The Chinese company Baofeng (and also others from China) offer incredible good handheld transceivers for a very low price ($ 30 to 40 each). These devices usually are 2-band radios for 2m and 70cm. The transmission power is 4 to 8 watts, which is enough to cover more than 20 miles in the open field. The devices are robust and splash-proof. I find that totally amazing, especially for the low price. Only disadvantage: operation of these devices is prohibited in most countries if the operator doesn't have a HAM license. BTW, this post isn't meant to be surreptitious advertising. Long live capitalism!
China is a totalitarian, inhumane one-party state. But they're top in foreign trade. Not everything they sell is good. But everything is cheap and that's a clear advantage for the customer.
Radio communication is hard in a city, especially when all participants are at the street level. What devices did you use (manufacturer, type, etc.)?
Theres some radios on ebay that all you have to do is remove one tiny resistor and they can transmit on police frequencies.
There are several police bands in the US: https://www.fcc.gov/public-safety/p...and-licensing-division/public-safety-spectrum This nice radio has some of them: https://www.amazon.com/ABBREE-136-520MHz-Multi-Functional-Amateur-Speaker/dp/B07XZ81SKB But I think the cops won't be amused if you call them directly on police radio instead of dialing 911.
They use repeater systems: https://en.wikipedia.org/wiki/Radio_repeater Radio amateurs also use repeaters to increase their range.
