QZSS selection


My team is currently looking at the M+ system and I was told by support that the QZSS satellite constellations are accesible (My company is based in Japan so this is fairly big news)

I was looking at the antennas on their website and none of them show the QZSS constellations as acceptable bands so am I missing something here…?

I read elsewhere this is for PPK only, which is fine, but doesn`t my choice of antenna directly impact this…?

Hi Kristofer,

Welcome to our community!

Our receiver can work with the QZSS constellation, but our GNSS antenna can’t track them. You can find 3rd-party multi-band GNSS antennas that can track the Japanese system.

The 3rd-party antenna must meet these requirements not to damage the unit:

  • The antenna connector on Reach M+’s side is an MCX female
  • The DC bias is 3.3 V
  • The output current is 100 mA

You shouldn’t worry if you can’t find a suitable antenna. You can work with other constellation signals, which should be enough for good results, even in Japan.


Hello Csanad,

Thank you for the information!
I believe by those requirements this antenna should also work?

The reason we are particular about QZSS is that it provides certain assurances for customers in the survey realm as well as issues we have had with LiDAR systems that have not been able to pick up reception.


Sorry that I partially misled you before, let me correct myself.

Our antenna actually can track some bands of the QZSS signal, but not all of them. It’s because the QZSS constellation sends signals partly on the same frequencies as other satellite systems.

The linked antenna can work with our device, but it’s more or less the same as ours. It still can’t track all of the QZSS signals.

Hello Csanad,

Sorry I responded by email but I will leave here so the community can also know.

I will check with my engineers but if I am reading the specs correctly then this antenna should also work? (I am not quite sure if the electrical specs they are talking about are output or input…)

Hi Kris,

Both antennas, ours and the linked, are multi-band. They are equally capable of tracking the same bands, but they both can’t track the aforementioned L6 band.

Both Reach M+ and Reach M2 can work with multi-band GNSS antennas. However, M+ wouldn’t be able to exploit the full potential of the antenna since it’s a single-band device.

The linked antenna can work with voltages between 3.0 - 5.0 V, which is met by Reach’s 3.3 V antenna DC bias. The DC current is also appropriate because 15 mA is lower than 100 mA.

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Hello Csanad,

I think based on that information we will be going with the M2
am I right in assuming we can always purchase a base afterwards and can link it at any time?

I also apologize, I would rather not ask here but my engineer is wondering if you could confirm that either of these antennas meet the power requirements by the M2?

TW7876_Datasheet_v1.pdf (tallysman.com)

Tallysman®-HC976-Datasheet.pdf (amtechs.co.jp)

Hi Kris,

Yes, you can totally do that. One factor to keep in mind is that multi-band rovers can only work with multi-band bases. So if you’re planning on buying a base, I’d recommend Reach RS2.

Both antennas could work with Reach M2 or M+, but I’d surely go with the second one. As I understand, it can work with all the same constellations as ours and the missing L6. The first one can track L6 but lacks the capabilities to track the more usual GPS (L2) and GLONASS (G2) frequencies.

Hello Csanad,

Sorry, but I had one clarification.
The antenna connector on the Reach M2`s side, is it also an MCX female?

In either case does that mean when looking at antennas they should have a female or male MCX? (in other words were you telling me what connector the antenna should have?)

Hi Kris,

You need a Male MCX antenna connector. However, you can also connect SMA or TNC antenna using an adapter.