Reviewed by Mike Barrett

We are doing this for four reasons:

 
1. My only experience of GPS had been using a Navman sleeve on my iPAQ and I wanted to see how the traditional GPS units compared.

 
2. We wanted to see how we could interface handheld GPS devices to the Pocket PC and how it performed.

 
3. At some point we will exhaust the market for Pocket GPS devices and will want to branch out into other areas of GPS.

4. When we started Pocket GPS, we had a flood of emails and messages requesting that we don't stick to Pocket GPS Receivers and also produce reviews on handheld and in-car systems, and this is the main reason why we have produced the Garmin review, and hopefully many more in the future!

The equipment reviewed here was loaned to us by GPS Warehouse, who provided the Garmin GPSMAP 76, and the Map Source software, and PC-Mobile who provided the cables for connecting the Garmin to the iPAQ.

Warning. The author and Pocket GPS present this article as an evaluation of the Garmin GPSMAP 76 based on their own experience.  It is your responsibility to ensure that it is used in a safe manner and is suitable for your requirements.

 
The Author and Pocket GPS accept no responsibility for accident, loss, damage or injury however caused.

What do you get?
The Garmin GPSMAP 76 receiver priced at around £329.99 including VAT comes complete with a quick reference guide, a full manual, and an interface cable to a PC.

The Garmin comes with a base map but has been designed to work with a number of additional downloadable maps.  The one we reviewed was the Europe MetroGuide which on a double CD provides management software and map data for the Garmin courtesy of NavTech Maps.

This software is priced at £99.99 from GPS Warehouse

The cable set provided by PC-Mobile is a number of modular pluggable cables which can be set into a number of configurations or you can by a new adapter for another Pocket PC without having to by a complete lead set.

Garmin GPSMAP 76 Specification
The manufacturer's specification are quoted here.

Navigation Features
Waypoints/icons: 500 with name and graphic symbol, 10 nearest (automatic), 10 proximity
Routes: 50 reversible routes with up to 50 points each, plus MOB and TracBack® modes
Tracks: Automatic track log; 10 saved tracks let you retrace your path in both directions
Trip computer: Current speed, average speed, resetable max. speed, trip timer and trip distance
Alarms: Anchor drag, approach and arrival, off-course, proximity waypoint, shallow water and deep water
Tables: Built-in celestial tables for best times to fish and hunt, sun and moon rise, set and location
Map datums: More than 100 plus user datum
Position format: Lat/Lon, UTM/UPS, OSGB, Maidenhead, MGRS, Loran TDs and other grids, including user grid

GPS Performance
Receiver: WAAS-enabled, 12 parallel channel GPS receiver continuously tracks and uses up to 12 satellites to compute and update your position

Acquisition times:
Warm: Approximately 15 seconds
Cold: Approximately 45 seconds
AutoLocate™ Approximately 2 minutes

Update rate: 1/second, continuous

Antenna:
Built-in quadrifilar, with external antenna connection (MCX)

GPS accuracy:
Position: < 15 meters, 95% typical*
Velocity: 0.05 meter/sec steady state
DGPS (USCG) accuracy:
Position: 3-5 meters, 95% typical*
Velocity: 0.05 meter/sec steady state
DGPS (WAAS) accuracy:
Position: < 3 meters, 95% typical*
Velocity: 0.05 meter/sec steady state
Dynamics: 6 g's

Interfaces:
RS232 with NMEA 0183, RTCM 104 DGPS data format and proprietary GARMIN

Differential:
DGPS (USCG and WAAS capable)

The Garmin GPSMAP76 receiver fits quite nicely into the palm of your hand.  It is controlled by a small 4 way rocker pad surrounded by eight function buttons.

The unit is reportedly completely waterproof and will even float if dropped overboard from a boat. Needless to say as this was a loan unit we did not verify that.  One nice feature is that the base of the receiver is rubberised so will stay pretty much where you place it and will not slip out of your hand easily.

The display is a four shade FSTN screen with backlight.  It has a high resolution screen of 180 by 240 pixels.

On the back of the receiver there is the quarter turn battery locking mechanism hiding the two AA sized batteries.  It is possible to use rechargeable cells, but you must bear in mind that they supply 2.4 volts as opposed to 3 volts.

The operational life of a pair of AA batteries is such that it does not break the bank using non-rechargeable alkaline batteries.

GPS Satellite Fixing
Well the first thing to do was get a satellite fix.  Having been used to other units I put some fresh batteries in the receiver stuck it on the windowsill and went to make a cup of coffee.  Imagine my surprise to return after a minute to find that the receiver had managed to perform a factory fix in that time.

This became a common theme throughout my experience with the Garmin. In the morning I would place it in the car and switch on, before I had started the car I normally had a fix, an average of 7 to 20 seconds after having been turned off overnight. The longest fix I had was 47 seconds which did concern me a bit despite the weather very heavily overcast and raining.  This had not had a detrimental effect on the unit before, and the reason became apparent pretty soon after though, the batteries had been exhausted.  With fresh batteries in the unit fixed again the next day within 15 seconds again after having no power for 24 hours.

Holding a fix is just as important as getting the first fix, and here the Garmin excelled.  During my testing in the car the Garmin managed to lock onto at least 2 and sometimes more than my other GPS system. Even with the receiver deep in the car between the seats it still managed to hold onto as many satellites as my other unit in prime position on the windscreen. Amazingly the GPS receiver even managed to hold a lock when in my pocket whilst walking in the woods. It did occasionally loose a fix in these conditions but almost as soon as I pulled it out of my pocket it re-acquired the lock.

WAAS what is it? WAAS stands for Wide Area Augmentation System.  It's a system of satellites and ground stations that provide GPS signal corrections, giving you even better position accuracy.  How much better? Try an average of up to five times better.  A WAAS-capable receiver can give you a position accuracy of better than three meters, 95 percent of the time, and you don't have to purchase additional receiving equipment or pay service fees to utilize WAAS.  You can find out more about WAAS at http://www.garmin.com/aboutGPS/waas.html

OK so WAAS is good, but it does not come configured as standard. You need to go into the Setup Menu and enable WAAS as shown on the left. Once enabled you need to initialise the receiver with a good view of the sky and you should see your GPS fixes change into Differential fixes.

How can you tell if you are getting WAAS fixes?  First of all on the sky page you will see differential fix messages and in the satellite strength bars a 'D' will appear indicating that the satellite is being used in the WAAS fix.  The image below shows a 3D Differential fix which was obtained on my office windowsill.

The sequence and messages displayed are as follows:

• Acquiring Satellites is displayed when the receiver is first switched on, or if you have lost your fix for some reason. This means that the unit is attempting to get a fix.
• 2D GPS Location is shown when the GPS receiver has a fix on 3 satellites. When you get a 2D fix the receiver can display your position but not your altitude.
• 3D GPS Location is displayed when there is a fix on 4 or more satellites. In this mode the GPS unit can display both position and altitude.
• 2D Differential Location indicates that the receiver is using either DGPS or WAAS differential data on 3 satellites
• 3D Differential Location shows that the GPS unit is receiving differential data on 4 or more satellites. This is the most accurate fix you get with this receiver.

In Use
The first time I used this was at home on my laptop. The iPAQ cables had not turned up so I used the supplied PC connection cable. The unit can be set up to output data in a number of different ways as shown in the picture to the right.

I choose the NMEA option. The baud rate is automatically set to 4800 and cannot be changed.  This I successfully connected to OziExplorer, Fugawi and AutoRoute 2002.

I also used the unit with just the base map installed around my local area. This I found to be somewhat disappointing as the roads did not line up with with the GPS location very well, being over 1/2 a mile out in some cases. This I knew was the base map at fault and not the receiver as it provided accurate positioning when connected to my PC software. The base map contained only the major roads in my area, suitable for locating your position, subject to the noted error above.

I loaded the Map Source MetroGuide software and went out again.  This time the maps were spot on. They located me exactly where I was.  The roads are sources from the NavTech database. The data on the disks I loaded was a little out of date, not showing a road that was opened at the end of last year, but apart from that was very accurate for the areas that I travelled in.  They were also useful when out walking, though not showing footpaths, you could see when you were near roads.  Setting waypoints and routes was reasonably easy and using both OziExplorer and Fugawi I was able to transfer the data to the Garmin.

The Garmin has sets of displays named pages. These are the Satellite Page, the Map Page, the Compass page, the Highway page, the Route page.

The satellite page has been discussed above and provides basic information about the satellite positions and strengths.  It also shows details such as your position in selected co-ordinates, speed, height and accuracy.

The map page shows the available map data, superimposed with you route, waypoints, tracks etc.

You can either have a full screen map or you can show some information at the top of the screen.  By default the fields are your speed, and the distance to the next waypoint on your route.

By pressing the menu button you can set up the fields displayed on the screen, and other options for the map display.

In general this applies to all pages. Pressing the menu button displays context sensitive options for the page as shown on the right. Pressing the menu button again will display the main setup menu.

The other pages are displayed here.  To the left is the highway page whilst to the right is the compass page.

The highway page shows a 3D representation of the current map. Placed on the display are the waypoint labels and also the track where visible.  The large black line shows the path to the next waypoint on the route.

Unfortunately the example shown here is in the middle of some woods so the roads are not visible in this shot.

Connecting it up
One of the beauties of this system is the ability of the Garmin to connect to just about anything with a serial port. This means that you can connect to your PDA, laptop, or even PC.

Why I hear you ask, would you want to connect it to a PC ?  The answer is simple, you can upload the Map Source maps, routes, and waypoints from the computer to the Garmin.  You can also download your routes, tracks, and waypoints from the receiver to the computer.  Of course if you have a laptop computer you can actually connect the Garmin to it and use GPS aware applications, like Autoroute, Fugawi, or OziExplorer, and plot your position.

The following day my iPAQ cables were delivered from PC-Mobile and I was in business.  The cables all fitted perfectly but I could not find the COM port settings to connect to.  I searched through all of my Compaq documentation and could not find any reference to the com port at the bottom of the iPAQ.

Eventually a call to Dave solved the problem. I had an Compaq micro keyboard which connects to the bottom of the iPAQ and uses COM port 1.  Even when the keyboard is not attached the keyboard driver is loaded.  This has to be disabled prior to connecting the Garmin (or infact most GPS Receivers using this COM port).  Once this was achieved the Garmin connected to all my programmes without a problem.  The output from the Garmin is NMEA as 4800 baud.

When in use the Garmin had a fix even before I had connected the system up let alone started the car.  Having got a fix it was able to retain the fix better than the other iPAQ GPS hardware systems I used.  The downside was that there are more cables to try and tidy away from view and the Garmin was running on battery power though it did last over 16 hours on one set of batteries.

I was testing Trafcam and Tom Tom Navigator but you can only have one GPS application connected at a time.  Connecting the Garmin solved that issue, because I now had 2 GPS feeds.  I did successfully run both Trafcam and Navigator with Trafcam on the Garmin and Navigator running from the Navman.  This was quite a cumbersome set up but effective.  The only thing that I did note was that the system did seem to slow down considerably when approaching a Trafcam "safety" camera, and the number of satellites fixed by the Navman dropped from 4-5 without Trafcam to 2-4 with.  I suspect that this was mainly due to the additional processing power required to run two applications of this sort together. That said it was still a very useable system.

I was most upset when I had to send the Garmin to Dave.  Using a traditional handheld GPS had shown me how other systems can work.  No more constant soft resetting of the iPAQ to get and keep a satellite fix and juggling with software to get the system up and running.  No two minute plus waits to get a fix.  All I had to do was switch on and wait for less than 30 seconds and everything is working. The best thing about it was that the iPAQ could be turned off and on again and just pick up where it left off, something I had never been able to do before.  Pure bliss!

Strengths and Weaknesses
The unit tested is one of the top of the range of handheld GPS systems available.  For my purposes it had too many features on it as I really only wanted a GPS receiver with a serial link to the iPAQ, so this was a very expensive solution.  Garmin and others do produce cheaper units for just over £100 which compare favourably in price to sleeve and Compact Flash GPS devices.

The flexibility of the system is good, this is the first GPS receiver that I had which could be used on it's own, with a Laptop, or with a PDA. This allowed me to do just about anything I wanted to with GPS applications.  The only drawback in this configuration was the cable link between the GPSMAP 76 and the PDA.  This was more of a problem when cycling as I needed to mount both devices.  In the end I just used the Garmin and connected it to the iPAQ when I wanted to check the map on Fugawi or OziExplorerCE.

The biggest plus has to be the TTFF and the units ability to retain the fix even in adverse and unsuitable  conditions. Fixing took slightly longer when travelling but on the occasions that I tried it whilst moving between 40 and 50MPH the system fixed in under 40 seconds.

Purchase from

Conclusion

Manufacturers Website

http://www.garmin.com 

Pocket GPS Reviewer

Mike Barrett

Pocket GPS Reviewer Website

http://www.bwww.co.uk

Rating

Construction

Installation

Useability

Robustness

Overall Rating 97%

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