VFO Model 200

The Model 200 Variable Frequency Oscillator is a fully solid state unit intended to replace the crystal functions in amateur transmitters operating in the 10 through 80 meter bands. Low drift operation is achieved by using a permeability tuned oscillator with temperature compensated components, a three stage amplifier chain following the oscillator, and an all solid state circuit for low overall temperature change during operations.

All amateur bands, 10 through 80, are covered, each with a separate dial scale. Vernier tuning with approximately a 25 to 1 ratio permits easy adjustment, quickly and accurately. Multiples of the VFO output frequency are used on the 20, 15, and 10 meter bands; on 80 and 40 meters, the output frequency is used directly. The amateur segments of each dial scale are denoted as widened lower horizontal baselines and the Novice segments as widened upper baselines.

The VFO is compatible with almost all known amateur transmitters using either grid block or cathode keying, with minor transmitter modifications necessary to insure peak and stable operation in some cases.

• Band Coverage (MHz)

• Load Impedance: 80 pF (including cable), 50 K ohms or more.
• Output Voltage: 20 volts rms on 80, 35 volts rms on 40, min.
• Keying Modes: VFO output may be keyed directly, or with grid block systems, along with the transmitter.
• Grid Block Voltages: VFO operates with key line potentials between -50 and -150 VDC.
• Accuracy: +/- 5 kHz on fundamental
• Drift: Less than 100 Hz after 1/2 hour warm-up.
• Power Source: 115 VAC, 60 Hz. (Unit convertible to 12 VDC operation.)
• Controls: Main Tuning, Band Switch, Mode Switch (Off-Tune-Key-Lock)
• Physical: HWD, 4-5/8" x 7-1/4" x 7-1/2". Case aluminum with plastic end panels. Cream and wood grain trim. Weight 3 lbs.