Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...
Ah, hadn't spotted the latches. I've used something similar in the past, might still have a couple around somewhere, but my first inclination would be to convert them to standard screw types. That's assuming they would fit of course, but Anthony's photos suggest they should. Regards Nigel GM8PZR In a message dated 24/10/2014 06:26:26 GMT Daylight Time, tmiller11...@verizon.net writes: I am surprised the schematics for these have not surfaced yet. Are they not out of support now? I got a set and am awaiting on a power supply and some connectors. Anyone have a source for the latches for the D connectors? Tom - Original Message - From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 23, 2014 10:39 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... My curiosity got the better of me so I ordered these earlier this week and received them today. I've powered both up and quickly measured the 10MHz output. I don't yet have a GPS antenna feed that I can connect, so couldn't check that out. And I need to look into why both of the units have the Fault and StdBy lights illuminated. I was surprised how compact they are and they weight next to nothing. And they are very nicely made. I took the tops off both and took some photos (see http://goo.gl/87e8GG), but have not ventured into unscrewing everything to get to the bottom of the boards. From the top, I didn't immediately spot anything extra on the board for the 10MHz out. All the extras appear to be for the GPS, but the underside of the boards may tell a different story. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 23, 2014 12:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... My units came in today. What I got appears to be new-in-box. It's probably the only thing I'll ever get with a blue Agilent sticker on the box. =) It has a yellow Symmetricom notice inside the box. The circuit board appears to be the same on both units, but that says nothing about the firmware, of course. The REF-1 has an Oncore receiver labeled TM-AB - whichever one that is, small parts to support it, and a TNC connector for the GPS receiver. The REF-0 is missing everything related to the receiver, and has an SMA for the 10MHz output in the space where the REF-1 has the TNC along with a few extra small parts. This is a shared space with both SMA and TNC pads, though they don't seem to share the same electrical path. Since the SMA and TNC share the same physical space, even if the 10MHz is available somewhere, you'd have to do some surgery on the case before you could bring it out. Probably by adding a hole in the case for the GPS antenna and using the pad space for the SMA. It will be a day or two before I have the bits to apply power and connect an antenna. So, that's what I know. I'd probably just break something if I tried to find and bring out the 10MHz, so I'll have to leave that to someone else. But, the appropriate signals need to get between the boards, so I wonder what's on the Interface pins? Maybe just arbitration, 1PPS, and sawtooth comms? In my case, I do need the 10MHz, so I'm just as happy to have bought both units at this point. Maybe, down the road, someone will come up with the mods to convert a REF-1 into a REF-0, and vice versa, unless the firmware prevents that. Bob From: GandalfG8--- via time-nuts time-nuts@febo.com To: time-nuts@febo.com Sent: Tuesday, October 21, 2014 5:59 AM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... It seems from the auction revision table that this seller has been offering these for some time, so perhaps another hidden gem:-), but it's perhaps also worth noting that if this system functions on similar principles to earlier RFTG kit then the GPS conditioning is only applied to the unit actually containing the GPS module, with the other unit intended as a standby should the first one fail. In other words, unless the system redundancy is really required most users would probably only need the GPS based unit, or would at least be better off buying two of those for the same money that the matched pair would cost. The only advantage, as far as I'm aware anyway, of the non-GPS unit is that it contains a 10MHz output. However, Skip Withrow published modification details in January 2013 showing how straightforward it was to add the the 10MHz output, to the RFTGm-II-XO module, the PCB location for the socket was already available, so I would suspect
Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...
At the bottom right of the page is a list of slidelocks. You should be able to put together what you need from that. http://www.mouser.com/catalogviewer/default.aspx?page=1605highlight=706-160X10689Xcatalogculture=en-UScatalog=647 Bob - AE6RV From: Tom Miller tmiller11...@verizon.net To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 23, 2014 11:27 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... I am surprised the schematics for these have not surfaced yet. Are they not out of support now? I got a set and am awaiting on a power supply and some connectors. Anyone have a source for the latches for the D connectors? Tom - Original Message - From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 23, 2014 10:39 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... My curiosity got the better of me so I ordered these earlier this week and received them today. I've powered both up and quickly measured the 10MHz output. I don't yet have a GPS antenna feed that I can connect, so couldn't check that out. And I need to look into why both of the units have the Fault and StdBy lights illuminated. I was surprised how compact they are and they weight next to nothing. And they are very nicely made. I took the tops off both and took some photos (see http://goo.gl/87e8GG), but have not ventured into unscrewing everything to get to the bottom of the boards. From the top, I didn't immediately spot anything extra on the board for the 10MHz out. All the extras appear to be for the GPS, but the underside of the boards may tell a different story. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 23, 2014 12:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... My units came in today. What I got appears to be new-in-box. It's probably the only thing I'll ever get with a blue Agilent sticker on the box. =) It has a yellow Symmetricom notice inside the box. The circuit board appears to be the same on both units, but that says nothing about the firmware, of course. The REF-1 has an Oncore receiver labeled TM-AB - whichever one that is, small parts to support it, and a TNC connector for the GPS receiver. The REF-0 is missing everything related to the receiver, and has an SMA for the 10MHz output in the space where the REF-1 has the TNC along with a few extra small parts. This is a shared space with both SMA and TNC pads, though they don't seem to share the same electrical path. Since the SMA and TNC share the same physical space, even if the 10MHz is available somewhere, you'd have to do some surgery on the case before you could bring it out. Probably by adding a hole in the case for the GPS antenna and using the pad space for the SMA. It will be a day or two before I have the bits to apply power and connect an antenna. So, that's what I know. I'd probably just break something if I tried to find and bring out the 10MHz, so I'll have to leave that to someone else. But, the appropriate signals need to get between the boards, so I wonder what's on the Interface pins? Maybe just arbitration, 1PPS, and sawtooth comms? In my case, I do need the 10MHz, so I'm just as happy to have bought both units at this point. Maybe, down the road, someone will come up with the mods to convert a REF-1 into a REF-0, and vice versa, unless the firmware prevents that. Bob From: GandalfG8--- via time-nuts time-nuts@febo.com To: time-nuts@febo.com Sent: Tuesday, October 21, 2014 5:59 AM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... It seems from the auction revision table that this seller has been offering these for some time, so perhaps another hidden gem:-), but it's perhaps also worth noting that if this system functions on similar principles to earlier RFTG kit then the GPS conditioning is only applied to the unit actually containing the GPS module, with the other unit intended as a standby should the first one fail. In other words, unless the system redundancy is really required most users would probably only need the GPS based unit, or would at least be better off buying two of those for the same money that the matched pair would cost. The only advantage, as far as I'm aware anyway, of the non-GPS unit is that it contains a 10MHz output. However, Skip Withrow published modification details in January 2013 showing how straightforward it was to add the the 10MHz output, to the RFTGm-II-XO module, the PCB location for the socket was already available,
Re: [time-nuts] If any of your USB devices have stopped working lately...
On Thu, Oct 23, 2014 at 09:02:37PM -0500, Bill Dailey wrote: Well..if they didn't properly license the technology... They should be disabled. The problem is the fine print...where FTDI also states they won't support any chip they actually made before 2012...so some of those being disabled are possibly true counterfeits, and some are legitimate but insecured FTDI chips. --msa ___ 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] If any of your USB devices have stopped working lately...
On Fri, 24 Oct 2014 01:45:16 + Mark Sims hol...@hotmail.com wrote: Happened to a friend of mine. All his Arduino stuff died. This could be the reason: http://www.eevblog.com/forum/reviews/ftdi-driver-kills-fake-ftdi-ft232 Short story: FTDI released a new version of their USB driver (via Windows automatic updates no less) that bricks other vendor's compatible versions of their interface chip. They also updated their license file to indicate that this may happen... except you never get a chance to decline the new license with automatic driver updates. I can just hear the class action lawyers drooling... ___ time-nuts mailing As a rule of thumb, never let windows update anything that isn't from Microsoft. What I do is if MS says I should update something, I go to that manufacturer and look at the update. MS update has been known to supply the wrong update when it comes to non-MS software. ___ 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] If any of your USB devices have stopped working lately...
I read somewhere that you can pay FTDI and re-enable the devices but further in the article it said they would be permanently disabled in windows. Confusing. On Thu, Oct 23, 2014 at 10:47 PM, jim s jwsm...@jwsss.com wrote: Petty BS. If they want to disable the competitors, rev the device to have something that they can use to id their devices, and leave the other driver alone. USB supposed to put the widest support in the host end, and the secret sauce in the device. If they have a problem, they will not produce anyone with a dead device wanting to ever do business with them by disabling infringing devices. If they put out a message or such, but still worked with their driver fine. Else I will expect a generic unsigned driver to be out, which can be installed and will again work with all. That isn't desirable for anyone, but if that is what it takes to get going, most will install the unsigned driver, then mark FTDI devices forever off their list. They aren't the only ones with the secret sauce. I've seen several others, and had I known about them planning to do this would have gone with them, and not FTDI. There are only a few things that I have that have incorporated FTDI in, and I'm going to look at dumping that code and device now. Jim On 10/23/2014 8:01 PM, Paul Berger wrote: Unfortunately the issue that FTDI is trying to combat is counterfeiters, and I think you will find that the counterfeit devices will report the same product and vendor id as the genuine ones. The product and vendor ids are how the OS identifies a device and how they decide which device driver should be used. Apparently at least some of these counterfeit devices are not perfect copies or else a device driver would be unable distinguish them from genuine. It is like a number of years ago when cable TV companies where having a lot of trouble with counterfeit cable descramblers, they found a flaw in the code used in them and transmitted what became know as a magic bullet that caused them to fail. Paul. On 2014-10-23 11:30 PM, Chris Albertson wrote: On Thu, Oct 23, 2014 at 7:05 PM, paul swed paulsw...@gmail.com wrote: Umm I think its profoundly hard to know one way or another what chip you have in a widget. Before you buy it yes, you can't know. But it's trivial to find out after you own it. For example click the Apple logo then choose about this Mac and the data is there. For example it says this random USB thumb drive I have is Product ID: 0x3260 Vendor ID: 0x0aec (Neodio Technologies Corporation) Version: 1.00 Serial Number: 20040602032741578 This same exact information is logged every time the device is inserted to my Linux system too. I assume MS Windows will tell you all the vendor info as well. The vendor IDs are handed out to manufacturers by an outfit at usb.org . So, check your devices. It's not hard to find out about the ones you have. This is pretty insane actually. I buy products that I believe are legit no way to know just as if the cpu in my acer or emachines not legal. Heck I have no idea. Regards Paul WB8TSL On Thu, Oct 23, 2014 at 10:02 PM, Bill Dailey docdai...@gmail.com wrote: Well..if they didn't properly license the technology... They should be disabled. Sent from my iPad On Oct 23, 2014, at 8:45 PM, Mark Sims hol...@hotmail.com wrote: Happened to a friend of mine. All his Arduino stuff died. This could be the reason: http://www.eevblog.com/forum/reviews/ftdi-driver-kills- fake-ftdi-ft232 Short story: FTDI released a new version of their USB driver (via Windows automatic updates no less) that bricks other vendor's compatible versions of their interface chip. They also updated their license file to indicate that this may happen... except you never get a chance to decline the new license with automatic driver updates. I can just hear the class action lawyers drooling... ___ 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 -- 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 -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/
Re: [time-nuts] If any of your USB devices have stopped working lately...
Hi Licensing a legit USB ID costs money, both up front and ongoing. Writing drivers that keep up with the OS rev’s costs money. Supporting all this stuff with web sites and on the phone costs money. FTDI supports their products much better than the “other guys” you could buy from. That’s why they counterfeit the FTDI parts. If FTDI continues to support “all the old stuff” forever, then the counterfeiters simply dupe the old parts. Free ride / lower price / fewer costs. FTDI does all the support for their products. They have *no* responsibility to support stuff that was stolen from them. How much does the silicon cost on a typical chip - a few cents. How much does all the support stuff cost - a buck or more. The difference is not a small one at all. Bob On Oct 23, 2014, at 11:47 PM, jim s jwsm...@jwsss.com wrote: Petty BS. If they want to disable the competitors, rev the device to have something that they can use to id their devices, and leave the other driver alone. USB supposed to put the widest support in the host end, and the secret sauce in the device. If they have a problem, they will not produce anyone with a dead device wanting to ever do business with them by disabling infringing devices. If they put out a message or such, but still worked with their driver fine. Else I will expect a generic unsigned driver to be out, which can be installed and will again work with all. That isn't desirable for anyone, but if that is what it takes to get going, most will install the unsigned driver, then mark FTDI devices forever off their list. They aren't the only ones with the secret sauce. I've seen several others, and had I known about them planning to do this would have gone with them, and not FTDI. There are only a few things that I have that have incorporated FTDI in, and I'm going to look at dumping that code and device now. Jim On 10/23/2014 8:01 PM, Paul Berger wrote: Unfortunately the issue that FTDI is trying to combat is counterfeiters, and I think you will find that the counterfeit devices will report the same product and vendor id as the genuine ones. The product and vendor ids are how the OS identifies a device and how they decide which device driver should be used. Apparently at least some of these counterfeit devices are not perfect copies or else a device driver would be unable distinguish them from genuine. It is like a number of years ago when cable TV companies where having a lot of trouble with counterfeit cable descramblers, they found a flaw in the code used in them and transmitted what became know as a magic bullet that caused them to fail. Paul. On 2014-10-23 11:30 PM, Chris Albertson wrote: On Thu, Oct 23, 2014 at 7:05 PM, paul swed paulsw...@gmail.com wrote: Umm I think its profoundly hard to know one way or another what chip you have in a widget. Before you buy it yes, you can't know. But it's trivial to find out after you own it. For example click the Apple logo then choose about this Mac and the data is there. For example it says this random USB thumb drive I have is Product ID: 0x3260 Vendor ID: 0x0aec (Neodio Technologies Corporation) Version: 1.00 Serial Number: 20040602032741578 This same exact information is logged every time the device is inserted to my Linux system too. I assume MS Windows will tell you all the vendor info as well. The vendor IDs are handed out to manufacturers by an outfit at usb.org. So, check your devices. It's not hard to find out about the ones you have. This is pretty insane actually. I buy products that I believe are legit no way to know just as if the cpu in my acer or emachines not legal. Heck I have no idea. Regards Paul WB8TSL On Thu, Oct 23, 2014 at 10:02 PM, Bill Dailey docdai...@gmail.com wrote: Well..if they didn't properly license the technology... They should be disabled. Sent from my iPad On Oct 23, 2014, at 8:45 PM, Mark Sims hol...@hotmail.com wrote: Happened to a friend of mine. All his Arduino stuff died. This could be the reason: http://www.eevblog.com/forum/reviews/ftdi-driver-kills-fake-ftdi-ft232 Short story: FTDI released a new version of their USB driver (via Windows automatic updates no less) that bricks other vendor's compatible versions of their interface chip. They also updated their license file to indicate that this may happen... except you never get a chance to decline the new license with automatic driver updates. I can just hear the class action lawyers drooling... ___ 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
Re: [time-nuts] If any of your USB devices have stopped working lately...
On 10/23/14, 9:14 PM, John Allen wrote: Hi Rick - I believe it was CompuServe (which AOL later bought.) It didn't really cause any trouble... Regards, John K1AE -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Richard (Rick) Karlquist Sent: Thursday, October 23, 2014 10:31 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] If any of your USB devices have stopped working lately... This dispute reminds me of another one. A long long time ago, .gif was the internet standard for encoding photographs. Far and away the favorite. Then the owner (was it AOL?) decided to enforce their patent by getting snotty with end users. Almost overnight, .gif virtually disappeared off the face of the earth, to be replaced by .jpg, previously an also-ran. The IP holder got their wish We wish people would stop free loading on our IP.. Be careful what you wish for as the saying goes. Let's see if history repeats itself. Rick It wasn't GIF, per se (which was promulgated by CompuServe), but the fact that it is LZW compression, which was patented by Welch and assigned to Unisys in the mid 80s (so the patent has expired by now) Other compression schemes by Lempel and Ziv were also patented (earlier). ___ 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] If any of your USB devices have stopped working lately...
Jim Lux wrote: ... This dispute reminds me of another one. A long long time ago, .gif was the internet standard for encoding photographs. Far and away the favorite. Then the owner (was it AOL?) decided to enforce their patent by getting snotty with end users. Almost overnight, .gif virtually disappeared off the face of the earth, to be replaced by .jpg, previously an also-ran. The IP holder got their wish We wish people would stop free loading on our IP.. Be careful what you wish for as the saying goes. Let's see if history repeats itself. Rick It wasn't GIF, per se (which was promulgated by CompuServe), but the fact that it is LZW compression, which was patented by Welch and assigned to Unisys in the mid 80s (so the patent has expired by now) Other compression schemes by Lempel and Ziv were also patented (earlier). Yep! The thing we need to bear in mind is that Welch, etal, were pretty well compensated by the customers to which they had licensed the LZW algorithms. The free users were paying nothing to LZW, and were causing LZW's licensed customers to wonder why they were paying big bucks for algorithms that were being universally used for free. So, even though GIF (which had nothing to do with LZW, other than infringing the patent) lost its great market share, that happening had no apparent effect on LZW's bottom line. A different company (Microsoft), when faced with a very similar situation (MSBasic on CPM systems), leveraged the publicity and good will provided by the free users, into the leviathan company that is Microsoft today. LZW took the straight hard line and eschewed the fame and glory that came with being the heart of the GIF adhoc standard, and where are they today? Business is a tricky business. -Chuck Harris ___ 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] Efratom FRT-H Lamp removal and supply schematic
Hi all, I've been working on bringing two Efratom FRT units back to life. One is locking in 10min, and the other took about an hour, but lost lock after 8h. Any advice on how to unscrew the Rb bulb on the FRK assy? either is galled/very tight or left handed thread? also, does anyone have a schematic for the FRT supply that includes a thermistor screwed on the unit chassis ? I've found an operation and service manual on the net, but doesn't quite match these units' power supply. Both were DOA, fixed both units divider/buffer assemblies by replacing 10u shorted tantalum caps, and one FRK assy by replacing a mosfet for the lock monitor out. Funny for the curious, one is labeled efratom frt, and the newer one has a Panav RIBIDIUM FREQUENCY STANDARD (sic) rebranded front panel. Yes. Also has a Ribidium lamp (sic) position in the front selector. Cheers, Sebastian ___ 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] If any of your USB devices have stopped working lately...
just look that: http://zeptobars.ru/en/read/FTDI-FT232RL-real-vs-fake-supereal 73 Alex ___ 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] If any of your USB devices have stopped working lately...
Thanks, that was the final link I hope someone would post. I have many more links, but this is not the right forum for that. Now, everyone - STOP posting FTDI information to time-nuts. We are a precise time frequency list. If you want to discuss FTDI or Windows driver issues please subscribe to the excellent http://www.eevblog.com, or several other electronics, hobby, hacker, Windows, legal, business, USB forums that deal with stuff like this. It's all over the net. It's really quite interesting, at many levels! It hits me too. But it doesn't belong here. So, please keep time-nuts about precision time frequency. Use the rest of the web for non-TF stuff. Thanks, /tvb ___ 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] Efratom FRT-H Lamp removal and supply schematic
Sebastion, Let the unit warm up for 10 minutes, then power down and then try the lamp removal. It turns CCW to remove. Use a BIG screwdriver! Cheers, Corby ___ 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] GPS for ntp
Joe, et al. I put some info at: http://leapsecond.com/pages/reyax/ Here's what you need to know about those Reyax GPS boards: 1) These are simple, well-made, low-cost, tiny GPS boards. Four models are available, based on three u-blox chips. The prices are $14 $16 $20 $27. 2) The 3 chips are u-blox MAX-7C, NEO-7N, NEO-M8N. See http://www.u-blox.com for chip info. Board documentation: http://www.reyax.com/Module/GPS/RYN25AI/RYN25AI.pdf http://www.reyax.com/Module/GPS/RY725AI/RY725AI.pdf http://www.reyax.com/Module/GPS/RY825AI/RY825AI.pdf 3) The 4 boards available: http://www.ebay.com/itm/171493874434 http://www.ebay.com/itm/181553452840 http://www.ebay.com/itm/181562403752 http://www.ebay.com/itm/181566850426 4) The only difference between the $14 RYN25AI and $16 RYN25DI is that RYN25DI adds a ±10 V RS232 transceiver. The other 3 boards have a typical inverted logic-level (3.3V) serial interface, suitable for uP or SBC or UART/USB interface chip. I have no affiliation with seller reyax but their boards seem a step above some of the other GPS stuff on eBay. In general I gravitate to low-cost GPS receiver breakout boards with serial I/O and clean 1PPS output. It's amazing how well these integrated antenna boards work: a truly 3-pin timing solution: power, ground, 1PPS. Note these are not timing receivers in the sense of RINEX output or external clock input or position-hold with sawtooth correction. But for less demanding work, the ±20 ns level that many of these receivers offer more than enough. 5) You can also find similar boards from US sellers such as http://parallax.com/ , http://adafruit.com/ , http://sparkfun.com/ 6) All of this is grossly overkill for NTP (at the 1 ms or even 1 us level). But if some of you are pushing NTP to sub-microsecond limits, cheap GPS/1PPS receivers like this are of interest. For more details, including almost medical-grade photos of a GPS patch antenna, see: http://leapsecond.com/pages/reyax/ /tvb - Original Message - From: Joseph Gray jg...@zianet.com To: brian.ing...@systematicsw.ab.ca; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 23, 2014 9:18 PM Subject: Re: [time-nuts] GPS for ntp OK, I see source of the confusion. There is a difference of one character in the two part numbers. The RYN25 has the older Ublox chipset. The RY725 has the Neo-7N chipset. There is only a $6 difference in price. I think I'll get a few to play with. Joe Gray W5JG ___ 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] Changing ADEV, (was Phase, One edge or two?)
Bob Camp posted (Wed Oct 22 20:38:47 EDT 2014) Re: [time-nuts] Phase, One edge or two? ADEV most certainly does change with time, even for short tau's. Can you elaborate? Such as when, why, what kind of change, how much change, at how short of tau's, over how long of time, and using what type Oscillators? Do you know what in the freq or Phase plot is causing the ADEV to change? There all kinds of Oscillator things that change over time and/or need a lot of time to properly measure, but I was under the impression that this is not the case for short tau ADEV. Of the many OCXO type Oscillators that I've tested (HP10811 MV89), seldom have I seen any significant change (say greater than 10%), in the short tau (0.01 sec to 1 sec) ADEV values, after the systematic type errors are removed. (even when starting soon after turn on) ADEV is used to measure random types of noise so there are of course the statistical uncertainty variations that are a function of the number of valid data points. I find that using a minimum of a thousand points at each tau gives good consistent results. What I have seen when measuring the ADEV on time nut type Osc, is that it generally takes only a couple of minutes to get enough samples to reliability predict what the short term tau is when using a fast (120 sps), high resolution (0.1ps) tester. Trouble shooting hint: If the 0.1 sec to 10 second ADEV tau plot is not flat on a good time nut type undisciplined OXCO, then the first places to look for problems is in the tester, or the setup, or the procedure, not the oscillator. ws ___ 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] GPS for ntp
Tom, Thanks for the information and your comments as to the suitability of these units. First hand knowledge is always appreciated. I had already figured out that there were four models :-) I was reading the documentation from ublox and the time stamping interrupt caught my eye. However, it is listed as only being available on the R model. I can't find anyone selling that model. Timestamping a message to the nearest 100 ns is what I am after. If I can't do it directly with the ublox, I'll have to look at the PRU on the Beaglebone. It has a 200 Mhz clock and single cycle instructions. Joe Gray W5JG On Oct 24, 2014 1:39 PM, Tom Van Baak t...@leapsecond.com wrote: Joe, et al. I put some info at: http://leapsecond.com/pages/reyax/ Here's what you need to know about those Reyax GPS boards: 1) These are simple, well-made, low-cost, tiny GPS boards. Four models are available, based on three u-blox chips. The prices are $14 $16 $20 $27. 2) The 3 chips are u-blox MAX-7C, NEO-7N, NEO-M8N. See http://www.u-blox.com for chip info. Board documentation: http://www.reyax.com/Module/GPS/RYN25AI/RYN25AI.pdf http://www.reyax.com/Module/GPS/RY725AI/RY725AI.pdf http://www.reyax.com/Module/GPS/RY825AI/RY825AI.pdf 3) The 4 boards available: http://www.ebay.com/itm/171493874434 http://www.ebay.com/itm/181553452840 http://www.ebay.com/itm/181562403752 http://www.ebay.com/itm/181566850426 4) The only difference between the $14 RYN25AI and $16 RYN25DI is that RYN25DI adds a ±10 V RS232 transceiver. The other 3 boards have a typical inverted logic-level (3.3V) serial interface, suitable for uP or SBC or UART/USB interface chip. I have no affiliation with seller reyax but their boards seem a step above some of the other GPS stuff on eBay. In general I gravitate to low-cost GPS receiver breakout boards with serial I/O and clean 1PPS output. It's amazing how well these integrated antenna boards work: a truly 3-pin timing solution: power, ground, 1PPS. Note these are not timing receivers in the sense of RINEX output or external clock input or position-hold with sawtooth correction. But for less demanding work, the ±20 ns level that many of these receivers offer more than enough. 5) You can also find similar boards from US sellers such as http://parallax.com/ , http://adafruit.com/ , http://sparkfun.com/ 6) All of this is grossly overkill for NTP (at the 1 ms or even 1 us level). But if some of you are pushing NTP to sub-microsecond limits, cheap GPS/1PPS receivers like this are of interest. For more details, including almost medical-grade photos of a GPS patch antenna, see: http://leapsecond.com/pages/reyax/ /tvb - Original Message - From: Joseph Gray jg...@zianet.com To: brian.ing...@systematicsw.ab.ca; Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 23, 2014 9:18 PM Subject: Re: [time-nuts] GPS for ntp OK, I see source of the confusion. There is a difference of one character in the two part numbers. The RYN25 has the older Ublox chipset. The RY725 has the Neo-7N chipset. There is only a $6 difference in price. I think I'll get a few to play with. Joe Gray W5JG ___ 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] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...
Anthony Roby aroby at antamy.com wrote: My curiosity got the better of me so I ordered these earlier this week and received them today. I've powered both up and quickly measured the 10MHz output. I don't yet have a GPS antenna feed that I can connect, so couldn't check that out. And I need to look into why both of the units have the Fault and StdBy lights illuminated. I was surprised how compact they are and they weight next to nothing. And they are very nicely made. I took the tops off both and took some photos (see http://goo.gl/87e8GG), but have not ventured into unscrewing everything to get to the bottom of the boards. From the top, I didn't immediately spot anything extra on the board for the 10MHz out. All the extras appear to be for the GPS, but the underside of the boards may tell a different story. Without an antenna the units will not operate properly and the ON light will stay off. Near the front of the oscillator on the edge of the board is a hole marked J8. This is the 5Mhz sine wave from the oscillator and I fed this through a capacitor to my buffer amp to get 5Mhz out. -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] Changing ADEV, (was Phase, One edge or two?)
ADEV most certainly does change with time, even for short tau's. Can you elaborate? Such as when, why, what kind of change, how much change, at how short of tau's, over how long of time, and using what type Oscillators? Do you know what in the freq or Phase plot is causing the ADEV to change? I'm happy to let Bob answer his own claim here. I'm curious as well. Unless he's talking about thermal noise, in which case I now believe him 100%. OTOH, for time intervals of minutes to hours or days, the plotted ADEV can often vary. When in doubt, enable error bars in your ADEV calculations or use DAVAR in Stable32, or use Trace History of TmeLab to expose how little or much the computed ADEV depends on tau and N. In general, never do an ADEV calculation without visually checking the phase or frequency time series first. Of the many OCXO type Oscillators that I've tested (HP10811 MV89), seldom have I seen any significant change (say greater than 10%), in the short tau (0.01 sec to 1 sec) ADEV values, after the systematic type errors are removed. (even when starting soon after turn on) This is not my experience at all. Let's figure out what's happening to you. If all your standards look sort the same from tau 0.01 to tau 0.1 to tau 1 then either you need more oscillators to play with or maybe you have a measurement problem. This is especially true if you are doing post-comparator averaging. Averaging, by definition, tends to remove noise, to smooth things out. If your goal is to measure noise, the last thing you want to do is create any electronics or use any analog or digital or numerical filtering that removes or reduces the very thing you're trying to measure. I remind you of this page http://leapsecond.com/pages/adev-avg/ of the perils of averaging data. For most of the world, there's signal and noise. Signal good. Noise bad. But for us, measuring precision clocks, the noise is the signal. So don't do anything that removes or reduces noise. ADEV is used to measure random types of noise so there are of course the statistical uncertainty variations that are a function of the number of valid data points. I find that using a minimum of a thousand points at each tau gives good consistent results. Are you crazy? The minimum is just 3 or 4 or 5 data points. Not 1000! You should not see much difference at 10 or 100 or 1000 points. If so, something is wrong with your measurement model. If ADEV(tau) is *that* dependent on tau, check the frequency time-series. Consider removing drift or using HDEV instead of ADEV. We need to talk. If your logic was true, we'd all have to wait 3 years before we could compute the ADEV of a GPSDO at tau 1 day. /tvb ___ 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] GPS for ntp
On 24/10/2014 21:33, Joseph Gray wrote: Timestamping a message to the nearest 100 ns is what I am after. If I can't do it directly with the ublox, I'll have to look at the PRU on the Beaglebone. It has a 200 Mhz clock and single cycle instructions. The BBB has no less than 8 peripherals that will do event capture at under 100ns resolution, no need to mess around with the PRU. To be fair, pretty much any microprocessor would be capable of doing this, and an arduino or pic could be a lot cheaper way to go depending on your requirements. If you need to stick to a BBB: DMTIMER's 4 to 7 will do hardware capture, but they operate at 'only' 25mhz. The SoC also contains 3 eCAP units which operate at the OCP bus speed (100mhz / 10ns resolution) and can store up to 4 events. The last unit is also an eCAP unit, but it's a PRUSS peripheral and operates at the PRUSS clock speed (200mhz / 5ns resolution). The surprise is you _don't_ actually need to write PRU code to access it, all the PRUSS peripherals can also be controlled from the main ARM core (and similarly the PRU can access all the SoC peripherals). Using two hardware capture units, you can implement a simple (or as complex as you want to make it) interval timer and follow Tom's posting from a few days ago: https://www.febo.com/pipermail/time-nuts/2014-October/087356.html Cheers Simon ___ 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] Changing ADEV, (was Phase, One edge or two?)
Tom, On 10/24/2014 11:31 PM, Tom Van Baak wrote: ADEV most certainly does change with time, even for short tau's. Can you elaborate? Such as when, why, what kind of change, how much change, at how short of tau's, over how long of time, and using what type Oscillators? Do you know what in the freq or Phase plot is causing the ADEV to change? I'm happy to let Bob answer his own claim here. I'm curious as well. Unless he's talking about thermal noise, in which case I now believe him 100%. OTOH, for time intervals of minutes to hours or days, the plotted ADEV can often vary. When in doubt, enable error bars in your ADEV calculations or use DAVAR in Stable32, or use Trace History of TmeLab to expose how little or much the computed ADEV depends on tau and N. In general, never do an ADEV calculation without visually checking the phase or frequency time series first. You should make sure that you remove all forms of systematic effects before turning the residue random noise over to ADEV. If you have random noise being modulated in amplitude, you need to measure long enough for the averaging end not to have a great impact on the result. Of the many OCXO type Oscillators that I've tested (HP10811 MV89), seldom have I seen any significant change (say greater than 10%), in the short tau (0.01 sec to 1 sec) ADEV values, after the systematic type errors are removed. (even when starting soon after turn on) This is not my experience at all. Let's figure out what's happening to you. If all your standards look sort the same from tau 0.01 to tau 0.1 to tau 1 then either you need more oscillators to play with or maybe you have a measurement problem. This is especially true if you are doing post-comparator averaging. Averaging, by definition, tends to remove noise, to smooth things out. If your goal is to measure noise, the last thing you want to do is create any electronics or use any analog or digital or numerical filtering that removes or reduces the very thing you're trying to measure. I remind you of this page http://leapsecond.com/pages/adev-avg/ of the perils of averaging data. For most of the world, there's signal and noise. Signal good. Noise bad. But for us, measuring precision clocks, the noise is the signal. So don't do anything that removes or reduces noise. Systematic signals is however disturbances for the ADEV. ADEV is used to measure random types of noise so there are of course the statistical uncertainty variations that are a function of the number of valid data points. I find that using a minimum of a thousand points at each tau gives good consistent results. Are you crazy? The minimum is just 3 or 4 or 5 data points. Not 1000! You should not see much difference at 10 or 100 or 1000 points. If so, something is wrong with your measurement model. If ADEV(tau) is *that* dependent on tau, check the frequency time-series. Consider removing drift or using HDEV instead of ADEV. We need to talk. If your logic was true, we'd all have to wait 3 years before we could compute the ADEV of a GPSDO at tau 1 day. No, he is not crazy on this point. While the algorithm only needs 3 points to produce a value, that value will have so bad degrees of freedom that the confidence interval is WAAAY out there. The reason that we don't need to wait 3 years for tau of 1 day is that we learned to use interleaving spans of time. We have since had much more development in the algorithms to improve the degrees of freedom for the same N samples, all in an effort to achieve as small confidence interval as possible. Also, the degrees of freedom achieved varies with the tau0 multiple m, and with dominant noise-type. A great way to illustrate the point of degrees of freedom and the number of sample-points needed to get tight confidence intervals is to see how the high-tau end of a curve updates in TimeLab and behaves as the jiggeling end of a long rope, and as more samples comes in, the jiggeling end moves towards higher taus, but for a particular tau, the amplitude of the jiggeling decreases until it almost stops. This is the effect of the confidence intervals becoming tighter, the range within the real value is becomes smaller and eventually is very tight. The modern algorithms like TOTAL and Theo can cram out really impressive degrees of freedom for a particular set of N and m compared to older algorithms, which effectively translates into tighter confidence intervals for the same N and m. Cheers, Magnus ___ 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] Lucent KS-24361/Z3812A GPSDO initial setup
Sorry if these comments are a bit naive, but this is my first exposure to a Z38xx. I've got mine powered on and connected to the antenna. After referring to Stewart's original post (once again) I've managed to download HP's SATSTAT and get it running. When I connected to the REF-1 unit (with the receiver) all I get is comms errors. But when I connect to REF-0, Satstat seems quite happy. It's reporting the unit as a Z3812A. Is REF-0 the only one you can connect to, or is REF-1 mute till it's happy with the GPS receiver? The mode says Power-Up: GPS Acquisition, so I guess that's OK. I think things are progressing. It's attempting to survey, but reporting Suspended: poor geometry. I suppose with a little more time this will work itself out? It seems to be slowly tracking more sats, as it's now up to 5. I wonder if there's a way to shortcut the survey process using Satstat? I've got a 48 hour survey done on this antenna with the LEA-6T, so I should be able to input those figures, right? I'll see if I can find anything in a Satstat manual I found. Bob - AE6RV ___ 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] Changing ADEV, (was Phase, One edge or two?)
Hi Grab an OCXO that has been powered off for a long time. Turn it on and start plotting ADEV. Do it from about 10 minutes after turn on. Run 15 to 30 minute tests every so often for the first few hours. Come back the next day and run the same series for a few hours. Repeat a week later, and a month later. Curve fit out the drift and run the ADEV numbers out to 100 seconds tau. That’s true even if you compare the best of each batch. It really is getting better. Do that on enough oscillators and you will indeed find many that do get better (like 2X better for some, 10 or 20% for others) on ADEV after they have been on a while. —— Run an OCXO and watch the ADEV on the Time Pod. Look at enough of them and you will find some that drop ADEV for a while (say 10 minutes or so) and then climb by a bit (say 1.5:1). Hmmm, what’s going on? Look at the phase plot and there’s an abrupt shift in phase over some period ( which depends on the cause, there’s more than one possibility). Let’s say it’s 10 seconds. The whole ADEV plot climbs, not just the part for 10 second tau. Why - there’s energy there both at short and long tau. —— Look at a GPSDO / disciplined oscillator / temperature compensated Rb. Let it run for a good long time. If it’s got a loop that steps out to *long* time constants, it may only bump the frequency once every 15 minutes or longer. Plot the ADEV over the time segment when it steps and compare it to the time period it does not step. Short tau ADEV is worse at the step. Look at a very normal OCXO on your TimePod. After 100 seconds, the 1 second ADEV *should* be pretty well determined. After 1000 seconds it should be *very* well determined. Flip on the error bars if you want an idea of how good it should be. Watch for a while, Does it move outside the error bars? H ….. It’s not the error bars that are the problem. The math is correct. The statistics are what is the issue. The ADEV hast changed for the worse as the run has gone on. It’s a very common thing. ——— Those are just the first few off the top of my head. Bob On Oct 24, 2014, at 5:31 PM, Tom Van Baak t...@leapsecond.com wrote: ADEV most certainly does change with time, even for short tau's. Can you elaborate? Such as when, why, what kind of change, how much change, at how short of tau's, over how long of time, and using what type Oscillators? Do you know what in the freq or Phase plot is causing the ADEV to change? I'm happy to let Bob answer his own claim here. I'm curious as well. Unless he's talking about thermal noise, in which case I now believe him 100%. OTOH, for time intervals of minutes to hours or days, the plotted ADEV can often vary. When in doubt, enable error bars in your ADEV calculations or use DAVAR in Stable32, or use Trace History of TmeLab to expose how little or much the computed ADEV depends on tau and N. In general, never do an ADEV calculation without visually checking the phase or frequency time series first. Of the many OCXO type Oscillators that I've tested (HP10811 MV89), seldom have I seen any significant change (say greater than 10%), in the short tau (0.01 sec to 1 sec) ADEV values, after the systematic type errors are removed. (even when starting soon after turn on) This is not my experience at all. Let's figure out what's happening to you. If all your standards look sort the same from tau 0.01 to tau 0.1 to tau 1 then either you need more oscillators to play with or maybe you have a measurement problem. This is especially true if you are doing post-comparator averaging. Averaging, by definition, tends to remove noise, to smooth things out. If your goal is to measure noise, the last thing you want to do is create any electronics or use any analog or digital or numerical filtering that removes or reduces the very thing you're trying to measure. I remind you of this page http://leapsecond.com/pages/adev-avg/ of the perils of averaging data. For most of the world, there's signal and noise. Signal good. Noise bad. But for us, measuring precision clocks, the noise is the signal. So don't do anything that removes or reduces noise. ADEV is used to measure random types of noise so there are of course the statistical uncertainty variations that are a function of the number of valid data points. I find that using a minimum of a thousand points at each tau gives good consistent results. Are you crazy? The minimum is just 3 or 4 or 5 data points. Not 1000! You should not see much difference at 10 or 100 or 1000 points. If so, something is wrong with your measurement model. If ADEV(tau) is *that* dependent on tau, check the frequency time-series. Consider removing drift or using HDEV instead of ADEV. We need to talk. If your logic was true, we'd all have to wait 3 years before we could compute the ADEV of a GPSDO at tau 1 day. /tvb
Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812...
Hi The days of published schematics started to draw to a close 15 or 20 years ago. By the time the Z3xxx’s came out, they probably didn’t even generate a “publication ready” schematic. Troubleshooting this sort of gizmo simply does not make economic sense. Swap out the power supply, swap out the OCXO, swap out the GPS module, swap out the front panel ( or any other attached board). If that doesn’t fix it - scrap out the unit. If you are not going to use the schematic for repairs, the only thing it does is make it easy for your competition to clone the device. The “swap whole assemblies” thing started at least 10 years before the schematics went away. Back then you could easily see why. Custom ASIC this, custom screened / selected that, non-standard something else. Guess what *always* broke? Guess which part took a “factory only” test set to calibrate if you did somehow replace it? (hint - they are the same part ….). It’s not just the field repair end of things that have gone this way. The manufacturing line has done the same thing. Put it together right the first time. Scrap something less than 0.5% of the finished assemblies. You can’t afford to set up to replace stuff like fine pitch BGA’s for the money you would recover on 0.5%. Spend the same money on process control as you used to on troubleshooting. You’ll drive the 0.5% down to 0.3% (which is how you got from 10% to 5% to 3% to 1.5% to 1% to 0.5% …). The flip side of the repair approach is reliability. Monitor the return rate on “fixed” units for a while and it’s pretty easy to spot a pattern. That was true even back in the 1970’s. Back then a “no trouble found” return didn’t count against your numbers. Those days are long long gone….. Run repaired units through a full blown battery of qualification testing and see what happens. Yes you can indeed find / buy / get “rectified” gear. Any more it’s mostly done by board swapping and re-testing. Much of what they get back is indeed NTF. Test it and back out it goes. Read the reviews on rectified gear and you can see the result. All that said. There have been a number of attempts to trace out schematics of some of these goodies. Things like the FEI Rb’s, the TBolt’s, and other similar parts are typical candidates. In each case you get to the boundary of a CPU and / or a FPGA pretty fast. In some cases there are code dumps on the CPU’s. I have not seen any dumps on the FPGA’s. With most designs, once you put a fairly large FPGA (not a CPLD) on the board, you have moved most of the “schematic” into it. What’s left on the pcb around it is just the analog this and that you could not pull into the FPGA. That seems to stop these efforts dead. The Z3xxx’s are done with varying levels of integration. The newer ones (like the Trimble completion) tend to be more “big CPU plus big FPGA” surrounded by not much else. Could you trace one out? Sure, if they didn’t set the security bits. Would it take some custom gear, yes, but not all *that* custom. eBay will provide you with all you need for less than the cost of a Z3xxx. Are the FPGA dumps easy to turn into a schematic - not so much. You are talking about a lot of time to reverse one of these boards back to the schematic stage. Bob On Oct 24, 2014, at 12:27 AM, Tom Miller tmiller11...@verizon.net wrote: I am surprised the schematics for these have not surfaced yet. Are they not out of support now? I got a set and am awaiting on a power supply and some connectors. Anyone have a source for the latches for the D connectors? Tom - Original Message - From: Anthony Roby ar...@antamy.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Thursday, October 23, 2014 10:39 PM Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A, Z3812... My curiosity got the better of me so I ordered these earlier this week and received them today. I've powered both up and quickly measured the 10MHz output. I don't yet have a GPS antenna feed that I can connect, so couldn't check that out. And I need to look into why both of the units have the Fault and StdBy lights illuminated. I was surprised how compact they are and they weight next to nothing. And they are very nicely made. I took the tops off both and took some photos (see http://goo.gl/87e8GG), but have not ventured into unscrewing everything to get to the bottom of the boards. From the top, I didn't immediately spot anything extra on the board for the 10MHz out. All the extras appear to be for the GPS, but the underside of the boards may tell a different story. Anthony -Original Message- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Stewart Sent: Thursday, October 23, 2014 12:20 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Lucent KS-24361, HP/Symmetricom Z3809A, Z3810A, Z3811A,
