Note
QST, Jun 1954, p. 77.
The Ranger is a flexible transmitter/exciter covering the 160-10 bands with a power input of 75 watts CW, 65 watts phone to a 6146 final. The P-P 1614s in Class AB1 provide 100% modulation and could serve as drivers for a separate high-power modulator.
The Ranger has an internal dual-voltage power supply utilizing choke-input filtering. It supplies 500–525 VDC for the final amplifier/modulators and 300–320 VDC for the low-level RF and audio stages. An auxiliary 9-pin octal-style socket on the rear chassis provides easy access to these internal potentials, audio driver outputs, and filament voltages for powering external equipment or interfacing with a larger power amplifier.
Frequency coverage: 160, 80, 40, 20, 15, 11, and 10 meters.
Modes: Supports CW , AM.
Output Power Ratings: 40 to 45 watts AM, and 45 to 50 watts CW.
VFO: Patterned after the Johnson Model 122, it utilizes a series-tuned Colpitts circuit with separate tank circuits for the 1.75–2.0 MHz and 7.00–7.425 MHz ranges.
Crystal operation: two crystal positions
Final Amplifier & Pi-Network: Employs a 6146 beam power amplifier paired with a band-switched pi-network plate circuit. It is designed to match unbalanced antenna impedances from 50 to 500 ohms on all bands, extending from 25 to 2000 ohms on frequencies above 7 MHz, while offering excellent harmonic suppression.
Audio Modulator Section: Features a built-in speech amplifier and a modulator capable of delivering 33 watts of audio power. It includes plate saturation limiting to minimize overmodulation and a tertiary feedback winding for improved stability and flat response.
Tube Complement (12 total)
– 6AU6: Variable Frequency Oscillator (VFO)
– (2) 6CL): One acts as the Crystal Oscillator / Isolator-Multiplier, and the second serves as the Buffer stage
– 6146: Final RF Power Amplifier
– 6AQ5: Clamper tube (protects the 6146 final from excitation failure)
– 12AX7: Dual-triode first and second audio speech amplifiers
– 12AU7: Parallel-connected audio power driver
– (2) 1614: Push-pull Class $AB_1$ modulators
– 5R4GY: High-voltage rectifier
– 6AX5GT: Low-voltage rectifier
– OA2: Voltage regulator tube for the VFO circuit
References
Adding PTT. CQ, Feb 1957, p. 37.
Use with Heath SB-10. CQ, May 1964, p. 41.
