Last week I saw an old Heathkit IP-18 power supply on eBay for $50 OBO, free shipping. I don’t really need another PS, but I’m a Heathkit builder and a big fan. So I offered $30, thinking the seller would not take it. But a few hours later the message came that the seller had
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Its not hard to make a signal tracer from an old AM radio. You need 60 mm of red and black flexible twisted pair, a 0.22 uF, 100V capacitor, a small black alligator clip, a 50 mm length of shrink tubing that will fit over the following probe, and a thin 100 mm long piece
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I got this frequency counter and crystal tester mainly for the frequency counter. Today I decided to test a few crystals, and was successful with ones above 10 MHz but not at 4 MHz. The two capacitors labeled C2 and C3 are the feedback to the crystal, and they were originally 22 pF. So I
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Here is a writeup from another radio enthusiast about his newly purchased Mega 328 uC based component tester. They come in handy for testing electrolytic capacitors especially for ESR – equivalent series resistance. The tester will also test silicon and germanium transistors, handy for making a judgment on how leaky it is. I have a
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This is from Electronics Illustrated Projects 1968. It shows crystal sockets, but instead a RF coil may be used and its value will be about 220 microhenrys. And C1 and C2 will have to be changed to bring the frequency down to the AM band. The germanium transistors are no longer available so silicon transistors
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From fb group Decades ago I bought a 100W, 28V big old soldering iron for a dollar at a garage sale. I have it connected to a big old unregulated power supply. It works good for the very seldom times I need that much heat. I could do stained glass windows with that beast!
From FB group Building Transistor Radios, Aug 6 This also happens with the meter movements of old analog meters. The iron particles get into the magnet assembly and stop the coil from moving. The only way I’ve found that gets rid of the iron particles is to very gently put a thin piece of steel
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Also photo posted to FB group Building Transistor Radios. I got several of these Wien Bridge Oscillator kits from an eBay seller in China. They are built using the circuit from http://redcircuits.com/Page13.htm More information can be found on the wiki for this oscillator. The kits come with no instructions, so to assemble it, use this red circuits
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From FB group Hobby Electronics When a manufacturer purchases parts for the product they are making, they expect to receive what the engineers department had specified in the department’s documents. When the parts are received, the Quality Control department is supposed to check to see if the parts received meet the engineering documents. I know
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For FB group Building Transistor Radios When I started building regen receivers, the first thing I found I needed was a simple signal generator. I have a function generator, but every time I want a different frequency, I had to readjust the controls. So I built a few RF oscillators to put close to the
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