GPS down

 Hello all,

Camped on the beach at sunny Ningaloo. At least it is sunny now Bought a new HDI 7 chirp before I left and did a basic setup, working fine.  It is mounted near my old Sitex and its external aerial which didnt appear to bother it. Probably ran for about 3 hours before I came up here. Day one, working fine, then after about an hour, signal lost. Hour or two later the sitex starts misbehaving as well. Sitex was coming and going, Lowrance refused to fix at all. Next day turned them both on and they worked perfectly up until they were shut off an hour later when the boat came out due to bad weather. Yesterday, neither worked at all. Today neither worked  until the Sitex came on after about three hours and kept fixing until shut down, albeit with a rather poor quality fix. Could the proximity of the external aerial be giving hte lowrances internal aerial grief? Turn the Sitex off and the  Lowrance still won't fix. Or do I have a dud HDI 7 and coincidentally the Sitex is having problems? Asked another bloke and he said he was also having problems, no-one else on the radio seems to want to comment. Tried a reset, but don't have the manual with me, don't think it was a full sytem reset.


Posts: 5745

Date Joined: 18/01/12

 you can download the manual

Sat, 2015-06-20 15:07

 you can download the manual online easy enough, but be careful of a full reset, losing marks, save to an SD first?

____________________________________________________________________________

 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.

 

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

Still something wrong

Sat, 2015-06-20 19:05

 Sitex came up this afternoon but hit and miss, poor quality fixes, Lowrance still noy playing the game. Reset I did said I would not lose any info, which i didn't so I'm guessing it was just a reset to parameters rather than a full reboot.

Posts: 218

Date Joined: 08/03/09

Perhaps try

Sun, 2015-06-21 08:40

each one on a different 12V power source to isolate them from each other, ensure that they are getting at least 12V.  This will at least make sure it is not a power supply problem or an interference issue.  If they are both currently on the same 12V supply it could be a shitty connection somewhere so if you can rig up a direct connection to a battery to test.

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

Downloaded the factory manual

Sun, 2015-06-21 13:57

 No mention of a full reboot in there,only the parameter reset where you don't lose any info which I have already done. and no updates available on the Lowrance website. I''ll go back out the boat directly to investigate possible voltage drop--I rewired it myself and ran a new feed to the common supply bus earlier in the year after I first bought it, so it should be ok--mind you, i've had a new secondhand motor installed since then so i'd better investigate what they might have done. It all worked perfectly this morning upon startup, for several hours, then went down and nothing since

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

I may have found the problem

Sun, 2015-06-21 20:05

 When I got it back from the motor instal, I noticed cranking battery had the positive for the  accessories supply off it.(from cold side of the battery switch.) I wondered why they had done this-the previous installation was twins, battery switch for each and a common switch to parallel both. I told them I wanted accessories off the second (smaller) battery. When i pulled the covers off the hard- to- access battery boxes, I found the negative for the accessories was off the second battery, which was smaller than the cranking battery. Now,the negatives are joined directly between the two, so, electrically,it really should make no difference. But i changed the positive feed to the cold side of the second battery switch and the problems just went away. They both fired straight up, and continued to work, and properly, all afternoon while we annoyed the local squid population. Tomorrow will tell. Didn't get a chance to really check the fishfinder side of things as we didn't get more than 4 meters of water under the keel, but that had been pretty crap, too.

Posts: 274

Date Joined: 08/10/13

Yes

Sun, 2015-06-21 20:18

 Having 2 gps antennas next to each other can effect signal but its not common. Just a question with the old unit. With some external aerial wiring the antenna can be powered up all the time even when the unit is off, maybe isolate the 2 supplies completely. Run the power to the new unit straight from a seperate battery and disconnect all other power at the battery to the rest of the boat  and give it a go. That will rule out interferance.

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

Found the problem

Tue, 2015-06-23 19:47

 It was the UHF radio I had fitted and not used until I came up here. Only found it by forgetting to turn it on this morning GPS's were working fine, turned it on, both went off. it Is like a switch, turn it off, both come striaght back up. Tried moving it as far away as I could, problem become intermittent but still there. Not voltage drop, as everything is off the same bus, and turning on large drains like the bilge pump or lights has no effect.

Posts: 5745

Date Joined: 18/01/12

interesting followupAnother

Wed, 2015-06-24 07:39

interesting followup

Another good reason to get rid of the UHF for a VHF

When you say "tried moving it further away" did you move the head unit or the aerial?

____________________________________________________________________________

 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.

 

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

Horses for courses.

Tue, 2015-06-30 12:24

 UHF is the preferred method  here at Ningaloo station, as we use Duplex Ch 1 via a repeater on the hill. Always someone listening. I moved the head unit, and it definitley improved a little, but I won't be moving the aerial as the boat is permanently in the water and can only be launched retrieved on low tides with the right weather. I will try disconnecting the aerial (without trying to transmit, obviously) with the unit on and see what that does.