Hunting down sources of intermod on the AM MW BC band

[Jeffhs]

That can happen if you are near any 50kW AM radio station, even these days. Here in northeastern Ohio, the transmitters and towers for all AM, FM and TV stations serving Cleveland are located in the southwestern Cleveland suburb of Parma, Ohio. I'm sure some if not most folks living in the shadow of the 50kW AM towers located in that city have the same problem now that cbenham's dad had in Cincy in the 1930s. The signal from a 50kW AM radio tower (let alone two or more) at a mile or two or less is tremendous, and can wreak all sorts of havoc. My grandmother had a cottage that was located about five miles from the transmitter towers of a 50kW AM station. That station came in very well on 1220 kHz, its fundamental frequency, and also could be heard anywhere from about 600 to 640 kHz at the low end of the dial as well. In the 1970s, I lived in a Cleveland suburb that had a local FM station on 92.3 MHz, 27.5kW ERP. I lived on the next street over from where the tower and studios were located (I could see the tower's red lights from my bedroom window after sundown), and the station literally boomed in -- on my stereo FM radio, at 92.3 and also between other local stations, on channel 6 of my Silvertone roundie color TV (yup, that's how strong the signal was), and even on my dad's Ampex "Micro 88" solid-state stereo cassette tape deck.

I now live in a very small town about five miles from a 1kW AM station. The signal from that station doesn't bother anything in my apartment (I have an electric stove here; however, the station doesn't come in over the burner coils!), but it does come in at two spots (1460kHz, the fundamental, and 560kHz) on the AM/FM digital tuner in my Aiwa bookshelf stereo. I chalk that up to just plain poor design of the AM tuner's front end. I had a Zenith stereo that would pick up short wave (no kidding) on the AM broadcast band after dark; I chalked that up to poor front-end design as well. In fact, the AM tuner in the Zenith stereo wasn't all that great at receiving local stations in the daytime either, and I lived in a suburb at the time that always has very good reception of all Cleveland stations on AM and FM. To this day I'm convinced that the AM tuner in my Zenith integrated stereo system was not much better than a crystal set.