Certification - I know it doesn't matter where I live, but it doesn't hurt when what somebody doesn't know doesn't hurt them....

The TWS/RWS-434 pair work in the 432Mhz band, On/Off keying (A.S.K.???). Still I don't think it matters. If you sell them as a commercial product, I think they have to be certified.

Now if you sell them as a hobby/experimental type deal, that's a different story.

Range on the TWS, I suppose I could get longer if I put more effort into the antenna efficiency at both ends. But like I said, the ranges stated above were with simple wire whip antennas, not even the stuff kind, just a chunk of wire hanging out in the wind.

JDG