VMA430 + external antenna + 1pps

Hi, I 'd like to make the VMA430 (GPS) delivering 1PPS and using one external antenna, connected to the SMA connector. (regular active patch antenna )

The module is supposed to work with embeded ceramic antenna or external antenna, but i can’t find anything related to selecting the source.

from my tests, it looks like the signal out from the external antenna is not used (one other GPS module from another manufacturer actually does in the same configuration).

the 1PPS signal is generated in a non continuous way, making me think the GPS signal comes from the integrated antenna. Indeed the module is currently inside a steel case, with bad reception condition, whereas the external antenna is located outside with very good reception conditions.

please advise , thanks in advance

1 Like


We have receive information about your question from our manufactuer:

The extra antenna is working. Normally we using the normal GPS antenna like photo as attached,

We do not use 1PPS antenna, not sure how is it working, for this type of 1PPS antenna.

For this GPS module, the products come with 2 antenna, and there are case for it.
When the signal is too weak, then it need to add extra antenna.

It’s not possible to select between the antennas. There’s no choice.
When removing the capacitor C2, the build in antenne will not working.

Best Regards,
Velleman Support