cachinggear.co.uk

One problem that geocachers encounter at some stage of their new hobby is GPS reception. There is nothing worse than being 3 miles into a walk - to find that the geocache you are trying to find can’t be because you’re GPS just won’t lock on!!

GPS Reception can be a bit of a black-art - some people have the knack - some don’t… However there are a few steps you can take to improve your reception:

Improve your physical position: Seems obvious - but moving to somewhere with better sight of the sky usually helps. Most reception problems are caused by large objects (trees or buildings) blocking the GPS’ sight of the sky. Moving to somewhere where there is sight of the sky will allow the GPS to lock-on and sometimes you can go back to the position you were in and still have a lock - albeit weaker.

Buy a better GPS: Again - pretty obvious - but can be costly. GPS devices use different chipsets and antenna - generally the more expensive GPS’s contain better chipsets and better antena. Be careful to check with other cachers when you are thinking of a new GPS as one that has a bad reception under tree cover is almost useless!! GPS devices with the SirfStar III chipset are the best on the market at the moment.

Hold it correctly: Different GPS devices have different positions for antenna. GPSMAP devices are generally designed for completely vertical orientation, similar for etrex. Others are designed for hand-held or flat usage.

External antenna: A bit sad - but you can buy external antenna - these are generally good for fitting to cars - rather than use hand-held though!

Classic Peter-Kay stylee: Hold the GPS vertically into the air as high as you can - seems a bit silly - but often seems to help with GPS locks!!

Turn it on+off: On the odd occasion you can be in a situation where the GPS has the clearest view of the sky it could ever possibly have - but still you don’t get a lock…. It’s a strange one - and probably due to errors in the chipset firmware. A simple turn on/off often does the trick and you quickly get a lock

The weather: I’ve often found that the weather significantly affects my ability to get a lock. There don’t seem to be any specific conditions where I’ll think “Oh - my GPS will be iffy today”… This is presumably due to the same type of interference seen by radio hams etc.

Other things to watch out for:

Movement: When you first buy a GPS - it has often travelled a long distance (via post for example), especially if it’s second-hand. When moved - a GPS needs to ‘re-learn’ it’s position - and figure out which satellites it can ’see’. Therefore you will often need to leave a GPS for quite a few minutes to lock-on correctly.

Battery Life: One thing that will completely affect your ability to get a GPS lock is if your batteries are dead!! (Best to have some replacements to hand!).