3 ms·
> Shortwave radio (1.5MHz-30MHz) reflects off the ionosphere and can be received intercontinentally. This includes a couple of ISM bands in which unlicensed o
by teraflop 9y ago
> Shortwave radio (1.5MHz-30MHz) reflects off the ionosphere and can be received intercontinentally. This includes a couple of ISM bands in which unlicensed operation is permitted internationally: 13553–13567 kHz (22 meters) and 26957–27283 kHz (11 meters) [...] QRPers consider anything below 1 watt as "extremely low power", or QRPp, and they consider a thousand miles per watt as a difficult benchmark to meet.
Unfortunately, the maximum legally allowed transmitter power is on the order of milliwatts for the 22m ISM band, and tens of microwatts for the 11m band. (At least in the US; see 47 CFR § 15.225, 15.227)
- skykooler 9y agoGiven the range of these signals, does the US government have a say if you were to transmit at 1 watt from, say, South America?
- vvanders 9y agoThat's usually the role of the ITU[1]. [1] https://en.wikipedia.org/wiki/International_Telecommunication_Union https://en.wikipedia.org/wiki/International_Telecommunicatio...