Multi GNSS GPSDOs - Page 1
Forum section: electronics / general

author: Electro Fan
author_rank: Super Contributor
timestamp: July 14, 2019, 10:59:08 pm
content: Are there any under $200 GPSDOs that will work with all or most of the following? If not, what's the entry level GPSDO that will work with all/most of these? Any recommendations welcome.Global Positioning System (United States)GLONASS (Russia)Galileo (EU)BeiDou (China)QZSS (Japan)IRNSS ― NAVIC (India)Other?Will Lady Heather work with all of these?

author: kj7e
author_rank: Frequent Contributor
timestamp: July 14, 2019, 11:25:30 pm
content: LH does not care about the GSV Talker ID and will show you all the constellation data output by the GNSS RX.In my case, I already had a BG7TBL GPSDO with a u-blox NEO-M7, so it was an easy upgrade to swap it out for an NEO-M8T. I also had to swap out my PCTEL GPS L1 Timing antenna for a GNSS Multiband PCTEL antenna. I see GLONASS, BeiDou, Galileo (though not working at this time), and of course GPS. I think upgrading the BG7TBL boxes are about the lest expensive option right now. If you go that route, there is a 400+ page book for the M8T that you will need to read through as the chip needs to be configured in order to work. Not difficult but its a bit daunting at first.

author: hamster_nz
author_rank: Super Contributor
timestamp: July 15, 2019, 12:14:19 am
content: A multi-system receiver seems to be a good idea... I wonder when Galileo will be back online.

author: texaspyro
author_rank: Super Contributor
timestamp: July 15, 2019, 01:13:08 am
content: Quote from: kj7e on July 14, 2019, 11:25:30 pmIf the receiver is sending NMEA data and you specify the receiver type using the /rx command line option, Heather will try to configure it to use its native binary format. Binary formats give much better control and monitoring than NMEA.

author: Electro Fan
author_rank: Super Contributor
timestamp: July 15, 2019, 08:55:32 pm
content: Quote from: kj7e on July 14, 2019, 11:25:30 pmVery cool.With the M8T and the GNSS Multiband PCTEL antenna you get U.S. GPS and EU Galileo plus either Russia GLONASS or China Beidou? Your BG7TBL with the M8T supports 3 of the 4 simultaneously? Or do you need to reload Lady Heather and switch between the constellations?

author: kj7e
author_rank: Frequent Contributor
timestamp: July 17, 2019, 02:20:23 pm
content: The M8T is a 32 channel RX that can support 3 simultaneous constellations, but there is a matrix on which. I had it set for GPS, Galileo and BDS, but removed Galileo until its officially back on-line. I cant enable GLONASS while BDS is enabled but IIRC you can enable GPS, Galileo and GLONASS.Here is a screen shot of both of my modded BG7TBL GPSDO's using the same antenna via a 2 way RF splitter, showing the "Survey In" results set for minimum of 86400 sec and 0.1m using just GPS and BDS. I enabled Galileo just to show you how many Sat's can be tracked at once. My settings are conservative and I'm filtering out any signals <20 C/N0 or <15 deg ele from the NAV solution. They both seem to agree quite well.Also added a photo with GPS, Galileo and GLONASS enabled.

author: Theboel
author_rank: Frequent Contributor
timestamp: July 18, 2019, 03:45:46 pm
content: Hi kj7e,Are You replace the GPS module in BG7TBL with M8T ?and You can access the M8T with Ublox software ?73

author: kj7e
author_rank: Frequent Contributor
timestamp: July 18, 2019, 04:34:13 pm
content: Quote from: Theboel on July 18, 2019, 03:45:46 pmYes, that is correct.

author: testpoint1
author_rank: Frequent Contributor
timestamp: July 25, 2019, 04:22:55 am
content: less than 100 USD, will:https://www.eevblog.com/forum/metrology/the-smallest-gpsdo-in-the-world/msg2467803/#msg2467803