I have a Samsung GPSR, which is a Symmetricom Z3805A.  It looks like a Z3801A, except it has a front panel power switch.  On the rear panel it shows its made by Symmetricom and it has stickers inside on the PCB showing Symmetricom Z3805A, etc.  Runs off of 28 volts DC.  It also uses the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to 10 Mhz. The unit runs, but it has the March 2004 rollover date problem. The unit uses a Furuno GT-8031B GPS receiver.  The GPS receiver has the form factor of a Motorola M12+ receiver and then the Furuno receiver is mounted on an adapter board that has the form factor of the elder Motorola PVT/Oncore VP receivers. The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA like protocol. I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they will not do it.  I think its because they are timing only receivers and only run binary.  I also tried to put a Motorola Oncore VP in the unit that was set to the 6 channel mode and binary and the Samsung unit gave a front panel fault about 30 seconds after power up. Does anybody have any experience with a replacement GPS receiver for this unit ? Thanks.

Hi, I would look at Synergy they have a number of UBLOX modules specifically designed for vintage Motorola receivers. Cheers, Tom Knox SR Test and Measurement Engineer Phoenix Research Group / Ascent Concepts and Technology 4870 Meredith Way Apt 102 Boulder, Co 80303 Formerly of: 357 Fox Lane Superior Co 80027 303-554-0307 actast@hotmail.com https://www.thedenverchannel.com/news/marshall-fire/superior-man-moving-forward-after-losing-dream-research-lab-during-marshall-fire "Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein ________________________________ From: bryon via time-nuts <time-nuts@lists.febo.com> Sent: Sunday, November 10, 2024 9:45 PM To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> Cc: bryon <kd4fm@aol.com> Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem I have a Samsung GPSR, which is a Symmetricom Z3805A. It looks like a Z3801A, except it has a front panel power switch. On the rear panel it shows its made by Symmetricom and it has stickers inside on the PCB showing Symmetricom Z3805A, etc. Runs off of 28 volts DC. It also uses the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to 10 Mhz. The unit runs, but it has the March 2004 rollover date problem. The unit uses a Furuno GT-8031B GPS receiver. The GPS receiver has the form factor of a Motorola M12+ receiver and then the Furuno receiver is mounted on an adapter board that has the form factor of the elder Motorola PVT/Oncore VP receivers. The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA like protocol. I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they will not do it. I think its because they are timing only receivers and only run binary. I also tried to put a Motorola Oncore VP in the unit that was set to the 6 channel mode and binary and the Samsung unit gave a front panel fault about 30 seconds after power up. Does anybody have any experience with a replacement GPS receiver for this unit ? Thanks. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-leave@lists.febo.com

Hi, it is a old version of NMEA protocol, I ever made a PCB (using GT-8031F card) this year to replace it (correct the GPS rollover problem), but seems few people need it, so I did not sell it, now I am moving, need to find which box include the PCB (I have more than 50 boxes to move). for the old Z3801A or Z3805A, using Motorola M6 or M8 GPS module, need to upgrade the firmware (replace the 4 firmware chip easily). On 11/11/2024 12:19 AM, Tom Knox via time-nuts wrote: > Hi, > I would look at Synergy they have a number of UBLOX modules specifically designed for vintage Motorola > receivers. > Cheers, > Tom Knox > SR Test and Measurement Engineer > Phoenix Research Group / Ascent Concepts and Technology > 4870 Meredith Way Apt 102 > Boulder, Co 80303 > Formerly of: > 357 Fox Lane > Superior Co 80027 > 303-554-0307 > actast@hotmail.com > > https://www.thedenverchannel.com/news/marshall-fire/superior-man-moving-forward-after-losing-dream-research-lab-during-marshall-fire > > "Peace is not the absence of violence, but the presence of Justice" Both MLK and Albert Einstein > ________________________________ > From: bryon via time-nuts <time-nuts@lists.febo.com> > Sent: Sunday, November 10, 2024 9:45 PM > To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> > Cc: bryon <kd4fm@aol.com> > Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem > > I have a Samsung GPSR, which is a Symmetricom Z3805A. It looks like a > Z3801A, except it has a front panel power switch. On the rear panel it > shows its made by Symmetricom and it has stickers inside on the PCB > showing Symmetricom Z3805A, etc. Runs off of 28 volts DC. It also uses > the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to 10 Mhz. > > The unit runs, but it has the March 2004 rollover date problem. > > The unit uses a Furuno GT-8031B GPS receiver. The GPS receiver has the > form factor of a Motorola M12+ receiver and then the Furuno receiver is > mounted on an adapter board that has the form factor of the elder > Motorola PVT/Oncore VP receivers. > > The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA > like protocol. > > I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they > will not do it. I think its because they are timing only receivers and > only run binary. I also tried to put a Motorola Oncore VP in the unit > that was set to the 6 channel mode and binary and the Samsung unit gave > a front panel fault about 30 seconds after power up. > > Does anybody have any experience with a replacement GPS receiver for > this unit ? > > Thanks. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

Thank you.  I did confirm that the Furuno GPS receiver ran NMEA. I pulled the receiver out of the Samsung-Symmetricom Z3805A and mounted the Furuno GPS receiver in a stand alone receiver enclosure and all I could see it doing was generic NMEA at 9600 BPS. I understand the moving, I have also just moved.  I am very much interest in your replacement efforts. Just for info, to the list, the Hewlett-Packard Z3805A used Motorola GPS receiver in the binary mode. Also the Z3801A. Somewhere down the line, after H-P sold the Time-Frequency division to Symmetricom, it appears Symmetricom redesign the Z3805A units.  The main PC board on the bottom of the Z3805A looks like the original in the Z3801A, Z3805A and the 58303.  The switching power supply board mounted above it looks the same. Some models used the HP double oven 10811 oscillator and then they changed to using the MTI-260 oscillator mounted on a new PC board and it doubles the 5 Mhz output of the MTI-260 to 10 Mhz.  Also the Furuno GPS receiver GT-8031B is a 12 channel receiver and I regularly see the GPSDO running with 9-10-11 satellites in GPSCon software.  It just has the March 2005 rollover date problem, like a lot of elder GPS receiver. On 11/10/24 23:42, Scott Qi via time-nuts wrote: > Hi, it is a old version of NMEA protocol, I ever made a PCB (using > GT-8031F card) this year to replace it (correct the GPS rollover > problem), but seems few people need it, so I did not sell it, now I am > moving, need to find which box include the PCB (I have more than 50 > boxes to move). > > for the old Z3801A or Z3805A, using Motorola M6 or M8 GPS module, need > to upgrade the firmware (replace the 4 firmware chip easily). > > On 11/11/2024 12:19 AM, Tom Knox via time-nuts wrote: >> Hi, >> I would look at Synergy they have a number of UBLOX modules >> specifically designed for vintage Motorola >> receivers. >> Cheers, >> Tom Knox >> >> ________________________________ >> From: bryon via time-nuts <time-nuts@lists.febo.com> >> Sent: Sunday, November 10, 2024 9:45 PM >> To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> >> Cc: bryon <kd4fm@aol.com> >> Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem >> >> I have a Samsung GPSR, which is a Symmetricom Z3805A.  It looks like a >> Z3801A, except it has a front panel power switch.  On the rear panel it >> shows its made by Symmetricom and it has stickers inside on the PCB >> showing Symmetricom Z3805A, etc.  Runs off of 28 volts DC.  It also uses >> the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to >> 10 Mhz. >> >> The unit runs, but it has the March 2004 rollover date problem. >> >> The unit uses a Furuno GT-8031B GPS receiver.  The GPS receiver has the >> form factor of a Motorola M12+ receiver and then the Furuno receiver is >> mounted on an adapter board that has the form factor of the elder >> Motorola PVT/Oncore VP receivers. >> >> The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA >> like protocol. >> >> I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they >> will not do it.  I think its because they are timing only receivers and >> only run binary.  I also tried to put a Motorola Oncore VP in the unit >> that was set to the 6 channel mode and binary and the Samsung unit gave >> a front panel fault about 30 seconds after power up. >> >> Does anybody have any experience with a replacement GPS receiver for >> this unit ? >> >> Thanks. >

Hi NMEA is a very basic protocol. You put ASCII “text” commands and get back “text” as a response. If you are doing it on a serial port, you can type the commands and read the results. It does not include the information typically needed to “do a GPSDO”. The folks who came up with NMEA realized that it would never be able to cover 100% of what people needed to do. They allowed proprietary extensions to the protocol. They are still serial commands and they go in the same way as any other NMEA request. They simply are not part of the default command set. In addition, the basic NMEA protocol has been extended a couple of times to cover various new features. Various GNSS systems have been added since NMEA first came out. They now are covered in modern versions of the protocol. In some cases these changes confuse older firmware. Binary protocols are very different than NMEA and they are a whole world onto themselves. Matching up what this or that firmware “needs” typically is a matter of dealing with a handful of queries and responses. Working out exactly *what* those are for a specific version of firmware is a non-trivial task. Very minor things can and do create very random seeming problems. Bob > On Nov 11, 2024, at 2:05 AM, Brett Fanoga via time-nuts <time-nuts@lists.febo.com> wrote: > > Thank you. I did confirm that the Furuno GPS receiver ran NMEA. I pulled the receiver out of the Samsung-Symmetricom Z3805A and mounted the Furuno GPS receiver in a stand alone receiver enclosure and all I could see it doing was generic NMEA at 9600 BPS. > > I understand the moving, I have also just moved. I am very much interest in your replacement efforts. > > Just for info, to the list, the Hewlett-Packard Z3805A used Motorola GPS receiver in the binary mode. Also the Z3801A. > > Somewhere down the line, after H-P sold the Time-Frequency division to Symmetricom, it appears Symmetricom redesign the Z3805A units. The main PC board on the bottom of the Z3805A looks like the original in the Z3801A, Z3805A and the 58303. The switching power supply board mounted above it looks the same. Some models used the HP double oven 10811 oscillator and then they changed to using the MTI-260 oscillator mounted on a new PC board and it doubles the 5 Mhz output of the MTI-260 to 10 Mhz. Also the Furuno GPS receiver GT-8031B is a 12 channel receiver and I regularly see the GPSDO running with 9-10-11 satellites in GPSCon software. It just has the March 2005 rollover date problem, like a lot of elder GPS receiver. > > > > On 11/10/24 23:42, Scott Qi via time-nuts wrote: >> Hi, it is a old version of NMEA protocol, I ever made a PCB (using GT-8031F card) this year to replace it (correct the GPS rollover problem), but seems few people need it, so I did not sell it, now I am moving, need to find which box include the PCB (I have more than 50 boxes to move). >> >> for the old Z3801A or Z3805A, using Motorola M6 or M8 GPS module, need to upgrade the firmware (replace the 4 firmware chip easily). >> > > >> On 11/11/2024 12:19 AM, Tom Knox via time-nuts wrote: >>> Hi, >>> I would look at Synergy they have a number of UBLOX modules specifically designed for vintage Motorola >>> receivers. >>> Cheers, >>> Tom Knox >>> >>> ________________________________ >>> From: bryon via time-nuts <time-nuts@lists.febo.com> >>> Sent: Sunday, November 10, 2024 9:45 PM >>> To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> >>> Cc: bryon <kd4fm@aol.com> >>> Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem >>> >>> I have a Samsung GPSR, which is a Symmetricom Z3805A. It looks like a >>> Z3801A, except it has a front panel power switch. On the rear panel it >>> shows its made by Symmetricom and it has stickers inside on the PCB >>> showing Symmetricom Z3805A, etc. Runs off of 28 volts DC. It also uses >>> the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to 10 Mhz. >>> >>> The unit runs, but it has the March 2004 rollover date problem. >>> >>> The unit uses a Furuno GT-8031B GPS receiver. The GPS receiver has the >>> form factor of a Motorola M12+ receiver and then the Furuno receiver is >>> mounted on an adapter board that has the form factor of the elder >>> Motorola PVT/Oncore VP receivers. >>> >>> The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA >>> like protocol. >>> >>> I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they >>> will not do it. I think its because they are timing only receivers and >>> only run binary. I also tried to put a Motorola Oncore VP in the unit >>> that was set to the 6 channel mode and binary and the Samsung unit gave >>> a front panel fault about 30 seconds after power up. >>> >>> Does anybody have any experience with a replacement GPS receiver for >>> this unit ? >>> >>> Thanks. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

If you’re adventurous, you should be able to reuse the Furuno interposer that I made for the same reason: https://tomverbeure.github.io/2024/08/18/Fixing-the-Symmetricom-S200-GPS-Week-Number-Rollover-Problem.html. In my case, it used the binary protocol instead of NMEA, but it should be simple enough to change the interposer firmware to detect and output NMEA. Tom > On Nov 11, 2024, at 10:26 AM, Bob Camp via time-nuts <time-nuts@lists.febo.com> wrote: > > Hi > > NMEA is a very basic protocol. You put ASCII “text” commands and get back “text” as a response. If you are doing it on a serial port, you can type the commands and read the results. It does not include the information typically needed to “do a GPSDO”. > > The folks who came up with NMEA realized that it would never be able to cover 100% of what people needed to do. They allowed proprietary extensions to the protocol. They are still serial commands and they go in the same way as any other NMEA request. They simply are not part of the default command set. > > In addition, the basic NMEA protocol has been extended a couple of times to cover various new features. Various GNSS systems have been added since NMEA first came out. They now are covered in modern versions of the protocol. In some cases these changes confuse older firmware. > > Binary protocols are very different than NMEA and they are a whole world onto themselves. > > Matching up what this or that firmware “needs” typically is a matter of dealing with a handful of queries and responses. Working out exactly *what* those are for a specific version of firmware is a non-trivial task. Very minor things can and do create very random seeming problems. > > Bob > >> On Nov 11, 2024, at 2:05 AM, Brett Fanoga via time-nuts <time-nuts@lists.febo.com> wrote: >> >> Thank you. I did confirm that the Furuno GPS receiver ran NMEA. I pulled the receiver out of the Samsung-Symmetricom Z3805A and mounted the Furuno GPS receiver in a stand alone receiver enclosure and all I could see it doing was generic NMEA at 9600 BPS. >> >> I understand the moving, I have also just moved. I am very much interest in your replacement efforts. >> >> Just for info, to the list, the Hewlett-Packard Z3805A used Motorola GPS receiver in the binary mode. Also the Z3801A. >> >> Somewhere down the line, after H-P sold the Time-Frequency division to Symmetricom, it appears Symmetricom redesign the Z3805A units. The main PC board on the bottom of the Z3805A looks like the original in the Z3801A, Z3805A and the 58303. The switching power supply board mounted above it looks the same. Some models used the HP double oven 10811 oscillator and then they changed to using the MTI-260 oscillator mounted on a new PC board and it doubles the 5 Mhz output of the MTI-260 to 10 Mhz. Also the Furuno GPS receiver GT-8031B is a 12 channel receiver and I regularly see the GPSDO running with 9-10-11 satellites in GPSCon software. It just has the March 2005 rollover date problem, like a lot of elder GPS receiver. >> >> >> >>> On 11/10/24 23:42, Scott Qi via time-nuts wrote: >>> Hi, it is a old version of NMEA protocol, I ever made a PCB (using GT-8031F card) this year to replace it (correct the GPS rollover problem), but seems few people need it, so I did not sell it, now I am moving, need to find which box include the PCB (I have more than 50 boxes to move). >>> >>> for the old Z3801A or Z3805A, using Motorola M6 or M8 GPS module, need to upgrade the firmware (replace the 4 firmware chip easily). >>> >> >> >>> On 11/11/2024 12:19 AM, Tom Knox via time-nuts wrote: >>>> Hi, >>>> I would look at Synergy they have a number of UBLOX modules specifically designed for vintage Motorola >>>> receivers. >>>> Cheers, >>>> Tom Knox >>>> >>>> ________________________________ >>>> From: bryon via time-nuts <time-nuts@lists.febo.com> >>>> Sent: Sunday, November 10, 2024 9:45 PM >>>> To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> >>>> Cc: bryon <kd4fm@aol.com> >>>> Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem >>>> >>>> I have a Samsung GPSR, which is a Symmetricom Z3805A. It looks like a >>>> Z3801A, except it has a front panel power switch. On the rear panel it >>>> shows its made by Symmetricom and it has stickers inside on the PCB >>>> showing Symmetricom Z3805A, etc. Runs off of 28 volts DC. It also uses >>>> the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to 10 Mhz. >>>> >>>> The unit runs, but it has the March 2004 rollover date problem. >>>> >>>> The unit uses a Furuno GT-8031B GPS receiver. The GPS receiver has the >>>> form factor of a Motorola M12+ receiver and then the Furuno receiver is >>>> mounted on an adapter board that has the form factor of the elder >>>> Motorola PVT/Oncore VP receivers. >>>> >>>> The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA >>>> like protocol. >>>> >>>> I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they >>>> will not do it. I think its because they are timing only receivers and >>>> only run binary. I also tried to put a Motorola Oncore VP in the unit >>>> that was set to the 6 channel mode and binary and the Samsung unit gave >>>> a front panel fault about 30 seconds after power up. >>>> >>>> Does anybody have any experience with a replacement GPS receiver for >>>> this unit ? >>>> >>>> Thanks. >>> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe send an email to time-nuts-leave@lists.febo.com > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

Hi, after one month moved to VA, now I can find the GPS board I designed in box, it using the NMEA 2.0, so only can use the Furuno GT-80, can use in Z3801A, Z3805A, 58503A (no VFD), very easy, replaced the 4 firmware chips, and replaced the old M6 or M8 Motorola GPS. their is no 1024 weeks rollover problem for the board, please check the picture "gps.jpg". btw, 58503B using different firmware chip, can not use the scheme. so, 58503B only to die. Regards/Scott On 11/11/2024 2:05 AM, Brett Fanoga via time-nuts wrote: > Thank you. I did confirm that the Furuno GPS receiver ran NMEA. I > pulled the receiver out of the Samsung-Symmetricom Z3805A and mounted > the Furuno GPS receiver in a stand alone receiver enclosure and all I > could see it doing was generic NMEA at 9600 BPS. > > I understand the moving, I have also just moved.  I am very much > interest in your replacement efforts. > > Just for info, to the list, the Hewlett-Packard Z3805A used Motorola > GPS receiver in the binary mode. Also the Z3801A. > > Somewhere down the line, after H-P sold the Time-Frequency division to > Symmetricom, it appears Symmetricom redesign the Z3805A units.  The > main PC board on the bottom of the Z3805A looks like the original in > the Z3801A, Z3805A and the 58303.  The switching power supply board > mounted above it looks the same. Some models used the HP double oven > 10811 oscillator and then they changed to using the MTI-260 oscillator > mounted on a new PC board and it doubles the 5 Mhz output of the > MTI-260 to 10 Mhz.  Also the Furuno GPS receiver GT-8031B is a 12 > channel receiver and I regularly see the GPSDO running with 9-10-11 > satellites in GPSCon software.  It just has the March 2005 rollover > date problem, like a lot of elder GPS receiver. > > > > On 11/10/24 23:42, Scott Qi via time-nuts wrote: >> Hi, it is a old version of NMEA protocol, I ever made a PCB (using >> GT-8031F card) this year to replace it (correct the GPS rollover >> problem), but seems few people need it, so I did not sell it, now I >> am moving, need to find which box include the PCB (I have more than >> 50 boxes to move). >> >> for the old Z3801A or Z3805A, using Motorola M6 or M8 GPS module, >> need to upgrade the firmware (replace the 4 firmware chip easily). >> > > >> On 11/11/2024 12:19 AM, Tom Knox via time-nuts wrote: >>> Hi, >>> I would look at Synergy they have a number of UBLOX modules >>> specifically designed for vintage Motorola >>> receivers. >>> Cheers, >>> Tom Knox >>> >>> ________________________________ >>> From: bryon via time-nuts <time-nuts@lists.febo.com> >>> Sent: Sunday, November 10, 2024 9:45 PM >>> To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> >>> Cc: bryon <kd4fm@aol.com> >>> Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem >>> >>> I have a Samsung GPSR, which is a Symmetricom Z3805A.  It looks like a >>> Z3801A, except it has a front panel power switch.  On the rear panel it >>> shows its made by Symmetricom and it has stickers inside on the PCB >>> showing Symmetricom Z3805A, etc.  Runs off of 28 volts DC.  It also uses >>> the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to >>> 10 Mhz. >>> >>> The unit runs, but it has the March 2004 rollover date problem. >>> >>> The unit uses a Furuno GT-8031B GPS receiver.  The GPS receiver has the >>> form factor of a Motorola M12+ receiver and then the Furuno receiver is >>> mounted on an adapter board that has the form factor of the elder >>> Motorola PVT/Oncore VP receivers. >>> >>> The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA >>> like protocol. >>> >>> I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they >>> will not do it.  I think its because they are timing only receivers and >>> only run binary.  I also tried to put a Motorola Oncore VP in the unit >>> that was set to the 6 channel mode and binary and the Samsung unit gave >>> a front panel fault about 30 seconds after power up. >>> >>> Does anybody have any experience with a replacement GPS receiver for >>> this unit ? >>> >>> Thanks. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com

Hi All, So how does someone get the firmware chips to make this GPS change? My Z3805A is using the Motorola GPS. I would love to upgrade to something with more channels. Does this change also apply to the Z3801A? Bob -----Original Message----- From: Scott Qi via time-nuts <time-nuts@lists.febo.com> Sent: Saturday, December 21, 2024 12:43 AM To: timenut@mi7.us; Discussion of precise time and frequency measurement <time-nuts@lists.febo.com> Cc: Scott Qi <scott.qi@gmail.com> Subject: [time-nuts] Re: Samsung-Symmetricom GPSDO Rollover Problem Importance: High Hi, after one month moved to VA, now I can find the GPS board I designed in box, it using the NMEA 2.0, so only can use the Furuno GT-80, can use in Z3801A, Z3805A, 58503A (no VFD), very easy, replaced the 4 firmware chips, and replaced the old M6 or M8 Motorola GPS. their is no 1024 weeks rollover problem for the board, please check the picture "gps.jpg". btw, 58503B using different firmware chip, can not use the scheme. so, 58503B only to die. Regards/Scott On 11/11/2024 2:05 AM, Brett Fanoga via time-nuts wrote: > Thank you. I did confirm that the Furuno GPS receiver ran NMEA. I > pulled the receiver out of the Samsung-Symmetricom Z3805A and mounted > the Furuno GPS receiver in a stand alone receiver enclosure and all I > could see it doing was generic NMEA at 9600 BPS. > > I understand the moving, I have also just moved. I am very much > interest in your replacement efforts. > > Just for info, to the list, the Hewlett-Packard Z3805A used Motorola > GPS receiver in the binary mode. Also the Z3801A. > > Somewhere down the line, after H-P sold the Time-Frequency division to > Symmetricom, it appears Symmetricom redesign the Z3805A units. The > main PC board on the bottom of the Z3805A looks like the original in > the Z3801A, Z3805A and the 58303. The switching power supply board > mounted above it looks the same. Some models used the HP double oven > 10811 oscillator and then they changed to using the MTI-260 oscillator > mounted on a new PC board and it doubles the 5 Mhz output of the > MTI-260 to 10 Mhz. Also the Furuno GPS receiver GT-8031B is a 12 > channel receiver and I regularly see the GPSDO running with 9-10-11 > satellites in GPSCon software. It just has the March 2005 rollover > date problem, like a lot of elder GPS receiver. > > > > On 11/10/24 23:42, Scott Qi via time-nuts wrote: >> Hi, it is a old version of NMEA protocol, I ever made a PCB (using >> GT-8031F card) this year to replace it (correct the GPS rollover >> problem), but seems few people need it, so I did not sell it, now I >> am moving, need to find which box include the PCB (I have more than >> 50 boxes to move). >> >> for the old Z3801A or Z3805A, using Motorola M6 or M8 GPS module, >> need to upgrade the firmware (replace the 4 firmware chip easily). >> > > >> On 11/11/2024 12:19 AM, Tom Knox via time-nuts wrote: >>> Hi, >>> I would look at Synergy they have a number of UBLOX modules >>> specifically designed for vintage Motorola >>> receivers. >>> Cheers, >>> Tom Knox >>> >>> ________________________________ >>> From: bryon via time-nuts <time-nuts@lists.febo.com> >>> Sent: Sunday, November 10, 2024 9:45 PM >>> To: time-nuts@lists.febo.com <time-nuts@lists.febo.com> >>> Cc: bryon <kd4fm@aol.com> >>> Subject: [time-nuts] Samsung-Symmetricom GPSDO Rollover Problem >>> >>> I have a Samsung GPSR, which is a Symmetricom Z3805A. It looks like a >>> Z3801A, except it has a front panel power switch. On the rear panel it >>> shows its made by Symmetricom and it has stickers inside on the PCB >>> showing Symmetricom Z3805A, etc. Runs off of 28 volts DC. It also uses >>> the MTI-260 5 Mhz oscillator on a 5 Mhz doubler board to get back to >>> 10 Mhz. >>> >>> The unit runs, but it has the March 2004 rollover date problem. >>> >>> The unit uses a Furuno GT-8031B GPS receiver. The GPS receiver has the >>> form factor of a Motorola M12+ receiver and then the Furuno receiver is >>> mounted on an adapter board that has the form factor of the elder >>> Motorola PVT/Oncore VP receivers. >>> >>> The Furuno runs 9600 BPS and the basic data sheet states it runs NMEA >>> like protocol. >>> >>> I attempted to put a LEA-6T and a M12+ into NMEA mode at 9600, but they >>> will not do it. I think its because they are timing only receivers and >>> only run binary. I also tried to put a Motorola Oncore VP in the unit >>> that was set to the 6 channel mode and binary and the Samsung unit gave >>> a front panel fault about 30 seconds after power up. >>> >>> Does anybody have any experience with a replacement GPS receiver for >>> this unit ? >>> >>> Thanks. >> > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-leave@lists.febo.com