bg7tbl gpsdo master reference

[notfaded1]

Are you guys saying that although the units are advertised as supporting two systems you are actually getting 3 (GPS + Galileo + Beidou)?

Yes you can enable more than one GNSS constellation but from all I've read if you want accurate timing you should choose one with GPS and not more than one.  Mine came with GPS and Galileo and it came with SBAS enabled as well.

Regards,

Bill

[Diabolo]

Hello,

@BiggieJohn.
BG7TBL to install a resistance R29, what is its value?
What are the references of U6 and U7?



Thanks.
Regards


Diabolo

[cdev]

How many Beidou sats are you getting at once? I have skytraq GPS - several years old that supports beidou. Usually I only get one beidou sat at any time but I have not changed the mode and it is available. I find that when it is receiving beidou the position becomes rock solid stable. I am using it with a standard ceramic GPS antenna with no LNA, just a passive Taoglas ceramic patch antenna on a small ground plane (an old DVD) The Beidou does add positional stability, quite a bit. But once its been on for awhile it is stable all the time. Iguess what the beidou sats effect is greatly reducing the time it takes for the 3d fix to calm down in all three directions.

EDIT: BTW I have the GPS1-TMG-26N which looks identical to yours. It will receive GLONASS which is not far from GPS, just a tiny bit higher.  I am currently using that with my GPSDO 24/7

I could be wrong, but I think the setting NMEA protocol to v4.1 enables the position fix flags for Galileo and BeiDou to be sent out of the receiver, but does not affect the Navigation input to the receiver.  Regardless, I found that little tidbit of info in Sec 31.1.3 of the Protocol manual, now u-center shows me all the tracked SV's.  In order for the BG7TBL MCU to run and update the LCD, I had to set the Main Talker ID to GPS, the MCU does not like the extra flags.

Edit: I had to set the main talker ID to GPS for my older 2017-12 version, the newer 2018-06 does not care and can be left to automatic, this is nice as u-center and LH will properly show the Galileo and BeiDou.

I am using a narrow band L1 Timing antenna now. Going to swap it out for a multiband GNSS antenna, although the L1 narrow band antenna does seem to be receiving Galileo well.  Right now I have the GNSS types set for GPS, SBAS, and Galileo.

Edit: Now using a PCTEL GNSS multi band antenna and see BeiDou, GLONAS and Galileo;
https://www.pctel.com/antenna-product/global-gnss-timing-reference-antenna-gnss1-tmg-26n/

[kj7e]

How many Beidou sats are you getting at once? I have skytraq GPS - several years old that supports beidou. Usually I only get one beidou sat at any time but I have not changed the mode and it is available. I find that when it is receiving beidou the position becomes rock solid stable. I am using it with a standard ceramic GPS antenna with no LNA, just a passive Taoglas ceramic patch antenna on a small ground plane (an old DVD) The Beidou does add positional stability, quite a bit. But once its been on for awhile it is stable all the time. Iguess what the beidou sats effect is greatly reducing the time it takes for the 3d fix to calm down in all three directions.

EDIT: BTW I have the GPS1-TMG-26N which looks identical to yours. It will receive GLONASS which is not far from GPS, just a tiny bit higher.  I am currently using that with my GPSDO 24/7

I could be wrong, but I think the setting NMEA protocol to v4.1 enables the position fix flags for Galileo and BeiDou to be sent out of the receiver, but does not affect the Navigation input to the receiver.  Regardless, I found that little tidbit of info in Sec 31.1.3 of the Protocol manual, now u-center shows me all the tracked SV's.  In order for the BG7TBL MCU to run and update the LCD, I had to set the Main Talker ID to GPS, the MCU does not like the extra flags.

Edit: I had to set the main talker ID to GPS for my older 2017-12 version, the newer 2018-06 does not care and can be left to automatic, this is nice as u-center and LH will properly show the Galileo and BeiDou.

I am using a narrow band L1 Timing antenna now. Going to swap it out for a multiband GNSS antenna, although the L1 narrow band antenna does seem to be receiving Galileo well.  Right now I have the GNSS types set for GPS, SBAS, and Galileo.

Edit: Now using a PCTEL GNSS multi band antenna and see BeiDou, GLONAS and Galileo;
https://www.pctel.com/antenna-product/global-gnss-timing-reference-antenna-gnss1-tmg-26n/

The GPS-TMG-26N wont see BeiDou, you need the GNSS1-TMG-26N which will.  I see 8-12 BeiDou with the GNSS antenna.

[cdev]

How many Beidou sats are you getting at once? I have skytraq GPS - several years old that supports beidou. Usually I only get one beidou sat at any time but I have not changed the mode and it is available. I find that when it is receiving beidou the position becomes rock solid stable. I am using it with a standard ceramic GPS antenna with no LNA, just a passive Taoglas ceramic patch antenna on a small ground plane (an old DVD) The Beidou does add positional stability, quite a bit. But once its been on for awhile it is stable all the time. I guess what the beidou sats effect is greatly reducing the time it takes for the 3d fix to calm down in all three directions.

EDIT: BTW I have the GPS1-TMG-26N which looks identical to yours. It will receive GLONASS which is not far from GPS, just a tiny bit higher.  I am currently using that with my GPSDO 24/7

I could be wrong, but I think the setting NMEA protocol to v4.1 enables the position fix flags for Galileo and BeiDou to be sent out of the receiver, but does not affect the Navigation input to the receiver.  Regardless, I found that little tidbit of info in Sec 31.1.3 of the Protocol manual, now u-center shows me all the tracked SV's.  In order for the BG7TBL MCU to run and update the LCD, I had to set the Main Talker ID to GPS, the MCU does not like the extra flags.

Edit: I had to set the main talker ID to GPS for my older 2017-12 version, the newer 2018-06 does not care and can be left to automatic, this is nice as u-center and LH will properly show the Galileo and BeiDou.

I am using a narrow band L1 Timing antenna now. Going to swap it out for a multiband GNSS antenna, although the L1 narrow band antenna does seem to be receiving Galileo well.  Right now I have the GNSS types set for GPS, SBAS, and Galileo.

Edit: Now using a PCTEL GNSS multi band antenna and see BeiDou, GLONAS and Galileo;
https://www.pctel.com/antenna-product/global-gnss-timing-reference-antenna-gnss1-tmg-26n/

The GPS-TMG-26N wont see BeiDou, you need the GNSS1-TMG-26N which will.  I see 8-12 BeiDou with the GNSS antenna.

I'm in the Western Hemisphere, at approximately 41 N  74 west  Are you in Asia/Australia or Europe? I'd expect you would get more satellites there.

The GNSSRadar web site shows how many sats are visible from a given spot. It's telling me I can only receive one Beidou satellite here. They are geosychronous SVs Also, my receiver was made in 2015. So its not at all new. What kind of ublox chip does the BG7TBL contain under the (tape?) ?

http://www.taroz.net/GNSS-Radar.html

[kj7e]

How many Beidou sats are you getting at once? I have skytraq GPS - several years old that supports beidou. Usually I only get one beidou sat at any time but I have not changed the mode and it is available. I find that when it is receiving beidou the position becomes rock solid stable. I am using it with a standard ceramic GPS antenna with no LNA, just a passive Taoglas ceramic patch antenna on a small ground plane (an old DVD) The Beidou does add positional stability, quite a bit. But once its been on for awhile it is stable all the time. I guess what the beidou sats effect is greatly reducing the time it takes for the 3d fix to calm down in all three directions.

EDIT: BTW I have the GPS1-TMG-26N which looks identical to yours. It will receive GLONASS which is not far from GPS, just a tiny bit higher.  I am currently using that with my GPSDO 24/7

I could be wrong, but I think the setting NMEA protocol to v4.1 enables the position fix flags for Galileo and BeiDou to be sent out of the receiver, but does not affect the Navigation input to the receiver.  Regardless, I found that little tidbit of info in Sec 31.1.3 of the Protocol manual, now u-center shows me all the tracked SV's.  In order for the BG7TBL MCU to run and update the LCD, I had to set the Main Talker ID to GPS, the MCU does not like the extra flags.

Edit: I had to set the main talker ID to GPS for my older 2017-12 version, the newer 2018-06 does not care and can be left to automatic, this is nice as u-center and LH will properly show the Galileo and BeiDou.

I am using a narrow band L1 Timing antenna now. Going to swap it out for a multiband GNSS antenna, although the L1 narrow band antenna does seem to be receiving Galileo well.  Right now I have the GNSS types set for GPS, SBAS, and Galileo.

Edit: Now using a PCTEL GNSS multi band antenna and see BeiDou, GLONAS and Galileo;
https://www.pctel.com/antenna-product/global-gnss-timing-reference-antenna-gnss1-tmg-26n/

The GPS-TMG-26N wont see BeiDou, you need the GNSS1-TMG-26N which will.  I see 8-12 BeiDou with the GNSS antenna.

I'm in the Western Hemisphere, at approximately 41 N  74 west  Are you in Asia/Australia or Europe? I'd expect you would get more satellites there.

The GNSSRadar web site shows how many sats are visible from a given spot. It's telling me I can only receive one Beidou satellite here. They are geosychronous SVs Also, my receiver was made in 2015. So its not at all new. What kind of ublox chip does the BG7TBL contain under the (tape?) ?

http://www.taroz.net/GNSS-Radar.html

Sorry, I was working off my memory.  Looking at U-Center now I see 4 BeiDou and 8 Galileo (this was what I was thinking of).

[DaveR]

How many Beidou sats are you getting at once?

I haven't looked at this forum for a while, but I happened to be looking at Beidou + Galileo last night, and remember counting 9 Beidou and 8 Galileo after the unit had been on for an hour or so, here in Northern England.  U-Center was configured to allow 12 max from each system.

Regards,
Dave

[cdev]

My GPS is either too old or I need to change the Talker ID setting or something like that, will need to check it out using the (skytraq) manufacturers utility. If you see them in northern england then I should be able to see more here in NE US unless my GPS only supports previous generation which is quite possible..

How many Beidou sats are you getting at once?

I haven't looked at this forum for a while, but I happened to be looking at Beidou + Galileo last night, and remember counting 9 Beidou and 8 Galileo after the unit had been on for an hour or so, here in Northern England.  U-Center was configured to allow 12 max from each system.

Regards,
Dave

[Fennec]

Wich receiver do you use? Because if you have the simple BG7TBL GPSDO you easely can change the U-Blox module.
https://www.eevblog.com/forum/testgear/bg7tbl-gpsdo-master-reference/msg2493726/#msg2493726

[cdev]

This GPS is not used right now in a GPSDO, (although I'd like to try them in one)  I have a bunch of very tiny, coin sized navspark (sktraq) minis (cost US $6.75 each) that are quite sensitive GPS/Beidou NAVSPARK GPSs. I use them now in various devices for keeping GPS time, they are very good at acquiring and maintaining a GPS lock. also they can be put into position hold mode.. No TRAIM though. Once stationary, they do settle down into a very small circle, though. The Beidou is kind of old, they are at least 5 yrs old. So its entirely likely that their firmware does not support newer flavor of Beidou, and i can live with that because otherwise they work really well.  For a long time I've wanted to build them into a GPSDO, I bet they would make an excellent one. If I do that I will likely use Lars' design.

Wich receiver do you use? Because if you have the simple BG7TBL GPSDO you easely can change the U-Blox module.
https://www.eevblog.com/forum/testgear/bg7tbl-gpsdo-master-reference/msg2493726/#msg2493726

[Fennec]

Hmm and what does it has to do with the BG7TBL ?

[Electro Fan]

With a BG7TBL, which I think has a U-blox 7 receiver, when using u-center, I'm trying to figure out how to use the GNSS config.  It lets you select various systems (GPS, Galileo, etc.) and edit min/max, enable, etc.  Does it need a send command after doing such edits, or just close the window (and say yes to send), etc. or is there some other way to save the edits?  Also, is the software or the receiver smart enough to only allow selection of the satellite system(s) actually being received by the receiver, or will it let you toggle anything to an enabled state?

This is my first experience with u-center - seems filled with possibilities.  If anyone has the executive summary on how to quickly get the most of u-center, that would be cool to see/know.

Somewhat off topic, but while we are discussing u-center, I can get the BG7TBL to connect easily to u-center and Lady Heather, but my Star 4+ doesn't seem to want to connect to u-center (it connects nicely to Lady Heather)... maybe there is no u-blox receiver in the Star 4+? Or is there some other reason it doesn't want to communicate with u-center?  (kinda stupid question, I know).  Thx

[texaspyro]

Early versions of the Star-4 based boxes brought out the GPS data (TxD only?) to the RS-232 board.  When I figured out the protocol of the Star-4 management port that talks to the GPSDO using TL1 commands, he modified his design to use that port on the RS-232 connector.

[DaveR]

With a BG7TBL, which I think has a U-blox 7 receiver, when using u-center, I'm trying to figure out how to use the GNSS config.

Which BG7TBL model have you got?  If U-Center says the receiver is an M7, then it will only only pick up either GPS or Glonass, but not both at the same time.  The latest BG7TBL has an M8 chip, which can receive three of the four GNSS systems at once, except for GPS+Glonass+Beidou.  If you want all four GNSS you'll need to upgrade to the ublox M9 chip.  All is explained in the ublox datasheets for the receiver chips.

After using GNSS Config in U-Center, you need to use the Send button at the bottom of the pane to make the changes active.  Note that this only changes the configuration in the volatile memory of the chip, so changes are lost after a reboot.  If you want to make them permanent you also need to Save the new configuration (to the non-volatile memory) after the Send command (see the U-Center manual for details).  The NAV5 menu allows you to set a minimum elevation mask for all satellites (I use 15 degrees), which produces more accurate results than the default 5 degrees.  Most of the other options you can set (lots of them!) are either self-explanatory or not applicable for simple uses.  It doesn't really take that long to skim through the manual to find out what else the program can do.

If the U-Center won't connect to the Star 4+ it suggests that it doesn't use a ublox receiver, as the software only works with ublox protocols.

Regards,
Dave

[Fennec]

Note that this only changes the configuration in the volatile memory of the chip, so changes are lost after a reboot. 

Yepp, because the Ublox-Modules are Chinese clones and has no flash RAM.

[Ringmodulator]

Hi,

I am trying to get used to my new BG7TBL 2019-10-20 with the u-blox m8/8 (according u-center) and the topic GPS timing is new to me.

It should have GPS and Gallileo enabled.
In the u-center configuration GMMS Config, I can see, that GPS, SBAS, QZSS and GLONASS is configured and enabled.

When I additionally enable Gallileo, the RUN LED stops blinking, but the unit is still running and works also with Lady Heather.
Visual GPS is then not working, although it reports incomming data on the NEMA Monitor.

Any hints for configuring this unit for best timing performance are welcome. Location is Germany.

Thanks
Chris

Edit:
It looks llike whenn Lady Heather is switched from the NMEA mode to the ublox mode, the GPSDO switches also in the ublox mode and the run LED stops blinking.
Switching back to NMEA mode in LH with /rxn will bring the unit back in the "normal" mode and the run LED starts bilking again. Visual GPS also works again then.

This could be the explanation for the unit with integrated display, where the display stops to work as soon as the gps module is switsched to ublos protocol.

[Ringmodulator]

Here the infos from my model:

Front:
GNSS Disciplined Oscillator
BG7TBL 2019-10-20

Bootmessages:

$GNTXT,01,01,02,u-blox AG - www.u-blox.com*4E
$GNTXT,01,01,02,HW UBX-M8030 00080000*60
$GNTXT,01,01,02,ROM CORE 3.01 (107888)*2B
$GNTXT,01,01,02,FWVER=SPG 3.01*46
$GNTXT,01,01,02,PROTVER=18.00*11
$GNTXT,01,01,02,GPS;GLO;GAL;BDS*77
$GNTXT,01,01,02,SBAS;IMES;QZSS*49
$GNTXT,01,01,02,GNSS OTP=GPS;GLO*37
$GNTXT,01,01,02,LLC=FFFFFFFF-FFFFFFFF-FFFFFFFF-FFFFFFFF-FFFFFFFD*2F
$GNTXT,01,01,02,ANTSUPERV=*22
$GNTXT,01,01,02,ANTSTATUS=DONTKNOW*2D
$GNTXT,01,01,02,PF=3FF*4B
$GNRMC,213619.49,V,,,,,,,200620,,,N*66
$GNVTG,,,,,,,,,N*2E


According U-center: u-blox M8/8

Supports GPS, SBAS, Gallileo, BeiDou, IMES, QZSS, GLONASS

PCB date: 2020-04-06


Request for Help:

I accidently set the receiver to the default receiver configuration in u-center.
I suppose, that there have been made custom changes in the configuration for GPSDO use.

I would be thankful, if someone with the same unit, or u-blox module, would send his configuration.
This can simply be done in U-center ->Tools -> Receiver Configuration ->"transfer GNSS ->file"

Chris

[BreakingOhmsLaw]

Another set of 2019-10-20 version images.

[ea4dr]

Hello, Hi, I just bought a unit like this and I am having a hard time getting the GPS to sync. Where do you have the antenna placed? It gives me a long time to synchronize and even many days it doesn't. Do you use the included antenna? Thank you very much, regards

Gerardo

[mk_]

Hi

start a new thread and do not hijack an old one with unrelated posts.

[ea4dr]

sorry for the inconvenience, thanks

[Ringmodulator]

Hi Gerado,

my unit (see my post above) locks very fast, within minutes with the supplied antenna inside at the window on the ground floor between rows of 4 store bulidings and only a small segment of free sky. GPS, Glonass and Gallileo activated, locks about 20 sats, of course probably a lot of them via reflections.

Looks like there is an issue with your unit.

You can try with Lady Heather or U-center to connect to the u-blox chip and see whats going on.

Maybe, the antenna is defective?

Chris

Hello, Hi, I just bought a unit like this and I am having a hard time getting the GPS to sync. Where do you have the antenna placed? It gives me a long time to synchronize and even many days it doesn't. Do you use the included antenna? Thank you very much, regards

Gerardo

[notfaded1]

Ringmodulator is correct... it should lock onto many SAT's quickly even in a window.  It does of course work much better now that I connected mine to the roof antenna through my GPS splitter.  If it's a bad antenna (the ones it ships with are cheap) that's an easy fix.  I've also heard of some bad solder joints on some units so that might be worth looking at as well.

Bill

[noreply]

I just spotted this thread - so thought best to post some pictures of my recent arrival.

2020-03-02

Notable observations ...

GPS lock takes about 60 seconds
- I have standard antenna (as shipped) behind glass on window ledge
- must have good 'sky' coverage - location is London.

The OCXO
- ALM led goes off
- temperature stability to be ok
- within 10 minutes 
- this sounds 'too good'
- I would have expected more time for the oscillator to be disciplined.

I did however 'run' the device for over 8 hours the day before.

My guess is that the OCXO was already disciplined
- and when 'restarting' the device next day (I'm still testing)
- it takes much less time to get 'disciplined'.

Please feel free to chime-in with your experiences
- and any corrections to my 'noob' observations 

So far happy with the performance
- just need to get some 'other' reference to fully test the bg7tbl gpsdo and its OCXO stability 

See below for some photos - including PCB

[MegaVolt]

Give links to buy new GPSDO