Doug KB8M did a beautiful job with his Michigan Mighty Mite. But, as often happens, it still didn't work. He turned to us for advice. I gave him a long list of things to check, but Pete brought the power of superior tribal knowledge to the problem and spotted the defect immediately: The transistor was in backwards. It is a P2N2222. That means the pin out it C-B-E not the usual E-B-C. I had fallen into this trap with one of my BITX rigs and had to pull out and reverse many of those transistors. Fortunately for Doug he had used a socket for the transistor. TRGHS!!!!!!!!!!!!! JOO!!!!!!!!!!!
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Look for one of the cheap Chinese eBay testers GM328A they are only a few dollars and they do LCR and give pinouts for diodes and transistors FETs the lot! Got a junk box full of old transistors, just test them quickly Bill. Cannot be without mine.
ReplyDelete73 David GM4JJJ
The Mighty Mite needs a mate!
ReplyDeleteI will also say it has "soul". My 8-yr old son Wyatt helped me wind the coil. He was excited to see/hear the MMM transmit on our receiver. I used a socket for the transistor and crystal. When I made the PCB I even etched "CBE" at the transistor socket so I wouldn't do that! Fun times
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ReplyDeleteThis is Fine Business.....you've passed a couple of the first tests for lifetime membership in the International Brotherhood of Electronic Wizards. Putting a transistor in a circuit backwards is the little known first rite of passage immediately followed by experiencing JOO! Congratulations on the beautiful little build - and really super that Wyatt helped you out. That is how it begins!
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