Kraus's radio astronomy textbook has or used to have a chapter on this topic. Its all a matter of distance. I never had a problem detecting legacy NTSC analog

Kraus's radio astronomy textbook has or used to have a chapter on this topic. Its all a matter of distance. I never had a problem detecting legacy NTSC analog TV from the east or west against the backdrop of the sun out to dozens of miles. The same equations that apply to Jupiter's decametric radiation would apply to our own analog TV broadcasts. The numbers IIRC are not terribly impressive, if you knew exactly the modulation scheme and frequencies and power levels in advance and devoted a long term monitoring program to sampling excellent data using a better antenna than our civilization could realistically build, then it would be quite realistic to detect old fashioned NTSC TV out to a couple dozen light years at least. The problem is technology marches on fast, and the idea of pumping out megawatt class narrow band signals for mass media seems very temporary indeed, we're done with that as a civilization and that era barely lasted a couple decades. Its not a "radio cone" its a "radio donut". The engineering required to detect my wifi signals from earth orbit would be insane; the aliens will never detect my youtube viewing. Toward the end of the analog era, I had cable TV which theoretically wasn't radiating any signals at all out into space. It would be like trying to detect and track and do intel on the 2023 Russian navy by detecting spruce trees from orbit, because in the old days sailing ship spars required straight long spruce trees to build, so in 1700 whomever controlled the spruce forests controlled the seas. Looking at spruce forests from space is just not conceptually a useful way to even consider doing intel about a modern naval missile cruiser or a nuke sub. Or another example, no matter how hard you scan for mammoth herds and mammoth fur from space, you won't figure out much about our petrochemical spandex based yoga pants clothing industry in 2023. You can't just use a bigger telescope, its conceptually not going to work. Now if you had spies or observes or space probes detecting and relaying the story back home, maybe back home they could build something?