In December last year I ordered these MTX-90 glow discharge thyratrons from Bulgaria. They took a bit of time to arrive, but they were well priced and they should be handy for some neat projects. They can be used converting low-power electrical signals, as well as for operating as relays. Because they contain neon at low pressure, they also glow when they conduct, so they can serve as indicators as well.
0 Comments
Back in December 2021, I tried to make this old school transistor radio from a book called The Boys' 2nd Book of Radio and Electronics by Alfred P. Morgan (1957). Unfortunately it was not successful. I thought the problem was because the loopstick I used was not quite correct. Recently I was able to finally buy the Miller 6300 loopstick that was supposed to be used in this circuit. However that did not really fix the problem. After posting to a FB group, someone spotted a wiring error, and also suggested adding a 10kohm resistor. Indeed it did turn out I had a wiring issue which was the cause of my troubles. Not sure how I missed that twice before, but I did.
The addition of the 10 K resistor was not absolutely necessary, but it did result in better audio, so I kept it in. It is a strange radio. To tune it, you use the loopstick, and fine tune it (or tune out interfering stations) with the variable capacitor. It works, but you do need a long wire antenna and ground. It is basically a crystal radio with an amplifier. It is hard to eliminate a local station, but it does eventually reduce it enough so other stations are easily heard. |
AuthorCharles Baetsen holds a Bachelor and a Master's degree in Engineering Physics from McMaster University in Hamilton, Canada. Archives
February 2024
Categories
All
|