Monthly Archives: May 2026

Winding Your Own Transformers.

If you are in need of an unobtainium transformer, you can always just make your own! As the elementary student of electricity has learned, a transformer consists of nothing more than two coils of wire wound on a suitable core. In practice, it’s a bit more complicated than that, but not much more. The hardest part is probably coming up with a suitable core, but that is explained in the diagram at left.  The finished product is shown above.  If you need complete instructions, they were published 85 years ago in the April and May 1941 issues of the British magazine Practical Mechanics.

For a student looking for a unique science fair project, this series of articles will give many ideas.



1941 Phono Oscillator

Eighty-five years ago this month, the May 1941 issue of Radio Craft carried this circuit for a simple phono oscillator. It had been sent in to the magazine by one Eugene Simpson of Naperville, IL, who pointed out that there had been a lot of interest recently in phono oscillators, and many enthusiasts were looking for a simple circuit. He recommended tuning the coil to the high end of the broadcast band, and cautioned not to use an antenna, as “The F.C.C. doesn’t like people who do otherwise!”