Crystal radio kit, need some help figuring out how it works

[Ed in Tx]

Originally Posted by old_tv_nut

Did anyone mention that you need a long wire antenna, like on the order of 30-50 feet?

I used to use the aluminum window frame in my bedroom for an antenna. Worked great! Growing up in a house within a few miles of AM transmitters at 1080, 1310 ans 1480 kHz I could pick up all 3 stations mixed together at the same time. Simple crystal sets are not very selective.

[old_tv_nut]

There have been reports of houses within a mile or two of 50 kW stations producing program sound in the heating ducts - not sure how loud or even how factual this was, but it's a neat urban legend, at least.

[old_coot88]

Check out this guy's crystal DXing setup..

https://www.youtube.com/watch?v=Bw4IiTR3Tqw

[Electronic M]

If you are a reasonable distance from a high power station you can take the rectified audio from one crystal set and use it to power a transistor on a regenerative reciever (and or an RF amp stage or AF amp stage) and get increased sensitivity, selectivity and audio output power in the second tuner.

I've heard of successful FM crystal radios using slope detection of the FM signal too (probably very rare beasts I'd imagine).

[Jeffhs]

Originally Posted by old_tv_nut

There have been reports of houses within a mile or two of 50 kW stations producing program sound in the heating ducts - not sure how loud or even how factual this was, but it's a neat urban legend, at least.

It's not just urban legend. I have read of people within a short distance of powerful AM radio stations receiving the signals on, believe it or not, the burner coils of electric stoves. I guess if the signal is strong enough, just about anything can receive it and be heard. There have even been reports of people receiving very strong AM radio signals on tooth fillings or braces, again if the signal is strong enough (50kW), and if the person is close enough (within perhaps 500 feet or so) to the station's tower(s).

In the early 1970s, I lived just about a third of a mile from a local FM station. I could see the transmitter tower from my bedroom window (I lived on the top floor of a three-story house at the time), and the signal came in like gangbusters. I was hearing the signal between stations on all my FM radios, as well as on channel 6 of an old color TV I owned and even, to my dumbfounded surprise, on the 10-meter amateur band on an old Hallicrafters amateur communications receiver in my Novice class amateur radio station at the time. The station's signal was so strong (and I was only within almost literally a stone's throw from the tower) that it was overloading (!) the receiver's front end.

There is a 1000-watt AM station near my apartment where I live today which, thankfully, doesn't cause me any trouble from strong signals (I am perhaps one or two miles from the station's tower), but I can imagine folks living a lot closer to that station's towers being able to hear it between stations and even, like my experience with the FM station where I formerly lived, hearing it on stove burners and even, if the person lived extremely close (within a few hundred feet or less(!)) to the towers, on bedsprings.

BTW, I no longer live anywhere near that radio station which was taking over my FM radios in the 1970s (thank goodness!); in fact, several years ago (in the 1980s, IIRC) the radio station itself was moved to another town a few miles away, and I now personally live in a very small town some 20 miles from the city to which that station is licensed.

However, you can be sure I will never forget the experiences I had when I lived literally in the shadow (!) of that station's tower. One of the other places in the Cleveland area where this kind of thing can happen is the city of Parma, Ohio, west of Cleveland, where many if not most of Cleveland's AM and FM radio stations' towers are located. Most of the AM stations are 50kW flamethrowers, with the FM stations having ERPs in the tens of thousands (!) of watts. Again, I am very glad I never lived in that area, and left the city many years ago where that 27.5-kW FM station was giving me more grief than I wanted in the first place; however, I had no choice in the matter when I lived there, as I was 16 years old and was living in that area (Cleveland Heights, Ohio) very much against my will (very, very long story, OT, and something I wish I could forget, but I know darn well I never will).

[vortalexfan]

Originally Posted by Jeffhs

It's not just urban legend. I have read of people within a short distance of powerful AM radio stations receiving the signals on, believe it or not, the burner coils of electric stoves. I guess if the signal is strong enough, just about anything can receive it and be heard. There have even been reports of people receiving very strong AM radio signals on tooth fillings or braces, again if the signal is strong enough (50kW), and if the person is close enough (within perhaps 500 feet or so) to the station's tower(s).

In the early 1970s, I lived just about a third of a mile from a local FM station. I could see the transmitter tower from my bedroom window (I lived on the top floor of a three-story house at the time), and the signal came in like gangbusters. I was hearing the signal between stations on all my FM radios, as well as on channel 6 of an old color TV I owned and even, to my dumbfounded surprise, on the 10-meter amateur band on an old Hallicrafters amateur communications receiver in my Novice class amateur radio station at the time. The station's signal was so strong (and I was only within almost literally a stone's throw from the tower) that it was overloading (!) the receiver's front end.

There is a 1000-watt AM station near my apartment where I live today which, thankfully, doesn't cause me any trouble from strong signals (I am perhaps one or two miles from the station's tower), but I can imagine folks living a lot closer to that station's towers being able to hear it between stations and even, like my experience with the FM station where I formerly lived, hearing it on stove burners and even, if the person lived extremely close (within a few hundred feet or less(!)) to the towers, on bedsprings.

BTW, I no longer live anywhere near that radio station which was taking over my FM radios in the 1970s (thank goodness!); in fact, several years ago (in the 1980s, IIRC) the radio station itself was moved to another town a few miles away, and I now personally live in a very small town some 20 miles from the city to which that station is licensed.

However, you can be sure I will never forget the experiences I had when I lived literally in the shadow (!) of that station's tower. One of the other places in the Cleveland area where this kind of thing can happen is the city of Parma, Ohio, west of Cleveland, where many if not most of Cleveland's AM and FM radio stations' towers are located. Most of the AM stations are 50kW flamethrowers, with the FM stations having ERPs in the tens of thousands (!) of watts. Again, I am very glad I never lived in that area, and left the city many years ago where that 27.5-kW FM station was giving me more grief than I wanted in the first place; however, I had no choice in the matter when I lived there, as I was 16 years old and was living in that area (Cleveland Heights, Ohio) very much against my will (very, very long story, OT, and something I wish I could forget, but I know darn well I never will).

There's a couple of FM Stations near me that are 50kW Flamethrower Stations that also have many repeaters stations across Indiana, Michiagan and Ohio (going down as far as the Kokomo area of central Indiana most of Southwestern Michigan, the Richmond area of east central Indiana, Southeastern Michigan, and Northwestern Ohio and they are both Contemporary Christian Music stations that also play a lot of Bible Teaching programs throughout the day) which the stations I'm referring to is WFRN that is based out of Elkhart, Indiana (just down the road from where I live) and WBCL out of Fort Wayne, Indiana, and both stations of which have been around since 1970s (the early days of the Jesus Movement in America, which is where the concept of Contemporary Christian Music came from originally.)

And WFRN the first station I mentioned does the same thing that you mentioned that the station you lived near did to you, and that's because the frequency that their station broadcasts at is 104.7 is a "multiple" of the FM IF Frequency of 10.7 MHz so then basically their station comes in on pretty much every spot that is a "multiple" of the FM IF Frequency on a poorly aligned or poorly designed FM Radio.

[dtvmcdonald]

I used to live across the street from a 5 kW am station. I was about 100 yards from the closest guy wire tiedown. I hooked up a good ground, a wire draped across the street connected to the guy wire as high as I could reach, a tuned circuit, a galena
(PbS)/tungsten-tip diode, and an output transformer. I got excellent volume on
my low efficiency stereo speakers.

It didn't work without a tuned circuit because I was 1/2 mile from
a different 2 kW station. That one produced loud signals on headphones,
but not a speaker.

[Titan1a]

Just go looking on the web for crystal set schematics. They all orient the same way.