Re: [time-nuts] UPS for my time rack
HA! That was good. I started working at Tektronix in September 1987 and we used VAX computers in our major field offices for order processing in the late 80's and early 90s. They batched their daily results to our headquarters in Oregon every night on "high speed" modems on special phone lines. We had daily and weekly backups at each office onto open reel tape. The UPS horror story I can relate was at a major airline underground computer center in the 90's. I was waiting to train a group on a high power curve tracer they had purchased to test SCR's every time one of their UPS inverters blew up (which must have been moderately often). I was waiting in the supervisor's office, which had two telephones. One of the was fire engine red, which I thought was reserved for the Hot Line with Russia in Washington. The supervisor told me that if the red phone rang it would be a call directly from the well-known CEO of the airline. It seems that sometime before a worker was using a large wrench (which was not conformally coated) directly above the critical location where the switch between the UPS output nd city power was located. When the wrench fell it shorted the single point of failure in their system, stopping their reservation and flight system operation systems. So the maintenance department suddenly received a red hotline phone for the CEO to call when the UPS failed. Anything can (and will) fail, and as your story about the VAX improper manual reboot shows good intentions can turn into epic fails. When I owned a small business in the mid-80's I was contacted by a local company in central Texas with a small VAX and CDC disk drive who had a major failure at his data entry company. He knew he wasn't perfroming backups so thought it was a good time to perform preventative maintenance on the physically large CDC removable disk pack drive (with a huge magnet and large voice coil actuator). The company owner decided to clean the "sock" disk drive air filter, so he removed it and vacuumed it off. He then made a command decision that he should use the clean side of the filter now (since one side had been filthy) and inverted the sock filter before reinstalling it. Gasp!! Shortly after the drive spun up a large dust particle was sucked off the dirty side of the filter (now in the previously clean drive chamber) and he heard a disk head bouncing around the inside of the drive. It was (of course) the servo head. Remember that they had no backups. The drive was transported to CDC headquarters and they declared it a lost cause. The small company owner asked me (and probably others) if I would help him strap a good drive to the bad one and fabricate an arm between the good and bad drive head acuators so the good drive servo track would move the bad drive heads (with other required rewiring to get the drives to work "together"). I told him NO and walked out without wasting my time explaining how servo tracks really worked and the mechanical and electrical engineering fallacies in this crazy scheme. No, I would not take a penny of his money to try any portion any of that scheme! His company soon went bankrupt, I believe. -- Bill Byrom N5BB On Mon, Oct 12, 2015, at 01:28 AM, Bill Hawkins wrote: > My apologies in advance for further putting tension on this OT thread, > but one of the great stories from the early days of Usenet concerned a > really large UPS system for a data center. In the late 80s the Digital > Equipment Corp VAX computer was among the most powerful you could buy. > If you can accept that amount of time travel, follow this link: > > http://www.hactrn.net/sra/vaxen.html > > or Google "vaxen immortal power" > > The reference to October 19, 1987, is to the first computer failure to > have a major effect on the stock market. > > Enjoy, as they say > > Bill Hawkins > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] UBLOX LEA-5T Programming?
Hi It’s “happy” either way (as in, it will accept the pulse). The stability will be degraded due to hanging bridges if you don’t have sawtooth correction. Bob > On Oct 12, 2015, at 6:13 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> A $25 Ref-0 with the same GPS and a (now) documented MCU will do the same >> thing as any other GPSDO. > > Does anybody know if the Ref-0 expects a clean PPS from the Ref-1 OCXO, or is > it happy with what comes out of a typical GPS unit? > > > > -- > These are my opinions. I hate spam. > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] UBLOX LEA-5T Programming?
Hi, The REF-0 will accept a PPS signal from a non-timing GPS. I use the u-blox NEO-6M for a lot of my testing. That module can be had in the $12 range online. I have also gotten the REF-0 to lock to a Venus GPS and an FE-5680B rubidium standard. Of course, using a less stable PPS signal will give you less performance out of the REF-0. I have some information about operating the REF-0 standalone documented on my blog: http://syncchannel.blogspot.com Dan > On Oct 12, 2015, at 6:13 PM, Hal Murray wrote: > > > kb...@n1k.org said: >> A $25 Ref-0 with the same GPS and a (now) documented MCU will do the same >> thing as any other GPSDO. > > Does anybody know if the Ref-0 expects a clean PPS from the Ref-1 OCXO, or is > it happy with what comes out of a typical GPS unit? > > > > -- > These are my opinions. I hate spam. > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] UBLOX LEA-5T Programming?
kb...@n1k.org said: > A $25 Ref-0 with the same GPS and a (now) documented MCU will do the same > thing as any other GPSDO. Does anybody know if the Ref-0 expects a clean PPS from the Ref-1 OCXO, or is it happy with what comes out of a typical GPS unit? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt and David Partridge divider board question
Hi A little quick clarification for those who don’t spend a lot of time studying PC board electro-magnetics: Reference conductor = that thing you labeled ground on the pc board. Ground = when you trip while walking the dog, it’s the thing you hit ( = earth) No that’s not the complete story, but it’s enough to get you going. = Think of what happens to a box with big leads on either side of it. Consider equal length cables. Looks a lot like a dipole with a connection in the center doesn’t it? That’s exactly what happens in some situations. The cables pick up the RF and max current hits right in the middle … === Hope that helps. Bob > On Oct 12, 2015, at 4:25 PM, Chris Caudle wrote: > > On Mon, October 12, 2015 9:08 am, Chris Wilson wrote: >> I have found when the TX is on at 136kHz the Trimble / divider >> baord output goes wild and a clean square wave goes seemingly random >> on my scope with noise. > > How are your input and output cables physically configured? I noticed on > the link that Dave just posted that he uses a divider board inside a > conductive enclosure, and the input connectors are fed from short coax > cables which have their shields all connected to the same metal panel of > the enclosure. > The printed circuit board has input and outputs on opposite ends of the > board, and the connector shells appear to be connected to the circuit > reference conductor, which means that if the input and output cable > shields are not close together and connected together electrically very > well, all the shield current will be forced to flow across the printed > circuit board reference conductor. Perhaps with your transmitter > operating so closely it is resulting in a lot of ground bounce at the > various components on the divider board. > As you say, connecting the 10MHz directly without the divider in place > would help confirm or eliminate that possibility. > > -- > Chris Caudle > > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt and David Partridge divider board question
On Mon, October 12, 2015 9:08 am, Chris Wilson wrote: > I have found when the TX is on at 136kHz the Trimble / divider > baord output goes wild and a clean square wave goes seemingly random > on my scope with noise. How are your input and output cables physically configured? I noticed on the link that Dave just posted that he uses a divider board inside a conductive enclosure, and the input connectors are fed from short coax cables which have their shields all connected to the same metal panel of the enclosure. The printed circuit board has input and outputs on opposite ends of the board, and the connector shells appear to be connected to the circuit reference conductor, which means that if the input and output cable shields are not close together and connected together electrically very well, all the shield current will be forced to flow across the printed circuit board reference conductor. Perhaps with your transmitter operating so closely it is resulting in a lot of ground bounce at the various components on the divider board. As you say, connecting the 10MHz directly without the divider in place would help confirm or eliminate that possibility. -- Chris Caudle ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Trimble Thunderbolt and David Partridge divider board question
Hi The 10 MHz out of the TBolt is pretty much straight off the internal OCXO with only modest buffering. If the whole TBolt dies, you still get a clean looking 10 MHz out. Best guess is that the problem is in the divider board. That said, it’s RF overloading a system. The RF could easily be coming in through the TBolt and that’s the point that the fix (RF isolation) needs to be applied. It’s also quite possible that it’s coming back up the lines that are connected to the divider. Simple approach to debug the issue (check to see if the problem is there after each step): 1) Pull the antenna off of the TBolt, it will still work fine with no antenna. 2) Pull any serial cables off of the TBolt 3) Disconnect any cables off of the divider that aren’t needed for the TS-590. 4) Add a big fat ground strap between the TBolt and the divider 5) Add a big fat ground strap between the divider and the TS-590 6) Minimize the cable length between the TBolt and divider, same with divider and TS-590 If you have made it this far with no fix, chokes on the power supplies are the next step. Bob > On Oct 12, 2015, at 10:08 AM, Chris Wilson wrote: > > > > 12/10/2015 14:58 > > I have had my Trimble and Dave's divider board for many years and it's > on 24 hours a day, seven days a week, no problems. > https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4QFjAAahUKEwjr27ewjb3IAhVMVhQKHVmJALI&url=http%3A%2F%2Fwww.perdrix.co.uk%2FFrequencyDivider%2FFrequency%2520Divider%25202.1.pdf&usg=AFQjCNHiXeXt-NZksvMBKYHfkJPf5mn_Fw&sig2=YJooGHWI_easGkSZHUVPJgThe > Trimble uses a mushroom roof mounted aerial. I have recently built up > an amateur band 136Khz station giving about 800 Watts into a terribly > inefficient (electrically very very short) Marconi T aerial witha > horizontal wire loop capacitive top hat. I have used the 10MHz out of > Dave's divider board to lock a master oscillator in my Kenwood TS-590 > transceiver, which is the driver for my 136kHz amp, giving just 0 dBm > out. I have found when the TX is on at 136kHz the Trimble / divider > baord output goes wild and a clean square wave goes seemingly random > on my scope with noise. This unlocks the TS-590, blah blah. > > My questions are, is this likely to be RF affecting the Trimble, or > the board? the baord feeds a panel in my shck with its vearious > frequency divisions, the 10MHz output goes to the Kenwood TS-590 > reference locking gizmo. The scope shows noise from a disconnected > RG-316 co-ax at the panel end. Should I get up in the loft and try > connecting the 10MHz direct from the Trimble and leave the board out > as a test? Does anyone know if a strong 136kHz signal is likely to > affect the Trimble itself? > > Thanks. > > -- > Best Regards, > Chris Wilson. > mailto: ch...@chriswilson.tv > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Trimble Thunderbolt and David Partridge divider boardquestion
>Tom Van Baak tvb at LeapSecond.com >Mon Oct 12 11:31:17 EDT 2015 > >"For those of you who want to follow the link Chris provided >without his personal google search metadata, the correct URL is: > http://www.perdrix.co.uk/FrequencyDivider/Frequency%20Divider%202.pdf I believe that the link above shows photos of the original board from 2008 and the link below goes to photos of the updated 2010 board that I bought that has 4 added 6800 Mf capacitors. Pretty much the same other than that. http://www.perdrix.co.uk/FrequencyDivider/ -Arthur ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Jackson Labs M12M Replacement Receiver
Tom, The JLT M12M replacement receiver should work in the Commsync II. If you find any issues we would work to fix them a firmware update. Keith Keith On Wed, Oct 7, 2015 at 8:46 PM, Tom Knox wrote: > In my humble opinion Jackson Labs continues to raise the bar in GPS time > and frequency with products that are compact, reasonably price, and most of > all offer exceptional performance. Any idea if these will plug and play in > my FEI/Zyfer Commsync II"s > Thanks All > Thomas Knox > > > > > Date: Wed, 7 Oct 2015 14:44:03 -0700 > > From: keith.loise...@gmail.com > > To: time-nuts@febo.com > > Subject: Re: [time-nuts] Jackson Labs M12M Replacement Receiver > > > > If you are interested in purchasing you can do so directly through our > ebay > > listing here: > > http://www.ebay.com/itm/-/181896123655 > > > > But, please contact me if you have any questions. > > > > Thanks, > > Keith > > > > > > > > Keith > > > > On Wed, Oct 7, 2015 at 7:14 AM, Keith Loiselle > > > wrote: > > > > > Hello everyone, > > > > > > > > > > > > Since there are many Fury GPSDO users here and many other users of the > > > Motorola M12+ and M12M timing receivers, we wanted to introduce our new > > > product which is an M12M compatible timing and navigation receiver that > > > uses the latest uBlox M8T GNSS receiver, and is a one-to-one > replacement > > > for the aging, and hard to use Motorola/iLotus GPS receiver. > > > > > > > > > > > > This is kind of like a super M12M, with significant improvements in the > > > 1PPS timing accuracy and stability, support for receiving two of any > of the > > > standard GNSS systems at any one time (GPS with SBAS, Glonass, QZSS, > > > BeiDou, and soon Galileo), and true plug-and-play operation. It should > work > > > in pretty much most Motorola M12+ and M12M binary command applications. > > > > > > > > > > > > The unit is a form-fit-function compatible replacement for the > M12M/M12+ > > > receivers, and has been qualified on the JLT Fury GPSDO as well as the > > > Microsemi/Symmetricom XLI, and provides a massive upgrade in GNSS > > > performance such as -167dBm tracking capability (think indoors > reception > > > may now be possible under certain circumstances), 72 channels > capability > > > for very fast cold-start and re-acquisition, and multi-GNSS support. > > > > > > > > > > > > It has some additional features such as: > > > > > > * Two USB ports, one for easy SCPI control, one for full access to > the > > > uBlox commands for setup, as well as Carrier Phase, Almanac, and > Ephemeris > > > data. The unit can also be powered via the USB ports and used > stand-alone > > > sitting on a desk etc. There is no setup required though > out-of-the-box, > > > all setup is optional > > > > > > * 7-Segment LED status display and 5 additional status LEDs show GNSS > > > status, fix status, signal strength, UTC time, and number of sats > tracked > > > > > > * DIP switch for easy configuration of which GNSS systems should be > > > enabled, Position Hold mode versus 3D Mobile mode, etc (these settings > can > > > be over-written by USB commands) > > > > > > * 1Hz to 10MHz+ buffered Synthesized (NCO) output that is > > > frequency-locked to the GNSS system, and can be easily configured > through > > > the USB ports > > > > > > * Position Hold mode with Auto Survey, or full 3D mobile mode > (selectable > > > via USB, Motorola binary command, or via the DIP switch), supporting > full > > > Auto Kalman setup depending on vehicle dynamics (including > auto-selection > > > of Carrier Phase versus Doppler tracking etc) > > > > > > You can find out more in the User Manual and Spec Sheet available here: > > > > > > > > > > http://www.jackson-labs.com/assets/uploads/main/M12M_replacement_UserManual.pdf > > > > > > > > > and > > > > > > > > > > > > > http://www.jackson-labs.com/assets/uploads/main/M12M_replacement_Specsheet.pdf > > > > > > We are making this unit available to Time Nuts users for a special > pricing > > > of $185 per unit plus shipping. Pricing will revert to the list price > of > > > $220 at the end of this month. We are asking for anyone using the M12+ > or > > > M12M receivers in other than the Fury or XLI GPSDOs to help us test > > > compatibility with those systems, and hope to have as many different > > > products as possible tested out with your help. > > > > > > > > > > > > Please contact me OFFLINE(!) if you are interested in this unit. > > > > > > Thanks, > > > Keith > > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list --
Re: [time-nuts] Trimble Thunderbolt and David Partridge divider boardquestion
For those of you who want to follow the link Chris provided without his personal google search metadata, the correct URL is: http://www.perdrix.co.uk/FrequencyDivider/Frequency%20Divider%202.pdf /tvb - Original Message - From: "Chris Wilson" To: "Discussion of precise time and frequency measurement" Sent: Monday, October 12, 2015 7:08 AM Subject: [time-nuts] Trimble Thunderbolt and David Partridge divider boardquestion > 12/10/2015 14:58 > > I have had my Trimble and Dave's divider board for many years and it's > on 24 hours a day, seven days a week, no problems. > https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4QFjAAahUKEwjr27ewjb3IAhVMVhQKHVmJALI&url=http%3A%2F%2Fwww.perdrix.co.uk%2FFrequencyDivider%2FFrequency%2520Divider%25202.1.pdf&usg=AFQjCNHiXeXt-NZksvMBKYHfkJPf5mn_Fw&sig2=YJooGHWI_easGkSZHUVPJgThe > Trimble uses a mushroom roof mounted aerial. I have recently built up ... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Trimble Thunderbolt and David Partridge divider board question
12/10/2015 14:58 I have had my Trimble and Dave's divider board for many years and it's on 24 hours a day, seven days a week, no problems. https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4QFjAAahUKEwjr27ewjb3IAhVMVhQKHVmJALI&url=http%3A%2F%2Fwww.perdrix.co.uk%2FFrequencyDivider%2FFrequency%2520Divider%25202.1.pdf&usg=AFQjCNHiXeXt-NZksvMBKYHfkJPf5mn_Fw&sig2=YJooGHWI_easGkSZHUVPJgThe Trimble uses a mushroom roof mounted aerial. I have recently built up an amateur band 136Khz station giving about 800 Watts into a terribly inefficient (electrically very very short) Marconi T aerial witha horizontal wire loop capacitive top hat. I have used the 10MHz out of Dave's divider board to lock a master oscillator in my Kenwood TS-590 transceiver, which is the driver for my 136kHz amp, giving just 0 dBm out. I have found when the TX is on at 136kHz the Trimble / divider baord output goes wild and a clean square wave goes seemingly random on my scope with noise. This unlocks the TS-590, blah blah. My questions are, is this likely to be RF affecting the Trimble, or the board? the baord feeds a panel in my shck with its vearious frequency divisions, the 10MHz output goes to the Kenwood TS-590 reference locking gizmo. The scope shows noise from a disconnected RG-316 co-ax at the panel end. Should I get up in the loft and try connecting the 10MHz direct from the Trimble and leave the board out as a test? Does anyone know if a strong 136kHz signal is likely to affect the Trimble itself? Thanks. -- Best Regards, Chris Wilson. mailto: ch...@chriswilson.tv ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] UPS for my time rack
My apologies in advance for further putting tension on this OT thread, but one of the great stories from the early days of Usenet concerned a really large UPS system for a data center. In the late 80s the Digital Equipment Corp VAX computer was among the most powerful you could buy. If you can accept that amount of time travel, follow this link: http://www.hactrn.net/sra/vaxen.html or Google "vaxen immortal power" The reference to October 19, 1987, is to the first computer failure to have a major effect on the stock market. Enjoy, as they say Bill Hawkins ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
