1220-A

The General Radio 1220-A Unit Klystron Oscillator was introduced in Catalog O (1956) and remained available through Catalog S (1965).

The Type 1220-A is the foundation of for the Unit Klystron Oscillator series and supplied without a Klystron. It contains all fixtures to adapt the various Klystron tubes. All that is required to change the frequency range is the appropriate Klystron tube. An internal 1 kHz oscillator followed by a Schmitt trigger provides internal square-wave modulation.

The 1220-A requires an external power supply, the 1201-B is recommended. The external supply can't supply all the voltages required by the Klystron, so an internal supply is needed which takes 6.3 V_AC from the 1201-B to develop the regulated Repeller voltage and an unregulated voltage for the Schmitt trigger circuit.

The front panel accepts external modulation selected by the modulation switch as required.

Specifications

• Frequency Range: Depends upon klystron tube used (refer to table below)
• Modulation Internal: Internal 1 kHz square wave, adjustable within +15 Hz
• Modulation External: External square wave, 50 Hz to 200 kHz; sine or square-wave modulating signal of at least 15 V_RMS required
• Modulation FM: at least 15 MHz excursion obtainable with less than 3 dB change in output; at 60 Hz, an RMS input of about 10 V is suitable.

Klystron Oscillator Data

Type	Frequency Range	Tube	Output [mW]
1220-A1	2700-2960 MHz	726-C	100
1220-A2	2950-3275 MHz	6043	90
1220-A3	3400-3960 MHz	2K29	90
1220-A4	3840-4460 MHz	2K56	75
1220-A5	4240-4910 MHz	2K22	100
1220-A6	5100-5900 MHz	6115	80
1220-A7	5925-6450 MHz	QK404	100
1220-A8	6200-7425 MHz	5976	90

Links

• Experimenter March 1956 describing Type 1220-A

Photos

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