Like a police officer’s handheld radio is able to transmit to another unit let’s say 10 miles away, and he’s able to do that with ease. How is this possible? How come handheld radios that we have access to can’t do that? I know this probably sounds dumb to most of ya’ll but
In: 108
The FCC reserves several frequency bands for various government agencies.
In radio, there is generally a tradeoff between higher and lower frequencies.
Higher frequencies are good at going through stuff (walls, roofs, trees, etc). Lower frequencies tend to bounce off of things.
It gets particularly interesting because even high frequencies (at least the ones we use in radio) aren’t good at going through really huge things (like the earth). Low frequencies are so good at bouncing off stuff that they can bounce off the ionsphere.
Practically that means that high frequencies tend to get you a very clear signal with limited range at high power usage. Lower frequencies get you a noisy signal but over huge ranges at low power usage(people have bounced radio calls to the other side of the earth).
Police typically operate at short ranges so they use the higher frequencies. The power usage only matters when you’re transmitting so they’ll send those to “repeaters”. Those are basically radios that listen on one frequency and forward the signal to an other frequency that they pump a lot of power into. You can repeat that process to increase the range or even have segments that go over wires. That’s how you can listen in on police scanners in other cities over the interent.
Latest Answers