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.

If the reliability of the public electricity supply is to be maintained in the future, routine diagnostic testing of transformers by the power utilities is no longer optional – it’s a necessity, ...

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 ...