That thing was highly annoying. Maybe 2-3 pecks per second. ISTR that by 1980 it was common knowledge among radio types that the signal was for over-the-horizon radar.

For you non-radio folks, the frequency range given in the article (HF 3-30 MHz) has the useful property of being refracted by the ionosphere back to earth over long (beyond the 40-mile horizon) distances. Higher frequencies refract less. Sunlight and other less regular radiation from the sun influences the amount of refraction, so the optimum frequency for a given distance varies (thus the woodpecker tended to wander across the dial).

Great photos of the antennas.

Every time I visit this link from my phone I get pop-up virus scams that make it totally unreadable (I have to close the browser tabs to do anything). I find it happens on other sites too, but usually they're clickbait sites I don't really care about. It's the something I can do about this from my phone, or does the website just allow shitty scam advertisers?

Shitty scam advertisers most likely. I run into that a lot on my phone.

Ok thanks. The same websites are fine from my computer so I wasn't sure.

Same here. Are you running an ad blocker on your computer too?

No. I've been thinking about it though.