Re: [time-nuts] Spectracom 8140T Line Tap Schematic
Hi Julien, Earlier replies that discussed removing the DC supply from the 8140 outputs gave me the impression your requirement was to connect directly the outputs of the 8140 without line tap modules, which is what I was addressing with my recent suggestion of a series capacitor, but can see now that's not the case. If you were to build your own termination the same principle would still apply of course but perhaps another option for a reasonably compact solution, aside from a coaxial DC block followed by a 50 ohm termination, might be a DC blocking attenuator followed by a BNC shorting dust cap, as the latter are generally quite small. For example, current Ebay item 332461304064 is a DC blocked 20dB attenuator, they are also available in pairs at a slight discount, and that fitted with a shorting cap would give you a return loss of 40dB, which is probably as good as you'd get from most 50 ohm terminations anyway and would save having to build your own. The VersaTaps phase lock an internal crystal, any frequency between 4 and 20MHz, to the 10MHz input and then provide an output at the crystal frequency or the crystal frequency divided by a fixed integer between 1 and 8,192, so in that sense yes they're a synthesiser but the few I've seen were still supplied preset for a specific frequency. However, "versatile" does not necessarilly mean quick or convenient to reprogram. Aside from perhaps needing to change the crystal the division ratio needs to be set by adding or removing links across pairs of holes in the circuit board. Those holes are on a standard 0.1inch pitch so fitting headers that would take shorting links should be straightfoward enough, and I suspect what was originally intended, but the units I have were supplied preprogrammed using resistor style wire ended zero ohm links mounted above the circuit board and soldered from below. Reprogramming one of these would involve unsoldering and perhaps removing all the connectors etc in order to remove the circuit board, so I'd certainly make darn sure they had headers fitted before being returned to the box! Nigel, GM8PZR -Original Message- From: Julien Goodwin To: gandalfg8 ; Discussion of precise time and frequency measurement Sent: Thu, 14 Jun 2018 11:36 Subject: Re: [time-nuts] Spectracom 8140T Line Tap Schematic I'm somewhat tempted to take the schematic and see if I can fit it in the comparatively tiny Pomona boxes, although I have far too many side projects already, enough 10MHz taps, and I still need to do the terminators. The VersaTaps are supposed to be an actual synthesizer IIRC. ___ 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] Spectracom 8140T Line Tap Schematic
This is probably now well past its sell by date but over the years there have been a number of requests here for schematics of the Spectracom 8140T Line Taps as used with the 8140 Frequency Distribution Amp. The standard reply has always been that no schematics were available from Spectracom, which is true, and that tracing one out wasn't a viable option either as the 8140T modules were potted in some kind of foam, but a few years ago I made an interesting discovery about the 8140T that enabled me to quickly produce a sketched schematic followed by the intention of posting it here just as soon as I'd turned it into something a bit more legible. Unfortunately those good intentions got left behind as other projects came along and it was only the recent posts regarding removal of the DC feed from the outputs of the 8140 that reminded me this was still a work in progress, or more to the point, remarkably little progress:-( BTW, with reference to removing the DC supply on the 8140 outputs, although it is possible to effect this by removing internal components by far the most straightforward arrangement, and most easily reversible, would be to use an inline DC blocking capacitor of between say 100 and 470 nF, just as is already very commonly used with remotely powered HF active receiving antennas. Anyways back to the 8140T schematic, I have now posted on mediafire the schematic of an 8140T10, the basic 10MHz in 10MHz out version, complete with far too many assorted internal photos plus details of said interesting discovery, with extra brownie points to anyone who might already be thinking foam and cardboard sandwiches:-) http://www.mediafire.com/file/rx9np48l8nwbe3g/8140TLineTap.zip Nigel, GM8PZR ___ 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] Sayrosa 607B Frequency Synthesiser
Perhaps not a very common item, and probably restricted to the UK, but I have seen these mentioned here before. The 607B was a very nice 2 to 30MHz synthesiser used as the drive unit in the UK Diplomatic Service Piccolo radio system. Both Sayrosa and Piccolo are long gone, and information has always been hard to come by, but I've just scanned the 607B Training Manual and 607B Technical Handbook and uploaded PDF versions of both to Mediafire. This documentation is quite limited but so far is all I've ever seen for the 607B. Both can be found in a single file at http://www.mediafire.com/file/c6vv5t71cq741sd/Sayrosa%20607B.zip For what it's worth, my experience with these has been that by far the most common fault is the familiar shorted tantalum syndrome. Nigel GM8PZR ___ 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] Tektronix FCA3103 ADEV measurement tau setting problem
I have a Tek FCA3103 300 MHz counter that measures ADEV as a built in function. When I bring up the settings menu for the measurement, it has an entry window for "tau" (the averaging time, IE "sigma sub y of tau"). It defaults to 200 ms. I can enter larger values and ADEV gives reasonably results. However, if I enter smaller values, even 199 ms, I don't get any error on the display, but I get clearly erroneous results for ADEV. I read the manual and cannot find anything to the effect that the instrument doesn't work for less than 200 ms. BTW, I asked Tek "customer no support" about it and they were clueless. --- Hi Rick, The Tek FCA3100 is a rebadged Pendulum CNT91 and Pendulum became part of Spectracom. Unless I'm missing something, the FCA3103 is the FCA3100 with 3GHz input C fitted. I've also found that Tektronix tech support seemed to know very little about these but, in the past anyway, found Spectracom in the UK to be very helpful. I'm not sure about the current status as Spectracom now seems to redirect to Pendulum as a separate company again. Unfortunately, I can't help with your enquiry, and am also somewhat confused, as I don't recall seeing a settings entry window for "tau" as a settings option for the built in ADEV function. I take it you do mean the built in option as in displaying results on the built in screen, or are you also using some external software? If you are just usin the built in display I'd be interested to hear what firmware version your FCA3103 is showing in the "About" screen My FCA3100 is showing the firmware version as 1.28s of 25 Aug 2010, which seems to match the latest available Tektronix download but I'm wondering now if there are unlisted updates. Nigel, GM8PZR ___ 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] Trueposition GPSDO CTS version for UK buyers
This is a nice GPSDO but there doesn't seem to be too many about these days compared with the earlier Bliley version, and searching the usual channels from the UK currently seems to brings up just one, Ebay ref 152981122366. 39.99 USD is a pretty good price, and despite being described as used it does look pretty much like new from the photo, but shipping to the UK is 55 USD, so already a total of 95 USD, plus a fair chance of tax and handling charges on top. A slightly different search though brings up Ebay ref 162691061234 for a complete Trueposition LMU300, with said GPSDO still safely tucked inside, and that for only 39 USD, plus shipping and taxes paid up front via the global shipping program. The total works out at just under 85USD each, and with no local charges to worry about, what was that about no brainer? :-) Ok, so it's no longer quite your $40 GPSDO, and aside from a few cables and fans, and perhaps the box, much of the rest of it is probably not to useful, but again all looks to be as new, cal seals intact on the one I've had arrive so far, and it does seem to be the cheapest option for UK buyers, which leaves me a bit surprised these haven't sold out sooner. Usual disclaimer, no vested interest whatsover, but with just three left if you hesitate I might buy another whilst you're thinking about it:-) Nigel, GM8PZR ___ 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] TruePosition GPSDO Holdover Issues
Hi Hal, and thanks for that. In my case at least there's no problem with making plots from live data as Lady Heather will do that for me, it's just the time taken to collect the data for each plot that could be an issue. I'd just been wondering aloud whether any of the online simulations for instantaneous plots against location could be persuaded to quickly build a longer term prediction, but then it occured to me that as I was looking to break the rules anyway the chances of that might be quite small:-) Nigel, GM8PZR It's not hard to make your own plots. This is from 66 38' north. http://users.megapathdsl.net/~hmurray/time-nuts/Arctic/Polar-A.png If anybody wants to play, I'll put the code on the web. There are several steps. First is to collect the data. I have a python script that grabs everything from a NMEA device and logs each line with a time stamp. The GPS orbit period is 12 hours so you need 12 hours of data to see everything. But there are 30 satellites, so a few hours will show the hole. The next step is to extract the data into a useful format. That's another python script. Then, just feed that to gunplot. ___ 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] TruePosition GPSDO Holdover Issues
Yes, and we're quite a bit north of Hadrian's wall:-) I've always been aware of the hole, it's just that I've always pointed GPS antennas straight up without stopping before to consider whether or not that's necessarilly the best option, but now it occurs to me that it might not be for this location. Whatever the optimum might be there's obviously going to be a limit but I do think it might worth pursuing. Web sites such as "In The Sky.org" can generate useful plots for any specified location and time but I don't know if there's anything that will allow building a projected map over a period, and I don't suppose there's going to be anything anyway that allows experimatation with antenna angle etc, so that really leaves using lady H to generate the plots in real time, which she does do really well but for something like this might be akin to watching grass grow:-) Nigel, GM8PZR -Original Message- From: Bob kb8tq To: gandalfg8 ; Discussion of precise time and frequency measurement Sent: Tue, 15 May 2018 17:44 Subject: Re: [time-nuts] TruePosition GPSDO Holdover Issues Hi If you are in the northern hemisphere and looking at GPS satellite tracks, there will always be a “hole” in the track plots to the north. The orbits do not cross either of the poles. More or less they make it about to Hadrian’s Wall and that’s it. Bob > On May 15, 2018, at 12:38 PM, gandalfg8--- via time-nuts > wrote: > > > Thanks Bob, and others, for comments on this. > > From my observations with this running in position hold mode following a self > survey, and based on previous experience in this location, my general > impression is still that the TruePosition GPSDO does seem more prone to > dropping into holdover than others I've used here under similar circumstances. > > Having said that though, now running on a better sited antenna giving > consistently higher signal strengths and with always at least 5 sats > indicated, not counting PRN120:-), it hasn't dropped into holdover in the > past 40 hours or so, so it is only under more marginal conditions that it > would be evident. > > As a bonus, the slightly tilted antenna is so far looking to be a reasonable > success, with the hole to the north noticeably reduced and tending more to a > closed circle and signal levels generally higher all round too, partially at > least perhaps due to a change in antenna gain but either way another can of > worms opened and begging further investigation:-) > > Nigel, GM8PZR > > > > > From: Bob kb8tq > Discussion of precise time and frequency measurement > Sent: Sun, 13 May 2018 19:05 > Subject: Re: [time-nuts] TruePosition GPSDO Holdover Issues > > Hi > > When you are looking at timing, the SBAS / WAAS sat’s really don’t count as > part of the total > of 4 that you need for a basic fix. There also iis the subtle distinction of > “tracking” vs “locked to” > on some devices. Tracking means we might get adequate data soon and locked > means it is > good enough to use on those devices.In that case, only the “locked” sats > count towards the > minimum of 4 that you must have. > > Past the minimum of 4 rule, most GPSDO’s also want to see that set of devices > for some period > of time before they come out of holdover. You will drop in very quickly ( a > second or two), but come > out slowly ( many minutes). Local noise can in some cases be enough to put > you in holdover. > > Bob > >> On May 13, 2018, at 1:13 PM, gandalfg8--- via time-nuts >> wrote: >> >> The location at 55N, 5W, isn't ideal, there's quite a large hole to the >> north but this isn't something I've seen here before with any other GPS >> module or GPSDO. >> >> When first noticed I'm sure it was whilst tracking six or seven sats, it was >> certainly five or more, which is why I commented in the first place, it was >> only later I thought there might be some correlation with it tracking low >> numbers. >> >> There doesn't seem to be any adjustment for elevation mask on these, at >> least not via Lady H, but I've switched now from a flat survey antenna to a >> Symmetricom pod on a stub mast, so I can cheat a bit and angle it south >> slightly:-) >> >> It'll take some time to build up a picture of the effect of that but it's >> tracking 8 sats at the moment. >> Inmarsat-3, PRN120, seems to have joined in the mix now and keeps popping on >> and off the bottom of the list but I'm not sure whether or not that could >> contribute anything useful anyway. >> >> Nigel, G
Re: [time-nuts] TruePosition GPSDO Holdover Issues
Thanks Bob, and others, for comments on this. >From my observations with this running in position hold mode following a self >survey, and based on previous experience in this location, my general >impression is still that the TruePosition GPSDO does seem more prone to >dropping into holdover than others I've used here under similar circumstances. Having said that though, now running on a better sited antenna giving consistently higher signal strengths and with always at least 5 sats indicated, not counting PRN120:-), it hasn't dropped into holdover in the past 40 hours or so, so it is only under more marginal conditions that it would be evident. As a bonus, the slightly tilted antenna is so far looking to be a reasonable success, with the hole to the north noticeably reduced and tending more to a closed circle and signal levels generally higher all round too, partially at least perhaps due to a change in antenna gain but either way another can of worms opened and begging further investigation:-) Nigel, GM8PZR From: Bob kb8tq Discussion of precise time and frequency measurement Sent: Sun, 13 May 2018 19:05 Subject: Re: [time-nuts] TruePosition GPSDO Holdover Issues Hi When you are looking at timing, the SBAS / WAAS sat’s really don’t count as part of the total of 4 that you need for a basic fix. There also iis the subtle distinction of “tracking” vs “locked to” on some devices. Tracking means we might get adequate data soon and locked means it is good enough to use on those devices.In that case, only the “locked” sats count towards the minimum of 4 that you must have. Past the minimum of 4 rule, most GPSDO’s also want to see that set of devices for some period of time before they come out of holdover. You will drop in very quickly ( a second or two), but come out slowly ( many minutes). Local noise can in some cases be enough to put you in holdover. Bob > On May 13, 2018, at 1:13 PM, gandalfg8--- via time-nuts > wrote: > > The location at 55N, 5W, isn't ideal, there's quite a large hole to the north > but this isn't something I've seen here before with any other GPS module or > GPSDO. > > When first noticed I'm sure it was whilst tracking six or seven sats, it was > certainly five or more, which is why I commented in the first place, it was > only later I thought there might be some correlation with it tracking low > numbers. > > There doesn't seem to be any adjustment for elevation mask on these, at least > not via Lady H, but I've switched now from a flat survey antenna to a > Symmetricom pod on a stub mast, so I can cheat a bit and angle it south > slightly:-) > > It'll take some time to build up a picture of the effect of that but it's > tracking 8 sats at the moment. > Inmarsat-3, PRN120, seems to have joined in the mix now and keeps popping on > and off the bottom of the list but I'm not sure whether or not that could > contribute anything useful anyway. > > Nigel, GM8PZR > > > ___ > 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] TruePosition GPSDO Holdover Issues
The location at 55N, 5W, isn't ideal, there's quite a large hole to the north but this isn't something I've seen here before with any other GPS module or GPSDO. When first noticed I'm sure it was whilst tracking six or seven sats, it was certainly five or more, which is why I commented in the first place, it was only later I thought there might be some correlation with it tracking low numbers. There doesn't seem to be any adjustment for elevation mask on these, at least not via Lady H, but I've switched now from a flat survey antenna to a Symmetricom pod on a stub mast, so I can cheat a bit and angle it south slightly:-) It'll take some time to build up a picture of the effect of that but it's tracking 8 sats at the moment. Inmarsat-3, PRN120, seems to have joined in the mix now and keeps popping on and off the bottom of the list but I'm not sure whether or not that could contribute anything useful anyway. Nigel, GM8PZR ___ 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] TruePosition GPSDO Holdover Issues
Ok, I give up I've been logging this with Lady H and was watching again this afternoon as the sat count dropped but this time there was no dropping into holdover as the number of sats dropped from four to threedamn, it just carried on doing its thing until the count went up again:-) I'm still seeing the occasional reported random holdover event but am still no nearer to knowing why. Otherwise it's a nice unit and does handle the holdover well, even a longer event yesterday whilst there was a supposed antenna fault didn't reflect into the frequency plots, but time to call a halt for now. Nigel, GM8PZR ___ 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] TruePosition GPSDO Holdover Issues
Today using Lady Heather I have observed the TruePostion GPSDO dropping into holdover as the number of tracked sats dropped from four to three. There does seem to be some hysteresis in the system though, the number of tracked sats eventually dropped to two and then the unit came out of holdover as the number increased from two to three. I can't say that this explains all the holdover events I've seen but it does seem to explain at least some of them. Nigel, GM8PZR ___ 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] TruePosition GPSDO Holdover Issues
I've had one of the cheap TruePosition GPSDOs running here for the past week, this is the earlier version with the Bliley oscillator, and as Mark reported have been seeing what I consider to be excessive holdover reports from Lady Heather. At 55 degrees north the number of Sats visible can be a bit variable, and with this running on an indoor antenna probably even more so, but I've run plenty of other GPSDOs here in similar fashion and have not seen this before. I've not been running Lady H in logging mode, just running in the background when this PC is on so all a bit hit and miss, but I have been seeing holdover reports every day and with the time building up as the day goes by. The time never exceeds 5 or 6 minutes though so if it was just being used as a reference without monitoring the status this could easily go unnoticed. The LMU300 Location Measurement Unit that this comes from will need to track four Sats for positioning purposes, and the manual for that does state that the LMU300 will indicate a holdover alarm when "The LMU cannot lock on to the minimum number (4) of GPS satellites and the LMU GPS receiver board has been in holdover for over 15 minutes", and I had started to wonder if the firmware in the GPSDO might also be treating less than four Sats tracked as a holdover situation. Earlier this afternoon I happened to catch it with between three or four Sats being tracked and it did seem to be dropping in and out of holdover as the number varied, once the number of tracked Sats increased again and stayed there, it's been six for some time now, it settled down again and hasn't returned to holdover since. Hardly the stuff of scientific observation I know, and I need to start logging what's happening, but it does seem more likely now that these units could be reporting a holdover event when the number of tracked Sats drops below four. Nigel, GM8PZR ___ 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] Dual GPSDO - any advantage?
Unless I copied the number incorrectly earlier it does seem likely that Ebay has pulled that auction. It may still be showing up to those who "bought" them but a straight search on that number returns nothing, either in completed or running listings, nor does it show up now in searches for "Trimble GPSDO" which is how I found it earlier. If anyone's interested, and in case there's still any doubts, one version of the Bob Mokia listing under his Ebay ID of amoj1010, that was copied photos and all to provide this auction, is still current and is # 252162780444. Nigel, GM8PZR ___ 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] Dual GPSDO - any advantage?
Is this auction # 273145006434, actually showing at $9.77 here in the UK, and from a recently registered zero rated seller? If so, and given that the auction text, and perhaps the photos too, seem to be taken from one or more of Bob Mokia's auctions dating back a couple of years or so, and that this price is approximately $100 below the norm, perhaps a degree of caution might be worthwhile. It's either a very sad mistake, from the seller's point of view anyway, or perhaps something a little more devious! Nigel, GM8PZR I`ve just bought two GPSDO`s from China @ US$9-50 each [This is not an error!] They are stated as being new, and use a Trimball dual oven OCXO. I plan to run these in parallel [2 antennas, 2 feedlines, and 2 GPSDO`s] It`s been said that a man with two watches is never happy - unless, of course, they agree with each other ;-). Being identical the outputs should be coherent, unless one becomes faulty [one advantage of having two - any discrepancy and you know something must be wrong]], but is there some crafty way I can squeeze a little more "accuracy" out of two than if I only used one? TIA for your commentsDonald Brett Collie ZL4GX PS : I have no connection to the eBay seller. The US$9-50 seems to include a basic puck antenna, long downlead, and 4 interseries adaptors ___ 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] Z3801A OCXO manual trimming
Crazy thought.Could you just force a DC offset into the EFC assuming the internal varicap is not out of range. It would be simply adding a resistor to pull up or down to see if you can get a bit of pull and allow the dac to move back in range a bit. Its a band aid. I know its sort of crazy. But ripping the oven apart really is no fun at all. Regards Paul WB8TSL ** Not really such a crazy thought, I've done this on a Trimble-Nortel NTGS50AA where the original 34310-T oscillator had "aged" beyond the 3 to 6 Volt EFC range. On a unit that was refusing to lock the oscillator was removed and confirmed to require an EFC voltage of approx 6.5 Volts for an output frequency of 10 MHz. As other tested samples of this oscillator, although admittedly not many, required around 4.5 volts there does remain the possibility of an actual internal fault but it did test on the bench as otherwise ok. Using a simple unity gain level shifter based on a few resistors and a TL071 op amp, just because there was one to hand, the EFC voltage from the control circuit was shifted 2 Volts high and the unit then behaved as expected. The effects of temperature, supply variation, etc on the modified circuit were not investigated as this was only a short term test but it certainly looked to be a viable proposition, to the extent that rather than fit a replaccement 34310-T that board was fitted with SMB connectors using the pads provided to keep as a test bed. Nigel GM8PZR ___ 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] CSAC Project(was CSAC purchase)
Hi The CSAC spec sheet calls out an aging rate of 0.9 ppb per month as “typical”. There is also a temperature spec of 0.4 ppb. If both are correct for your sample (*and* aging is linear ) you would be out by roughly 10 ppb per year. There also is a voltage stability spec that might be impacted depending on how you manage power. Taking the 30 ppb = 1 second number, you are at a 1 second / year rate after 3 years. At that point, you have already drifted by a second, if the assumptions are correct. This makes a massive assumption that the aging stays at the “typical” rate for years. It’s a very good guess that it does not. Is it going to be 1/3 or 1/10 of typical over that period? Who knows. Bottom line, you are going to be pretty far from 1 second per 100 years with a CSAC based wrist watch, if it runs for years (or even for months). It *will* do *way* better than a TCXO or OCXO based watch over months or years. It’s still not perfect. Bob - "if it runs for years (or even months)" sounds like an informed comment:-) When searching for some data recently I came across a report which might be relevant. "A Second Look at Chip Scale Atomic Clocks for Long Term Precision Timing", written by Alan T. Gardner and John A. Collins of the Woods Hole Oceanographic Institution, details their experience with a number of earlier and more recent CSAC modules and their findings make for very interesting reading. At the time of writing a copy is available here www.obsip.org/documents/Gardner_IEEE_Oceans_2016.pdf Nigel GM8PZR ___ 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] European Electronics Systems Radio Clock Model 100
Hi Steve, The name EES, or European Electronics Services Ltd, has been used more than once, latest registration appears to be only about a year ago, and might well have been used at one time by Siemens, but I think the company you're looking for is, or was, EES Technology Ltd. This eventually became Time and Frequency Solutions in Witham who were taken over a year or so ago by Brandywine Communications in the US. I'm still pretty sure that Radiocode clocks were also part of the earlier mix but can't confirm that right now. If checking Companies House records take a look at the filing history of Time and Frequency Solutions here, especially early name changes. https://beta.companieshouse.gov.uk/company/02627556 I've never used my model 100s, not quite sure why just never got round to it, but they seem to have started out as straight MSF receivers, some of which at least were sold to the MOD as transportable units in wooden carrying cases with mains PSU and battery back up, and the update of these to GPS seems to have been carried out some time later. The mod included the addition of a separately packaged diecast box with a GPS antenna on top, and containing a Motorola Oncore GPS module on an interface board. I've just checked an antenna unit and it turns out the Oncore module is a UT+, which is a bit more recent than expected:-) I don't know if the GPS interface provides a stand alone 60KHz signal to the EES 100 or whether that was also modified, although I suspect the latter, and don't know either if the "updated" ES100s could also still operate as an off air MSF, which may be one reason why I've not used them. Are yours the GPS version or originals? Nigel GM8PZR In a message dated 14/12/2017 12:47:27 GMT Standard Time, st...@g8ebm.com writes: Nigel The link to Siemens came from Companies House searches on the name. They reference the link to Siemens and mention Christchurch as a base (however that could just have been a registered office for accounting purposes and not the engineering / production location). I have several model 100 units and was just about to put one in a timing rack at the museum. Regards Steve G8EBM Original Message Subject: [time-nuts] European Electronics Systems Radio Clock Model 100 From: GandalfG8--- via time-nuts Date: Thu, December 14, 2017 1:59 am To: time-nuts@febo.com Does anyone have a service manual or any information on the Europeanlectronics Systems (EES) Radio Clock Model 100. The company was part of Siemens but closed down in 2005. The Model 100 was supplied by Plessey Defence Systems to the UK military. Some models could be GPS disciplined Any information would be gratefully received for the Radio Communication Museum of Great Britain. (thanks to Robert with the hint about plain text !!) Steve Haseldine G8EBM -- Now there's interesting! With EES being quite a small outfit based in Maldon, Essex, or so I thought, I'm surprised to hear they were ever part of Siemens, are you sure about that? For some reason I thought they eventually became part of Radiocode Clocks, although I could well be wrong on that also, something not entirely unheard of :-), but do seem to recall several mergers etc amongst the various UK off air standards outfits. I've got a few EES MSF and Droitwich clocks, including the earlier SFR060A and SFR200B, plus a 201 at the top of one of my racks in constant use, but despite having some EES documentation I never did find much on the model 100. With half a dozen or so of the GPS conditioned versions of the model 100 sitting in my garage I would also welcome some documentation. My notes made several years ago seem to have disappeared but I do remember being convinced that the GPS option was very much an aftermarket afterthought, for that read bodge:-), based on a retrofit Motorola Oncore if I remember correctly, and not really something to get very excited about. Regards, Nigel GM8PZR ___ 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] European Electronics Systems Radio Clock Model 100
Does anyone have a service manual or any information on the Europeanlectronics Systems (EES) Radio Clock Model 100. The company was part of Siemens but closed down in 2005. The Model 100 was supplied by Plessey Defence Systems to the UK military. Some models could be GPS disciplined Any information would be gratefully received for the Radio Communication Museum of Great Britain. (thanks to Robert with the hint about plain text !!) Steve Haseldine G8EBM -- Now there's interesting! With EES being quite a small outfit based in Maldon, Essex, or so I thought, I'm surprised to hear they were ever part of Siemens, are you sure about that? For some reason I thought they eventually became part of Radiocode Clocks, although I could well be wrong on that also, something not entirely unheard of :-), but do seem to recall several mergers etc amongst the various UK off air standards outfits. I've got a few EES MSF and Droitwich clocks, including the earlier SFR060A and SFR200B, plus a 201 at the top of one of my racks in constant use, but despite having some EES documentation I never did find much on the model 100. With half a dozen or so of the GPS conditioned versions of the model 100 sitting in my garage I would also welcome some documentation. My notes made several years ago seem to have disappeared but I do remember being convinced that the GPS option was very much an aftermarket afterthought, for that read bodge:-), based on a retrofit Motorola Oncore if I remember correctly, and not really something to get very excited about. Regards, Nigel GM8PZR ___ 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] Programmed Test Sources PTS-x10
The Programmed Test Sources PTS-x10 manual is available from Mediafire http://www.mediafire.com/file/ak193b371mbb3vc/PTS_X10.pdf ___ 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] Programmed Test Sources PTS250
The PTS250 manual is available from mediafire as either a 55MB standard pdf file or a 41MB OCR pdf file. https://www.mediafire.com/file/v8vd4o33d7ta1rd/PTS250.pdf https://www.mediafire.com/file/5hp2hj1la7wws2s/PTS250%20OCR.pdf ___ 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] R&S XSRM Rubidium Standard
Thanks for the replies to this, both on and off list. Repairs to the wiring turned out to be fairly straightforward and all now seems to be basically functional, but there still remains the problem of the lamp. I am told that the FRK lamp is not a direct replacement, the base is smaller, but that it might be possible to modify one to fit. Which leads to another question, does anyone know of a source of spare working FRK lamps, or even just one? Nigel, GM8PZR -- A friend of mine has bought a just out of calibration R & S XSRM Rubidium standard from one of the so called "recyclers" on Ebay. Although the price was good, and it came with the off air receiver, phase meter, and frequency divider, it looks to have been heavily decommissioned with deliberate damage to the internal wiring and the rubidium lamp removed. We've found the relevant manuals online and he's confident he can repair the wiring but he still needs to locate a lamp. If anyone has a working lamp available, or might know where one could be obtained, please contact me off list. He did comment that the lamp assembly looked as though it might accept the lamp from an Efratom FRK, can anyone confirm this? Alternatively, is there likely to be any risk of damage to the FRK lamp or to the XSRM lamp driver if he tries it but it's not compatible? Nigel, GM8PZR ___ 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] R&S XSRM Rubidium Standard
A friend of mine has bought a just out of calibration R & S XSRM Rubidium standard from one of the so called "recyclers" on Ebay. Although the price was good, and it came with the off air receiver, phase meter, and frequency divider, it looks to have been heavily decommissioned with deliberate damage to the internal wiring and the rubidium lamp removed. We've found the relevant manuals online and he's confident he can repair the wiring but he still needs to locate a lamp. If anyone has a working lamp available, or might know where one could be obtained, please contact me off list. He did comment that the lamp assembly looked as though it might accept the lamp from an Efratom FRK, can anyone confirm this? Alternatively, is there likely to be any risk of damage to the FRK lamp or to the XSRM lamp driver if he tries it but it's not compatible? Nigel GM8PZR ___ 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] HP5090A Off Air Standard Receiver
I'm sure there's various ways of doing it, a phase locked oscillator perhaps, dividing 10MHz by 50, or perhaps my preferred lazy method of dividing 800KHz by 4:-) It really doesn't really matter all that much, the initial comment was just that it might be better to provide a 200KHz signal from an alternative source rather than attempt to modify the 5090 to accept 198KHz and the implementation itself should be quite straightforward. Nigel, GM8PZR In a message dated 19/06/2017 14:46:59 GMT Summer Time, cjaysh...@gmail.com writes: If it's just locking to the carrier I wonder if it'd be possible to use a suitably modified PICDiv clocked from a 'standard' 10MHz GPS locked device like the Lucent? On 19 June 2017 at 14:19, GandalfG8--- via time-nuts wrote: I suppose a converter from 198KHz could be an option but I know of at least one other experimenter who's run into problems with the Teleswitch modulation on the Droitwich signal when trying something similar with a 5090A. Although, from one point of view, running it from the present 198KHz signal might be considered the ultimate goal it's the operation of the hardware itself that's of more interest to me in this instance, so I'm quite happy just to feed it with an accurate 200KHz signal from whatever other sources are available. Nigel, GM8PZR How about building a frequency converter to produce 200KHz; mixing the incoming RF (198KHz) with 2KHz derived from the output of the unit, On 18/06/2017 21:17, GandalfG8--- via time-nuts wrote: > Hi Pete That's quite good timing, if you'll pardon the expression:-), as I uploaded a pdf version of the 5090A manual to mediafire a couple of months ago _http://www.mediafire.com/file/http://www.mediafire.com/filehttp://www.medi_ (http://www.mediafire.com/file/u0bf1eips89uo3h/HP_5090A_Ops_and_Service.pdf) I know a few others have considered converting the 5090A to 198KHz but it's not straightforward and I believe the general consensus has been that it's not really worth the effort. I have a 5090B which I'm hoping to get up and running when it finally reaches the top of the to do list and my view is that it would be much better to leave the original electronics undisturbed and to drive it with a 200 KHz signal divided down from a from a GPSDO or a rubidium module, although having one of the latter already running at 800KHz does leave me a bit biased:-) Regards Nigel, GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to _https://www.febo.com/cgi-bin/https://www.febo.com/cgi-b_ (https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts) and follow the instructions there. -- Clint. No trees were harmed in the sending of this mail. However, a large number of electrons were greatly inconvenienced. ___ 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] HP5090A Off Air Standard Receiver
I suppose a converter from 198KHz could be an option but I know of at least one other experimenter who's run into problems with the Teleswitch modulation on the Droitwich signal when trying something similar with a 5090A. Although, from one point of view, running it from the present 198KHz signal might be considered the ultimate goal it's the operation of the hardware itself that's of more interest to me in this instance, so I'm quite happy just to feed it with an accurate 200KHz signal from whatever other sources are available. Nigel, GM8PZR How about building a frequency converter to produce 200KHz; mixing the incoming RF (198KHz) with 2KHz derived from the output of the unit, On 18/06/2017 21:17, GandalfG8--- via time-nuts wrote: > Hi Pete That's quite good timing, if you'll pardon the expression:-), as I uploaded a pdf version of the 5090A manual to mediafire a couple of months ago http://www.mediafire.com/file/u0bf1eips89uo3h/HP_5090A_Ops_and_Service.pdf I know a few others have considered converting the 5090A to 198KHz but it's not straightforward and I believe the general consensus has been that it's not really worth the effort. I have a 5090B which I'm hoping to get up and running when it finally reaches the top of the to do list and my view is that it would be much better to leave the original electronics undisturbed and to drive it with a 200 KHz signal divided down from a from a GPSDO or a rubidium module, although having one of the latter already running at 800KHz does leave me a bit biased:-) Regards Nigel, GM8PZR ___ 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] Halcyon OFS
Hi Clint, There seems to have been very little information available from Halcyon on either the OFS or PFS off air references. All I've seen is the OFS alignment document that Stephen is already sending to you. There were two versions of the OFS1, the later version had similar proportions to a Quartzlock 2A whilst the earlier was in a taller case and not so wide. That board in the alignment notes seems to match reasonably closely to a couple of photos I have of the earlier circuit board. I'll send you copies of those photos for reference as they might help you pinpoint any changes if they match your unit, but I've got no information on the later board so not sure how similar that might be. The off air section of the PFS1 was significantly different to the earlier OFS1 at least. Nigel, GM8PZR I have been given a Halcyon Electronics OFS1 standard which seems to work, it's a version that has 198KHz and 162KHz selector on the fron and after areasonable period of time it displays 'lock' and gives a nicely stable 1,10 and 10 MHz output on the front panel BNCs, (I know, it should be 1,5 and 10MHz out, read on) Does anyone know of a PDF manual? This version has two KHz crystals insideit and I'd like to see how/if it's been modified so a manual with a schematic would be even more useful. Clint ___ 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] HP5090A Off Air Standard Receiver
Um... I'm sure this response was well intended, so thank you for that and for the advice, but I do feel that Attila's earlier reply explained my reasoning remarkably well. Under consideration is the taking of a very nice example of an older and now unusable off air frequency reference, a little bit of interesting history perhaps, and putting it back on the air without any form of internal modification. So what's the point? Well that's it, other than the satisfaction of doing it there really is no point, other than perhaps, to quote one of my wife's favourite sayings, "just because":-) Time code receivers are not really my thing, each to their own I guess, but a no doubt somewhat unhealthy obsession with reasonably precise frequency generation does mean that finding a more modern frequency source to drive it may not be too much of a problem:-) Nigel, GM8PZR On 06/18/2017 04:17 PM, GandalfG8--- via time-nuts wrote:> I have a 5090B which I'm hoping to get up and running when it finally > reaches the top of the to do list and my view is that it would be much better to > leave the original electronics undisturbed and to drive it with a 200 KHz > signal divided down from a from a GPSDO or a rubidium module, although > having one of the latter already running at 800KHz does leave me a bit > biased:-) What in the world would the point of that be!? It appears to be a long-obsolete product, so have you searched for more modern time code receivers from timing instrumentation (Meinberg, Brandywine, et al.) and surplus vendors? It'll probably be pretty expensive, for it's probably much less popular than WWVB and DCF77. Have you tried the latter? It might be receivable from Britain, and I've seen some surplus DCF77 receivers (e.g., an old ISA card). -Ruslan ___ 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] HP5090A Off Air Standard Receiver
Hi Pete That's quite good timing, if you'll pardon the expression:-), as I uploaded a pdf version of the 5090A manual to mediafire a couple of months ago http://www.mediafire.com/file/u0bf1eips89uo3h/HP_5090A_Ops_and_Service.pdf I know a few others have considered converting the 5090A to 198KHz but it's not straightforward and I believe the general consensus has been that it's not really worth the effort. I have a 5090B which I'm hoping to get up and running when it finally reaches the top of the to do list and my view is that it would be much better to leave the original electronics undisturbed and to drive it with a 200 KHz signal divided down from a from a GPSDO or a rubidium module, although having one of the latter already running at 800KHz does leave me a bit biased:-) Regards Nigel, GM8PZR Does anyone happen to have an electronic copy of the user / technical manual they would share with me?All expenses covered. This rather unusual unit was produced in the UK in the days or the rather sensible 200kHz Droitwich transmissions. Im considering reworking the unit to the newer 198kHz standard. PeteG4GJL ___ 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] Brandywine GPS-4 OCXO
Although there doesn't seem to be anything similar in the GPS4 manual, the Brandywine GPS8 manual does carry a table of various oscillator options on page 33. The OCXOs listed there are either from from Milliren or HCD Research. Nigel, GM8PZR Hi, Does someone happen to know what OCXO sits in the Brandywine GPS-4 GPSDO? It's pretty good sized OCXO, possibly double-oven. It has a screw on the side which I presume opens up to the trimmer position. If someone could share info it would be useful. 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] Brandywine GPS-4 OCXO
I really don't know just how relevant this might be, but some Brandywine products are/were rebadged units from Time and Frequency Solutions in the UK, or perhaps vice versa. I'm not sure if TFS had an equivalent of the GPS4 but certainly both companies sold versions of the GPS8 and the TFS GPS8LN uses a Milliren 250-0504, a 5MHz SC cut OCXO, so perhaps the GPS4 might also use a Milliren oscillator? Nigel, GM8PZR Hi, Does someone happen to know what OCXO sits in the Brandywine GPS-4 GPSDO? It's pretty good sized OCXO, possibly double-oven. It has a screw on the side which I presume opens up to the trimmer position. If someone could share info it would be useful. 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.
Re: [time-nuts] Anthorn eLoran
Yes, noticed here it was off again and am pretty sure you're right about maintenance, just don't remember them starting at 0700 in the past:-) Nigel, GM8PZR In a message dated 10/05/2017 10:58:31 GMT Summer Time, i...@g7iii.net writes: On 09/05/17 20:28, moGandalfG8--- via time-nuts wrote: > Iain Young wrote: > I now have all four with green tracking lights, so looks good to go > > Thanks Iain, > > Also looking good here now so seems like I cried wolf after all, although > very happy it wasn't anything more permanent:-) > I noted this morning, mine were all "Red" again. This very much suggests antenna maintenance (Off while they work on it during the day, and on once they've finished the day's work before starting work on it again the next morning, rather like they do with MSF next door) Iain ___ 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] Anthorn eLoran
Iain Young wrote: I now have all four with green tracking lights, so looks good to go Thanks Iain, Also looking good here now so seems like I cried wolf after all, although very happy it wasn't anything more permanent:-) Nigel, GM8PZR ___ 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] Anthorn eLoran
Is anybody monitoring eLoran from Anthorn? I'm less than 100 miles from the transmitter but an FS700 has been unable to find the signal for several days. Last time this happened though it turned out to be a local antenna problem so I didn't want to cry wolf until I found time to take a closer look. I'm now monitoring the signal with an LF receiver and spectrum display using a different antenna and the usual 100KHz signal is missing. I am seeing a slowly drifting signal between 103 and 104 Khz that does look similar to a Loran signal but am not set up on this receiver to do more than just observe it so can't be sure just what it is. It might that there's a fault or the system is down for antenna maintenance, there's no alerts on either these days as there is for MSF, or perhaps it's something longer term. Anyone know what the score is? Nigel, GM8PZR ___ 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] HP E1938A question
I've confirmed that the software runs under Windows XP, but having seen it running I don't think I'll be able to do much with it without some form of instructions. However, I'll modify my test set up over the next day or so and see if I can get the software to see an E1938A then take it from there. Nigel, GM8PZR In a message dated 25/04/2017 17:17:59 GMT Summer Time, rich...@karlquist.com writes: I know that it will run on Windows 2000. It was originally written on Windows NT4. Rick On 4/24/2017 11:06 PM, gandal...@aol.com wrote: > Thanks Rick, I understand better now. > > The turn over label is still on the crystal but not the matching label > on the PCB. > > So far I've not been able to get the software to run but will try > with some older versions of Windows and see how it goes with those. > > Nigel GM8PZR > > In a message dated 24/04/2017 17:28:56 GMT Summer Time, > rich...@karlquist.com writes: > > The main issue is that the oven will no longer be at the > crystal turnover temperature. If you are using it in > a benign environment, you might not need the extreme > thermal performance enabled by being dead nuts on the > turnover. You still have an oven with thermal gain > in the 100's of thousands. > > The test software had the ability to sweep the oven temperature > and allow you to find the turn over. There was some way to > then set the oven to this temperature. I don't know if anyone > currently knows how to make the software do this anymore. > I knew at one time, but have long forgotten. > > Rick N6RK > > On 4/24/2017 5:41 AM, GandalfG8--- via time-nuts wrote: > > I've just received an Ebay purchased E1938A, haven't tested it yet > although > > I do have a 14 day return option, but unlike previous purchases > of these > > the serial number label is missing from the rear of the PCB so I > have no > > obvious way of knowing if the crystal is matched to the PCB. > > > > Does anybody know if there's any embedded information that can be > accessed > > that indicates the serial number of the board, or is there any > other way I > > can check if the crystal and PCB are matched? > > > > If not, what issues could I expect from an unmatched crystal and PCB? > > > > Nigel GM8PZR > > > > > > ___ > > 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] HP E1938A question
Thanks Rick, I understand better now. The turn over label is still on the crystal but not the matching label on the PCB. So far I've not been able to get the software to run but will try with some older versions of Windows and see how it goes with those. Nigel GM8PZR In a message dated 24/04/2017 17:28:56 GMT Summer Time, rich...@karlquist.com writes: The main issue is that the oven will no longer be at the crystal turnover temperature. If you are using it in a benign environment, you might not need the extreme thermal performance enabled by being dead nuts on the turnover. You still have an oven with thermal gain in the 100's of thousands. The test software had the ability to sweep the oven temperature and allow you to find the turn over. There was some way to then set the oven to this temperature. I don't know if anyone currently knows how to make the software do this anymore. I knew at one time, but have long forgotten. Rick N6RK On 4/24/2017 5:41 AM, GandalfG8--- via time-nuts wrote: > I've just received an Ebay purchased E1938A, haven't tested it yet although > I do have a 14 day return option, but unlike previous purchases of these > the serial number label is missing from the rear of the PCB so I have no > obvious way of knowing if the crystal is matched to the PCB. > > Does anybody know if there's any embedded information that can be accessed > that indicates the serial number of the board, or is there any other way I > can check if the crystal and PCB are matched? > > If not, what issues could I expect from an unmatched crystal and PCB? > > Nigel GM8PZR > > > ___ > 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] HP E1938A question
I've just received an Ebay purchased E1938A, haven't tested it yet although I do have a 14 day return option, but unlike previous purchases of these the serial number label is missing from the rear of the PCB so I have no obvious way of knowing if the crystal is matched to the PCB. Does anybody know if there's any embedded information that can be accessed that indicates the serial number of the board, or is there any other way I can check if the crystal and PCB are matched? If not, what issues could I expect from an unmatched crystal and PCB? Nigel GM8PZR ___ 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] HP 5090A Frequency Standard manual available
I've just uploaded a pdf version of the HP 5090A Ops and Service manual to Didier's site at. http://www.ko4bb.com For now at least it's also available at https://www.mediafire.com/?u0bf1eips89uo3h The 5090A was an HP product designed in the UK in the early 1960s and was an off air frequency standard intended for use with the BBC Droitwich broadcast service when it was broadcasting on 200KHz. If anyone has a copy of the 5090B manual they'd be willing to scan and share that would be very much appreciated, the A and B versions of the 5090 are quite different. Nigel GM8PZR ___ 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] ADEV query Timelab and TICC
Many thanks for the replies on this, what was initially intended as a quick "Hello World" test seems to have become far more interesting:-) I'll forward my results to Tom as requested and see where we go from there. Nigel GM8PZR ___ 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] ADEV query Timelab and TICC
Yesterday I used one of John's excellent TICC modules for the first time and initially set up a quick test using the 10MHz output from a Thunderbolt as the frequency reference to measure the 1PPS from an Oscilloquartz Star4 GPSDO, with the TICC output feeding a USB3 port on a Windows 10 PC running the 64 bit version of Timelab 1.29. I'll attach a copy of the test plots I'm referring to but just in case this doesn't get through I've also uploaded it to https://www.mediafire.com/?9bue90yp1e8ueu6 Using the basic settings as described in the TICC manual the first run was for 1 hour and seemed fine so I decided to extend the run time to 6 hours. The first 6 hour test started to follow the 1 hour plot as expected and I watched this on and off and can confirm it did so up to somewhere between the 100s and 1000s points on the x-axis, but some time after that the complete plot shifted upwards and then continued to completion to produce the magenta trace. I wasn't watching when it shifted so don't know if it was a jump or a gradual shift but did see it continue until completion. When I repeated the 6 hour test, again without changing anything, and hoping to observe the effect as it happened, it produced the green trace which was what I'd been expecting to start with. Since then I've made other test runs and again all seems to be as expected. I'm probably missing something obvious but don't understand what's happened here so any suggestions would be welcome. Throughout the tests I have been simultaneously streaming data from the Star4 to Lady Heather via a "proper" serial port on the same PC so did wonder if there might be some form of data conflict but it doesn't seem to have shown up as any obvious form of corruption and hasn't repeated itself. Nigel, GM8PZR Star4+ 170318.png Description: Binary data ___ 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] HP53132A Firmware Version 4613
How similar are the 131A and the 132A ? Is it possible to upgrade a 131 into 132 ? --- Interesting question! I suspect not, not in any straightforward fashion anyway, but I'm sure others would know better than me. >From a quick look at the component level service manuals the hardware does seem to be very similar, although just how similar would need a bit more detailed investigation, but then there's no guarantee the FPGA programming would be the same. I suppose an interesting experiment might be to drop a set of 53132A firmware ROMs into a 53131A, not something I've tried, but I wouldn't be at all surprised if they weren't recognised. Regards Nigel GM8PZR ___ 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] HP53132A Firmware Version 4613
I have just uploaded this firmware to Didier's (KO4BB) manuals site so it should be available for download in the near future. Regards Nigel GM8PZR ___ 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] HP 53132A ROM issue
Hi Colin, All the 5313x counter basic oscillators are indeed extraordinarily poor, and I've always assumed that their only purpose was to demonstrate that the unit was basically functional. A couple of years ago I upgraded a 53132A with serial prefix 3546 from firmware version 3403 to 4613, just a straight replacement without any problems so I would expect that your upgrade should have worked ok. The devices I used were Motorola M29F010CF-90 and I've seen confirmation from another user that 29F010-120ns should also work ok. If it's any help I can send you a copy of the firmware files I used. They came from EEVblog with comments that they were copied from HP originals supplied in 2010. Regards Nigel GM8PZR I recently acquired an older HP 53132A frequency counter offeBay. It did not come equipped with an option oscillator. The standaloneperformance of the existing oscillator is extraordinarily poor although thecounter works well running off my house standard. I decided to update theversion 3703 memory to version 4613 which I have installed on my newer Agilent 53132A.The serial number prefix for the eBay counter is 3736A so I assumed that theupgrade would work based on the HP assembly – level service guide that I have. When I installed a freshlyprogrammed set of 4 ROM’s the counter would not power up. The fan ran butnothing else. When I re-installed the 3703 chips everything returned to normal.Is there a hardware difference between the older and the newer HP/Agilent boards or am I missing something else? ___ 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] FE-5680A GPS discipline board on sale now
Nick, This looks very interesting but just wondering, will there be an option for end users to reprogram the board themselves just in case there does turn out to be any bugs in the software, and if so would you be making updates available? Regards Nigel GM8PZR ___ 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] MSF 60KHz Problems?
Thanks to all who've commented on this. All the reports I've received have suggested that MSF is behaving normally and I've taken a closer look at my antenna system, where I've found more loss at 60KHz than expected in the multicoupler I've been using. With this bypassed and a stronger signal I've also identified some varying levels of close in interference around 60KHz, so it looks to be time for a more detailed look at the antenna system overall. Regards Nigel GM8PZR ___ 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] MSF 60KHz Problems?
Is anyone else seeing anthing unusual with the MSF 60KHz signal from Anthorn? For the past 24 hours or so, at least, all I've been monitoring here, approx 100 miles from Anthorn, is what seems to be a much weaker than usual carrier that's pulsing at significantly faster than once per second. It's weak enough that I wondered at first if it possibly wasn't even MSF but something else on the same frequency. There's no scheduled maintenance in my diary and I haven't been able to find reference online to any problems, my first concern was that it might be an antenna problem but the Anthorn eLoran signals on 100KHz seem to be coming in fine on the same antenna. What's really odd though is that several minutes ago I powered up an EES MSF clock from that same antenna feed and this has now synchronised and is displaying the correct time. Regards Nigel GM8PZR ___ 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] Datum/Symmetricom BC637 series GPS/Timing Cards
I now have a copy of this firmware upgrade courtesy of another list member, and just wanted to say a public thank you. Regards Nigel GM8PZR In February Microsemi announced the release of version 8 software (firmware) for these cards, intended to resolve some problems caused by the GPS module, which was at one time anyway a Trimble Ace 3... If anyone has a copy of this software they could share, or perhaps a currently approved registration that would enable location and download of the firmware and update instructions, that would be very much appreciated. ___ 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] Datum/Symmetricom BC637 series GPS/Timing Cards
In February Microsemi announced the release of version 8 software (firmware) for these cards, intended to resolve some problems caused by the GPS module, which was at one time anyway a Trimble Ace 3. I have been trying to download this firmware from Microsemi but they no longer accept my Symmetricom login, even though they did initially following re-registration, telling me they won't accept my AOL email address but now require a "proper" address, such as a company address, which is all good fun seeing as how I've been retired for several years:-) If anyone has a copy of this software they could share, or perhaps a currently approved registration that would enable location and download of the firmware and update instructions, that would be very much appreciated. Regards Nigel GM8PZR ___ 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] Adapting my GPSDO to the FE-5680A
Thanks. I’ve taken your suggestion for the sine-to-square converter. I believe there are two separate commands for tuning the 5680 - one is “ temporary” and one writes through to the EEPROM. I’ll be using the latter, of course. --- I'm surprised nobody else seems to have commented on this but I'm pretty sure that using the write to EEPROM option on an automatically and regularly repeated basis could be somewhat akin to applying the kiss of death. Obviously the threat will depend upon how frequently it's decided the incremental change needs applying, presumably quite a bit less frequently for a rubidium module than a crystal oscillator, but in the longer term could it not approach the limits for the device? I would have thought the "temporary" option is to be preferred, and certainly this is what I've always used when manually adjusting FE5680As, until such time as I'm sure the applied value is close enough to be stored permanently. Other than needing to start over in the case of power removal I can't see any obvious disadvantages to this, and if the software can be made to report the current increment on request then presumably that could be noted every few months or so and perhaps an updated value permanently programmed, or even as infrequently as once a year say shouldn't really be too much of an issue. Nigel GM8PZR ___ 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] Conditioning Rubidium Oscillators
I'm sure I won't be the only one receiving newsletters from Precise Time and Frequency Inc, but I thought it worth mentioning their latest white paper as it offers some thoughts on the conditioning of rubidium standards via RS232 control. "Rubidium Control - A Different Approach" can be found here http://ptfinc.com/resources/ A very basic registration is required but I've always found their mailings to be interesting and informative whilst never being intrusive, and there's always an unsubscribe option anyway. Please not that I have no affiliation whatsoever, just passing on something I found interesting. Regards Nigel GM8PZR ___ 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] Navsymm Proteus GPS CDU Software
Hi Thomas, If you haven't already seen them I made a couple of posts regarding this unit last November in response to a similar question, and these might help with running the software etc. I've uploaded a file containing the manual and software to Mega.nz .. https://mega.nz/#!eVggzQDD!BD76z_UMLGtjhJmvO-APeW-A7bMIVEY7oZUI389IEAE A bit of a messy link but they encrypt all downloads as a matter of course and that includes the key, any problems please let me know and I can send it direct but decided to post it here in case others are interested. If someone could upload this to Didier's manual site that would be appreciated, I've had a few problems again recently with attempted uploads from here. Regards Nigel GM8PZR Hello Time-Nuts, I have recently come into possession of a Navsymm Proteus GPS Time and Frequency Generator. Also known under Navstar Systems. There have been various postings about this piece of kit, in some of which there was a mention of the CDU software which allows to configure it. The thing powers up but does not lock on. The manual says this could be the case if it was moved since last locked and it may need configuring. To cut a long story short, does anybody have the CDU software and could it be “shared”? It seems to need an old-style PC but that won’t be a problem around here. I will meanwhile check if any sense can be made of its outputs, in case there is some hardware problem. Thanks in advance, Thomas. ___ 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] Tait reference
Are these the references with a rubidium oscillator ? They seem to have similar models with OCXOs etc. http://www.ebay.co.uk/itm/111862884745 --- Well now, how's this for a happy coincidence. I've just received an email from a friend who bought a Tait T801 from that very same auction, asking about the rubidium module that he found inside it:-) Regards Nigel Gm8PZR ___ 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] Tait reference
Thank you Nigel, I've also taken a gamble on one of these units and am keeping my fingers crossed that it has a Rb standard in it. The service manual is most interesting, it looks like I could use one of the two 'loops' to lock a different OCXO, with a little tinkering it could be a very useful unit as there's plenty of space inside for additions and modifications. Are these the references with a rubidium oscillator ? They seem to have similar models with OCXOs etc. http://www.ebay.co.uk/itm/111862884745 Hi Clint, As far as I know, from the outside they all look the same and that's the problem, there's no way I can tell you from the available photos whether or not those references have the rubidium oscillator. I'd like to think they do, and will keep my fingers crossed for you, but unless you can get more info from the seller it'll just be a case of wait and see. Chances are that if the original batch was supplied with the rubidium modules then these will be too, might even be part of that same batch as I said earlier, but there's still the possibility they might not be the same or might have been got at somewhere along the line. I've just found an online photo that will show you what they "should" look like inside http://embarrados.com/market/item/111793998037/Tait-T801-Rubidium-Frequency- Standard Regards Nigel GM8PZR ___ 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] Tait reference
Are these the references with a rubidium oscillator ? They seem to have similar models with OCXOs etc. http://www.ebay.co.uk/itm/111862884745 Hi Adrian, The T801 first seems to have hit the UK surplus market around 2005/2006, I was told a batch of a couple of hundred, and units from that release were still trickling through until around 2011 at least. These were released by West Yorkshire Police when updating their UHF mobile network and did contain rubidium standards. The T801 contains dual nominal 12.8MHz synthesisers with very fine switched preset adjustment for base station synchronisation. These are locked to an external reference and can accept selected integer frequencies from 1 to 10Mhz and also 12.8MHz. If the internal 10MHz rubidium module is fitted and used as the reference then a short BNC link is required to couple the internal reference output to the external reference input. These were originally sold on Ebay with particular reference to the rubidium module, for most purchasers the 12.8MHz synthesiser board would probably have been of little interest, so I'm surprised to see no reference to the rubidium module with the several recent auctions. This may be due to lack of familiarity on the part of the seller but I certainly wouldn't want to take anything for granted without asking. I'm not sure either if the recent Ebay offerings are tail end leftovers from that first batch or represent a more recent release, but I have seen a number of failures with the rubidium modules in those bought between 2005 and 2011. One at least was physically faulty with others refusing to lock, either at time of purchase or subsequently, I have some of the latter still on the ever growing "to do" pile. According to the manual the rubidium module, where fitted, was originally a Quartzlock TF4010A, but all units I've seen have been fitted with FEI FE5660A modules. This required a degree of modification to the chassis and to the heatsink and the quality of that work is often poor, so quite likely a field "upgrade". The unit also contains a DC-DC convertor to derive the 24 Volt supply for the rubidium module from the 13.8 Volt input. The lock on the front panel is just an ON/OFF keyswitch, if the key is missing all those I've seen have been left in the ON position but it's easily bypassed anyway. I've tried uploading my scan of the manual to Didier's site but gave up after repeated page reset errors, it is now available here.. http://www.mediafire.com/view/0x5sa7o0s9pgc4s/Tait_T801_Frequency_Reference. pdf Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
> It seems to me that the code they use for the 6731M signal is botched, > anybody who can confirm ? Indeed, see the attached plot (from a recording I made earlier this evening): the master signal is totally lacking the 180 degree phase code modulation, while the slave signal does have it. Regards, Pieter-Tjerk, PA3FWM I didn't get a chance to check yesterday but am currently locked onto both the "Lessay" Master and the Anthorn Y station so I assume these problems are resolved, for now at least:-) Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
> It seems to me that the code they use for the 6731M signal is botched, > anybody who can confirm ? Indeed, see the attached plot (from a recording I made earlier this evening): the master signal is totally lacking the 180 degree phase code modulation, while the slave signal does have it. Regards, Pieter-Tjerk, PA3FWM - This explains exactly what I've been seeing here on the FS700s. By default the FS700 runs in an "Auto" mode, where given a valid GRI it searches and locks to the station with the highest signal strength, but with both Master and Y channels now having the same amplitude this obviously becomes a very close call. This wasn't an issue until yesterday afternoon, but with both operational units producing errors I eventually realised this was only when they were trying to lock to the Master and that they would still lock ok to the Y channel, manually selecting the Y channel resolved the problem. Whether or not the current situation is deliberate or unintended, having the Master present again, even in a restricted fashion, does at least restore proper channel identification:-) Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
It seems to me that the code they use for the 6731M signal is botched, anybody who can confirm ? Ah well, as of 1915 the FS700s seem to be locking ok again but still with the monitored signal dropping out from time to time so I guess we just need to be patient and treat it as work in progress. Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
It seems to me that the code they use for the 6731M signal is botched, anybody who can confirm ? Something's certainly not right at the moment. This morning all was working fine with both Master and Y stations locked on different receivers, but I had to go out for a few hours and when I returned sometime after 1400, although I could still see a loran transmission on 100KHz, nothing would lock and I was getting various errors reported, including "Can't match phase code". As of 1815 this situation continues, although I'm still seeing occasional signal dropouts and then recovery, so perhaps they're still working on it. Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
Yes, they've been switching back and forth between one or two channels all day, with the one channel state always being just the usual Anthorn Y channel and the two channels always being Master plus the Y channel. Sometimes the overall signal levels have been fluctuating quite a bit at 100 Miles from Anthorn, more so than usual, and when in the two channel state both channels have always been at the same signal level, although on a few occasions the signal has shut down altogether for several minutes at a time. As it's now nearly 1850, and still transmitting Master and slave rather than reverting to just the slave as it did at the end of the day yesterday, I'm even more encouraged to hope this might become the norm for some time at least. Regards Nigel GM8PZR In a message dated 05/01/2016 17:29:11 GMT Standard Time, p...@phk.freebsd.dk writes: I see both a master and slave on 6731 from Denmark now. Same signal strength: http://phk.freebsd.dk/misc/_.svg -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Loran Europe Lessay seems to be back on air?
Hi David, I've only used Loran specific hardware receivers for actual decoding, so no doubt others will be better able to answer your question re suitable software, but one thing to watch out for is that the stations don't actually transmit a named identifier. With all stations transmitting at 100KHz, identification depends on the pre-allocated group repetition interval (GRI), with the secondary stations in a particular group being identified by their time relationship to the master. Purpose made receivers that identify stations by name do so from internally stored data, which is why my FS700s always insist that Anthorn is really Loop Head in Ireland, SRS jumped the gun a bit but never issued an updated PROM after the proposed station at Loop Head didn't go into service:-) It's certainly fun just monitoring today though, both Master and Y station are back at the moment but the modulation's been changing about enough to suggest someone might even be trying to play tunes on it:-) Regards Nigel GM8PZR I'm receiving pulses on 100 kHz with AirSpy and a SpyVerter, but I have no Windows software to decode the signal and determine just which LORAN it is. Can anyone recommend suitable Windows software? Being located in Edinburgh the signal is reasonable strong. Thanks, David ___ 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] Loran Europe Lessay seems to be back on air?
The experiment continues. Earlier today both the Master and Y channels were showing again, then at 1200 the signal disappeared completely, to be back at 1206 but not long enough for the FS700 to lock before it went again. All good fun:-) Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
This could just be wishful thinking but I'm still hoping it might stay for some time yet. The UK General Lighthouse Authorities have been running their eLoran trials since 2007 so perhaps they found sufficient incentive within that time to keep going. Time will tell, but as you suggest I'm just going to enjoy it for as long as it lasts or, with a bit of luck, for as long as I do:-) Nigel GM8PZR In a message dated 04/01/2016 20:06:16 GMT Standard Time, paulsw...@gmail.com writes: Nigel In the US at least for the eastern half of the country the test station has been on lately for several weeks at a shot. Not exactly the old days but a great resource besides GPS to check my various references and note offsets and such using the austrons and SRS. I would agree 1 db difference is nothing and its the same station.Enjoy it while you have it. Regards Paul WB8TSL On Mon, Jan 4, 2016 at 2:26 PM, GandalfG8--- via time-nuts <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > wrote: >As of 1725, 4th January, Lessay seems to have been transmitting again for >at least 30 minutes, and showing the same or a slightly stronger signal >here on the west coast of Scotland than Anthorn. Are you sure it's not UK trying to rig something up for their eLoran trials ? = I'm pretty sure now that's exactly what it was, and keeping my fingers crossed it'll be permanent once they finish playing:-) Regards Nigel GM8PZR ___ time-nuts mailing list -- _time-nuts@febo.com_ (mailto: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] Loran Europe Lessay seems to be back on air?
I'm pretty sure it was Anthorn. It was showing as the Master and Y stations, and the individual signal levels as indicated on an FS700 were within 1dB, which would seem a reasonable tolerance on equal signal levels given that the FS700 only reports to the nearest 1dB anyway:-) Still just showing Anthorn's "own" signal for now but I'll check again during working hours tomorrow. Although I've seen it claimed otherwise I never found anything to suggest Anthorn would be closing down with the other stations anyway so wasn't surprised when it didn't. I hadn't considered this latest scenario but it does make sense if they intend to keep going for now. Regards Nigel GM8PZR In a message dated 04/01/2016 19:19:30 GMT Standard Time, paulsw...@gmail.com writes: I somewhat may guess its Anthorn. My 2 cents from across the ocean. The Brits are pretty good about shutting things down. The fact that Anthorn stayed operational was pretty odd even if you thought the new years parties got in the way. Lets face it drink beer with friends or shut a transmitter in some far away place. I know my choice. They can easily dual rate Anthorn. But then the signal level should be equal. On eLORAN tests in the US its a Master and the Y station. But its one transmitter. The same transmitter has no problem with some other rate running at the same time. Regards Paul WB8TSL On Mon, Jan 4, 2016 at 1:19 PM, Poul-Henning Kamp <_phk@phk.freebsd.dk_ (mailto:p...@phk.freebsd.dk) > wrote: In message <_576b98.2a1f5672.43bc052e@aol.com_ (mailto:576b98.2a1f5672.43bc0...@aol.com) >, GandalfG8--- via time-nuts writes: >As of 1725, 4th January, Lessay seems to have been transmitting again for >at least 30 minutes, and showing the same or a slightly stronger signal >here on the west coast of Scotland than Anthorn. Are you sure it's not UK trying to rig something up for their eLoran trials ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- _time-nuts@febo.com_ (mailto: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] Loran Europe Lessay seems to be back on air?
>As of 1725, 4th January, Lessay seems to have been transmitting again for >at least 30 minutes, and showing the same or a slightly stronger signal >here on the west coast of Scotland than Anthorn. Are you sure it's not UK trying to rig something up for their eLoran trials ? = I'm pretty sure now that's exactly what it was, and keeping my fingers crossed it'll be permanent once they finish playing:-) Regards Nigel GM8PZR ___ 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] Loran Europe Lessay seems to be back on air?
Definitely something unusual going on, overall signal level as monitored on an SDR is significantly lower than normal and seems to have dropped out from time to time, and as of approximately 1750 the master signal is no longer present. Regards Nigel GM8PZR In a message dated 04/01/2016 17:26:06 GMT Standard Time, gandal...@aol.com writes: As of 1725, 4th January, Lessay seems to have been transmitting again for at least 30 minutes, and showing the same or a slightly stronger signal here on the west coast of Scotland than Anthorn. I've never seen this before, Anthorn is much closer and has always been a stronger signal so I'm quite intrigued, and tempted to wonder whether Anthorn is now also transmitting the master signal. Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Loran Europe Lessay seems to be back on air?
As of 1725, 4th January, Lessay seems to have been transmitting again for at least 30 minutes, and showing the same or a slightly stronger signal here on the west coast of Scotland than Anthorn. I've never seen this before, Anthorn is much closer and has always been a stronger signal so I'm quite intrigued, and tempted to wonder whether Anthorn is now also transmitting the master signal. Regards Nigel GM8PZR ___ 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] Problems with WinOncore12 2.1X3 and an M12+T
I'm currently testing a Motorola M12+T receiver for possible use in a GPS-disciplined 10MHz oscillator. At the moment, I'm using WinOncore12 version 2.1X3 to communicate with it. Hi Phil All versions of WinOncore are pretty old by now, so you might want to try Synergy's SynTac software, which is a Synergy commissioned version of TAC32. An evaluation copy of the latest version is here. http://www.synergy-gps.com/index.php?option=com_content&task=view&id=185&Ite mid=196 The evaluation software expires after 30 days but can be registered for $59 if you find it does what you need. Regards Nigel GM8PZR ___ 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] Loran-C Norway/France/Germany shutdown
Looks like Sylt went off-air in addition to the Norway and France stations. Perhaps it is not a permanent decommissioning. It might just be coincidence, but at around 0145 on Jan 1st the Sylt web site link on the Loran-C Europe web site was reporting a 404 not found error:-( Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Loran-C Europe
As far as I can tell, in the 6731 chain there is just one station still operating, this at 0200 on 1st January 2016. My FS700s are reporting no master found so Lessay has gone, and I suspect Soustons also. Without the master I'm not seeing any identification of the one station I'm now receiving but I'm sure from its monitored signal that it's Anthorn. Let's hope this one keeps going for a while. Regards, and best wishes to all for 2016 Nigel GM8PZR ___ 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] Lessay and Soutons French LORAN Stations Shutting Down
Hi Iain I too received this news, sad day indeed:-( I've regularly received Lessay ok on the 2100 when Anthorn has been down so can't say I've ever received a slave, Anthorn, with the master, Lessay actually out of range but although I've not specifically monitored to check I've never been aware of losing Anthorn just because Lessay is off air, which of course is as it should be. I don't recall receiving Sylt from here on the 2100 but found an FS700 locked to it recently, presumably with both Anthorn and Lessay off air simultaneously. Regards Nigel GM8PZR ___ 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] Navsymm Proteus
Hi Graham, That link isn't fitted here either, and I don't know its intended purpose, but most of the adjacent component locations aren't populated either so I suspect that on my unit at least there's a fair chance it's not part of the active circuitry, although it is difficult to be sure. I don't generally record time from my GPS kit but adding and/or removing that link whilst the unit is running and locked doesn't show any obvious effect on frequency plotted against time, nor does it seem to affect the deviation. Regards Nigel GM8PZR -- Does anyone know the purpose of the jumper to the left of the three power supply jumpers. I have one receiver which does a periodic lurch of its time deviation, but when I fitted a jumper it apparently stopped. Was this a coincidence? Graham Baxter ___ 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 E frequency pulling
Al, Thanks for the good idea, that would certainly have saved me a bit of work:-), but the switch box inserted in the coax line with the counter input set to high impedance performs the same function, straight through connection with the option to switch in a 50 ohm shunt resistor, and it's quite clear that the frequency shift is virtually instantaneous. Nigel GM8PZR Nigel, Set your counter to high impedance. Then install a T connector on the input. Then you can install or remove a 50 ohm terminator on the T while plotting the results. Then you can see how fast the frequency shift is depending on the load. AL, k9si ___ 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 E frequency pulling.
My bet is interaction of the load current and power supply with the EFC and/or OCXO - Well, I haven't started probing the hardware yet, I was hoping I might get some confirmation first as to whether what I I'm seeing is an anomaly for this one or just par for the course with the Tbolt E, but as far as Lady Heather indicates there's no step change in the EFC that matches the frequency change, rather a gradual change after the event as the conditioning seeks to correct the displacement. Nigel GM8PZR ___ 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 E frequency pulling.
> Before I start probing any deeper I'd be interested to hear if anyone > else come across this with the Thunderbolt E. Is it thermal? Can you measure the frequency shift before it has time to warm up? Switching the impedance at the counter itself resets any plot that's in progress, which does introduce some delay, so I put together a small switch box that could be inserted into the coax and confirmed it's a rapid effect that's unlikely to be thermal. It's even more observable with disciplining turned off and there's no attempt to correct it, I can toggle back and forth between the two frequencies just by switching the load. One thing I did get wrong though when transposing my notes, switching from low to high impedance at the 10Mhz output will increase the frequency, with high to low decreasing it again, which is the reverse of what I originally posted...whoops:-) Nigel GM8PZR ___ 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 E frequency pulling.
Please note that this question refers to the branded "Thunderbolt E" GPSDO, in a silver coloured case with blue label and using a single 24V supply, and not the gold coloured "Thunderbolt" that is often found marked "Rev E". Whilst testing a Thunderbolt E I've observed that the frequency of the 10MHz output is affected by the load impedance. Switching a counter input impedance from 50ohms to 1Mohm for example will decrease the frequency around 1 part in 10^9, and this is reflected in a consequent increase in the DAC voltage over the course of a few minutes with the frequency recovering at the same time. Similarly, with the frequency steady with a 1Mohm load, switching to 50ohms will increase the frequency by a similar amount with the DAC voltage decreasing to provide correction. I'm familiar with the concept of frequency pulling in oscillators but would have expected the Thunderbolt E output to be better buffered than this, it's certainly not something I've experienced with the gold cased Thunderbolts. Before I start probing any deeper I'd be interested to hear if anyone else come across this with the Thunderbolt E. Regards Nigel GM8PZR ___ 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] 3GHz prescaler for Pendulum counters
Hi Arthur Thanks for the feedback, that's an interesting find and obviously something to keep in mind. As you know Pawel originally designed the prescaler for the CNT85/PM6685, although in earlier Ebay listings he did comment that it also worked for the CNT80/PM6680, and taking a look at the schematics I can see now that the detection circuit you refer to for the CNT81 is different to that in the CNT80 and also to that in later models. In the CNT80 the selection resistors were returned directly to ground, that 100K common resistor was introduced with the CNT81 but was promptly dropped again for the CNT85 onwards. It would seem, in this respect anyway, that you drew the short straw:-) Interesting too to see your comments regarding orientation, although from the CNT85 onwards this again seems to have been something that was standardised. Glad to hear you got it sorted though, I'm still more than happy with mine and certainly agree that it's a really good deal. Regards Nigel GM8PZR Just a note to say that I bought one of these prescaler boards for my CNT-81. One problem is the way the board mounts in the CNT-81 the "in" connector is toward the back instead of toward the front like some of the other counters and I had to make a longer input cable. Pawel does now know this and maybe a different cable can be included for these counters in case you can't make one. Be sure to check on this so there aren't any surprises... ___ 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] NAVSTAR proteus GPS time and frequency unit
An update on this just in case anyone else interested... I've confirmed that the Symmetricom CDU software for the Proteus GPS unit will run fine under Windows 7 on a 2009 HP dual-core laptop using a Prolific USB to RS232 convertor. There is no option to select baud rates etc in the CDU software, just the option to select the appropriate COM port between 1 and 4. The Proteus here did not start up displaying the current date, probably not helped by this one not being used for several years, but once the correct date was set via the software it updated correctly and maintained it for short power disconnections at least. The antenna socket does feed 12 Volts to the antenna, although the originally supplied volute style antenna is not particularly sensitive and would definitely require a good outdoor location. A more sensitive Symmetricom 1280 provided reasonable results for indoor testing. Regards Nigel GM8PZR Hi all, I have the chance to buy a new boxed unit. Having glanced at the manual I understand that the configuration software runs under Windows 95 and uses a serial RS232 port. The only Windows box I have now runs Windows 10 and has USB only. So my questions are, can I run the config software under Windows 10 and will a USB to serial adaptor work with it? I will need to make a power supply for it as I think it requires 24 volts. That should be no problem. Any comments great fully received. Thanks in advance, Steve G0XAR ___ 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] NAVSTAR proteus GPS time and frequency unit
Hi Steve, I've got one of these, also came to me new in the box but that was around twelve years ago and other than a short period of testing has stayed there ever since, nothing wrong with it as far as I can remember just too much stuff, too much to do, and Thunderbolts and the like do take up a bit less space:-) How long do you have before you need to make a decision?, I can let you have a copy of the software if you want to play with that first, and the manual too if you don't have ongoing access to it at the moment. Interestingly, the Proteus software is badged Symmetricom, although I don't recall anything to suggest that they and Parthus had any working relationship. My manual indicates the software as suitable for Win95, Win98, and NT, which does rather show its age:-), but I've run it ok on a P4 WinXP machine using a standard RS232 port. I could try an installation under Win7 via a USB to serial adapter but my Proteus is tucked away in its box so I would need a bit of time to get it set up, and whilst that obviously won't confirm it will work with Win 10 it might at least be a step nearer. Unfortunately whilst the manual does give information on the message format for the time port output it doesn't for the control port, just refers to the supplied CDU software. Presumably it could be sniffed at the port but the manual does state that the messages are binary format and that a terminal emulator can't be used for control. The Proteus was supplied in 12, 24, and 48 Volt versions, and this will be indicated on the label on the unit. One thing to be aware of, just in case it doesn't come with original antenna, is that the antenna port feeds 12 Volts DC to the antenna, rather than 5 Volts, or even 3.3 Volts, as often found later. As far as I remember this isn't made clear in the manual. Week 1024 rollover is discussed in the manual and shouldn't have been an issue, at least that's what they said for the 1999 rollover:-), but again I can check that if you don't need to make a decision in the next day or so. Regards Nigel GM8PZR Hi all, I have the chance to buy a new boxed unit. Having glanced at the manual I understand that the configuration software runs under Windows 95 and uses a serial RS232 port. The only Windows box I have now runs Windows 10 and has USB only. So my questions are, can I run the config software under Windows 10 and will a USB to serial adaptor work with it? I will need to make a power supply for it as I think it requires 24 volts. That should be no problem. Any comments great fully received. Thanks in advance, Steve G0XAR ___ 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] GPS disciplined FE5680A
Following Nick's comment, under the subject "Z3801A and FE-5680A Allen Variances", that he briefly considered designing a board to GPS discipline the FE5680A, I'm pretty sure that a year or so ago just such a board was suggested as being close enough to completion to warrant a request for beta testers, with perhaps even a suggestion that it could be made available as a group purchase. Since then though, as far as I'm aware anyway, it just seems to have disappeared without trace, or did I miss something? Regards Nigel GM8PZR ___ 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] High Stability OCXO for Pendulum CNT-90
Hi Stan, The CNT90 service manual is available online from Fluke for their PM6690 rebadged version and is identical to the original, a search on "PM6690 Service" will find it. The manual contains a brief description of the oscillator and a schematic showing both the standard and ovened oscillators, and as far as I can tell from my CNT90 all required components for the ovened oscillator circuit, other than the oscillator itself, are already fitted to the PCB so just adding an appropriate oscillator would probably be all that's required. The standard and ovened oscillator circuits are completely separate, with individual outputs feeding the counter circuit and with individual ON/OFF control lines fed back, which suggests that both oscillators might be able to co-exist with auto selection depending on what's fitted. However, the circuit description states that only one or other of the oscillators is fitted, and the same internal calibration procedure is used for both, so it may be necessary to disable the standard oscillator, probably just removing the crystal would suffice, but I've not checked this. Playing with this is another of those things on my eternal to do list but as I've always used an external reference it's never been much of a priority. The manual indicates two versions of the ovened oscillator in the parts list, without identifying either, but it should be quite straightforward to wire up sample oscillators for off board tests to confirm possible co-existence and appropriate EFC characteristics etc. Plan Z of course might be for anyone who's got a CNT90/91 with the ovened oscillator fitted to lift the lid and take a look:-) Regards Nigel GM8PZR I have a Pendulum CNT-90 with the standard oscillator option. I notice that there is an open area on the main PCB where a higher stability reference would be installed. 1) Is it possible to install an aftermarket high stability reference oscillator into this stock CNT-90 and be able to use it? 2) If so, is it just a matter of soldering an appropriate OCXO module into the designated area on the PCB? 3) Will the CNT-90 automagically recognize it, or are there jumpers or other things that have to be done to enable it? 4) Any recommendations for a good, high stability reference to use? ___ 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] Ulrich Bangert Web Site
I don't know whether or not this is old news but I've just spotted that Ulrich's web site is live again. http://www.ulrich-bangert.de/index.html Regards Nigel GM8PZR ___ 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] 3GHz prescaler for Pendulum counters
So much for paranoid file hosting systems with OTT encryption!, the URL for the photos got truncated in the copying:-( Just adding "g" to the end of the link in my original post should suffice, or here, with a bit of luck:-), is the full link... https://mega.nz/#!qNYiDCzC!HHWEpI8TUDW6VO_fuyk34uU6Tr4V-pXRLru-DMtaq2g Regards Nigel GM8PZR ___ 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] 3GHz prescaler for Pendulum counters
A couple of years ago, my oh my doesn't time rush by when you're having fun?:-), I posted a recommendation for 3GHz prescalers from Pawel Witkowski, an Ebay seller in Poland, for the HP 53131 and 53132 counters. I'm now very happy to report that Pawel has also produced a similar prescaler for the Pendulum range of counters, his Ebay ID is pa-fko and a typical auction is 111794690250. Pawel actually lists these as being for the Philips/Fluke PM6685, this being the counter he designed them for, and with a comment that they also work with the PM6680, but those are rebadged Pendulum counters and a look at the service manuals suggested that the original Pendulum prescalers were likely to be a one module fits all solution, and this has turned out to be the case. For the past few weeks I've been using a pair of these modules, one fitted to a CNT90 and the other to a Tekktronix FCA3100, which is a rebadged CNT91, and I'm very happy with the results. Once installed the counter automatically recognises that it now has an input "C", and that's all there is to it. The built in statistical plotting options work for input C just as they do for inputs A and B, but note that the level measuring functions of inputs A and B are hardware dependent and aren't available for input C, this also applies to the original Pendulum prescalers. There's a graph of measured sensitivity and "application area" included with the auction photos and I'm seeing results that agree closely with that. Up to 1GHz I've run tests using a Marconi 2022E signal generator and above that I've been playing with a Chinese clone of the Anolog ADF4351 evaluation kit. I don't have any independent means of checking the levels from the ADF4351 kit above 1.5GHz but I've no reason to believe it's not performing as it should, certainly the frequency accuracy is as expected. The service manuals indicate that later models have extra pins on the prescaler connector but the functions of the rear sixteen pins have remained unchanged, and ensuring that the prescaler is mounted to the rear of the connector, regardless of the number of pins that leaves spare, is all that's required. A couple of points to note, the mounting clips shown in the auction photos are already fitted to the PM6685 but were not fitted to my CNT90 or FCA3100, so these had to be supplied with the prescaler. Anyone ordering these should make it clear what counter they will fitted to. There are two predrilled 2.5mm diameter holes in the front panel for the N connector that will accept M2.5 screws but the shape of the casting does not allow any nuts to be fitted. The prescaler board is provided with self tapping screws, although I chose to run an M3 tap through the holes and use standard screws, but I suspect the best solution would probably be to use M3 Taptite screws. For anyone who might be interested I've uploaded a file containing a set of similar photos for each counter showing stages of the installation, and also some photos of the counters under test and the ADF4351 module.. https://mega.nz/#!qNYiDCzC!HHWEpI8TUDW6VO_fuyk34uU6Tr4V-pXRLru-DMtaq2 Apologies for the messy looking link, it's nothing sinister, just that the site encrypts all files and most of that link is the decryption key. For these tests, both counters and both frequency sources were referenced to the same Trimble Thunderbolt. At 1GHz, using the Marconi 2022 signal generator, I checked sensitivity down to -40dBm, possibly could have gone lower but didn't see too much need for that:-) The ADF4351 evaluation kit only has selectable output levels of +5, +2, -1, and -4 dBm, so for higher frequencies I took a different approach and tested for the maximum frequency that would display properly on the counter at levels of -4dBm, as indicated by the ADF4351 software, and also at -7dBm and -10dBm by adding attenuators. The module was mounted a very short distance from the counter using semi-rigid coax to an SMA to N adapter, again this can be seen in the photos, and 23GHz rated Aeroflex 3dB SMA attenuators were added directly between the synthesiser module and the counter input, although this is not shown. Both counters worked fine at 3.00 GHz with the -4dBm signal and whilst there was a difference between the two counters as the frequency increased it's obvious that both would have worked fine at 3.00GHz with the -7dBm signal also and very close at -10dBm. It might be interesting to swap the modules between counters, to see if that has any effect on the overall sensitivity at higher frequencies but it's not something I've tried so far, and I don't see it as a problem either way. With the FCA3100 (CNT91), the limits I measured were. at -4dBm 3.500GHz at -7dBm 3.400GHz at -10dBm --- 3.325 GHz With the CNT90, the limits I measured were.. at -4dBm 3.200GHz at -7dBm
[time-nuts] Pendulum Counter Service Manuals
Spectracom have always seemed a bit "cautious" when it comes to releasing copies of the Pendulum Counter service manuals, I was sent a copy of the CNT90/91 manual when carrying out some repairs a few years ago but only after accepting a non disclosure agreement. Because of that I was quite surprised recently to find that Fluke have released the full service manual for many of their equivalents to the Pendulum counters, with these seeming to be identical to the pendulum originals but with name and model numbers changed. A similar situation exists for the Fluke and Pendulum user manuals but in this case both are widely available anyway. Recent searches have turned up service manuals for PM6680/CNT80, PM6681/CNT81, PM6685/CNT85, PM6690/CNT90. The only exception seems to be the CNT91, and as far as I can tell there never was a Fluke PM6691. The Pendulum CNT90/91 manual includes the revision A and B boards for the CNT90 as well as the later revision C used in the CNT91, whereas the Fluke PM6690 manual has no reference to the later board but does otherwise seem identical. Apologies if this is already common knowledge but I don't recall seeing any previous reference to it and thought it might of interest to other Pendulum users. Regards Nigel GM8PZR ___ 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] Symmetricom 8130A Software
In a 2005 White Paper singing the praises of "their", actually ex Datum, 8130A rubidium module, Symmetricom mentioned a small RS232 utility they referred to as 8130Comm. However, it isn't mentioned in the 8130A manual and I can't find anything else about it either online or within my own Symmetricom archives, could anyone confirm please whether or not this does actually exist, or better still have a copy they could share? Regards Nigel GM8PZR ___ 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] "Vanguard Ultra precision Golden Oscillator"
H I think I'm convinced, I had my doubts to start with and now have enough more to ensure I follow a different route:-) Regards Nigel GM8PZR Hi If they are indeed grabbing anything in that package and re-labeling it, I would be very careful. True TCXO’s (full compensation network) in that package are relatively rare compared to the enormous number of “precision XO’s” made in the same package. The XO’s had no real compensation. They simply relied on a packaged crystal to deliver a tighter stability than the open blank DIP XO’s of the same era. The other obvious issue of a relabel process would be that the one I get and review likely has no relation at all to the one you get and try to use. We could have parts each built to totally different specs and each made by who knows who. Bob ___ 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] "Vanguard Ultra precision Golden Oscillator"
Hi Bob, Just the sort of things I was wondering and lot's of questions indeed, that's why I asked, I didn't want to be the guinea pig:-) Regards Nigel GM8PZR Hi A few things I would wonder about: 1) Is it 0.1 ppm over 0 to 50C (or some other range)? If not, what is the temperature stability? 2) Does it run at 3.3V -or- at 5V (pick one) or do they run equally well at either voltage? 3) Since there is no EFC, is 0.1 ppm the set tolerance? If it’s not, what is the initial accuracy? Lots of questions, there’s not much information there. That may be due to the seller not having the information. It also may just be because nobody ever asked. The term TCXO can mean a variety of things to a different people …. The most encouraging thing is that there *is* a phase noise spec on it. Bob ___ 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] "Vanguard Ultra precision Golden Oscillator"
Hi Tim, Thanks for your comments and I did wonder about the plating, in the photo for the auction number I gave I couldn't decide if the bottom of the can was corroded or just badly plated. Regards Nigel GM8PZR Mainstream TCXO's moved entirely to surface-mount many years ago. These "Vanguard" DIP units have to be washed/replated RFE parts. It's a shame they are so completely relabeled because the original manufacturer/part number is nowhere to be found, and I'm sure this lost info would be interesting to a time-nut. They seem to be especially popular with audiophools (probably the gold). Tim N3QE ___ 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] "Vanguard Ultra precision Golden Oscillator"
The "Vanguard ultra precision Golden TCXO", their description not mine:-), has been listed on Ebay for a while now at various frequencies, and the 0.1 ppm spec caught my eye as a possible replacement for the around 6 or 7 ppm oscillator in a DDS function generator I've been using. One typical current auction, for a 25MHz unit, is 111071283814. Has anybody tried any of these and/or come across any more data elsewhere? Regards Nigel GM8PZR ___ 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] MtronPTI M9101 GPSDO
Keith, That's great news, thank you, and just what I was looking for:-) During my earlier searches I did come across an Mtron press release from 2010 detailing collaboration between themselves and JLT but it stated that the first product from that would be the Mtron 9107 so I just assumed that any prior numbering such as the M9101 would be a uniquely Mtron product and didn't think to investigate further. I must remember not to take things for granted:-) Regards, and thanks again, Nigel GM8PZR In a message dated 22/08/2015 18:19:14 GMT Daylight Time, keith.loise...@gmail.com writes: Nigel, The MtronPTI M9101 is just a private labeled Jackson Labs FireFly-IIA. You can download the Jackson Labs manual for the FireFly-IIA at the support section of our website here: http://www.jackson-labs.com/index.php/support Keith Keith On Thu, Aug 20, 2015 at 8:54 AM, GandalfG8--- via time-nuts <_time-nuts@febo.com_ (mailto:time-nuts@febo.com) > wrote: I've been trying to locate a manual for the MtronPTI M9101 series GPSDOs, an M9103 series manual would probably also be ok. There are references and links online to a PDF manuals section on the MtronPTI web site but those links just bring up errors and they seem to have removed everything other than the data sheets. If anybody has a copy they can share, or perhaps point me in the right direction to where I might find one, that would be very much appreciated. Regards Nigel GN8PZR ___ time-nuts mailing list -- _time-nuts@febo.com_ (mailto: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] MtronPTI M9101 GPSDO
I've been trying to locate a manual for the MtronPTI M9101 series GPSDOs, an M9103 series manual would probably also be ok. There are references and links online to a PDF manuals section on the MtronPTI web site but those links just bring up errors and they seem to have removed everything other than the data sheets. If anybody has a copy they can share, or perhaps point me in the right direction to where I might find one, that would be very much appreciated. Regards Nigel GN8PZR ___ 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] KS-24361 REF-0 standalone
I also did a quick write up recently about how I added the 10MHz test point output to my REF-1. Hi Daniel Many thanks for your 10Mhz write up for the REF-1, that's very interesting and a nice bit of detective work. Back in January I took a quick look at the underside of a REF-1 board in the area beneath the oscillator and identified what seemed to be a pick off point very close to the output of the 10MHz doubler. I'm pretty sure it was sinusoidal but can't remember for sure now and I never did find the time to get back to it and check it properly. I'll attach a copy of my very brief notes just in case it might give you a starting point for your search for a cleaner signal but if it doesn't get through to the list I'll send you a copy direct. Regards Nigel GM8PZR 10MHz Pick Off.pdf Description: Adobe PDF document ___ 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] KS-24361 REF-0 standalone
Hi Adrian, I've recently ordered two pairs to go with my earlier REF-1 units and found there was quite a significant saving on postage, even with the original packaging which I decided was a safer option, but don't forget there's a very high chance these days that you'll get hit with VAT and handling charges on import. Not much seems to scrape through anymore, unless the value is misquoted as is often the case from China but not generally elsewhere, and if you push the value of single shipment too high you could also be liable for customs duty !! Regards Nigel GM8PZR I've ordered some. Please contact me directly rather than via the list if you're interested in one or more. The seller will repackaged them to reduce shipping so they won't be boxed quite as advertised but should be good enough. ___ 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] KS-24361 EFC Error
Bevor I heat up the big soldering iron to remove the OCXO, I wanted to ask if anybody else experienced this before and if anybody can confirm that tuning voltage range is indeed 0..6 Volt. If so, replacing the OCXO should cure the problem. Hi Mathias I've not experience your problem with the KS-24361, but I have tested a few of these oscillators stand alone and can confirm that the reference voltage output has always been approximately 6 Volts and they do accept an EFC tuning voltage range of 6 Volts. Other than one faulty unit, on all those I've tested the EFC voltage has been very close to 3 Volts when the oscillator frequency was within a few parts in 10^11 of 5 MHz. For example, looking back at a couple of test results, one was at 2.9725 Volts and another at 3.0970 Volts. Regards Nigel GM8PZR Hey, hows about that, It seems like I might finally have found a way to reply to list messages straight from the archives without receiving them by email:-) ___ 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] Loran and SRS FS700 in the UK
The FS700 data sheet specifies the standard oscillator to be be an ovenised oscillator using an AT cut crystal, and the option 01 oscillator to be an ovenised oscillator using an SC cut crystal. The SC10 data sheet specifies it to be a "10MHz high stability oscillator using an SC cut crystal for low phase noise". All my units contain the SC10 SC cut crystal oscillator and all have identical markings with nothing to indicate any degree of selection, this was a significant factor in reaching my original conclusion. However one describes them these oscillators certainly don't match the specification for the standard oscillator but do seem to match that for the option 01 oscillator, soo:-) Regards Nigel GM8PZR In a message dated 11/07/2015 12:34:03 GMT Daylight Time, p...@phk.freebsd.dk writes: In message <12d5cf.69a88993.42d22...@aol.com>, gandal...@aol.com writes: >Another possibility of course is that the first unit was incorrectly >marked and none of them have the option 01 oscillator:-) I wouldn't trust selected OCXO's to be marked systematically in that case. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Loran and SRS FS700 in the UK
Hi Poul-Henning I agree that option 01 is stated to just mean a "better" oscillator, and I was a bit confused by what I found, but my second and third units, neither marked as option 01, have exactly the same oscillator fitted, according to the SRS label on the oscillator, as my first unit which is marked as having option 01. The only obvious difference is that both the second and third units have higher serial numbers than the first, which is why I suggested that perhaps fitting the option 01 oscillator became standard with later production. Another possibility of course is that the first unit was incorrectly marked and none of them have the option 01 oscillator:-) Regards Nigel GM8PZR In a message dated 11/07/2015 06:45:30 GMT Daylight Time, p...@phk.freebsd.dk writes: In message <10c4f9.7d4eacfb.42d19...@aol.com>, GandalfG8--- via time-nuts write s: >All three of my units seem to have the Option 01 oscillator fitted, >although only one states this on the option label, I belive option 01 doesn't mean "has an OCXO" but rather "has a better OCXO" -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Loran and SRS FS700 in the UK
Hi Iain I was also expecting a separate chain and GRI, but yes, 63710 seems to be all there is. Had me scratching my head for a while but for timing purposes at least it's just "business as usual":-) Those extra stations provide the localised corrections that are then transmitted via the exiasting transmitters. Regards Nigel GM8PZR In a message dated 11/07/2015 07:27:09 GMT Daylight Time, i...@g7iii.net writes: On 10/07/15 22:39, GandalfG8--- via time-nuts wrote: > This is a reply to the topic "Loran-C reception in the UK" with specific > emphasis on the Stanford Research FS700. > Apologies for starting a fresh topic but I'm still not able to take emails > from the list due to incompatibility problems with AOL and I don't see how > to reply to an existing subject directly from the archive, if anyone knows > how to do this please let me know. > > There is an excellent reference to eLoran in the UK, including downloadable > publications, starting here.. > http://www.gla-rrnav.org/radionavigation/eloran/index.html > > As far as I can tell, the Lessay chain, which includes the UK station at > Anthorn, is currently transmitting eLoran, with the extra data channel, > rather than Loran-C but this is totally backwards compatible and the FS700 runs > fine here, as does the Austron 2100 series. > This is why it's difficult to find specific GRIs quoted for eLoran as > opposed to Loran-C, it's effectively the same network, using the same > transmitters and GRIs. Right, so GRI 63710. I had heard a while back that there were some extra transmitters on the south coast specifically for eLORAN, but finding the ED's or if they are on the same GRI has proved fruitless so far. Iain ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Loran and SRS FS700 in the UK
This is a reply to the topic "Loran-C reception in the UK" with specific emphasis on the Stanford Research FS700. Apologies for starting a fresh topic but I'm still not able to take emails from the list due to incompatibility problems with AOL and I don't see how to reply to an existing subject directly from the archive, if anyone knows how to do this please let me know. There is an excellent reference to eLoran in the UK, including downloadable publications, starting here.. http://www.gla-rrnav.org/radionavigation/eloran/index.html As far as I can tell, the Lessay chain, which includes the UK station at Anthorn, is currently transmitting eLoran, with the extra data channel, rather than Loran-C but this is totally backwards compatible and the FS700 runs fine here, as does the Austron 2100 series. This is why it's difficult to find specific GRIs quoted for eLoran as opposed to Loran-C, it's effectively the same network, using the same transmitters and GRIs. It seems that enhanced accuracy for navigational purposes in harbour approaches etc is provided by Differential Loran Reference Stations, similar to differential GPS, with the correction data being transmitted on the eLoran data channel, more here.. http://www.trinityhouse.co.uk/news_info/press_releases/2013/uk_switches_gps_ backup_english_channel.html Again this will not affect operation of the FS700. I've run three FS700s in the UK, about 150 Km north west of Anthorn, but when Anthorn is down for maintenance I can also run quite happily from the master station at Lessay in France. Points to note. All three of my units seem to have the Option 01 oscillator fitted, although only one states this on the option label, so perhaps this became standard with later production. I don't know and wouldn't take it for granted but thought it worth a mention. The fitted oscillator in each unit is an identically specified SRS SC10. Mine are off air right now as I swap about stuff in the timing rack, and haven't really been run for much more than initial tests, albeit for quite long periods. My general impression so far is that the reported frequency offset might be a bit optimistic, this is compared with Thunderbolt GPSDOs, but I need to do more work on this. The latest FS700 firmware I have seen is version 1.20. The station identification data is stored in the firmware and this looks to be the only version with included data for the Lessay chain, although Anthorn identifies as Loop Head in Ireland, a proposed station that never went into service with Anthorn taking its slot. Attempts to edit the firmware to change the identification text resulted in boot failures with a faulty Eprom warning, presumably due to a checksum failure. I haven't pursued this. I can make the 1.20 firmware available if anyone would like a copy. There is a full FS700 manual available on the KO4BB manual site, complete with schematics. The schematics may not fully match the text though as a scanned set of schematics have been added to the last version of the online manual without schematics that was available from SRS. FS700s have become available on Ebay at very good prices since the USA Loran-C chain was closed down, that's why I have three:-), but it needs to be noted that these are mainly from "recycling" outfits, what we might once have referred to as scrap yards in the UK, and usually untested and with no warranty. On average mine have cost me about 200GBP each, including shipping and tax, but beware of some sellers still asking anything up to 1000USD before shipping and import tax. Packaging quality from these sources is definitely variable and only one of mine arrived undamaged. A particular weak spot is the cutout for the small mains transformer on the rear panel, one ding on the transformer can cause some severe panel distortion in that area, with possibly a strip down and some panel beating being required. Another weak spot is the flip up cover over the mains switch. Luck of the draw really, some outfits are better at packaging than others, but don't take this for granted and be prepared for some making good. That small mains transformer runs really hot, not too surprising perhaps, and I've seen at least one online photo showing two larger transformers mounted in the space towards the front of the unit. One or two probably depends on what's to hand but I would suggest a very worthwhile change. Mains voltage here is generally over 245 volts, so a bit on the high side, but I do believe that transformer is underrated. Small point, but a nuisance, there's no backlighting on the LCD display. Overall impression, an excellent unit with programmable output frequency and built in phasemeter, and I can't wait to get mine back on the air:-) Regards Nigel GM8PZR ___ time-nuts mailing list -- time-nuts@feb
[time-nuts] Austron 2100F Manual
I'm working on a 2100F Loran-C receiver that boots up ok and seems to pass the built in test routines, but after accepting a GRI it just sits in acquire mode. I know the signal is good. I've got the manual for the 2100 timing version, my scan of that is on the KO4BB manuals site if anybody needs it, but whilst they are quite similar there are differences and I would prefer to work from a copy of the 2100F manual if possible. Is anybody able to share a pdf copy of this please, or if someone could undertake the raw scanning, preferably TIF files (300dpi text 400dpi schematics seemed to work fine on the first one), I'd be happy to process these and return a finished pdf. Any replies off list if possible please as I can no longer receive list emails, including digests, due to unresolved compatibility problems with AOL. Regards Nigel GM8PZR ___ 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] For Sale New JLT LTE-Lite 20MHz UK Only
Having dived in with great enthusiasm as soon as the LTE-Lite was made available I've had it on test for a couple of days now and have not been disappointed, I'm very impressed. However, given the number of existing GPS and other off air systems and projects already running here I have to admit I might have been a bit over enthusiastic and I don't really have any immediate need for another one. Rather than park it on the shelf in its box for the time being, or leaving it just running in the background, I'd be happy to pass it on for what I paid for it to someone else in the UK who can make more immediate use of it. I'm not looking to make any profit on the transaction but I'm not looking to make a loss either, if that was the only option then I'd just keep it until I did find more use for it. With carriage and UK import taxes it cost me just over 165 GBP and I'd be willing to sell it for 175 GBP with the extra to cover tracked and insured next day delivery, or for 165 GBP to anyone able to collect from the west coast of Scotland. Although not actually saving anything significant on the cost the purchaser would be guaranteed fast delivery of a unit that's just come off test and is available now, and please note I would only want to ship this to the UK. The kit is totally as new and as in the original packaging as supplied, with the module itself, the antenna, two straight MMCX to BNC adapter cables, USB power adapter and USB lead, plus the instruction leaflet with optional 14pin DIL socket and 3 pin header still attached inside a small plastic bag. If any is interested please reply directly and not via the list, I'm back to just receiving daily digests due to ongoing problems with "live" list traffic sent to AOL so won't see replies to the list for some time, and I will be working on a first come first served basis. Regards Nigel GM8PZR ___ 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] update on LTE-Lite
Hi Said, Many thanks for your reply. I'd realised that R2 and R3 were in the paths of alternative power feeds but had managed to convince myself that both resistors were shown to be fitted in your auction photos, although I can now see quite clearly that whilst R2 is fitted, R3 isn't, whoops:-) I was hoping that removing the TXCO might be reasonably straightforward, it was after all your suggestion:-), but am now concerned that the RTV might have flowed under any components perhaps not fully seated and didn't want to take the risk of damaging anything. I'd also hoped it might prove possible to remove the onboard TCXO power by breaking one of the tracks on the LTE-Lite module itself but it sounds like that might have been a bit too optimistic. Whilst I'm pretty sure I would have stuck with the 20MHz version anyway, the initial enthusiastic rush did mean nearly 40 of us had already bought them before your comments regarding the harmonic mixing and the suggestion to use the 19.2MHz version reached the list, so to some extent at least that might help explain the numbers:-) Anyway, thanks very much again for making these available, I certainly don't see this as a significant issue so it's time to dive in and worry about the finer details later. Just out of interest, on the 10MHz version without the onboard TCXO, did the DIL oscillator end up socketed or soldered? Regards Nigel GM8PZR In a message dated 22/11/2014 18:01:18 GMT Standard Time, saidj...@jackson-labs.com writes: Nigel, CC'ing time nuts.. R2 and R3 are stuffing options, see the schematics in the user manual. Typically you don't have to solder anything. The default is set for the low-noise 3.0V to be fed to the DIP-14 tcxo for best performance. On removing the SMT Tcxo, this is not easy, but possible with a heat gun. Its easy to melt the adjacent switches though when doing that. The RTV over it should just peel off, but we have not tried that yet. There is no way to just remove power to the internal Tcxo unfortunately. This is why I had suggested the 19.2MHz version for people who want to use the external oscillator option, because that won't beat with your oscillator close-in. I was a bit surprised that so few of those 19.2MHz units sold compared to the significant numbers for 10/20MHz units. In either case I think the resulting beat spurs are typically lower than many other GPSDOs and oscillators have in their spurs, the CSAC with its spurs comes to mind.. Hope that helps, Said Sent from my iPad On Nov 22, 2014, at 6:08, _GandalfG8@aol.com_ (mailto:gandal...@aol.com) wrote: Hi Said, Sorry to bother you again, I'm not sure is this is an oversight or deliberate but I've just noticed that R2 has not been fitted to my evaluation board. I'm a bit concerned as this will affect power to the external oscillator and R2 would be difficult to fit now that SW2 is installed. I may have missed this if it was mentioned on the Time-Nuts list but there's a lot there to look through so thought it best to ask you direct. Regards Nigel GM8PZR In a message dated 30/10/2014 23:30:40 GMT Standard Time, _saidjack@jackson-labs.com_ (mailto:saidj...@jackson-labs.com) writes: Hello everyone, We wanted to give you an interim update on the LTE-Lite Evaluation kit builds. We are making good progress on the assembly. We are expecting to ship within the announced time frame, and are guiding the factory on a daily basis. We are using the time to improve the firmware and have made some upgrades with the help and efforts of a very well-known Time Nut (thanks much!) who I am certain will identify himself in due time. This development activity has revealed a sensitivity in the GPS receiver: the unit should not be changed from mobile mode to Position Hold (Timing) mode ROM/Flash firmware or vice versa while power is enabled, this could lead to Flash memory corruption. We are thus shipping the unit with a solder jumper that will require soldering-in two pins to get out of Timing mode and into mobile mode so as to avoid the possibility of a user accidentally inserting a jumper with power supplied to the unit, which could then corrupt the GPS Flash memory. We have also been able to upgrade the GPS Flash firmware in close cooperation with the vendor of the GPS receiver to make it more optimal for operation in a GPSDO, and these efforts have given us a GPS Flash firmware release that works well with our GPSDO algorithms and TCXOs. We will upgrade all of the GPS receivers prior to shipment with this specialized firmware release. We also have some good news on the 10MHz versions of the board: the 10MHz DIP-14 TCXOs are scheduled to arrive at our factory in about 5 weeks, so that will pull-in the delivery schedule significantly. We will continue to keep track of the schedule and update you with any changes. Lastly there has
Re: [time-nuts] My NTGS50AA failed
Hi Ignacio I'm sure removing the oscillator would make your faultfinding much more straightforward. When I removed mine I started out quite convinced I wouldn't be able to do it, even with the solder mostly removed from around the pins they were obviously quite a tight fit and all I had available at that time was a plunger type solder sucker and desoldering braid, as the bits on my old Pace desoldering kit were well past their best. The answer basically was lots of braid, lots of patience, and resisting like crazy any temptation to pull against a hole that wasn't fully released, but I certainly wouldn't want to do it that way again in a hurry. The desoldering gun I use now would make it easier but the holes are really a bit small for those oscillator pins. The good news though is that the connectors are there as a back up and fitting them definitely makes it more versatile. I had considered repeating the performance on another NTGS50AA and/or NTBW50AA, I really think I should but so far haven't found the courage:-) I think previous checks for 1PPS outputs might have been limited to the external connectors but it would make sense if it was available somewhere on the PCB, I'll try to get one powered up later and check your findings, if I can find a bit of space that us amongst the usual chaos! Regards Nigel GM8PZR In a message dated 13/11/2014 01:11:30 GMT Standard Time, eb4...@cembreros.jazztel.es writes: Hi Nigel, Thank you for the suggestions, I was trying to avoid the OCXO removal but I think that now it must be done. I was also playing with the idea of populating the connectors so an OCXO exchange could be easily made, this makes possible to try various oscillators. Meanwhile I has been probing and measuring a lot of points and by chance I found a very interesting thing: Probing TP33 (which is close to the Trimble chip (U2) and directly connected to pin 76) there is a 1PPS, 10 us wide signal. I've checked it and appears to be synchronous with the 1/2 PPS output so maybe it can be routed to an output, probably I'll replace the 1/2 PPS with it, using the existing drive circuit and connector since it is very straightforward. My only concern is if this signal only is there during the anomalous condition that I have now, I have to retest it after fixing it. I had asked several times if anybody had located a 1PPS signal on these units, but the responses were negative and I had not probed systematically the board before. Also I'm taking notes of the signals found and I'll try to make a partial schematic at least with the EFC circuitry. When I fix it I'll clean the notes and figures and I'll upload it to some place. Best regards, Ignacio El 12/11/2014 a las 11:47, GandalfG8--- via time-nuts escribió: Hi Ignacio I have removed a "faulty" oscillator from one of these, not one of my more relaxed moments and quite amazed when the board emerged totally undamaged, but proof at least that it can be done:-) With the oscillator removed there's access to two sets of connector pads that will either accept SMA or SMB connectors and after conducting tests on the original oscillator via flying leads just soldered to the board I decided not to fit a replacement to the board after all but to fit a couple of SMB connectors to make the setup more versatile, and to avoid the possibility of having to remove another oscillator in the future:-) Another advantage of these pads is that if the board does get damaged removing the oscillator they can still be used as an alternative. The connectors take the 10MHz from the oscillator into the board and the EFC control voltage out from the board to the oscillator, now there's a surprise:-), and oscillator power can be completely external if required. >From this it would seem that the reference supply from the oscillator itself is not used in practice, certainly not in the "offboard" case anyway. As others have suggested it seems likely your problem may not be the oscillator itself, but it still might be worth removing anyway to make testing and fault finding more straightforward. The maximum positive excursion of the NTGS50AA should be 6 volts, not 5 as you're seeing, and another indication it might be worth removing the oscillator to see how the board behaves stand alone. I've not seen what seemed to be the repeated attempts at lock that you mentioned previously, but then I wasn't even aware for a long time that the control voltage could drive below 3 volts as well as above it:-) This is my note from previous observation of my "faulty" unit - When first powered it brings up all LEDs and then switches to a green LED for a few