I built up this FM microphone from belza.cz. The circuit is super simple, uses only a single transistor. The output of the electret condenser microphone is coupled directly to the base of the RF oscillator, and causes the frequency modulation. However since the microphone has no amplification, it is not sensitive and the user must
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This remote control jammer circuit is basically the same circuit as a LED flasher, except that the timing capacitor is much smaller – .001 uF – so it flashes at a much higher frequency, around 38,000 times a second. The 9V battery is expensive; instead save money. Change the two IR LEDs from series to
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This photo was posted to the files section of the Yahoo group lost_technology. I’m including it here so others don’t have to sign up or log on to see the photo. Since this was from a group for antique stuff, we will assume that this radio circuit is very old and uses Germanium transistors. The
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Last month I put an antenna strap mount on my chimney and put a 6 foot piece of 1 inch galvanized pipe in it. Then I went shopping for an all channel TV antenna. I had a UHF antenna, but I figured that I should install a decent VHF/UHF antenna. I went to Radio Shack
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Whilte I was writing my blog about Homemade Components, I visited the Wikipedia page about the cat’s whisker detector, the active component in the crystal radio. I read the intro paragraph “A cat’s whisker detector (sometimes called a crystal detector) is an antique electronic component consisting of a thin wire that lightly touches a crystal
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Cyrodyl posted a schematic file named FET Dip Meter.PNG (you may have to be logged on and joined to the group to view this), and this is my comment about it. I posted this comment file to the Yahoo group RegenRX2, which is the overflow from the RegenRX group, which deals with regenerative receivers. Comments
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I wanted to listen to the morning news while I was preparing for work or whatever in the morning, but I didn’t need the full TV set in the bathroom. All I wanted was to hear the audio so I could catch the weather and a few newsworthy items. So I built a FM transmitter
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I came across this AM broadcast band transmitter project from a guy in Greece. It uses a single transistor to do everything, and a carbon microphone for audio modulation. There are some major drawbacks here. in Diag.4, the schematic shows the audio jack is connected directly across the R2, which has a few volts across
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Well, it’s Friday the 13th. We just had a Friday the 13th just 13 weeks ago, and we will have another one in 13 weeks. Wow! That’s almost spooky! Friday really was Friday the 13th for me and my co-workers. We had several network problems, one which required me to run from one building to
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The 1000 character limit of the Yahoo “regenrx” Group comments makes it necessary for my comment to go here. Also, I’d like to post the schematic here since they tend to drift away, never to be seen again. My major complaint about this receiver is that it uses a FET on the antenna input. FETs
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