Transmit as far as "EIGHT Miles". Does anyone know what type of power this would take? I imagine if they used a less noisy frequency combined with sensitive receiving equipment, it would not take much. I used to play with CB radios which has a cap at 4W, with a good antenna, one could transmit 7+ miles in good situations.
There's at least two things that limit the range of this system, compared to the CB radio you mention:
- less power available via USB
- less impressive antenna
It's a pretty much meaningless number without also talking about the antenna used both at the transmit and receive end. Carefully aimed high gain antennas can easily get that sort of range with power in the tens of milliwatt range. I've seen 100mW hobby-grade FPV gear doing 5+km with an omni directional antenna on the transmitter and only a high gain directional antenna at the receive end. With sophisticated enough gear at the recieve end, and an intentionally-aimed high-gain antenna at the transmitter, I'd bet getting 8 miles on single-digit mW of transmit power would be do-able.
(Note that 4Watts of 27Meg CB radio is well known for getting ionospheric "skip" and connecting over literally thousands of miles given the right conditions.)
I suppose it's possible, but if I were the NSA I wouldn't bet on getting a signal past the neighborhood distribution transformer. There's often enough disturbance on a building-wide circuit to cause problems with powerline networking. Your 42" LCD TV probably has enough power-conditioning circuitry to interfere with network signals.
If you have one of those briefcase-sized boosters, 8 miles could be pretty reliable.
If you have a huge antenna, a fraction of a watt in the shortwave band will easily get you across the country.
But presuming not shortwave and no particularly special antenna, a watt or two might do it.
For reference, cellphone radio signals are on the order of a watt or two, and they have no trouble reaching cell towers a mile or two away; maybe more.
This comes from my ham radio background and some of my individual experimenting.
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