GP30 and LS-6000 Re-Installation with DSC VHF

[Fishineer]

I have a GP30 and LS-6000 I have been using for 20+ years. I previously removed them and the GPA017 antenna and T-Top to restore boat. I had to cut cable about midway adjacent to a previous cut and splice by a previous owner to remove the T-Top. It is now time for reinstallation. I disassembled the TNC connector; everything seemed logical until I could not get the center stranded conductor to release from the heated center pin.

I bench tested the GP30 and everything displayed and responded normally with my way points and routes except I had no satellite info. Before disassembling the TNC I tried temporarily splicing the cut ends and even held the center conductor of the cut cable inside the coupling on the GP30 and the outside braided conductor to the outside, but no satellite signal. Since the unit had not been powered for 3 years, after 5 minutes of no satellite info, I entered local lat/long in case it was having trouble locking into the satellites. It operated normally when I turned it off 3 years ago. Since I was at home with lots of trees around, the view of the satellite constellation was somewhat limited and may be the problem.

I also unscrewed the antenna dome cap, removed the o-ring which was in good condition, two pairs of mounting screws and everything looked visually clean and intact; I reassembled the dome.

I realize these are old units and could be replaced with a more intuitive chartplotter, but they are good units that I am familiar with and I thought I would continue using them if I can get them re-installed and operating. So maybe I can obtain some much appreciated advice.

My questions:
1. Can I install a new TNC connector on the end of the 15-20 feet of remaining cable and expect acceptable performance?
2. Which antennae are compatible with the GP30? Some antennae have DGPS and WAAS capabilities, but the GP30 does not.
4. I have located and ordered a used Furuno 4-pin in/out cable (22S0021) to feed navigation data from the GP30 to the LS-6000. May I also connect the GP30 to a DSC VHF to feed navigational location information to the VHF?

Thanks for any help.

 

[Johnny Electron]

1. Can I install a new TNC connector on the end of the 15-20 feet of remaining cable and expect acceptable performance?

Yes, as long as the rest of the cable and antenna are fine it is okay to remove/replace the connector (pn 000-133-186).

2. Which antennae are compatible with the GP30? Some antennae have DGPS and WAAS capabilities, but the GP30 does not.

You can use most any Furuno coax GPS model antennas. The fact that they offer DGPS or WAAS is not a problem for the GP30. The GPA017 is the most common antenna used but you could use a GPA018 or GPA019 if you have one.

4. I have located and ordered a used Furuno 4-pin in/out cable (22S0021) to feed navigation data from the GP30 to the LS-6000. May I also connect the GP30 to a DSC VHF to feed navigational location information to the VHF?

Yes, you can have up to three listeners on one NMEA output. In the case of VHF we always count them as two listeners due to the current they draw. It is okay to connect both the LS6000 and the VHF to the output of the GP30 but I wouldn't add more than that.

 

[Fishineer]

Thank you for the assistance.
If the shorten cable will work, is the existing TNC normally considered re-useable (if the point can be cleaned out)?
I can purchase a used antenna with the unwanted 30 feet of excess cable for $50 or a 000-133-186 TNC for $40. I'll probably just buy the used antenna, but would like to know if the existing TNC is salvageable.

 

[Johnny Electron]

The factory installed TNC is reusable but you will normally need a good de-soldering iron to clean up the pin to reuse it. You can shorten the cable but it should have at least 10ft of cable. New GPA017 units with cable and connector normal run new for about $120 - $125 but there are a lot of good used ones out there too.

 

[Fishineer]

Thank you again for your help. I was able to remove the center wire from the pin by securing the wire stub in a vice and pulling on the tip of the pin with needle nose pliers while I heated the pin with a small torch. My soldering gun was just not hot enough to liquify the factory solder. It took about two seconds with the torch.

After reconnecting the 15-20 feet of cable to the TNC everything booted up, but still no satellites. So, I disassembled the antenna dome again and this time examined under the small aluminum cover where I discovered the two wires soldered on a 90 degree angle had separated. I probably caused this when I was struggling and probably twisting the cable to remove it from the T-Top. Once I soldered them back together I tried booting up again and this time everything worked normally and after 3-5 minutes the satellites starting locking in. When I compared the Lat and Long on the GP30 and my iPhone they were both within 0.002 minutes on Lat/Long (12 Ft) of each other. Great learning experience.
Thanks again for your help.

 

[Johnny Electron]

:jump :jump

 

[Fishineer]

Thanks again for making my first experience on the Furuno Forum successful.
I’m waiting for delivery of the 000-133-186 cable to complete the bench tests, but I did successfully connect to DCS VHF. The localized UTC time is accurate, but the date continues to be displayed as 13-OCT-00. Is there anyway to make it current?

 

[Johnny Electron]

Older GPS units have what is called a GPS rollover. It is a limitation caused by the hardware above our heads (Satellites) not on the ground. When a GPS core is designed (all of them not just ours) they basically begin a 20 year countdown to rollover. The date will be good for 20 years but then they roll back over. There is no fix to the unit. Nothing else is a problem to continue using these older units. They will still get GPS and time etc but the date will never be correct again. It isn't something you can fix without replacing the unit for a newer GPS unit.

 

[Fishineer]

Thank you for the explanation. Learn something new everyday.