Is there a limit on the number of radio receivers...

Post by **matthew1** » 24 Mar 2023, 17:49

Is there a limit on the number of radio receivers for any given broadcast, say, an FM radio broadcast?

Say it's 104.3 The Fan (Sports) here in Denver. Is there a situation where you can reach a number of receivers, and there is no signal left?

Does this question even make sense?

Post by **volvolugnut** » 25 Mar 2023, 08:49

I will take a shot at an answer. One of our physicists could better answer.

Radio receivers do not diminish the radio signal. They only read the signal and and amplify it using the receiver power. There is not limit to the number of radios receiving the transmitter signal.

The transmitted signal is limited by it's power and the distance from the transmitter not the number of radio receivers.

volvolugnut

Post by **matthew1** » 25 Mar 2023, 12:18

Thanks for your thoughts, VLN.

Another way to think of my question is to ask "Is there a way to absorb all the signal, if you've got enough receivers?"

Post by **BlackBart** » 25 Mar 2023, 14:50

I don’t think so - it’s an electromagnetic wave, correct?

dikidera · Post by **dikidera** » 25 Mar 2023, 19:09

Well intuitively, the answer would be yes? It's not my area of expertise, but when you think about it, we are interacting with the wave. Wave is energy and every time it hits an obstacle it definitely must impart some energy to it.

But probably insignificant effect for us for any practical thing.

Post by **abscate** » 01 Apr 2023, 01:59

You must extract energy from the wave in order to amplify it, so in theory you could drain the broadcast if something really popular like Volvo car talk is on in Ithaca. I recall from EE that typically AM radios start ftom about a picowatt or less, that’s 10E-12 watts. If everyone on earth had 10 radios tuned in, that would 10E11 extractions totaling 0.1 watt or less, while the station is pumping out about 50E3 watts or so. From that swag it looks pretty hard to drain the station power.