Gear

Can anyone please tell me why the GPS I was using on New Years Day at North Yorkshire Moors kept comming up with the message Weak Signal unable to locate. This is dispite there was no buildings for miles just open moor land but low cloud and some mist. Any information would be grateful

Easiest question first - where was the GPS and what sort of angle was it at.

Oh - and how thick was that cloud/mist? I've heard tell of problems in those conditions, but never experienced them (problems I mean) personally.

i've had that with a garmin gps60. took quite a while to get a fix. the geko 201 fixed very quickly.
puzzling.

Unit was held upright in hand. Cloud was thick and about 500-1000 ft light mist covering moorland visability was very good

Anywhere near Fylingdales??
Just a thought.

We were at Littlebeck, just 5 miles from Whitby. Just grateful I never fully rely on GPS I still believe in the ol' paper map and Silva compass. Thanks for all your advice

Just down the road from the 'Cheese Grater' then!

Did not see it but we came across the Hermitage and Foss falls. Brilliant day out and as we started at 09:00 in the morning on new years day was able to enjoy the views without any other people about.

Garmin dont have the best reception as they use an internal patch ariel. Mine used to be terrible at picking up signal when you turned it on. When research my new GPS I found out the following

The magellan (apart from the new explorist) use a more complex large ariel can't remember the name, quad helix or something.

The result is quite significant. I gave my old Garmin unit away when I got the magellan. Its almost instant in picking up satalites and has yet to drop signal for more than a few seconds

Running Man, did you have an eTrex? They use the old patch aerial, but all the newer Garmins (60-series, 70-series, don't know about the Geko) use a quad helix aerial. The quad helixes are best held vertically.

I don't know the technicalities, but my 72 is definitely more accurate than my eTrex. It's more often than not within 1 or 2m of the hill height, even without a barometric altimeter.

No mine was part of a timex speed system that used a Garmin GPS unit. It seem accurate when it had a signal. I used it for running and gave up with it as I'd sometime be waiting for 15 mins for it only not to work before I could go for a run.

ETrex and Gekos are best held flat.

I have moved on to a blue tooth unit and PDA.

I used a Garmin Etrex previously and had absolutely no problems in areas where you shouldn't get problems and only got problems in deep valleys and inside buildings which would be the case with most GPS reception. Dare I suggest that the unit you were using was either faulty or less sensitive than it should be?

Having said that, I now use a Pretec Blue tooth unit (as recommended by our own Dave Mycroft) and it too has an internal antennae. It is much smaller and is MUCH more sensitive than the old Etrex. I can obtain signals in some indoor locations, in deep sided valleys and it NEVER loses a signal when used in the vehicle, unlike the etrex did.

I have taken the two out and used them both for comparison and the blue tooth outperforms the extrex by far!

Thanks to all your help and advice. I will have to go out and look at replacing my unit. Will look at the Magellan.

i used a gps60 on bilsdale on new years day and had no signal problems whatsoever, with the unit quite often showing 20ft accuracy i kept the unit vertical all the time though, i also used my unit at about a 45 degree angle on a 40 odd mile pushbike ride on the 27th and again had no problems with coverage. i would think that your unit was either faulty or the good old yanks were cocking up the signal from fylingdales, i would suggest trying your unit somewhere else first before replacing it, try rosedale or bilsdale, you will be far enough away from fylingdales and have good open moorland.

RAF Fylingdales radar info (from Radomes.org):

"...

AN/FPS-115, AN/FPS-120, AN/FPS-123, AN/FPS-126

Raytheon builds the AN/FPS-115 "PAVE PAWS" phased-array missile-warning radars first deployed during the early 1980s.

These ninety-foot diameter circular-panel radars are mounted on two walls of a triangular-shaped pyramid structure. The antennas are designed to operate at a frequency of 420 to 450 MHz.

"PAVE PAWS" radars reportedly can detect targets at ranges approaching 3,000 miles.

There were originally four continental United States (CONUS) sites. Two of the original CONUS sites -- Cape Cod AFS, MA, and Beale AFB, CA -- are still in operation, and their radars were recently upgraded to the higher-power, more-capable AN/FPS-123 model.

The other two CONUS sites -- Robins AFB, GA, and Eldorado AFS, TX -- have now ceased operations. The radar from Eldorado AFS was relocated to Clear AFS, AK, replacing the older BMEWS radar there. The Clear AFS "PAVE PAWS" radar also has been upgraded to the AN/FPS-123 model.

Similar "PAVE PAWS" radars replaced the BMEWS radars at Thule AB, Greenland, and at RAF Fylingdales, UK. Thule AB received an AN/FPS-120 model, while RAF Fylingdales received an AN/FPS-126 model. The AN/FPS-126 is unique, having three radar faces, while the AN/FPS-120 and AN/FPS-123 each have two radar faces.

..."

The output power from one of the beasties might be enough to "desensitize" your GPS receiver even though it operates in the L-band and the radar is in the UHF band. The third harmonic of the radar frequency could also cause problems for a GPS.

Anthony

Before you replace your unit: eTrex are not designed to be held vertically, as you describe. If held vertically, etrex's do not work properly, and you frequently get the 'weak signal' error, because its antenna does not receive the signal efficiently from the satellites.

You need to hold an etrex horizontally, ie screen upward.

HTH

John

ah ha! that would account for the gps60 then - i was holding it horizontally.

Thanks John Spencer for that informatation. I never realised that. I am out training youngsters for the Gold award next week I will try that and see what happens. look out for a posting after next sat. with news.

John

I have a Geko 101 but have not had the opportunity to use it yet, is it best to hold it horizontally like the eTrex?