[time-nuts] LPRO accuracy
Hi Everyone, My GPSDO has been running for about a month now and the last frequency adjustments are: 09/24/2013 15:48:37 1301186 Freq 1.0484E-13 09/25/2013 15:53:26 1387875 Freq 4.7980E-13 09/30/2013 16:17:26 1821315 Freq -2.2965E-13 10/04/2013 16:36:38 2168067 Freq -3.2450E-13 10/07/2013 16:51:03 2428132 Freq -4.3682E-13 Is this about what should be expected? I am also trying to stabilize the LPRO temperature to minimize its influence. Thanks, Alan ___ 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] How much fluctuation does a typical Rb have?
Hi, So I've had my RFTG with a LPRO in it running for 2 weeks and it has made various corrections along the way: Time Elasped Change Type Change 09/09/2013 14:22:11 0 Power On 09/13/2013 14:55:40 347609 Freq -2.0524E-13 09/14/2013 15:00:30 434299 Freq -7.9048E-14 09/16/2013 15:10:08 607677 Freq -1.4628E-12 09/18/2013 15:19:45 781054 Freq 1.0041E-12 09/19/2013 15:24:34 867743 Freq -1.5560E-13 09/20/2013 15:29:23 954432 Freq -7.9048E-14 09/21/2013 15:34:12 1041121 Freq -3.2450E-13 09/23/2013 15:43:48 1214497 Freq -1.2866E-12 Is this pretty typical? I've had the unit temperature held pretty constant with a fan and a PID loop adjusting the speed to keep the temperature the same. Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, A couple more questions about the RFTG if you have a moment: What are you default values for Avg Sample, Time Corr Schedule, and Freq Corr Schedule. Mine are 5, 15, 1440... Also with yours up and running how often does it make adjustments? Mine has been running for 82 hours and has made no time adjustments and the three frequency adjustments (every 24 hours) are for 0.e+000. It would seem that it is pretty happy with where it is as all of my previous times were loaded with both time and frequency adjustments in an attempt to get itself set properly. Perhaps it finally did. I've attached a temperature sensor to the LPRO inside and am using a PID loop on an AVR to vary a fan rpm to keep the LPRO at a consistent temp. It seems to be keeping it at +/- 0.2 deg C and I've not bothered to try to tune the PID at all yet. Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Guido Küppers Sent: Friday, August 23, 2013 1:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Hi Alan, I haven't seen this behaviour yet, but then I have RFTG shut off for a couple of months since. 7168 is dividible by 7 and the result is 1024. You know the gps week wraps over from 1023 (0x3ff) to 0. Perhaps what you see is the consequence of some software workaround of this problem, in other words the RFTG thinks a gps week rollover must have happened and tries to correct the date. Have fun Guido Von Samsung Mobile gesendet Alan Kamrowski II ala...@earthlink.net hat geschrieben: Hi Guido, Do you have any idea why the unit interprets the date 7168 (0x1c00) days into the future? If I send it today's date in the correct Motorola format, this is how many days it adds to it. If I change the date to try another, it does the same thing. Any idea why? I can correct for it by subtracting 0x1c00 days before sending it, this just seems very odd. Thanks, Alan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Bob, I've got one of these: MCP9701A-E/TO-ND: http://www.digikey.com/product-search/en?x=0y=0lang=ensite=usKeyWords=MC P9701A-E%2FTO-ND Mounted to the connector side of the LPRO. I made a small aluminum bracket that fits under the hex head connector screws and clamps the TO92 to the LPRO case. It isn't at the physics end or taking the temperature of the base plate, but I am hoping that it will do. It outputs a voltage 400 mV = 0 deg C + 19.5 mV per deg C. I've got it feeding into an ADC channel on an AVR with a precision 2.5V reference. I've not calibrated it, but my ir temp sensor agrees pretty close to it, but calibration to a specific temp really isn't my goal, keeping the LRPO at the same temperature as much as possible is. Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Thursday, September 12, 2013 8:01 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Hi Be very careful of using the same sensor to control your loop and to determine how well the device is holding temperature. It's amazingly easy to fool yourself by a couple of orders of magnitude . The test is always to have a couple of other sensors located around the device and see what happens to them. That said, the real fun is to see how much thermal gain the loop has. If the outside temperature changes 100 C how much does your LPRO change? A 1 C change would be a thermal gain of 100X. Practical single stage controllers can get you into the 300 to 500 range. If your room ambient changes by 4C, the device should change by 0.04 C with a thermal gain of 100. Bob On Sep 12, 2013, at 8:52 PM, Alan Kamrowski II ala...@earthlink.net wrote: Hi Guido, A couple more questions about the RFTG if you have a moment: What are you default values for Avg Sample, Time Corr Schedule, and Freq Corr Schedule. Mine are 5, 15, 1440... Also with yours up and running how often does it make adjustments? Mine has been running for 82 hours and has made no time adjustments and the three frequency adjustments (every 24 hours) are for 0.e+000. It would seem that it is pretty happy with where it is as all of my previous times were loaded with both time and frequency adjustments in an attempt to get itself set properly. Perhaps it finally did. I've attached a temperature sensor to the LPRO inside and am using a PID loop on an AVR to vary a fan rpm to keep the LPRO at a consistent temp. It seems to be keeping it at +/- 0.2 deg C and I've not bothered to try to tune the PID at all yet. Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Guido Küppers Sent: Friday, August 23, 2013 1:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Hi Alan, I haven't seen this behaviour yet, but then I have RFTG shut off for a couple of months since. 7168 is dividible by 7 and the result is 1024. You know the gps week wraps over from 1023 (0x3ff) to 0. Perhaps what you see is the consequence of some software workaround of this problem, in other words the RFTG thinks a gps week rollover must have happened and tries to correct the date. Have fun Guido Von Samsung Mobile gesendet Alan Kamrowski II ala...@earthlink.net hat geschrieben: Hi Guido, Do you have any idea why the unit interprets the date 7168 (0x1c00) days into the future? If I send it today's date in the correct Motorola format, this is how many days it adds to it. If I change the date to try another, it does the same thing. Any idea why? I can correct for it by subtracting 0x1c00 days before sending it, this just seems very odd. Thanks, Alan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] RFTG GPSDO and other GPSDO questions...
Hi Everyone, I've had some fun and learned quite a bit trying to get my Lucent RFTG rubidium module to discipline itself to a GPS module. It has an interesting way of doing this that I'm not sure is the best or the worst, but it is constantly figuring out an average phase error between the gps 1pps signal and its own 1pps signal generated by dividing the Rb clock. It can make both time corrections (to correct the phase of the 1pps generated signal) and frequency corrections by changing the control voltage on the rubidium. I've been trying to figure out exactly how it works, but can only guess at some things. It measures an average phase error over a 5 minute interval right now, and clearly it is using a 10Mhz clocked device to do this. It usually bounces between a phase error of +40nS or -60nS and it can only make time corrections in 100nS increments. My theory is that if the average phase error is large enough that it can adjust for it then it will do so, for example an average phase error of 150nS would mean that it could adjust by 100nS leaving only 50nS. It tries to adjust the 1pps (time correction) every 15 minutes. It also calculates the delta between these average phase errors and I watched them for an hour and you will see things like +6nS delta followed by a -6nS delta and adding all the delta's together for the hour I got 0. I would think it might actually use these delta. I would think looking at this delta for a long period of time might be helpful for it to determine a frequency correction, but perhaps that isn't how it works. Maybe it looks at the adjustment it made (100nS) and the time between adjustments, say 10 hours to determine the frequency adjustment. I can't think that would be as accurate because it makes time adjustments on a 15 minute schedule. You can also tweak the time correction schedule and frequency correction schedule so I'm not sure they are relatable to each other or not. I just know that my unit has been running for 30 seconds and still hasn't made a 100ns adjustment. It has displayed no time adjustments and three frequency adjustments each for 0.e0. This got me to wondering - how do other GPSDO units work? Do they take days and weeks to build up enough data to discipline themselves or are there faster methods? Thanks, Alan ___ 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] LPRO questions...
Hi Magnus, Well, I went ahead and tried this again - 400 C, bulb spinning, back end of bulb upwards, 75 seconds. Kept the bulb in the same direction until it cooled. Lamp voltage did not go up, in fact it seemed to return back to 3.5V from 3.7V, but the lock time went down. It was running just over 5 minutes to lock (5m 7s), but it has now locked twice at 4m 7s and 4m 15s... I'm going to stop messing with it before I break it Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Friday, September 06, 2013 1:59 AM To: time-nuts@febo.com Subject: Re: [time-nuts] LPRO questions... Hi Alan, I used a fairly crude heat gun, and I looked at the lamp and was able to see when it had cleared since I had evaporated the rubidium from the glas. But it was not extreme heat (it's a small heat-gun anyway) or particular long time. I had to redo it and re-think it to figure out how to get the metal to deposit where I wanted, and what worked for me was to let the deposit area be high up, but it could just be that this was the part with most cooling, so it could have dominated. Cheers, Magnus On 09/06/2013 12:53 AM, Alan Kamrowski II wrote: Hi Magnus, Interesting. What temperature C do you use and for how long? Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Thursday, September 05, 2013 4:24 PM To: time-nuts@febo.com Subject: Re: [time-nuts] LPRO questions... On 09/05/2013 10:45 PM, Alan Kamrowski II wrote: Hi Bill, Where is the dimple? The bulb end looked circular and smooth? Do you mean the other end (back end which is visible even when the bulb is installed)? The bulb end points towards the entire assembly... The back end as mounted is where you want it to deposit. When I did it, it turned out that I better put the window side downwards so that when the vapor rose as it was hot, it hit the cooler side above it and settled there, that's how I reduced the shadowing on the window to clear. The reason it's a bad thing is that this thin coating will absorb exactly that wavelength you try to output. 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 mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Looking at this picture - where is the temperature sensor?
Hi Everyone, http://www.ko4bb.com/Manuals/05%29_GPS_Timing/RFTG-m/RFTG-m-rb_L105A_Hi_res/ lucent%283%29.jpg I'm trying to figure out where the RFTG gets its Rb module temperature and I think it has to be on the board above most likely in the upper left. The cutout is where the RB module is mounted and it has a heat sink tape or some sort of material on the bottom to help it thermally connect with the RFTG case. The PCB also has a thermal connection to the case through the pcb mount in the upper left.. Thanks, Alan ___ 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] LPRO questions...
Hi, Well, I had it apart so I went ahead and tried the heating process on the lamp. I don't see any splattering on the lamp at all of purple material, but I added some masking tape to the threads and put it in a drill to rotate it. I hit it with a hot air station at 350 deg C and rotated it for 60-90 seconds or so. The end result is a lamp that went from 3.5V to 3.7V. Did I do it long enough or hot enough? The repair guide I saw said something about a hot air gun and those can be 300-600 deg C... Thanks, Alan ___ 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] LPRO questions...
Hi Bill, Where is the dimple? The bulb end looked circular and smooth? Do you mean the other end (back end which is visible even when the bulb is installed)? The bulb end points towards the entire assembly... Thanks, Alan ___ 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] LPRO questions...
Hi Magnus, Interesting. What temperature C do you use and for how long? Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Magnus Danielson Sent: Thursday, September 05, 2013 4:24 PM To: time-nuts@febo.com Subject: Re: [time-nuts] LPRO questions... On 09/05/2013 10:45 PM, Alan Kamrowski II wrote: Hi Bill, Where is the dimple? The bulb end looked circular and smooth? Do you mean the other end (back end which is visible even when the bulb is installed)? The bulb end points towards the entire assembly... The back end as mounted is where you want it to deposit. When I did it, it turned out that I better put the window side downwards so that when the vapor rose as it was hot, it hit the cooler side above it and settled there, that's how I reduced the shadowing on the window to clear. The reason it's a bad thing is that this thin coating will absorb exactly that wavelength you try to output. 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 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] LPRO questions...
Hi, Curiously why is the Rb bulb designed the way it is? Having an open area in the base where a contact would normally be? What is the purpose of that? Also, does it have one conductor or two? If so, how? I only see the base... Thanks, Alan ___ 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] LPRO questions...
Hi, I've got an LPRO and my Rb lamp voltage is 3.5608V. I've read about bulb rejuvenation. I've looked through some of the repair manuals, but still have a few questions. #1 - how do you remove the cover? Is it just press fit into place? I see dimples on it and I wonder can I just pry the case of slowly without bending it to open it? #2 - I may have to open it anyway for a different reason - should I try to rejuvenate my lamp while it is open given the lamp voltage I have. #3 - If I should try it, how do you get the lamp out? I see what looks like a hex nut in photos - do you untwist this nut and the bulb comes out with it? #4 - The heat gun technique -if I make an adapter to hold the bulb in a drill or something that can spin it while applying the heat, is this a good plan? #5 - I see the xtal voltage mentioned (mine says 4.4672V) - what exactly is this? Thanks for your help and advice! Have a great day, Alan ___ 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] LPRO questions...
Hi, Thanks guys - it locks and stays locked so I'm not going to mess with it for now. Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, Do you have any idea why the unit interprets the date 7168 (0x1c00) days into the future? If I send it today's date in the correct Motorola format, this is how many days it adds to it. If I change the date to try another, it does the same thing. Any idea why? I can correct for it by subtracting 0x1c00 days before sending it, this just seems very odd. Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido and mc235960, It stopped doing it all of a sudden and is now accepting the date properly. I did numerous CPU resets on it and one power down/power up and it still did it. Telling the unit the date was old (1/1/1994) took fine so I kept increasing the year 1999, 2000, 2005, 2015 and finally back to 2013 and it stayed ok. The Motorola @@ea command doesn't have the GPS week in it so I'm not sure how the unit got where it was, but it does seem related to that somehow. I did try to send it 2050 to see how far it would go because the Motorola spec ends at 2017. Perhaps this triggered a fix gps date function in eeprom that added to the date to try to correct for the number of week rollover issue? Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Guido Küppers Sent: Friday, August 23, 2013 1:25 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Hi Alan, I haven't seen this behaviour yet, but then I have RFTG shut off for a couple of months since. 7168 is dividible by 7 and the result is 1024. You know the gps week wraps over from 1023 (0x3ff) to 0. Perhaps what you see is the consequence of some software workaround of this problem, in other words the RFTG thinks a gps week rollover must have happened and tries to correct the date. Have fun Guido Von Samsung Mobile gesendet Alan Kamrowski II ala...@earthlink.net hat geschrieben: Hi Guido, Do you have any idea why the unit interprets the date 7168 (0x1c00) days into the future? If I send it today's date in the correct Motorola format, this is how many days it adds to it. If I change the date to try another, it does the same thing. Any idea why? I can correct for it by subtracting 0x1c00 days before sending it, this just seems very odd. Thanks, Alan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Can someone post the @@Ea messages from a Motorola Oncore UT just powered up?
Hi Everyone, I'm converting a Neo 6M GPS data stream to the Motorla Oncore UT data stream my RFTG expects. When first turned on the 6M doesn't have a 1pps signal yet, but does post NMEA messages which lack data are invalid. My question is, what does the binary data stream from a Motorola Oncore UT look like? It is binary so if anyone has one and can capture a power on in hex that would be very helpful. Thanks, Alan ___ 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] Can someone post the @@Ea messages from a Motorola Oncore UT just powered up?
Hi Peter, Thank you for posting this - it is interesting. An @@Ea message only occurs once every 5 seconds? It seems odd that it comes up with 08-11-2017 at 12:00:00 My RFTGm-II-Rb doesn't seem to mind it isn't getting the @@En messages... Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Peter Bell Sent: Thursday, August 22, 2013 9:27 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Can someone post the @@Ea messages from a Motorola Oncore UT just powered up? The board on it's own comes up in a mode that doesn't send anything until it's initialized. The RFTG-m-XO is responsible for setting up the board. This is what you see on the RX line after powerup: Note that this is from WinOncore - the real data doesn't have the (Rx) prefix and the data is in binary rather than hex. After this, it repeats with one @@En message sent for every 12 @@Ea messages (Rx)@@Fa 8000 (Rx)@@Fa 8000 (Rx)@@Ea 081107E10C810900 19001B001300160014000200050009 (Rx)@@Aw 00 (Rx)@@Ay (Rx)@@Az (Rx)@@At 00 (Rx)@@Ag 0A (Rx)@@En 3C01000D01010001010202D009191B2FAF080013 16142FAF0800022FAF080005 (Rx)@@Ea 081107E10C0005810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C000A810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C000F810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0014810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0019810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C001E810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0023810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0028810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C002D810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0032810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0037810900 19001B001300160014000200050009 (Rx)@@Ea 081107E10C0100810900 19001B001300160014000200050009 On Thu, Aug 22, 2013 at 8:44 PM, Alan Kamrowski II ala...@earthlink.netwrote: Hi Everyone, I'm converting a Neo 6M GPS data stream to the Motorla Oncore UT data stream my RFTG expects. When first turned on the 6M doesn't have a 1pps signal yet, but does post NMEA messages which lack data are invalid. My question is, what does the binary data stream from a Motorola Oncore UT look like? It is binary so if anyone has one and can capture a power on in hex that would be very helpful. Thanks, Alan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, the one I used was a Oncore UT. The message needed for the RFTG is @@Ea.. So if I send the bytes: @@Ea.. it will accept the 1pps pulse? Any idea on the baud rate, 9600 N 8 1 ? Thanks for your help Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, I found a manual here: http://www.elgps.com/public_ftp/Documentos/SIRF_Protocol.pdf I don't see the @@Ea.. sequence anywhere. Is it NMEA or SIRF Binary? Any more tips before I try this? Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, So you didn't fake the data from the UT, you only made something to ask the UT to output it. I see some UT units on eBay, but I don't recognize the antenna connectors. I've got a small screw on antenna (SMA?), but the ones on eBay look like that small round push on like I've seen in notebook computers or something that looks like SMA, but doesn't seem to have threads - push on??? Does the UT require a specific antenna? Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, That´s exactly what I did, although I used the fake approach before that , when I didn't have a UT on hand. Was that successful? If I could just output the same data stream to it once a second with the pulse from an AVR or something that would be great. Do you still have this setup? Can you tell me what bytes are sent once per second so I can recreate sending them? Thanks so much, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Bob, All the UT cards that I have ever seen use the small push on antenna connector. I have never seen one that directly takes anything normal like an SMA or a BNC. You buy the card and then a bit of coax with the push on on one end and (normally) an SMA on the other end. The antenna for the UT is a normal 5V powered GPS antenna. Just about anything other than a +12V survey antenna will work. Thanks, I'll look for one of these. If you go shopping, go for one of the later cards. They work a lot better than the early ones. I saw a couple on eBay, but don't know anything about them, which ones are the later ones? Thanks for your help! Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, yes it worked. I'll have to look through my software projects and send you the source file. That would be awesome - thank you for looking! Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Guido Küppers Sent: Saturday, August 17, 2013 2:49 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Alan, yes it worked. I'll have to look through my software projects and send you the source file. Have fun, Guido Von Samsung Mobile gesendet Alan Kamrowski II ala...@earthlink.net hat geschrieben: Hi Guido, That´s exactly what I did, although I used the fake approach before that , when I didn't have a UT on hand. Was that successful? If I could just output the same data stream to it once a second with the pulse from an AVR or something that would be great. Do you still have this setup? Can you tell me what bytes are sent once per second so I can recreate sending them? Thanks so much, Alan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido,
yes it worked. I'll have to look through my software projects and send you the
source file.
Please do, so far my attempt is just failing.
I'm trying to send:
//transmit gps data
txserial_putc('@');
txserial_putc('@');
checksum=0;
checksum_putc('E');
checksum_putc('a');
checksum_putc(1); //month
checksum_putc(1); //day
checksum_putc(208); //year2 2000
checksum_putc(7);
checksum_putc(0); //h
checksum_putc(0); //m
checksum_putc(0); //s
checksum_putc(0); //frac40
checksum_putc(0);
checksum_putc(0);
checksum_putc(0);
checksum_putc(0); //lat4 0
checksum_putc(0);
checksum_putc(0);
checksum_putc(0);
checksum_putc(0); //long40
checksum_putc(0);
checksum_putc(0);
checksum_putc(0);
checksum_putc(0); //elip40
checksum_putc(0);
checksum_putc(0);
checksum_putc(0);
checksum_putc(0); //notused4 0
checksum_putc(0);
checksum_putc(0);
checksum_putc(0);
checksum_putc(0); //vel20
checksum_putc(0);
checksum_putc(0); //heading20
checksum_putc(0);
checksum_putc(0); //dop20
checksum_putc(0);
checksum_putc(0); //doptype 0
checksum_putc(12); //vissats 12
checksum_putc(8); //trackedsats 8
checksum_putc(0); //satid 0
checksum_putc(6); //trackmode sat time available
checksum_putc(0); //carrnoise
checksum_putc(2); //status using for time solution
checksum_putc(1); //2
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(2); //3
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(3); //4
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(4); //5
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(5); //6
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(6); //7
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(7); //8
checksum_putc(6);
checksum_putc(0);
checksum_putc(2);
checksum_putc(32); //receiverstat 3d fix
txserial_putc(checksum);
txserial_putc(13);
txserial_putc(10);
Thanks,
Alan
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Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Guido, Been there, done that. The RFTGm-RB can be disciplined if you connect the pps and the gps data stream coming from a motorola Oncore. Regards Guido I've pulled it apart and the board does show a connection to the EXT C-FIELD. That trace runs to a jumper labeled A C B and currently C B is shunted. Any particular Motorola oncore model required - I see a bunch of them on Ebay... Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Guido Küppers Sent: Friday, August 16, 2013 3:29 AM To: Rex; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Von Samsung Mobile gesendet Rex r...@sonic.net hat geschrieben: I don't think the rubidium module for these systems can be disciplined. I think they were only intended as a backup if the XO section or GPS failed. The XO section does discipline but I don't know the details. I'm not sure of the model number, Lucent had several variations on the same theme in that time frame. I had one of the rubidiums that may be the same as yours. Trying to trace out some of the circuits, I found that the EFC on the LPRO connector was not being used at all. On 8/15/2013 7:52 AM, Alan Kamrowski II wrote: Hi Everyone, I've only got the RFTGm-II-Rb module. I found an interface cable specification here: http://www.ko4bb.com/Manuals/05%29_GPS_Timing/RFTG-m/RFTGm%20Interface %20Cab le.pdf Does anyone know if feeding a 1pps signal to pin 9 might discipline it? Or does it need the other connections such as GPS data, etc. Is there a ground on this connector? Thanks! ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] LPRO 101 - does anyone know how much the C Field pot changes and what direction?
Hi Everyone, I'm going to try to calibrate my LPRO 101 to a GPS 1pps signal. Does anyone know what one turn clockwise of the c field adjustment pot will do to the signal in terms of ppb ? Thanks, Alan ___ 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] LPRO 101 - does anyone know how much the C Field pot changes and what direction?
Hi Brian, Just did this. Less than 0.005 Hz. Thank you - was clockwise 0.005 higher or lower? My Rb is about 0.000731284 fast according to my estimate. To really fine tune it, you need to used the C-field adjustment pin. This circuit is simple. A Linear Technology LT1236 precision 5V regulator and a 10 K linear 20+ turn pot. You can get a sample of the chip free from Linear Technology. It is connected to a RFTGm-II-Rb control board which already supplies the C-field adj pin... I may try to get a matching gps and feed it in to see if it will discipline. Do this with the LPRO in its enclosure after it has run at least a day. I can only get to the adjustment hole outside of the enclosure, but I've tried to put it in the same thermal condition it would be normally. It is sitting on top of a heat sink with a fan on it and the temp seems about the same it as usually is so hopefully this will not affect it. Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Everyone, I've only got the RFTGm-II-Rb module. I found an interface cable specification here: http://www.ko4bb.com/Manuals/05%29_GPS_Timing/RFTG-m/RFTGm%20Interface%20Cab le.pdf Does anyone know if feeding a 1pps signal to pin 9 might discipline it? Or does it need the other connections such as GPS data, etc. Is there a ground on this connector? Thanks! ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Rex, I don't think the rubidium module for these systems can be disciplined. I think they were only intended as a backup if the XO section or GPS failed. The XO section does discipline but I don't know the details. I was hoping since the rubidium module had a light for GPS and an input for the GPS that it also did the same thing. Trying to trace out some of the circuits, I found that the EFC on the LPRO connector was not being used at all. That is too bad, but that proves it all right. I tried to feed a 1pps signal into the interface pin 9 to see what would happen, but the NO GPS light never went off and it didn't pull the frequency at all. So far I've done a 4 hour run between the Rb and GPS and counted 13939010 Rb cycles to 13939 GPS 1pps pulses or 1000.0007174 Hz for the Rb. Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Bob, Is it 0.71 ppb off or 0.071 ppb off? This is how I calculated it: 13939010/13939 = 1000.000717411579022885429371 answer/1000 = 1.00717411579022885429371 answer-1 = 7.1741157902288542937083004519693e-11 answer*1e9 = 0.071741157902288542937083004519693 Thanks, Alan ___ 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] RFTGm-II-Rb - can you gps discipline it without the XO module?
Hi Bob, No biggie - just wanted to make sure I was calculating it right! :) Thanks, Alan -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: Thursday, August 15, 2013 7:35 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] RFTGm-II-Rb - can you gps discipline it without the XO module? Hi Must have blinked counting all the zeros .. Bob On Aug 15, 2013, at 6:36 PM, Alan Kamrowski II ala...@earthlink.net wrote: Hi Bob, Is it 0.71 ppb off or 0.071 ppb off? This is how I calculated it: 13939010/13939 = 1000.000717411579022885429371 answer/1000 = 1.00717411579022885429371 answer-1 = 7.1741157902288542937083004519693e-11 answer*1e9 = 0.071741157902288542937083004519693 Thanks, Alan ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
