Ok, so couple of buddies hit me up with a question I couldn't address, so I'm turning here, even though this may not be the right forum:
Output stage of a radio (we were discussing avionics): AC power of 5 watts at 125-Mhz is pumped into a power line (the 50-ohm cable), that terminates in a loop (the antenna of appropriate length). As the electrons zip back & forth, the change in direction of the resultant magnetic field creates an electromagnetic wave that then propagates outward, for many miles (line of sight or bouncing around based on freq, but irrelevant to discussion).
Why doesn't common household AC transmit a similar wave for thousands of miles?
The frequency is lower, but the electrons are still being whipped around
The power is many orders of magnitude higher
The power lines are not tuned to the frequency, but surely there's lines out there that happen to match, and even a mismatch should propagate a hefty signal.
Yes, you do get 60 cycle hum in a radio off station, but hardly what you'd expect for the power output. Considering the output power, an appropriate receiving antenna a few miles away should still be putting out sparks!
I'm not confusing a loop of wire within the magnetic field of the power line picking up current-I'm referring to the distant transmission of a 60-hz radio signal.
What's missing?
Any thoughts?
Output stage of a radio (we were discussing avionics): AC power of 5 watts at 125-Mhz is pumped into a power line (the 50-ohm cable), that terminates in a loop (the antenna of appropriate length). As the electrons zip back & forth, the change in direction of the resultant magnetic field creates an electromagnetic wave that then propagates outward, for many miles (line of sight or bouncing around based on freq, but irrelevant to discussion).
Why doesn't common household AC transmit a similar wave for thousands of miles?
The frequency is lower, but the electrons are still being whipped around
The power is many orders of magnitude higher
The power lines are not tuned to the frequency, but surely there's lines out there that happen to match, and even a mismatch should propagate a hefty signal.
Yes, you do get 60 cycle hum in a radio off station, but hardly what you'd expect for the power output. Considering the output power, an appropriate receiving antenna a few miles away should still be putting out sparks!
I'm not confusing a loop of wire within the magnetic field of the power line picking up current-I'm referring to the distant transmission of a 60-hz radio signal.
What's missing?
Any thoughts?