nmoore6676 said:
Unfortunately as an independent operator who didn't inherit alternate sits through acquisitions Mt. Wilson FM, which I believe was the first FM on the mountain, doesn't have the real estate for a fully redundant backup. I would say that if the STL dish was the problem that some kind of T-1 or IDSN backup might have been prudent but any of that is hindsight now. Anyway David Eduardo is right on and he knows whereof he speaks.
I don't think that being independent has too much to do with this situation; many stations up there have single sites.
The issue is that at the "side" of the crest KKGO is on it appears from first reports that there was more drifting and icing. I don't know if KKGO has multiple antennas mounted on one tower, but many of us have such a setup... if there is enough ice to kick antenna one off, there is enough to kick antenna two off in many cases.
For those that obviously do not understand, an antenna is a very precise mechanical device, and the weight or contraction or torsion of ice changes its ability to transmit on the tuned channel. In more severe cases, the antenna will start rejecting power, which goes back to the transmitter due to the mismatch... to much rejected power, called standing wave, and the transmitter automatically powers down over and over until, if really bad, it turns off.
Microwave antennas for radio are often "basketweave" metal tubing, not solid dishes like your DirecTV dish. Any ice on the actual antenna (not the basketweave reflector) and you have no STL. Ice can bring down power and phone lines, too. Add several of these together, and no matter if you have spent millions on the site, you will be off the air.
Interesting sidebar: Nautel, who make nice transmitters, originally started making beacons and maritime stuff. With the weather in Canada being what it is (like Mt. Wilson today but for 5 months of the year), there was a need for very reliable broadcast gear. This is where the modular transmitter came from... keep on the air, even if the engineer can't get there till next week, even if modules are out or there is high reflected power. Lots of stations have no redundancy... except for KFI, what AM in LA has back-up towers?