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
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>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.
The infrastructure will vary by the department and the geography they operate in, but the simple answer is: They use a device called a repeater to retransmit their signal to dispatch. For urban environments, the repeater is located in their car and is only moderately more powerful than their handheld radios. Here is one example:
[https://www.motorolasolutions.com/en_us/products/two-way-radios/project-25-radios/mobile-radios/dvr-lx.html](https://www.motorolasolutions.com/en_us/products/two-way-radios/project-25-radios/mobile-radios/dvr-lx.html)
Rural policing will have fixed repeaters located throughout the region at strategic locations – often atop towers, mountains, or high hills.
> 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
We can and do! HAM radio operators have repeaters located across the world that you can connect to and reach a wider region. For example, a repeater on a nearby mountain in Vancouver can reach Seattle WA with some regularity. The combination of power (25Watts) height, and antenna allow it to transmit further than a handheld radio at 5 Watts.
Most handheld consumer radios operate at 0.5-1 Watt. Handheld Motorolas operate around 5 watts of power. Vehicle radios can go up to 100 watts of power. Going higher usually requires an FCC license. Most of the bands operated on police freqs are completely different than handheld radios with less noise and interference. Some police bands require more or less wattage send/receive signals.
Moor Powar and a combination of repeater. Car radios can use 25 watts compared to 4 watts for non-police. Also the car can often act as a repeater for their lower power handheld.
Also ground repeaters which can be hundreds of watts or even 1,000+ sometimes.
*Note #1: Common power numbers. Not strictly.*
My local police dept dispatches for 7 towns in the area. They have a network of 8 radio repeaters on towers, which covers the area well, even in places with no cell phone service. The towers are all high in the air on top of the mountains. You only need to be within line of sight of 1 to get through at which point the signal is blasted out of all of the transmitters on the network all at once.
All of the radios transmit on a different frequency than they receive on so the repeaters don’t interfere with the transmissions.
Checkout radioreference.com for more info. You can search your area for all the frequencies / licenses in use in your area.
As others have mentioned police have licenses for the frequencies they operate on, and are able to use more powerful transmitters than your standard UHF radio. They also use VHF frequencies here as the longer wavelength travels further, though not as well through buildings.
Aircraft radios can reach over a hundred miles depending on altitude, it’s all about line of sight and what’s in-between (clouds mountains buildings etc)
I don’t know if cops use this, but plenty of security forces use PTT (Push-To-Talk) cellphones. Basically, this is a cellphone with special capabilities, hooked up to a special plan. They use regular cell towers and satellites, but they can set several different communication groups, and can choose to talk to any of those groups that they’re a part of.
Moment-by-moment, they’re operated much the same as a radio; you push a button that activates your mic and transmitter, and when you let go of the button, your mic shuts off. Basically they’re radios using cell signal.
I’ve never used this system, but I’ve bought a few ruggedized phones for construction use, and ruggedized phones often have PTT capability, so I looked into it. Seems really useful in some situations.
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