advice needed on GPS

leifus · #1 (**permalink**) 16-07-2009, 08:41 PM

I wasn't sure where to put this so I put it here as well as in the wildflower and walking and cycling forums...

anyway, I do a lot of recording for wilts and hamps wildlife trusts and I'm going to buy a GPS so that I can get at least 6-fig OS grid references when I find a plant. Preferably I would love it to work anywhere, rather than in one specific region but I'm aware this might not be possible.

Basically, I'm asking for advice as to which GPS I should buy for a reasonable amount of money (preferably below £100) that I can get my grid references from.

Thanks in advance for any help you can give

nigel_b · #2 (**permalink**) 19-07-2009, 08:40 PM

Garmin etrex H, £73.

Garmin have retained the etrex name across 2 very different products. You need the new, high-sensitivity version and I mention that so yuo dont buy "new-old stock" on the high street or a second hand etrex for £30 thinking its going to cut it.

We have been completely spoilt in the last few years with new features and much, much better receivers with lower prices than before.

You need to be familiar with datums and grid formats. Default datum is usually WGS84 but thats no good for the OS grid references you require so you need to change the datum to OSGB36, and change the position format to "British Grid".

That said, my new etrex changes the datum automatically when you change the position format from lat/long to OS grid references.

leifus · #3 (**permalink**) 19-07-2009, 09:05 PM

wow thanks

is it possible to enter a 10 fig GR into it and then it would point me in the right direction? Say, up to 5 m or something?

nigel_b · #4 (**permalink**) 21-07-2009, 07:17 PM

Quote:

Originally Posted by leifus

wow thanks

is it possible to enter a 10 fig GR into it and then it would point me in the right direction? Say, up to 5 m or something?

Yes.

The normal 6-digit OS grid ref you might be used to is actually the bottom left hand corner of a 100m x 100m square, e.g. SY 945 672

When inputting this into a Garmin (for example) Easting and Northing will need two extra digits e.g. SY 94594 67231

so the reference now becomes the bottom left hand corner of a square 1m x 1m!

leifus · #5 (**permalink**) 21-07-2009, 09:00 PM

Quote:

Originally Posted by nigel_b

Yes.

The normal 6-digit OS grid ref you might be used to is actually the bottom left hand corner of a 100m x 100m square, e.g. SY 945 672

When inputting this into a Garmin (for example) Easting and Northing will need two extra digits e.g. SY 94594 67231

so the reference now becomes the bottom left hand corner of a square 1m x 1m!

ahh that's brilliant

perfect in fact! thanks for the help

leifus · #6 (**permalink**) 01-02-2010, 08:13 PM

Quote:

Originally Posted by nigel_b

Yes.

The normal 6-digit OS grid ref you might be used to is actually the bottom left hand corner of a 100m x 100m square, e.g. SY 945 672

When inputting this into a Garmin (for example) Easting and Northing will need two extra digits e.g. SY 94594 67231

so the reference now becomes the bottom left hand corner of a square 1m x 1m!

Hi again Nigel,

I've got my GPS now and your instructions were very useful, thank you so much!

diggleken · #7 (**permalink**) 01-02-2010, 08:57 PM

I'll stick with a map and ruler.
Just call me old fashioned (and skint)!

Cheers
Ken

nigel_b · #8 (**permalink**) 01-02-2010, 09:36 PM

Excellent, let us know how you get on!

foxy mars · #9 (**permalink**) 24-02-2010, 03:03 PM

If anyone has a Garmin gps, you can get updates from their website. I've just updated my 2 Garmin's - etrex H and Venture this morning to get the latest software version. One thing about not using the gps for 6 months, is that the satellites don't lock on so easily and that takes about 10-20 to have it up and running again. So, a little tip for you.