http://blog.gmane.org/gmane.comp.time.nuts hourly 1 1901-01-01T00:00+00:00 http://gmane.org/img/gmane-25t.png http://gmane.org http://comments.gmane.org/gmane.comp.time.nuts/29836 <pre>Has anyone got the 55300a programming guide? Its on the Symetricom site but they have deemed I am not worthy of a login ): -marki </pre> Mark C. Stephens 2013-05-18T13:20:07 http://comments.gmane.org/gmane.comp.time.nuts/29830 <pre>Hi All, I was messing around with receiver before I made it permanoid and come across the following interesting tidbit. -mark scpi &gt; SYST:LANG "PFORTH" pForth $Revision: 1.2 $ p4th D &gt; watch scpi &gt; So typing watch exits the interpreter, but it also appears to reboot so don't mess with your master clock now... The following commands all seem to work, but I could write what I know about forth on the tip of my little finger: SYST:LANG "PFORTH" watch exits ---- Macro? ps s_rep mem_rep cal adc_read adc_temp adc_5v adc_p15v adc_m15v adc_oven adc_doven adc_ant_curr pr_adc_avg efc_write hdac_write hdac_all doven dmessage dmes_gpsm dmes_hmon dmes_klok dmes_pllp dmes_root dmes_scpi dmes_spoo dmes_curv dmes_all wr_eeprom clear_nv debug_psos clk_synch get_time set_time abr_stat print_stat stat_rate vis_stat_rate print_vis ext_msg_rate dop_stat_rate print_ext_msg print_bc gps_time gps_date gps_php gps_ph gps_cable_dly force_1pps efc_wr pr_efc pll_restart pll_debug lock phase_off pr_pll log_send print_clk_list crash leapsec eman q_eman q_gps_php q_gps_cable_dly avg clr_avg init_gps gps_query_all quiet_status master_reset pr_gps_debug clr_gps_debug pr_gps_cmds pr_avg pr_gps_istate pr_gps_id pr_1pps pr_time_raim disable_gps_cmds pstat gps_change gps_query pr_hold_cause loop_time pll_rep efc_rep sync_imm es_ascii --- language? over abs max min negate here fill pick rot -rot allot 2dup 2swap abort halt false true and not xor ?dup cmove cmove&gt; 2drop drop swap dup depth else then endif begin while repeat again until ?do loop +loop leave variable create constant literal mod /mod */mod sin cos emit space spaces (.") u.x decimal hex base state ['] forget words startup interpret expect type word count tib pad does recurse immediate fence unfence number execute watch root my_pid spawn ver delete suspend resume priority jam_x create_x delete_x send_x request_x signal_v wait_v get_v pause mode ident dev_init dev_open dev_close dev_read dev_write dev_ctrl !iodev user </pre> Mark C. Stephens 2013-05-18T11:23:54 http://comments.gmane.org/gmane.comp.time.nuts/29824 <pre> Hi, I bought a 34401A lately. It's all fine, except it's got a fault when measuring low ohm with 2-wires: the value runs (monotonic) from 0 to 30 oder 40 Ohms at a speed of say 1 ohm per second and after a while it decides to run back... When using 4-wires-measurement everything's alright. Did anyone have that problem before? Thank you Volker </pre> Volker Esper 2013-05-18T01:23:52 http://comments.gmane.org/gmane.comp.time.nuts/29814 <pre>I just received my first Morion MV89A. It came attached to a piece of the original PC board. I wonder how others have mounted theirs. One option seems to be to get a piece perf board (perhaps with solder pads). Another might be to leave it on the original PC board since that seems to have a nice ground plane and enough of the board remaining around the edges to mount the whole thing on stand-offs. I could remove the dozen or so capacitors and resistors on the original board. I am thinking of using at least one of these in an existing piece of equipment, so something simple is desirable. Thanks for any suggestions. Fred Bray </pre> Frederick Bray 2013-05-17T20:19:05 http://comments.gmane.org/gmane.comp.time.nuts/29801 <pre>A client company has sourced a quantity of 'New in Box' iSBC series memory modules manufactured by Intel in the 1980s for a MULTIBUS based computer system. These are still in their original, sealed packaging and have been stored (for 25 years) in controlled conditions. These cards are required as part of a refresh programme for a mission-critical application (electricity generation), which are currently using original Intel cards from the same era. The memory cards use a 64.1kHz oscillator module as the refresh clock for the DRAM. (I suspect that the oscillator module uses either a 2.5MHz or more likely a 5MHz crystal whose output is divided down within the module by 39 or 78 to 64.1kHz). As this oscillator is used only for DRAM refresh timing, the accuracy and drift are not particularly important. However, reliability is important - i.e. the oscillator must function, even if it is a few ppm off frequency. AS a matter of precaustion, all the tantalum and electrolytic capacitors on the NIB cards are to be replaced as a matter of course, and any socketed ICs will probably be removed, cleaned and replaced (to be decided). There are several dozen cards to be replaced. There is an option to replace the crystal oscillator module, but it is uncertain as to whether it makes sense to to the extra work. The replacement oscisllator module will be from a different supplier to the one Intel used, and would need some form of qualification. Is there a known failure mechanism whereby a cystal oscillator module that has been sat on a shelf (as part of a complete card) in a benign environment develops one or more characteristics that could impact it's reliability? regards Grant </pre> Grant Hodgson 2013-05-17T12:07:20 http://comments.gmane.org/gmane.comp.time.nuts/29795 <pre>Hi folks. I wouldn't call myself a time nut, so this is really an effort to ask for advice from some people who know the field. My first contact with time synchronisation was looking at the instrumentation clocks for the Woomera rocket test facility when I went out there for a few (large!) hobby rocket launches. I can't even remember the system's name but it used a series of pulses of various lengths to give a unique time code. But, I digress... I've not had much need for time synchronisation over the years, but in recent years NTP has been able to get me by. Unfortunately I'm now faced with a network that needs a moderately correct clock (I'm scared of using the word 'acurate' around you folks!) to the order of a few seconds or so, but with no possibility of an external internet connection (for a number of reasons). At present I'm using one PC running Windows Server as an SNTP server to synchronise all of the devices, as it is the only device in a physically secure location. This is inside a security-fob protected room. I can't get GPS signals in there, and the Australian radio clock network was shut down about ten years ago. Our CDMA network was turned off in 2008. Right now all I can think of is GSM, and while i know it's not terribly accurate it seems like it might be the easiest. It also might be that I've got tunnel vision and there's a simpler solution out there. I would be quite happy with some sort of dedicated GSM/NTP-server box, and there are Arduino/Raspberry Pi/Linux homebuilts for that out there, but I have been wondering if one of the fairly common GSM USB sticks could somehow be a time source to set the server clock? Regards, Grant </pre> Grant Waldram 2013-05-17T04:45:09 http://comments.gmane.org/gmane.comp.time.nuts/29781 <pre>Mark, The thread on your 2200 indicated that these downconverters were used by various manufacturers. I just happened on paybay item 280918789321 which may fit your app. regards, Mike </pre> mike cook 2013-05-16T05:57:11 http://comments.gmane.org/gmane.comp.time.nuts/29760 <pre> 15/05/2013 13:13 Is there any fairly easy way to multiply the output of a Thunderbolt to have a 500MHz reference at about 4dBm? Thanks. </pre> Chris Wilson 2013-05-15T12:14:45 http://comments.gmane.org/gmane.comp.time.nuts/29755 <pre> Watch 32 discordant metronomes achieve synchrony in a matter of minutes - PLL ? http://io9.com/5947112/watch-32-discordant-metronomes-achieve-synchrony-in-a-matter-of-minutes Cheers </pre> Raj 2013-05-15T06:52:16 http://comments.gmane.org/gmane.comp.time.nuts/29743 <pre>Hi! I am trying to figure out why NTP takes so long to react to oscillator changes... I want it to track the PPS from a Trimble Acutime as closely as possible. When checking ntptime on startup I see that the NTP daemon is using PLL and starts the adjustment interval at 8 s. It then increases to 16, 32, 64, 128 and stops at 256. I read in the documentation that this limit should be 128 but is now 256. --- start from http://www.ntp.org/ntpfaq/NTP-s-config-adv.htm --- intervals 57 says that there were 57 calibration intervals. When PPS pulses are arriving, this number should increase. Each frequency adjustment requires a good calibration interval. The length of the current calibration interval can be found as interval 128 s (128 seconds is the default maximum length). Remaining numbers count abnormal conditions as explained below. --- end --- How can I make it stop earlier? At 64 s for example? Any ideas? TIA, Miguel </pre> Miguel Barbosa Gonçalves 2013-05-15T00:30:56 http://comments.gmane.org/gmane.comp.time.nuts/29737 <pre>While sifting through some network logs in my day-job, I found where there was a solar flare on May 12th that may have had a negative impact on our customer's GPS receivers with a 20 second loss of tracking all GPS SVNs. Depending on the geometry of the flare and where the greatest impact was the outage may or may not have been an issue. Did any Time-Nuts notice any complete GPS outages on May 12th? -Brian, WA1ZMS </pre> Brian, WA1ZMS 2013-05-14T22:17:45 http://comments.gmane.org/gmane.comp.time.nuts/29712 <pre>Hello! What is needed now is to decode IRIG-B timecode and syncronize the system time (or hardware timer) to it with about 1 ms precision. Operating system is Linux based and runs on embedded environment. It should support both, AM modulated and digital pulse versions of IRIG-B (for now it's unsure which will be used). Is there any IRIG-B decoder chips or reference schematics available with full support for the standard? Google didn't find any ready solution for this need. It looks like only way to get this is to design it from scratch... </pre> Esa Heikkinen 2013-05-14T11:36:20 http://comments.gmane.org/gmane.comp.time.nuts/29707 <pre> I have just scored myself the oddest looking Austron 2200 GPS Satellite Receiver. It's a 3RU chassis, the service manual I got from K04BB's excellent site seems to only describe the 1 and 2 RU. Fortunately this comes with manuals which will be sent off to be scanned. However, it didn't come with the antenna/down convertor. I did a search of the time nuts history and apparently someone was offering these antenna for sale. But it seems it was a dead end. Failing one of the time nuts supplying me an antenna (anybody have a spare assembly they can sell me?) How often do the 2200 type antenna come up on Ebay? Many thanks, mark </pre> Mark C. Stephens 2013-05-14T07:02:30 http://comments.gmane.org/gmane.comp.time.nuts/29704 <pre>I wonder if the following scheme would work to improve measurement precision over USB for use with GPS devices or similar. Instead of USB interrupt transfers, which occur on 1 ms boundaries with some unknown epoch, use bulk transfers. In the good case, there are no other USB transactions in flight, the request goes out immediately, the device responds immediately, and the entire link has the lowest latency possible. If these conditions don't hold, the completion time will be delayed. Now use robust estimation techniques to get rid of these exceptions and instead follow the smooth line of best-case responses. NTP implementations do something like this already, but at longer timescales, and targeted at Internet links rather than a single local USB link. If the best-case response time is calibrated out, how good can this get? Microseconds? Cheers, Peter </pre> Peter Monta 2013-05-14T03:36:14 http://comments.gmane.org/gmane.comp.time.nuts/29701 <pre>Interesting product.. too bad they don't have a small antenna that could be integrated with it. (or maybe they do, and my browsing around didn't find it). I've got a bunch of applications coming up for something which needs synchronization at 1us to 1ms level for distributed data collection. The Garmin GPS18 is nice for now, but I'm always looking for things that might be at different levels of integration for other projects. </pre> Jim Lux 2013-05-14T03:00:41 http://comments.gmane.org/gmane.comp.time.nuts/29692 <pre>rummaged through archives and couldn't find anything.. I've got some GPS-18's with the RS232 and 1pps output. BUT, I'm wondering if anyone has tried to get timing with the USB version (Linux or Windows..), and if so, is getting 1 millisecond absolute accuracy feasible. The underlying USB thing has 8kHz frame rate, but I suspect that the serial port emulation (which is probably what they use) might not hold it that well. I can see there being some sort of fixed offset (going through hubs and such), but once the configuration is known, is that stable? Any practical advice? </pre> Jim Lux 2013-05-13T14:43:00 http://comments.gmane.org/gmane.comp.time.nuts/29690 <pre>I am trying to track down the HP 58503A/B firmware. Could some kind soul point me in the right direction please? mark Kind Regards, Mark Stephens Mark C Stephens | Customer service engineer | Non-Stop Computer Ltd * +61 2 9011 8186 | ( +61 428 256 334 | * marks-4ccEsDCvlg40n/F98K4Iww&lt; at &gt;public.gmane.org&lt;mailto:marks-4ccEsDCvlg40n/F98K4Iww&lt; at &gt;public.gmane.org&gt; Non-Stop Computer PTY LTD 79 Devon St North Epping NSW 2121 Australia Timezone: AEST (UTC +10) Email: service-4ccEsDCvlg40n/F98K4Iww&lt; at &gt;public.gmane.org&lt;mailto:service-4ccEsDCvlg40n/F98K4Iww&lt; at &gt;public.gmane.org&gt; </pre> Mark C. Stephens 2013-05-13T03:46:47 http://comments.gmane.org/gmane.comp.time.nuts/29677 <pre>Hi, Just recovered from my Nortel Trimble GPSDO twisted cable incident, now I have other problem now with Trimble GPS monitor program. I remember that I used it with my GPSDO when I bought it and Lady Heather still didn't supported it. Today I tried to use it again and it gives a series of error windows just when the GPSDO starts sending data and the program quits. Maybe is is caused by the program trying to communicate at 19200 Bd but the GPSDO sends at 9600 Bd, but I don't know if there is a way for changing the baud rate and anyway at the beginning it worked ok, I did the first auto surveys with it. Anybody has any clue? TYA, Ignacio EB4APL </pre> EB4APL 2013-05-12T22:14:36 http://comments.gmane.org/gmane.comp.time.nuts/29674 <pre>Hello, My NTGS50AA began doing weird things after I moved it to a new enclosure. Upon power up the monitor LEDs showed some activity and after a few seconds D2, D3 and D4 remained on. In normal operation D1 and D4 are on and D2 is off. D1 indicates comm failure with the cell tower equipment, which is normal (I don't have a cell tower) and D4 is the lock indicator. More annoying was that fact that Lady Heater was nor able to communicate with the equipment neither Trimble's GPS Monitor. After several hours tracing signals with astonishing findings I began to write a message to this group asking for help, I was assuming that the CPU had entered in a strange mode, maybe with a baud rate change or changed the message protocol, and I found that the GPSDO was sending data at 9600 Bd to pin 1 of the interface board but this pin is unconnected !!!. I was reviewing my photos in order to get more info for better documenting my call for help when I realized that the cable from the main board to the interface was plugged in the wrong way. I had connected it in the "right" way, pin 1 of the plug to pin 1 marker in the socket, but Trimble decided that instead of twisting the cable they laid it flat and used plugs without keys so they can be inserted reversed. I reversing one of the plugs and it worked ok. The weird and misleading thing is that the LEDs worked quite well, so I never thought of a cable reversal, now I marked both sockets in red where wire 1 should be connected, disregarding the factory triangle marking. It looks like the first time I assembled the unit I had the pictures in front of me and connected the cable following it. I send this notice to the list for the benefit of new users (and old ones like me also) because it can drive you nuts (and not of the time variety). Regards, Ignacio EB4APL </pre> EB4APL 2013-05-12T21:01:16 http://comments.gmane.org/gmane.comp.time.nuts/29666 <pre>If you like annoying, irregular clocks... http://en.wikipedia.org/wiki/Corpus_Clock </pre> Mark Sims 2013-05-12T20:21:03 http://comments.gmane.org/gmane.comp.time.nuts/29643 <pre> A low phase noise 10n MHz buffer amp is described in Linear Technology Design Note 514, for those looking for such a thing. All parts are specced. Don </pre> Don Latham 2013-05-12T03:22:53 Search the mailing list at Gmane query http://search.gmane.org/?group=$group=gmane.comp.time.nuts