Radio Transmission Basics.....

New to the forum and looking forward to learning from the knowledge on this forum....

My first quest is to understand the rating of Radio Transmitters, I work with radio units that transmit upto 2.5 Watts. They are simply black boxes to me and although I understand what they do in my day to day job of sending commands and indications to automated High Voltage Circuit Breakers spread across a 10 mile radius. it confuses me is that how does 2.5 Watts of power send a signal to another radio reciever upto 10 miles away, when 2.5 Watts in a filament lamp would barely glow. Then thinking about TV/RADIO Broadcasting the main Antenna near to me uses 1000 KW.

If anyone could in lamens terms, explain to me how a radio signal transmission can have a power rating and where is that power/energy used I would be very grateful.

I hope my rambling makes a little sense

Try this as a start

https://en.wikipedia.org/wiki/Radio

The key is the relationship between S/N (signal/noise) ratio and the maximum data bandwidth.
Search for Shannons theorem.
The transmissions you do with the 2.5W transmitter has extremely low bandwidth, maybe only a few Hz, so the S/N ratio at the receiver can be very low, so less tx power is needed.
A TV signal requires much more bandwidth, about 5 MHz for analog modulation, so the tx power for the same distance must be much higher.