The Hull Truth - Boating and Fishing Forum

Go Back   >
Search


Reply
 
Thread Tools Search this Thread
Old 04-07-2016, 12:44 PM   #1
Admirals Club
Thread Starter
 
Join Date: Feb 2013
Posts: 503
Default Vhf losing gps connection

Uniden um 415 wired to lowrance lms520c.

I have it wired properly and it has been working. I have noticed a few times that the radio may say check gps or if I go to the coordinate it will be flashing the last known location.

I'm wondering if it has something to do with the radio saying low voltage and restarting when I start the motor.

The connections are still good a heat shrinked.
mcsd63 is offline   Reply With Quote
Old 04-07-2016, 01:19 PM   #2
Senior Member
 
Join Date: Dec 2002
Location: Southeast Michigan
Posts: 1,700
Default

Quote:
Originally Posted by mcsd63 View Post
I'm wondering if [loss of signal to the radio from the GNSS receiver] has something to do with the radio saying low voltage and restarting when I start the [engine]
If the radio reboots when your start your engine, the effect should be the same as turning the radio power to ON from OFF.

To test to see if the radio goes into some odd state of partial operation, the next time you observe loss of signal at the radio from the GNSS receiver, turn off the radio power, wait ten seconds, and turn ON the radio power. If this clears the loss of signal alarm, then the radio was probably hung in some intermediate operating state.

A loss of signal from the GNSS could also just be due to the GNSS not having a position fix. Maybe it reboots when you start your engine, too. That may cause the GNSS receiver to lose a position fix for several minutes. Usually a GNSS receiver beginning from a "hot start" can get a fix in a few minutes. If the GNSS receiver was scrambled up by the voltage sag at engine start, it might take several minutes to get a fix. In worst case, it might take 15 minutes to get a fix.

Investigate the status of the GNSS receiver the next time the radio reports loss of signal from the GNSS. Maybe the GNSS is not sending a signal because it has no fix. The remedy will be in the GNSS receiver not in the radio.
jhebert is offline   Reply With Quote
Old 04-08-2016, 05:24 AM   #3
Senior Member
 
Join Date: May 2010
Location: Costa Rica and Sardinia (Italy)
Posts: 1,264
Default

How did you wired it?
NMEA183 or NMEA2000?
Chris
ChrigelKarrer is offline   Reply With Quote
Old 04-08-2016, 07:51 AM   #4
Admirals Club
Thread Starter
 
Join Date: Feb 2013
Posts: 503
Default

Quote:
Originally Posted by ChrigelKarrer View Post
How did you wired it?
NMEA183 or NMEA2000?
Chris

I believe it's 183. I know I wired it to a wire coming from the gps unit not a backbone wire.

Thanks for both replies.
mcsd63 is offline   Reply With Quote
Old 04-08-2016, 08:56 AM   #5
Senior Member
 
Join Date: May 2010
Location: Costa Rica and Sardinia (Italy)
Posts: 1,264
Default

Well,
i was unable install my new Garmin VHF200 with a NMEA183 connection for unknown reasons and
i had twice some problems with Yamaha fuel management measuring using NMEA183.
This let me believe that NMEA183 is not a very stable protocol.

But as you have "low Voltage" errors you mach check:
- connectors and power cables to the GPS and VHF
- all cables and connectors from the Batteries to the switches and from the switches to the bus bar(s) where the GPS and VHF is connected.
- Check the Battery and batter posts, clean them
- have the charge status and cranking amps checked

- cut 1-2 inch of the NMEA183 cables and solder them again to make sure they have a good connection

Once all seems to be fine then you may change VHF or the chart plotter with another, known good one

If this is too much trouble, just get a 250$ new VHF with integrated GPS chip.....

Chris
ChrigelKarrer is offline   Reply With Quote
Old 04-08-2016, 11:30 AM   #6
Senior MemberCaptains Club Member
 
Join Date: Jan 2007
Location: Tampa Florida
Posts: 2,482
Default

I would check the wire connections first and also need to have your batteries checked to see why you have low voltage
Rolandt03 is offline   Reply With Quote
Old 04-08-2016, 11:32 AM   #7
Admirals Club
Thread Starter
 
Join Date: Feb 2013
Posts: 503
Default

Quote:
Originally Posted by Rolandt03 View Post
I would check the wire connections first and also need to have your batteries checked to see why you have low voltage
I only get the low voltage alarm at startup. Next time I run the boat I'm going to turn the switch to all and see if I get the same results.
mcsd63 is offline   Reply With Quote
Old 04-08-2016, 12:03 PM   #8
Senior Member
 
Join Date: May 2010
Location: Costa Rica and Sardinia (Italy)
Posts: 1,264
Default

If you get a low voltage alarm at startup your voltage is low and will be recharged using it.
Reasons for this are:
a) somewhere is a stray current
b) your bilge pump(s) is working a lot
c) your battery is not holding charge
e) corroded cables and/or terminals

Chris
ChrigelKarrer is offline   Reply With Quote
Old 04-08-2016, 04:11 PM   #9
Senior Member
 
Join Date: Oct 2006
Location: LBI NJ
Posts: 1,370
Default

Just get a new Standard Horizon with built in GPS and DSC calling, I PROMISE you it's worth it...and you'll thank yourself every time you look at it's own internal GPS!!
Re-Bait is offline   Reply With Quote
Old 04-08-2016, 04:17 PM   #10
Admirals Club
Thread Starter
 
Join Date: Feb 2013
Posts: 503
Default

Quote:
Originally Posted by Re-Bait View Post
Just get a new Standard Horizon with built in GPS and DSC calling, I PROMISE you it's worth it...and you'll thank yourself every time you look at it's own internal GPS!!
I might consider that if had not just bought this one last fall.
mcsd63 is offline   Reply With Quote
Old 04-08-2016, 04:22 PM   #11
Senior Member
 
Join Date: Oct 2006
Location: LBI NJ
Posts: 1,370
Default

I hear that!! But they are 200 to 300 bucks, and really punch out. Every time I look at the GPS display on the VHF, it's super helpful. To be able to always see your lat long and speed at a glance without fiddling w my Garmin or furuno, I thank SH !!

And for $300 the GX2000......you get a AIS display of large vessels!!
Re-Bait is offline   Reply With Quote
Old 04-08-2016, 04:24 PM   #12
Admirals Club
 
Join Date: Aug 2013
Location: Fairhaven, MA
Posts: 7,093
Default

It's likely that one of your batteries doesn't have enough power to supply your electronics what they need when cranking the engine. I had a similar situation and use the "both" position when starting if the electronics are on. The reason was I have 2 deep cycle batteries and they have a lower CCA rating than a starting battery. Try the "both" setting and your problem will likely go away. Your GPS is probably losing its signal due to the voltage drop and thus also the VHF.
Cobia 217 is online now   Reply With Quote
Old 04-08-2016, 10:56 PM   #13
Admirals Club
 
Join Date: Dec 2010
Location: Bermuda
Posts: 839
Default

Subscribed
ohfishalee is online now   Reply With Quote
Old 04-09-2016, 01:12 PM   #14
Senior Member
 
Join Date: Dec 2002
Location: Southeast Michigan
Posts: 1,700
Default

Quote:
Originally Posted by ChrigelKarrer View Post
...This let me believe that NMEA183 is not a very stable protocol...
You might ask yourself this: how could a protocol survive for 30-years of global use if it really were unstable?
jhebert is offline   Reply With Quote
Old 04-09-2016, 01:40 PM   #15
Admirals Club
 
Join Date: Nov 2009
Location: Raleigh, NC
Posts: 2,529
Default

I bought a Standard Horizon GX1700 for $180 and they are running a $40 off mail in rebate right now. Has the GPS built in. Totally worth it.

Got tired of screwing with an intermittent NMEA0183 connection. I spent hours troubleshooting, soldiering and couldn't get it to be reliable.

Now I have a reliable signal if I ever need to use the DSC emergency feature, the quickest way to alert the CG and nearby boats in an emergency. And It serves as a backup GPS. It has basic nav features, if I lose the plotter offshore I can get back to the inlet.
dell30rb is offline   Reply With Quote
Old 04-09-2016, 03:14 PM   #16
Senior Member
 
Join Date: May 2010
Location: Costa Rica and Sardinia (Italy)
Posts: 1,264
Default

Quote:
You might ask yourself this: how could a protocol survive for 30-years of global use if it really were unstable?
I asked myself and found no answer, fact is that NMEA183 is a PITA to install/make work, then may intermittent working, can be not able to reconnect after a power drop (probably OP's problem).

NMEA183 worked for 30 years because some people paid a lot to a few technicians able to make it work buying hardware who was working together.
I was not able to connect Speed output from a Simrad CP32 plotter and then a Huminbird 998SI to my Yamaha non command link fuel management gauge, while connection worked between Garmin 7610xsv and Yamaha non command link fuel management gauge on my Venture 34 but works intermittent.

Reading, rereading installation manuals, searching in internet does not always make it work.Latest episode was that i was unable to make a NMEA183 connection between my Garmin 7610 xsv and my Garmin VHF200 even if all the NMEA183 parameters where on.
Once i got the t-piece, terminators and drop cable i connect it and woww, everything is working fine and as supposed with no hick-up's if power get lost.
And that is what i call a reliable protocol!

Chris
ChrigelKarrer is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off

Forum Jump


All times are GMT -7. The time now is 01:03 PM.


©2009 TheHullTruth.com

Powered by vBulletin® Version 3.9.3.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.