These have 22 channels. The first 14 are the usual FRS channels, the extra 8 are GMRS channels. You are supposed to register with the FCC and get a license to use the GMRS channels. In addition the first 7 channels when used in power boost mode are actually GMRS channels and require the GCC registration.
As an odd bonus, you can tune these into the NWS weather radio. The claim is 11 weather channels, of which 7 are NOAA. This is 162.4 (WXL30) in Tucson -- channel 2 on the T461, doesn't work for beans indoors, but is loud and clear outside.
All kinds of exuberant claims are made about range (up to 35 miles). This would have to be in an isolated area doing line of sight from a mountain top. More typical would be on the order of 1 mile in urban situations, and up to 3 miles on trails, but we will see.
The power boost is simple. There are two places to push to talk. Push up high on the button and you get 1.5 watts (and risk the wrath of the FCC if you have not registered). Push down low and you get 0.5 watts and potentially extend your battery life.
The battery is an interesting business. The radios are supplied with a NiMH battery, that is clearly three cells with a plastic case wrapped around them. This battery can only be charged in the radio using the USB cable (5 volt 500mA) and it takes 14 hours to charge. The truly weird thing is the battery is labelled as a mere 800 maH.
You can use AA alkaline batteries (so the radio will tolerate 4.5 volts). The fact that it usually runs from 3.6 volts (three NiMH in series) is just begging for some kind of conversion to use a 3.7 volt Li-ion battery, but the path of least resistance is to use three NiMH AA cells.
I put three AA eneloop batteries in my unit (rated at 2000 maH) and it certainly works just fine (and I can charge these outside of the unit much more easily!) The question is whether the radio will run 20/8 = 2.5 times longer!! It certainly should if you believe the ratings marked on the batteries, and apparently it can, so this is the way to go.
They say you will get 10 hours out of the NiMH pack and up to 26 hours out of a set of Alkaline batteries, which is pretty much in line with the 2.5 times factor. Only some experimenting will tell as they don't say a thing about using NiMH AA batteries. The real question is why the NiMH pack they supply is so wimpy.
It looks to me like putting three AA eneloops in these radios is a big win. You get 3 times the life of the silly OEM 800 maH battery. The only thing is that you cannot charge the Eneloops in the radio. You have to take them out and put them into a NiMH charger (which is what I want to do anyway, so no big deal for me).
Tom's Electronics pages / tom@mmto.org