Two-way Radios

How effective in mountainous or wooded terrain?

[MatthewHSE]

Our family is looking at vacationing in Rocky Mountain National Park this fall. Since we may occasionally split up for some hikes, we thought about getting a set of two-way radios to be able to maintain communication. But before I go spending a lot of money on a decent set, how effective are these things in wooded or hilly terrain? For instance, I obviously can't expect a 10-mile range set to actually achieve that in the woods - but will it still come close? Or, do trees drastically reduce the range?

The last thing I want is to depend on a set of radios that turns out to be useless. Better to not have them at all than to have them not work as expected. If anyone has experience in using two-way radios, I'd appreciate it if you'd share some things I should look for in a good set, what range is feasible, etc.

Thanks,

Matthew

[Macguru]

Hi Matthew,

I guess the maximum range you can expect from a consumer two way radios will be a maximum of 5 km (about 3 miles). Most consumer models will be limited to 3 KM, but will be better built for outdoors and will be half cheaper. I believe they all work on Family Radio Service (FRS) band. I think it's the best you can have at this time.

I believe the maximum power for FRS is 500 MiliWatts

If you want a range of 12 miles, you need a GMRS two-way radio, and it requires an FCC license. I think they are up to 2 watts of power

I bought a Motorola Talkabout (FRS band) last year, for my bike touring habbit. Range is decreased when building and trees are in the way. Mine has a maximum range of 5 km, but it drops to 1/2 KM in heavy folliage. Wou will get the maximum range only in line of sight conditions. Humid weather wont affect the range.

[skibum]

We've used the Motorola T6320 for years on the ski slopes. They are rated at about 2 miles which probably cuts down to a mile if the signal is going over a mountain. They're very durable and some of the models have weather radio & other unnecessary but nifty features.

There is also the T7400AA GMRS which is supposed to have a 7 mile range. You'd probably want to cut that range in half. If you're hiking, climbing, biking or skiing cliffs, they come in really handy for helping each other up/down intense terrain.

[Macguru]

Oops! I just learned that GMRS dont need any special licence in Canada. I think it was so last year when I shopped for it. You better check local regulations.

[trillianjedi]

GMRS can still be reduced to 1/2 km range by obsticles. It's not all about power. Radio waves at certain frequencies generally need line of site - there's only so much matter you can brute force your way through with power.

The attenuation provided by solid rock or foliage is massive - and at these frequencies, radio signals don't bounce off the ionosphere, so they simply don't make it through.

The last thing I want is to depend on a set of radios that turns out to be useless

The last thing you want to do is rely on two-way radio full stop. You absolutely must have mobile phones as backups - two way radio is great when you're at close range.

Expecting anything more than 1/4 - 1/2 km even out of GMRS is asking too much. Sure, you'll have times when both parties are on mountain tops and they'll work upwards of 100 miles apart and sound like you're yards away, but in the conditions you're looking at, line of sight conditions will rarely exist.

Having said that, the extra power GMRS gives you is worth having, but only if it's controllable - look for radios which have a low power option (50 or 100mW) - otherwise you'll cane the batteries in no time.

TJ

[MatthewHSE]

Thanks for the info, guys. At this point it looks like the radios will be a no-go. Even if a GMRS unit would work for us, I don't have the money to buy the radios and the license. And I don't think a 3-mile max range set will do us much good at all, given that many trails are much longer than that.

I guess mobile phones would be the way to go - but I can't afford those, either. So I guess it will be only group activities this time! ;) (Not so bad, after all, since we all like one another.)

[trillianjedi]

Mathew - I would suggest you buy a cheap pair of FRS for experimentation during your trip.

They're very cheap, and it would at least let you know whether two way radio is something that will work for you or not.

TJ