GPS advice please

[offrd]

I need to buy a GPS unit to plot the exact location of each install for the providers i install rural broadband for...

Now this GPS thing is new to me and i dont want to spash on something that wont do what i want it to...

The unit needs to give me my location with i believe a 7 digit readout, even the guy at BCL was a bit unsure.... So they must have different plotting??

It needs to have a goto function so i can add the gps location of wireless sites so when in the rain and fog installing customer units it can tell me the direction of the transmitter i need to align to.

Perhaps mapping functions like a navman so it can get so lost even i cant find me!

and if it was suitable for using on adventure rides then it would be great!

etrex, navman, uniden...

I have no idea, so many on the market!

Cheers

Duncan

[JATZ]

Personly I use a garmin 75cx, the csx would be a better option as it can take an sd card however the cx does what you have described.

Hope you've got plenty of time, asking gps stuff 'round her is like asking which tyres are best

[Nordy]

I have a Garmin GPSMap 60Cx which can do all you ask for.

[offrd]

How do they compare to a Garmin eTrex Vista GPS ??

[dhunt]

The unit needs to give me my location with i believe a 7 digit readout, even the guy at BCL was a bit unsure.... So they must have different plotting??

It needs to have a goto function so i can add the gps location of wireless sites so when in the rain and fog installing customer units it can tell me the direction of the transmitter i need to align to.

GPS position will be like -39.XXXXX,174.XXXXX.

We have used the Garmin nuvi series GPS's which in fleet management mode at least can be told to go to a particular GPS location. I would presume in normal mode they can still do this but can't say for sure.

[mowgli]

If you want to aim antenae you'll still need a wet compass and local magnetic deviation with most GPS units. Most of them point relative to your current direction of travel. If you're perched on a roof top then you ain't moving. The GPS pointer will be meaningless. Azimuth, range and (on some units) elevation should be pretty accurate though.

[offrd]

If you want to aim antenae you'll still need a wet compass and local magnetic deviation with most GPS units. Most of them point relative to your current direction of travel. If you're perched on a roof top then you ain't moving. The GPS pointer will be meaningless. Azimuth, range and (on some units) elevation should be pretty accurate though.

Ok... So i need to walk around the property to get the gps to read and take a visual reference, eg a tree, to use to aim the aerial. That could work?

[mowgli]

Ok... So i need to walk around the property to get the gps to read and take a visual reference, eg a tree, to use to aim the aerial. That could work?

Yup, that would do it. You'd be better walking in a straight line though.

[Nordy]

the 60CSx has a real compass rather than a gps compass that might work better?

[Pogo2]

and require some movement initially so that they can align themselves. If you go to the spot turn them on and wait for the location you will get a lat/long but the orientation might not be correct right away. Move a few metres in any direction and the direction indication will sort itself out. Then their pretty accurate. Some models take a bit of time to initialise (ie find themselves) can be 30 sec to a couple of minutes. Depends on where you are and how far you are from when you last turn it on as it wil look for satellites where it last found them. (Hope that makes sense)

I have a Garmin for aviation use and will always start it up a few minutes before I need to rely on it. Like the idea that Mowgli had of using a compass to quicky ascertain the direction you are pointing. Cheap and easy.

[cooneyr]

If you are going to be using one in fog or poor reception areas then you really want a H version etrex or GPSmap cause they have better GPS receivers.

The vista and the CSx gpsmap (S is the bit in the name that means it has a compass) units have magnetic compasses built in. They also have barometers built in.

All units will show and record to 7 sig fig but the accuracy is more affected by satellite reception quality than the 7 figs. 5m accuracy is equal to .005 minutes and the 5 is the 7th digit so no point in having more than 7 fig.

Pretty much all units will do goto but the mapping units will allow you to choose as the crow files or follow roads if you have the free NZ auto routing map.

Cheers R

[upshift]

Agree with all cooneyr's comments.

Couple of other things to consider are batteries and need to be rainproof. A handheld unit with high sensitivity, mapping function, normal dry cell powered (such as a couple of AA batts rather than some inbuilt lithium), electronic compass, and goto function is your best bet. There are free auto routing road maps available for Garmin units but (as far as I know) none for the other brands. Full set of NZ topo maps for Garmin around $160.

Hence a choice of a Garmin Vista HCx, 60CSx, 76Csx, or Colorado 300. Colorado 300 is the most expensive, best price I know is around $720 but quite a bit ahead of the others if you are also looking at using it for navigation simply because of the bigger screen and option of "navigation mode" display. Pic below shows both a 60CSx and Colorado with the same mapset, the free ones! Vista HCx is the cheapest but still a great unit, if $$$ is a factor then get that and you will not be disappointed.

Once you calibrate the electronic compass, fairly easy but need to do it every time you change the batteries, you can simply turn the unit on and get a heading without the need to move around. It works on the earths magnetic field just like a regular compass. You can choose between GPS compass (requires movement of the unit) or electronic compass. Mine is set to GPS compass but will auto switch to electronic if speed is below 10Km/h, hence walking or standing still speed.

[upshift]

Screenshot of compass on Colorado showing heading to a waypoint.

[offrd]

Thanks for the advice guys, just have to decide what Garmin to get..

[yamafitter]

If you are going to be using the GPS to scout out new trails you definitely want to get a Garmin with mapping features. Being as old as I am I also like to have a large screen so I can see at a glance what it is I am doing. That is way for the last number of years I have used a Garmin 276C though the new Zumo 550 works very well (specifically designed for bikes). I help lay out events here in Ontario Canada and would be lost without my Garmin.