General Radio Variable Air Condenser Model Type 539-B

Manufacturer: General Radio

Model Number: Type 539-B

Serial #: 1713

Equipment Description: Variable Air Condenser

Label Write-up:
A Condenser is an old word for capacitor. It is made of multiple plates of metal with an air gap for the dielectric. Half are fixed and the other half turn on a shaft so the plates interweave like pages on a book. When the two halves are apart the capacitance is low. As the shaft is turned and the halves come together the capacitance increases. It is used as part of an oscillator. Changing the capacitance of the circuit changes the frequency of the oscillator.

Dates Produced: 1930's & 1940's ?

Original Price:

The museum's inventory number: MRT-1161

Located at Museum in: Test Equipment Room