I apologize for my poor wording, though I fail to see what I was mistaken about in my reference.
It is utterly impossible to have massive broadcasting equipment. The maximum balloon height ever was 140,000 feet, and that was an extraordinary feat.
You know that density I calculated (.03 grams/Liter). Refute that while I explain how big this baloon of yours would have to be.
Broadcasting equipment with range of >30 miles straight down, plus a minimum 100 mile radius on the ground. That's not light, at least 50 kg. Propellers to keep it stationary and solar panels to power it are at a bare minimum (and this is very, very generous), 10 kg, not that it matters.
That's 60 kg. To keep that amount up, you need a size of 2,000 cubic meters. Assuming a perfect sphere, that's 7 meters in radius, or 14 meters in diameter.
But, that's not all. You also need the balloon. Nylon isn't heavy, but you need a lot of it. Say, 1 mm thickness. I know that most balloons aren't that thick, but most baloons don't stay up for decades at a time. The density of nylon is 1150 kg/cubic m
.03 = (60 kg+ 1150*.001*4*Pi*r^2)/(4/3 Pi r^3)
The solution is that the radius is almost 12 meters. Therefore, the balloon is At MINIMUM 20 meters across. That is supported by A METRIC TON of nylon. Even if there is no additional load, you need 11.5 meters of radius for the balloon to keep itself airborne. Did I forget to mention that I'm not counting the weight of the 1500 of cubic meters of helium in the baloon? Now, tell me how dozens or hundreds of 60 foot wide balls aren't showing up in everyone's telescopes and binoculars. Heck, you might even be able to see those with the naked eye. They should be observable everywhere, but they aren't.
Need I go on about how ludicrous your balloon concept is?