[CA] ga150 gps not detected by a125mfd.

[gerald]

I added a GA 150 GPS to my a125 mfd. The a125 is connected to ng backbone and is connected by network cable to an a65mfd. The GA 150 does not show up on the data source selection screen of the a125 into which it is plugged or the a65. It provides no gps when the 2 mfds internal gps are off. Is there any way to field test the G150? Everything else seems to be working well on the ng and network on both mfds.Thanks

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum gerald,

When a GA150 GPS Antenna is interfaced to the antenna socket of an a-Series or eS-Series MFD, the MFD's internal receiver will be used to process the satellite signals received by the GA150. Accordingly, when using the Data Sources feature to reflect that you desire to have the GA150's signal be used by the system, you will need to specify that the GPS source is the MFD which has been interfaced directly to the GA150.

[gerald]

Thank you for the prompt response . So the a125needs to be set on internal gps source "on" and the a65 on internal gps "off"? Is there any positive indication available somewhere to be sure the ga 150 is in fact working? On my old rs 130 there were the flashing led signals visible.

[Chuck - Raymarine - Moderator]

gerald,

Q1. So the a125needs to be set on internal gps source "on"?
A1. Yes

Q2. the a65 on internal gps "off"?
A2. Only if you will not be using the Data Sources feature to specify that the a125 MFD will serve as the system's source for GPS data.

Q3. On my old rs 130 there were the flashing led signals visible.
A3. Negative. After having configured the Data Sources feature or switching the a65 MFD's internal GPS to OFF, then the GPS Status dialog may be displayed using either MFD to view information concerning the GPS FIX which is being or has been acquired. A quality SD GPS FIX will produce a HDOP of 1.0 or less.

[gerald]

Thank you for your patience. If I set both a125 and a65 to use the a125 as gps source I can leave the a65 on internal? The a125 is also set as the master mfd. What is an SD GPS fix? Will the GPS fix status dialog show a specific set of findings identifying that the GA 150 was active for that fix? Thanks again

[Chuck - Raymarine - Moderator]

gerald,

Q1. If I set both a125 and a65 to use the a125 as gps source I can leave the a65 on internal?
A1. Yes, if the a125 has been selected as the system's source for GPS data, then it does not matter whether the a65's internal GPS sensor is configured ON or OFF, as you have directed the entire system to ignore all GPS data sources other than the a125. Whenever more than one source for any type of data selectable via the Data Sources feature is present within the system, then the Data Sources feature must be used to specify which source will be used for any type of data for which more than one source is present within the system.

Q2. What is an SD GPS fix? Will the GPS fix status dialog show a specific set of findings identifying that the GA 150 was active for that fix?
A2. SD - Satellite differential GPS position FIX ... also referred to as WAAS. To learn more about WAAS GPS technology, click here. The MFD's user interface does not provide any indication or settings to indicate that the GA150 has been interfaced to the system. The GA150 is typically installed to provide GPS satellite signal reception when a9x/a12x/eS9x/eS12x MFDs have been installed in a location which does not afford them an unobstructed view of the skies overhead.

[gerald]

Thank you again. The 125 is at the nav station but is receiving good gps signal strength. If I cover the 125 with a screen e.g a couple of metallic foil space blankets and the GPS signal is lost, connecting the ga150 with the antenna above deck should restore the signal. I am really looking for redundancy. Sound OK? Appreciate all the information!

[Chuck - Raymarine - Moderator]

Gerald,

Unlike adding a Raystar 150 GPS Sensor or the retired Raystar 130 GPS Sensor, adding a GA150 antenna does will not add GPS redundancy a the system, as it not adding any additional GPS receiver to the system. Adding the GA150 will simply increase the GPS signal strength received by the a125 MFD's GPS receiver ... see my last response. In contrast, addition of a GPS sensor such as the aforementioned Raystar 150 GPS Sensor will provide GPS redundancy within the system, as it is a GPS receiver and antenna, all within a single package.

I am assuming that you are intending to permanently mount the GA150 antenna where it will have an unobstructed view of the skies overhead and will be connecting it to the a125 MFD. If so, then covering the MFD with foil or enclosing within a metal box should have little to no effect upon the GPS satellite signal strength received and accordingly will have no effect upon its ability to acquire to acquire a GPS position FIX.