So, I has this old handheld

[Drinky Crow]

Garmin GPS 45 XL ain't used near twenty year. Put new batteries in, powered up, country and offset are correct but will fix on only one satellite at a time and alt./pos./and time are all fixed and wrong (mebbe right last time used?).
Don't see no obvious place to insert new software (if that's even possible) though there is a four male prong port, guess it output.
So, this thing is just debris now?

[Boatguy30]

I have an old Garmin myself. Has an excellent basemap is why I have it.

Anyway, I believe it just took a really long time to acquire. Maybe several hours last time I used it.

[StuM]

Try holding down Page and Start keys until the screen comes on then leave it with a clear view of the sky for at least a half an hour, if possible for many hours.


See


http://gpsinformation.net/main/eowgarmin.htm

[Drinky Crow]

Oh thanks very helpful will try that all tomorrow.

[GordMay]

Could it be something to do with the GPS Week Number Rollover?
Designed in the 1970’s, the computer systems on the GPS satellites represent weeks using a 10-bit number. This has a maximum value of 1024. After 1024 weeks have passed (or 19.7 years) the number rolls back to zero. This event happened once before, on August 21 and 22, 1999.
It occurred again on April 6, 2019, when the calendar of all GPS satellites reset back to zero.
I believe there were software fixes.
➥ https://techcrunch.com/2019/04/06/gp...ght-get-wacky/

[markcouz]

I have 2 similar era Garmin GPS, a GPS 90 Aviation (8 channel) and GPS 12 (12 channel). I followed the instructions on the website posted previously on this thread...

I found that after several hours they both gained 3D lock, the 8 channel unit bounced in and out of lock whereas the 12 channel unit was reliable- both produced accurate location and time but some bizarre date when NMEA info viewed on OpenCPN, but the thread does mention some Garmin software fix for this issue.

Note that (on both my units) the internal battery is dead, so if swithced off for any length of time the "last location" info is lost and so the lengthy procedure must be repeated.

There is a YouTube video about replacing the internal battery if you want to give this a go. I won't bother because I will use the GPS 12 powered 24/7 to feed location data to Icom 412 and 802 for DSC reporting only, not for navigation.

All this PITA required because my old Icom radios required NMEA data at 4800 bps where my current GPS data is at 38,000 bps.

[Siberian Sea]

Originally Posted by GordMay

Could it be something to do with the GPS Week Number Rollover?
Designed in the 1970’s, the computer systems on the GPS satellites represent weeks using a 10-bit number. This has a maximum value of 1024. After 1024 weeks have passed (or 19.7 years) the number rolls back to zero. This event happened once before, on August 21 and 22, 1999.
It occurred again on April 6, 2019, when the calendar of all GPS satellites reset back to zero.
I believe there were software fixes.
➥ https://techcrunch.com/2019/04/06/gp...ght-get-wacky/

I’m glade smart folks had figured all this out because I never would have. Thanks for the link

[roland stockham]

That 4 prong port is an old style interface that enables you to plug it into a computer. Not sure if Garmin still supplies the lead but if not you may be able to get one on Ebay. I would check the Garmin web site to see if they have firm-wear updates available to correct timing errors from the year roll over. No reason why it should not still work,GPS hasn't changed just won't have the modern accuracy, likely 'only' 100m!!!

[Dogscout]

Ive got an old Magellen 315 from the mid 90's. Like you I pulled it out of the drawer and put new batteries in it. Leave it outside on a clear day and it booted and worked. Its small, has no mapping but it does show bouys and nav aids. I keep it on the boat. It might be useful to compare data if I ever need to troubleshoot the new high tech systems and plotter.

[RobertoD]

I have an older Garmin GPSmap76S (B&W screen) which still works great, and I have the computer etc attachments. I hang onto it for backup - but I need a Lake Ontario map data package. Originally I believe it came on a CD and transferred from a computer. Anyone know/have suggestions where I may obtain that?? Thanks.

[Drinky Crow]

Originally Posted by StuM

Try holding down Page and Start keys until the screen comes on then leave it with a clear view of the sky for at least a half an hour, if possible for many hours.


See


EOWgarmin

Do you mean "Power and Page" I have no "Start" button.
Is that the method for "master clear", 'cause your link say no for XL45.
Have to wait until next week when it's not pouring rain.

[anacapaisland42]

Please note there has been a large increase recently in GPS spoofing, to the extent that some ships have had to use Radar for navigation in some circumstances.
Bill

Originally Posted by Drinky Crow

Garmin GPS 45 XL ain't used near twenty year. Put new batteries in, powered up, country and offset are correct but will fix on only one satellite at a time and alt./pos./and time are all fixed and wrong (mebbe right last time used?).
Don't see no obvious place to insert new software (if that's even possible) though there is a four male prong port, guess it output.
So, this thing is just debris now?

[anacapaisland42]

Originally Posted by anacapaisland42

Please note there has been a large increase recently in GPS spoofing, to the extent that some ships have had to use Radar for navigation in some circumstances.
Bill

U.S. Issues Renewed Mariner Warning on GPS Interference
dangers of gps interference


The United States issued a renewed warning to mariners of multiple instances of significant GPS interference. According to the U.S. Maritime Advisory, this interference is resulting in lost or inaccurate GPS signals affecting bridge navigation, GPS-based timing, and communications equipment. Satellite communications equipment they warn may also be impacted.

This renewed warning is non-specific to an area of the globe, but it notes over the last year, areas from which multiple instances have been reported include the eastern and central Mediterranean Sea, the Persian Gulf, and multiple Chinese ports.

Mariners are warned to exercise caution when underway and before getting underway and the advisory reaffirms safe navigation practices when experiencing GPS disruptions as well as encouraging prompt reporting.

The U.S. Coast Guard Navigation Center (NAVCEN) offers examples of techniques mariners can use if they experience GPS interference including using radars to mark bearings and distances on a paper chart or switching to the dead reckoning mode with a radar overlay on electronic charts, and using parallel indexing with multiple radars while underway. They reiterate that situational awareness, including verified position and velocity, is vital for safe and effective commercial operations and recommend consulting the NAVCEN and NATO Shipping Center websites which contain information regarding effective navigation practices for vessels experiencing GPS disruption.

Reports of interference or the more dangerous spoofing to convince mariners they are in a different position is nothing new to the industry. The US Coast Guard and Maritime Administration have issued numerous warnings to mariners. In June 2019, fourteen maritime organizations sent a letter to the US Coast Guard urging the commandant to raise the issue of jamming and spoofing of GPS and other systems with the International Maritime Organization.

At the beginning of 2020, the Trump administration directed the Department of Homeland Security, the Pentagon, and the Commerce Department to minimize the use of GPS systems for positioning and navigation due to the dangers from hacking.

The source of these types of disruptions often go unidentified according to experts but they have the potential to create significant confusion and slow the movement of ships. The potential exists to create bottlenecks in ports and major sea lanes or even to cause accidents. Most newer and larger commercial vessels have multiple systems with the greater danger being to smaller and older ships.