Solid-state ac supplies replace motor-generator and tap-changing transformers to offer the same tests at the push of a button • Solid-state ac-power sources combine the variable-frequency and ...

So you have an old tube-type transmitter as a backup. It ran perfectly when you last turned it on two years ago to substitute for your then-ailing solid-state main transmitter. Now you need it again.

Several companies are working on technologies that could replace large traditional power transformers with power semiconductors and smaller transformers mounted on circuit boards. Although they are ...