So this morning I woke up to watch the local news, like I do a lot of mornings, mainly to catch up on the weather but also because I really am old fashioned in a lot of ways. There's something about getting the weather on TV that's more fun than Google. But I digress.

When I turned on my television to go to the station I usually get my news from, I wasn't getting a signal. So I switched to a second local station. Once again, no signal. This happens from time to time, where the TV and the Antenna fall out of sync somehow, and all I have to do is a channel search and the channels are "re-discovered." So that's what I did. Except something weird happened.

About two thirds of my local channels all disappeared. I could not get them to come up with auto search and I could not get them to come up when I typed the channels in manually. Know what I did get though? Television channels from a couple of cities that are about 50-100 miles away. Literally as clear as if they were local stations. My antenna has a range of 50 miles, so I didn't even know those channels existed. Somehow though, somehow, my TV could not pick up local channels but could pick up channels that were literally out of broadcast range.

Dala and I went out for the day, it's literally been over eight hours later, and I turned on the TV and restarted a channel search, and everything is now back to normal. Dala looked something up on some space weather website and said there was a solar storm last night and this morning (she says it may still even be ongoing).

I've literally never had this happen before. If I was reading this from someone else on here, I wouldn't believe them. But it happened and now I'm curious as heck and I want to know how.

Any ideas?


kleinbl00:

https://en.wikipedia.org/wiki/Tropospheric_propagation

Li'l story. Wireless microphones, of the kind used in television production, use the same radio frequencies as VHF television broadcasts. Because transmitters interfere, these frequencies are allocated by the FCC to not overlap - this is why Albuquerque has channels 4, 5 and 7 while Denver has 3 and 6. So if you work in television production, you get good at learning what frequencies are likely to work, how to determine what frequencies work and what you need to do in order to get Miss Hotness on lav without being crushed by Geraldo Rivera.

We've got a lot of cast on a lot of mics in a highly intense radio environment and we pay experts several hundred dollars an hour to make sure everything works all the time. They come out, hem and haw for several days every season, and then we go for thousands of hours in a row without any problem.

Except for Bob.

About four years back, round about midnight-1am, Bob would start snatting and hissing and being otherwise unusable for no particular reason. We'd swap him to the spare mic, which was on a different frequency, and leave him there until morning. By morning, Bob's mic was fine again.

"What about Bob" became the game we all played at night. We had a bitchin' frequency scanner, we had a dozen seasoned RF professionals, we had everything. But it wasn't until I looked up recent license grants that we had an answer.

As it turns out, Bob's mic was at a harmonic of a religious TV station that had just started broadcasting... 120 miles away. And while we were normally fine, when the weather was just so and the thermal inversion hit (at about midnight), all of a sudden the tropospheric propagation from Jesus Television would bounce off the troposphere and squash Bob's transmitter like a bug. Once I knew that, I pulled up the spectrum wide enough to see JesusTV and Bob and looked at 'em at 11 and looked at 'em at 1. Sho'nuff, JesusTV clobbered the shit out of Bob.

We swapped frequencies between Bob and the spare such that Bob was on the spare frequency and the spare was using Bob's. It meant we didn't really have a spare after midnight when the weather was wrong... but then we re-freq'd everything the next season and it all worked out.

But yeah. High frequency RF is fuckn' voodoo.


posted by user-inactivated: 195 days ago