Raymarine Axiom 7 - external GPS

[SorinCT]

Hello!
I am having some issues with GPS signal and am looking for potential solutions. I have a Raymarine Axiom 7 at the helm (has internal GPS) but the GPS signal is weak and drops frequently. Some of the reasons i identified so far are: flush mount panel contains aluminum and may block signal, shading from PV array (also aluminum + stainless) and poor antenna capabilities for Axiom 7 (as per other owners feedback and tests in the local marina).

Before attempting to modify unit's location and mounting plate, i am researching what can be done in terms of externa GPS antenna. My best guess is that the coax or NMEA signal needs to get injected into the SeatalkNG network, either by a gateway or something similar. Is there any DIY solution to use non-Raymarine parts for this?

Current price for compatibe RS-150 antenna is 300 $, 60$ for SeatalkNG T-connector and backbone cable, plus shipping. 400$ to address these kind of problems is a bit too much seeing as equipment is almost new.

Network currently also has Raymarine Ray50 with internal GPS antenna, mounted at the nav console which is suffering from same issue with mostly unreliable signal.
Bavaria C36 - 2002, 3 cabin with typical layout, MFD at the helm console, VHF at nav desk, solar arch at the back.

Has anybody tried any other GPS antenna or arrangement to improve GPS signal?

[Yngmar]

There's no antenna connector for an external passive antenna, so you need a NMEA2k (that's what Seatalk NG really is) GPS receiver. It doesn't have to be a Raymarine one, there are many cheaper ones, like this for example: https://www.smgeurope.com/veratron-go-nmea-2000-gps-gnss-receiver.html

An AIS transmitter with NMEA2k output can also do the job if connected to the same bus.

[SorinCT]

I already have AIS700 transceiver with external antenna but it does not output the GPS data to the network. Is it possible to inject GPS data to the whole network or is it only output for NMEA 0183 VHF?

[Yngmar]

The Raymarine AIS 700 does have a NMEA2k output. Do you get AIS data on the plotter (triangles of ships moving around)? Then it's on the bus already and you may jus thave to tell the Axiom to use the external GPS source (not familiar with the firmware, but usually there's a setting for that).

If there's no AIS data on the plotter, the AIS 700 will need connecting to the Seatalk NG (N2k) bus.

[SorinCT]

AIS is connected to the network and sends AIS data to MFD. Also, for data sources of GPS i have only Internal GPS and VHF50, both suffering from poor signal. I think i need to toy with ProAIS2 software but i am unsure on what needs adjusting.