What makes digital broadcast transmission (like over-the-air TV) need less power (as little as 25%) to cover the same area as the previous analog transmitter?
In: 1
I got a some questions. I’m NOT challenging or arguing, I know enough about RF to know I DON’T know much at all, but I’m genuinely curious:
Same 6mhz wide channel, optimize each transmitting antenna differently if it matters, but you gotta be covering the same area.
Can you really get away with only 25% as much transmitter power out requirement for ATSC 1.0 as would be needed for analog NTSC? To cover the same approximate area with a sufficiently useable signal? For ATSC let’s say one physical 6mhz channel and not “cheat” by dividing the power up per sub channel or “stream”. ATSC is certainly way better use of SPECTRUM…
“IT’S digital, ons and offs, blips” may be ELI5 but it seems woefully inaccurate here. That transmitter signal is doing a whole lot more than just existing and not existing rapidly. 8VSB diagrams look to be “just a bit” more than “blips”.
On the analog side, actual power needed can vary a lot based on the content. I mean I don’t understand it, I have heard it’s inverse; dark = high power, bright =low power. I do understand the concept of analog video being a single continuously varying signal, with a bunch of extra “sync stuff” so the TV can “steer” it. Then you gotta jam color and audio in there. And we are Presented in Stereo (where available) aren’t we?
OK so when theoretical TV station WXYZ threw the switch from analog to digital, did their transmitter power bill go down by 75%? None of that power factor stuff, they’re shooting out the consumption with capacitors and inductors and stuff.
Latest Answers