GPS handhelds
Contents: GPS handhelds
Why use a dedicated handheld?
Screens >> Resolution l Emissive l Transmissive l Transflective l Touchscreens
Aerials
Maps >> Commercial l Cheap topo maps for Garmin
Operating systems
GPS compass vs 3-axis compass
Barometer and altimeter
Why use a dedicated handheld?
When our smartphones are so good, why would we bother with a dedicated GPS handheld?
Not all handhelds have all these features…
- They are purpose-built for the job.
- Robust and waterproof out of the box.
- More reliable. The unit doesn’t also have to do email, photos, music etc
- Better battery life and some have batteries that can be changed.
- Sunlight readable screens.
- Resistive touchscreens are unaffected by rain.
- Hardware buttons allow flawless use in the pouring rain and with gloves on.
- Larger aerials in some units may cope better in difficult conditions, like under a forest canopy.
- Accurate multi-band receivers are readily available. Better for difficult locations.
- Some Garmin units include satellite messaging technology which includes an SOS that works anywhere on earth, well away from any phone signal.
- Mounting options are normally available as standard.
If you’re new to the world of GPS navigation don’t be surprised to see the name ‘Garmin’ a lot. They are the largest manufacturer of GPS handhelds and completely dominate the market. A review of the ‘best GPS handhelds of the year’ might only have Garmins in the lineup. Here in the UK, if you’re buying new, you might only find units from just three companies, Garmin, SatMap or TwoNav and Satmap Systems Ltd has now closed.
Let me know if you know of some other manufacturers.
Screens
Screen resolution
This is one of the areas where smartphones blow dedicated handhelds out of the water. Smartphone screens offer amazing quality although they’re not normally very ‘sunlight readable’.
| Device | Pixel count | Screen diagonal |
| Garmin GPSMAP 64 | 160 x 240 | 2.60 in |
| eTrex 22x/32x | 240 x 320 | 2.20 in |
| Garmin GPSMAP 66 | 240 x 400 | 3.00 in |
| Satmap Active 20 | 320 x 480 | 3.43 in |
| TwoNav Adventura 2 | 480 x 640 | 3.70 in |
| Garmin Montana 700i | 480 x 800 | 5.00 in |
| iPhone X | 2436 x 1125 | 5.85 in |
Fewer pixels to illuminate in the handheld screens is probably partly why their battery life is better.
If you use reading glasses you might favour a bigger image over screen resolution. Note that the pixel count on the eTrex models is significantly higher than for the Garmin GPSMAP 64 which has a bigger screen. That makes the eTrex image nice and sharp but the features are small.
If you’re viewing converted paper mapping and want to take a closer look you can just zoom in. If you’re using a vector map on a Garmin that won’t work. If you find the text a little hard to read you can adjust this in settings.
Menu > Setup > Map > Advanced Map Setup > Text size (Points, Streets, etc) – Experiment with Street label and Land cover.
Emissive screens
These are what we find on regular smartphone screens. An array of coloured LEDs emit light when supplied with power. Easily seen indoors they’re not so clear outdoors and worst in bright sunlight.
A white screen uses maximum power and a black screen doesn’t need power. This is why using dark themes with a phone and phone apps will make the battery last longer.
Transmissive screens
These are LCD screens that use a permanent backlight to illuminate the screen image. If a handheld uses one of these then it will suffer from the same problems in sunlight as smartphones. The brighter the backlight can go, the better the screen will do in the sun. eg The Satmap Active 20 uses a transmissive screen and has a backlight boost button to help in bright sunlight.
The extra brightness required to keep a screen ‘sunlight readable’ will come at some cost to battery life.
Transflective screens
The clever design reflects ambient light off the back of the screen to make the image clearer as the light gets brighter. These screens don’t consume much power. In the full glare of the sun they look better. When the light isn’t so good they can be backlit. At night the light from a headtorch works and can spare the backlight.
Their power-efficient design makes them a good choice for GPS handhelds and they are used by many Garmin units.
We don’t see transflective screens on smartphones because they’re not good with video and don’t have such a rich colour palette.
There are phones from a company called HiSense that use colour e-ink screens that might rival transflective screens in the sun. They are also supposed to be very light on the battery. Website: global.hisense.com
Touchscreens
Regular smartphones and some GPS handhelds use ‘capacitive’ touch screens. The lightest touch from a fingertip changes the electrical properties of the screen at that point. However, in the pouring rain, water on the screen can spoil the party. The screen may not respond so well to your inputs. I generally wipe water off my waterproof bag before waking the phone to use it. If the rain is heavy and you want to scroll around the map then it’s a good idea to shield the phone until you’re done.
Wearing gloves is a non-starter. Unless you sew conductive thread (this exists) into your gloves fingertip or buy special gloves, then to use your finger you must take your glove off. A special capacitive stylus allows use with gloves on, if you can remember where you put it.
Some GPS handhelds use ‘resistive’ touchscreens to overcome problems with the rain. These screens need a physical press which deforms the screen slightly. Rain has no effect on them. They can be pressed with anything at all. The earlier Garmin Montana and Oregons used resistive screens. A handheld with buttons will work reliably whatever the weather and although a little slow, they are easy to use.
Aerials
Of necessity, the aerials used to pick up GPS signals in a smartphone are flat ‘patch’ aerials. When you’re out in the open they will get a good signal and position you accurately. However, if you start walking under a dense forest canopy or maybe into a deep narrow rocky gully then the GPS signals will be degraded. A ‘quad-helix’ aerial may perform better than a patch aerial and continue to provide a fix when a small patch aerial may lose the plot.
Smartphones, smaller Garmins and the Satmap Active 20 use patch aerials. The larger Garmins have better ‘quad-helix’ aerials housed in the ‘thumb’ sticking out of the top of the units.
Patch aerials are designed to be used when horizontal and quad-helix aerials work best when vertical.
Maps
Commercial mapping
Check with the company website that the maps you want are available for your device. As I type, OS mapping is available for Garmins, TwoNav and SatMap units.
Garmin – TOPO Great Britain v2 PRO 1:25K
Garmin say the pictured product includes “the official Ordnance Survey (OS) 1:25,000, 1:50,000 and 1:250,000 scale maps for all of Great Britain, it also offers on-trail guidance of the OS Detailed Path Network, available for thousands of kilometers of paths and trails in all British National Parks”. For £200 the ‘TOPO Great Britain v2 PRO 1:50k’ is the same but without the 1:25k OS Explorer mapping. Mapping for other countries is also available.
TwoNav – Great Britain Topo Full
Explorer 1:25k only mapping is available for £180 and 1:50k only for £110. The maps can also be bought a tile at a time. OSM mapping and commercial mapping for other countries is available too.
Cheap topo maps for Garmins
Don’t bother buying Garmin Topoactive mapping as this is based on OpenStreetMap data and may not include contours or great detail. Although the Garmin map format is proprietary it’s been reverse-engineered over the years. The format is now well understood. Using OpenData from the Ordnance Survey and free OpenStreetMap data, it’s possible to make very good Garmin-compatible topo maps. Quite a few third party map-makers do exactly that and these maps can be downloaded off the internet for free or very cheaply. This gives you access to good topo mapping for the UK and the world.
There are two maps in particular that I’d recommend for use in the UK. I have both on my devices.
The Great Britain JohnThornMap is about £15 to buy. This is the Garmin version of the map described here. It’s an OS/OSM hybrid map that is mostly OS data. It’s not routable.
Website: the-thorns.org.uk/mapping/walkers.html
TalkyToaster provides Garmin-compatible maps for the world described here. A detailed OSM-based topo map of the British Isles is available for about £13. This is available in a routable form. There is a good donation/free version that you can try. That might be all you need.
Website: talkytoaster.me.uk
Both these maps can also be used on the Garmin Fenix watches and installers are available for Basecamp on Windows and macOS desktops too. They should work on any compatible Garmin.
The TalkyToaster map contains many details not on the JohnThornMap and zooms better but it lacks good OS data like contours, crags, public rights of way and more, that are provided by the JohnThornMap. Both are a piece of cake to put on many Garmins. Instructions here.
There are many other sites where you can get good OSM-based topo maps for Garmins, see here.
Operating systems
A GPS handheld has an operating system dedicated to the unit. It doesn’t have to do a gazillion things like a phone’s OS does. Whilst the interface might be a bit basic, that simplicity means it’s more likely to be reliable.
A simpler OS will probably require a little less battery power too. Garmin claim 25 hours battery life for the eTrex 32x which is powered by two AAs and up to 180 hours for the GPSMAP 67 which has a captive lithium-ion battery.
GPS compass vs 3-axis compass
The 3-axis electronic compass in a dedicated handheld will be like a magnetometer-based compass in a smartphone (See Electronic compasses). A normal baseplate magnetic needle compass is more accurate and never needs calibrating.
A GPS compass will provide a direction based on your movement, as detected by the GPS. This will be reliably accurate. However, it only works when you’re moving. It’s no use for telling you which way to start walking after a snack break in the mist. However, once you start walking the GPS will work out which direction you’re heading and can show that on the GPS compass. Of limited value if you’re following a highlighted route.
Barometer and altimeter
Some handhelds will contain an air pressure sensor. This will work like those in a smartphone. Any associated barometric altimeter will require frequent calibration to stay accurate during the day. Some handhelds use information from the pressure sensor and GPS to provide a more accurate altitude.
When camping, seeing how the pressure changes overnight will give some clues as to how the weather will be. If the pressure has dropped then the weather may get worse. If the pressure gets higher then there’s hope for clearer drier days.