3 ms·
Horn antennas have radiation pattern tens of degrees wide, so it's difficult to target one room across the street. I'm not sure intersecting a few of them helps
by Jenda_ 5y ago
Horn antennas have radiation pattern tens of degrees wide, so it's difficult to target one room across the street. I'm not sure intersecting a few of them helps, maybe by a factor of two or so.
Back of the envelope math: per Wikipedia: "The gain of horn antennas ranges up to 25 dBi, with 10 - 20 dBi being typical." Let's say you are transmitting 4 kW with a 20 dBi horn, thus having 400 kW EIRP. At a distance of 15 meters, the energy spreads across a sphere of 4PI15^2 = 2800 m^2, for an energy density 140 W/m^2. So yes, this indeed exceeds health limits (in .cz: 50 W/m^2 for workers, 10 W/m^2 for civilians) and is kind a lot.
On the other hand, having a 400 kW EIRP source anywhere nearby should be immediately obvious to a NSA or probably anyone with almost any radio receiver, the interference would be terrible.
- bArray 5y ago> On the other hand, having a 400 kW EIRP source anywhere nearby should be immediately obvious to a NSA or probably anyone with almost any radio receiver, the interference would be terrible. This was exactly my thinking, somebody in the local area surely would have noticed this thing was turned on. You're not going to dump 400kW of energy without screwing with something. > So yes, this indeed exceeds health limits (in .cz: 50 W/m^2 for workers, 10 W/m^2 for civilians) and is kind a lot. Is that an enormous difference? It's three times health limits - but how long would you need to hold it there to get health problems? My guess is quite a while to fry your noodle?