You don’t normally think of a 3D printer as a necessity for an antenna project. However, if you are interested in making a handy portable antenna, you might want to melt some plastic. [N2MXX] has an ...

The author is a consultant in Carterton, New Zealand. This follows up his December article “Tuned Bandpass Filter Is Solution to Backup STL.” Many years ago, the active whip antenna and the active ...

All-American type T-1 toroidal antenna coil in original package. Marked: "[Indian head logo] / All-American / Patent Appld. For / Antenna Coupler / Type T-1 / Toroid Coil / All-American Radio Corp. / ...

One of the best tools in the engineer’s lightning protection toolbox is a tried, true and frequently underutilized friend, the ferrite toroid. The principle is quite simple. If you have two (or more) ...