From GRWiki
Jump to navigation Jump to search
General Radio 1330-A
Bridge Oscillator
General Radio 1330-A Bridge Oscillator

Available from 1951 to 1973

Catalog History
 Document Year Page
Catalog M 1951 150
Catalog N 1954 166
Catalog O 1956 110
Catalog P 1959 108
Catalog Q 1961 108
Catalog R 1963 111
Catalog S 1965 138
Catalog T 1968 218
Catalog U 1970 244
Catalog73 1973 318
(All manuals in PDF format unless noted otherwise)

The General Radio 1330-A Bridge Oscillator was introduced in Catalog M (1951) and remained available through Catalog 1973.

The Type 1330-A is a wide-range oscillator designed as a generator in bridge service. It can supply two fixed frequencies for audio-frequency bridges, or a variable frequency from 5 kHz to 50 MHz for RF bridge measurements. The 1330-A offers amplitude modulation of the variable RF oscillator by the two fixed audio oscillator frequencies. With its totally shielded aluminum case and carrying handles, it is portable and less expensive than a standard signal generator. The RF compartment is similar in design to the 1001-A Standard Signal Generator with its double-shielded, removable housing. The panel of the 1330-A can also be rack mounted.


  • Frequency Range: 400 Hz, 1000 Hz fixed frequencies; 5 kHz to 50 MHz in 8 ranges
  • Frequency Accuracy: ±5% for the fixed frequencies; ±2% for frequencies above 150 kHz
  • Envelope Distortion: Between 1% and 6% at the 60% modulation level
  • Output Voltage: fixed 12 V at the audio output; RF output is adjustable up to 10 V into 50 Ω