Northstar Help

[rrr]

Hi ,I need advise , I have dual helms with a 957 at each .The problem is I only have one antenna . Can I connect the 2 units with the NEMA connection ? Thanks in advance for any help you can send my way . Ray

[TROUBLE]

I have my fly bridge unit set up as a slave. One cat 5 cable to the master and your done. I have the 6000i models but they should be the same

Art

[Reefgeorge]

I only have one 957 so I don't know the answer to your question but be certain that you are using a Northstar antenna because its technically NEMA but has proprietary data so a generic NEMA antenna may not work.

George

[rrr]

Thanks for getting back to me . My 957 is an older unit and doesn't have a cat5 port and also I'm not talking about a second antenna I just want to hook the 2 units together and operate off 1 antenna if possible . Sorry for not being clear .

[Reefgeorge]

More than one “listener” can receive the output from the same 0183 “talker” up to a limit of 2-4 listeners, depending on who’s doing the “talking” or “listening” and dealing with single ended vs differential data lines.

Another option is to have the first 957 receive the antenna data and then retransmit nema 0183 out from the first units output port to the second 957.

[rrr]

More than one “listener” can receive the output from the same 0183 “talker” up to a limit of 2-4 listeners, depending on who’s doing the “talking” or “listening” and dealing with single ended vs differential data lines.

Another option is to have the first 957 receive the antenna data and then retransmit nema 0183 out from the first units output port to the second 957.

Hi George , Thanks for getting back to me . My knowledge of electronics is very limited , is what you are telling me is to hook the nema cable to both 957's . Do I need to connect all of the wires in those cables ? Thanks again Ray

[Reefgeorge]

No you would not connect all wires together because some of the wires are power from the 957 up to run the gps antenna and some of the wires are the data exchange between the antenna and the 957. The power should only come from one 957 which are :

5 black
6 white
7 red

The data lines are:

1 main rx blue
2 aux rx orange
3 main tx green
4 signal gnd brown

I cannot find a wiring diagram for the antenna itself, if you have one it will help us narrow down the wiring. If not we may have to experiment. Based on the 957 gps antenna port wiring it looks like the wiring is single ended meaning a positive signal wire and a common signal gnd wire for all data connections. Another thing I don’t know is if the connection is bidirectional since there is a transmit line at the 957 port on pin 3. Most gps antennas only transmit to the receiving unit but the Northstar does use a proprietary data stream, a generic nema antenna won’t work. If that’s the case then I don’t know if you can have two “listeners”/957’s from one “talker”/2201 antenna. Let’s assume that we only need to get the positive data line and the data gnd over to the other 957 unit. That is most likely pin 1 blue and pin 4 brown, those two wires would be common to both 957’s. I have not done this myself on these particular units but it’s common practice and I have done it with generic nema gps antennas and multiple listeners (chart plotter and radio for instance). The wild card is if the northstar transmits back to the antenna on pin 3 or if we need the aux rx on pin 2. We can do this one pin at a time to figure it out. There is an outside chance that this set up won’t tolerate the parallel wiring so cut and splice such that you can repair if needed.

If all of this does not work or if you have the large nema cable then you would leave the original gps antenna in at the 7 pin 957 connector and then send nema out to the other 957 via that large connector and then program the units to share the antenna data. That’s probably less risky if you have that cable or can find it on eBay.

Let me know what you decide to do and I will walk you through it.

[rrr]

No you would not connect all wires together because some of the wires are power from the 957 up to run the gps antenna and some of the wires are the data exchange between the antenna and the 957. The power should only come from one 957 which are :

5 black
6 white
7 red

The data lines are:

1 main rx blue
2 aux rx orange
3 main tx green
4 signal gnd brown

I cannot find a wiring diagram for the antenna itself, if you have one it will help us narrow down the wiring. If not we may have to experiment. Based on the 957 gps antenna port wiring it looks like the wiring is single ended meaning a positive signal wire and a common signal gnd wire for all data connections. Another thing I don’t know is if the connection is bidirectional since there is a transmit line at the 957 port on pin 3. Most gps antennas only transmit to the receiving unit but the Northstar does use a proprietary data stream, a generic nema antenna won’t work. If that’s the case then I don’t know if you can have two “listeners”/957’s from one “talker”/2201 antenna. Let’s assume that we only need to get the positive data line and the data gnd over to the other 957 unit. That is most likely pin 1 blue and pin 4 brown, those two wires would be common to both 957’s. I have not done this myself on these particular units but it’s common practice and I have done it with generic nema gps antennas and multiple listeners (chart plotter and radio for instance). The wild card is if the northstar transmits back to the antenna on pin 3 or if we need the aux rx on pin 2. We can do this one pin at a time to figure it out. There is an outside chance that this set up won’t tolerate the parallel wiring so cut and splice such that you can repair if needed.

If all of this does not work or if you have the large nema cable then you would leave the original gps antenna in at the 7 pin 957 connector and then send nema out to the other 957 via that large connector and then program the units to share the antenna data. That’s probably less risky if you have that cable or can find it on eBay.

Let me know what you decide to do and I will walk you through it.

Hi George , I've got the antenna diagram if you still have time . thanks Ray

[Reefgeorge]

Post the diagram or the connection list and we can get you squared away.