? Since the SI second is standardized as de duration of 9192631770 oscillation of the hyperfine transition of the atom 133Cs? If Cesium drifts, theren should be a more formal definition of the second (Such as density, maximum C-field or level of purity). Does anyone here has it? And also, something else i don't understand: Why do the newer GPS satellites rely on Rb standards rather than Cs standards? Since Rubidium is known as less precise than cesium? Is there a reliability issue there (Rb clocks are more reliable / longer MTBF tha Cesium clocks). I don't know... 73 de Normand Martel VE2UM (A PLL based 9192631770 synthesizer i once imagined...) 10 MHz ---(/250)--4PPS-, OCXO | | ,' | `-(/)---[Filter]---(VCO)--*--829.08 MHz--, | | | `---(/20727)---' | | ,41454 PPS(/2)' | `--(/)---[Filter]---(VCO)--*--1838.526354 MHz--, | | | `---(/44351)---' | | ,---' | `-(*5 SRD)--9192631770 Hz (to physics) __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] IC for 1 PPS Output
Even more El cheapo (and also more ailable from your spare parts drawer): A fast hex inverter (74F04/74HCT04 etc...) wired in a 1-5 configuration (one input inverter driving five output inverters) and then having each of the five output inverters driving a separate 240 (or 220) ohm resistor (keep the leads short). Then, simply connect the five 240 ohm resistor unused leads together and BINGO! You have a 50 (ok, 48 ohm!!!) driver! And having 240 ohm to drive, the inverters are not overloaded. 73 de Normand VE2UM --- Hans H. Jucker [EMAIL PROTECTED] wrote: Dear Robert You can either drive from A to B with the world finest German Maybach car or also with a British Mini Cooper. May be the SN74128 50ohms coax-cable driver is rather matched for this simple application ! Regards Hans ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] ...Your thoughts on the Trimble Resolution T?
Well, thanks for the advice! ...And also one other convincing (at least for me) feature: The M12+ has a choice of either a 1PPS precise signal or a 100PPS precise signal. For my application (GPS disciplined frequency standard), the 100PPS option will surely help settle the frequency for the few seconds after turn-on/reacquisition. But i saw a line, i'm not sure about: (specs for the M12M, the replacement (starting july 2006) of the M12+ Timing accuracy: Performance using clock granularity message: Better than 2ns, 1 sigma Better than 6ns, 6 sigma Performance NOT using clock granularity message: Better than 10ns, 1 sigma Better than 20ns, 6 sigma What's that clock granularity message? For me, It looks like a message telling the actual error of one particular 1PPs pulse. Does it sound right? And also, how do i know or decide the actual error range (1 / 6 sigma) Thanks all! --- [EMAIL PROTECTED] wrote: From the leapsecond.com website, it seems the Trimble gets 2.15E-011 at 1000s intervalls. The M12+ achieves 2.9E-012 at 1000s intervalls. The M12+ is speced at 10ns 1-Sigma, the Trimble seems to be 15ns at 1-Sigma. There is an M12+ follow-up modell comming soon which is even better than this data. Then there are the curious spikes that leapsecond.com mentions... Seems the Trimble is significantly worse than the Motorola GPS? bye, SJ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] ...Your toughts on the Trimble Resolution T?
Hi... I seriously think about buying a Trimble Resolution T timing GPS receiver for a GPS disciplined OCXO frequency standard (Brooks Shera W5OJM's project). Have someone worked with this receiver? The claimed maximum 1PPS to UTC error is 15ns, the best figure i saw yet on GPS receivers, and far better than the 50ns error of the famous, but obsolete and hard-to-find, Motorola Oncore UT. Also... Has someone built this project? It seems to be very well built and accurate. Thanks for your attention and 73 de Normand VE2UM Saint-Hubert, Qc. Canada __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] OSA 8600 Oscillators
Yep!!! I'm also interested in one of those oscillators... A quartz that rivals Rb is surely a good shot! So, price and availibility please... 73 de Normand VE2UM Montreal, Canada __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] ...Conexant (Rockwell) Jupiter behaving strangely
Hi... I currently use a Conexant (Rockwell) Jupiter GPS receiver to calibrate a standalone Oscilloquartz B541 OXCO as a local frequency standard, and, while being less accurate that a professionnal GPS slaved frequency standard, it far overmeets my needs. The beauty with the Conexant Jupiter is that it features a GPS precise 10kPPS (10kHz squarewave) signal, which is by far easier to work with than the well known 1PPS TIMEMARK found on most GPS receivers. My problem with the 10kPPS signal is that it doesn't lockup at each time the GPS receiver gets a fix if the backup battery is plugged-in. If i remove the backup battery, the 10kPPS signal locks-up everytime i cycle the receiver's power and get a fix. One more thing: The fix is good regardless of the 10kPPS lock condition... This screws me up! My temporary solution is to use the receiver without the battery backup, but this gives me a lenghty TTFF problem: The receiver takes a lot more time to get a fix if i don't plug-in the battery. Have you worked with this receiver and the 10 kPPS signal? Is there a way i could get sure this signal locks-up with the GPS clocks? When the receiver's 10kPPS doesn't lockup, it runs at 9998.8365 - 9998.8404 PPS, which is far more away than the initial (turn-on) out-of-lock (1.02PPS) condition. Thanks for your attention... Normand Martel VE2UM Montreal, Canada __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
