Stephen Hunter -- if you don't know who that is, you probably don't like novels about guns -- will be on the repeat show today of Northern Alliance, 1280 AM, at 9 pm.

I caught just the tail end of the show yesterday. It's usually great stuff. Most of 1280's programming is good, especially Dennis Prager and Michael Medved. Northern Alliance is several local bloggers, including the guys who helped bring down Dan Rather.

The only problem is, the station only has about 1.5 watts of power, so you have to be pretty much next to the transmitter antenna and turn your radio just right to hear it, and even then, after dark, it fades out pretty badly.

Anyway, Hunter will be talking about his new book, about the attempted assassination of Truman in 1950. Fascinating stuff.

The reason it fades out after dark is due to an FCC rule about reducing power output so it doesn't interfere with other radio stations throughout the US. The reasoning behind it is because the upper layers of the atmosphere combine at night, actually making a transmission go farther. Many AM stations are required to do just that.

Yup, a radio announcer for a tiny AM station once explained about that to me over a beer back in the 1970s -- back when you still had to get some sort of FCC radio-operator's license to be an announcer. He said, and I have noticed, that you can pick up AM stations from very far away after dark. Supposedly they can get WCCO in South America or whatever.

But of course, that's only if you have the kind of huge antennas people used to use when AM radio was big. The AM antennas built in to the standard radio today apparently are just no good at picking up signals from any distance. So my evening listening is pretty well reduced.

Come to think of it, though, you can supposedly listen online. I never have.

Most AM antennae are copper wound ferrite bar antennae, built right into the receiver. All in all, they pretty much suck. At night, if I want to listen to AM, I usually have to be in my truck.

Yup, I used to work for the campus radio station, and learned a lot from a grumpy engineer.

There are a (very) few "clear channel" AM stations allowed to broadcast at full power at night -- and they have nearly nationwide coverage at night. `CCO is, I think, one of those.

When I was a kid in California, I used to DX AM radio stations at night just to see what I could pick up. Of course, XERB out of Tijuana, broadcasting at several gazillion watts, would come in like gangbusters.

A small, low-powered FM station with a good antenna location can broadcast quite a distance. Back in the early 70s, I volunteered for KTAO radio, a 250 watt station with "studios" in Los Gatos, California--Silicon Valley. Our transmitter was on Mount Umunhum (sp?) and we could be heard quite well over a fairly large area. That meant I could annoy people in several counties with Balinese Monkey Chants.

"Border Radio" is a recently published book about high-powered stations just across the Mexican border that used to pump out a widely heard bunch of programming. Lot of country music and Bible thumping, plus life-enhancing elixirs. You might look into it and do us a book report.

Sorry, guess we're drifting away from guns here.

Not really...up until last summer I had a SONY radio that had an extremly bad antenna....thus I shot it with a pre 64 Winchester in 308, with a five shot group somewhare in 1 MOA.....................radio doesn't work any more, but the rifle still shoots sub-MOA...........

There, now we are back on track...............

You can listen to their intenetcast if you have broadband. Click on the "Listen live" button at
http://www.am1280thepatriot.com/

Even some of the big guys have to change pattern and/or power after sunset. I used to work for KXEL, a 50kw, station in Waterloo, IA. Their pattern was omnidirectional during the day, but a north cardioid pattern after dark to protect a small station down in AR or TX. You can hear KXEL at night all the way north of Red Lake, Ontario, but you probably can't pick it up in the daytime north of the Twin Cities.