What GPS External Antenna?

[bearbait]

Hi All,

I'm researching an external antenna for a Garmin GPS. I'm planning to use it mostly for survey and occasionally for nav in very difficult conditions. It will mostly be used on foot fixed to a stick poking out of the top of my rucsac (or on top of a baseball cap!); very occasionally will it vehicle mounted - probably on a dash - or outside if magnetic.

Any recommendations/steer clears on particular makes and models? Gilsson seems to well thought of.

Many TIA...

[squantrill]

If your mechanical minded build one! Im guessing now with out researching but satelletes respond better to flat arials so take two coat hangers cross them to form a cross connect this to the centre of the cable to plug in to the garmin. Cut a counterpoise (a bit of long wire) stick that to the outer best if you solder.. This should sort you out..

Simon

[Rebel]

I use a Gilsson with my Garmin.

http://www.gilsson.com/garmin_gps/garmin_antennas.htm

It has a removable built in magnet and when I bought mine they were throwing in the wind shield mount for free. The gain is much higher than the Garmin branded antenna.

I bought it from a US based eBay seller who specialized in that type of thing. He had good service and a wide range of products.

[Mikey P]

Alas, it's not quite as easy to build an antenna for GPS as it is for FM radio, telly, or even UHF Tacsat!

The frequencies involved - and the fact that the GPS signal at the earth is so weak - mean that the antenna has to be cut pretty accurately, especially if you want to get a decent gain over isotropic. Unfortunately, unless you are experienced in making patch antennas, this is one of those times when you just have to bite the bullet and buy commercial....:sigh: