Note
Popular Electronics, Dec 1961, p. 31.
QST, Jan 1962, inside back cover.
QST, Feb 1963, inside back cover.
QST, Mar 1964, p. 159.
The National NC-105 is a general-coverage broadcast and shortwave communications receiver. It features variable Q-multiplier selectivity, dedicated bandspread tuning with specialized calibration charts, an edge-reading illuminated S-meter, separate RF and audio gain controls, and Automatic Gain Control (AGC) operating across all modes.
Designed as an entry-level set aimed squarely at novices and budget-conscious hams, it bridged the gap between low-end entry receivers and higher-priced gear, retailing for $119.95 in a functional steel cabinet or $139.95 in hand-rubbed oiled walnut.
Features
– Large illuminated edge-reading "S" meter that operates on all modes of reception.
– Exclusive National peaking Q-multiplier that works on CW as well as AM.
– Separate product detector/BFO for CW and SSB reception.
– Continuous coverage from 550 KC to 30 MC across four separate bands.
– Automatic gain control (AGC) that operates across all reception modes, including CW and SSB.
– Bandspread calibration charts included for all popular amateur and foreign broadcast bands.
– Separate RF and audio gain controls.
– "Famous" distortion-free National noise limiter.
– Built-in 5-inch speaker.
– Front panel headphone jack.
– Full-wave transformer power supply.
– Exclusive tuner output.
Antenna Input: 50–300 ohms (unbalanced line input using a two-terminal strip marked A and G).
Selectivity & Q-Multiplier: Features a fixed-tuned peaking Q-multiplier continuously adjustable via a front-panel control from a 7 kHz broad bandwidth (for full-fidelity AM broadcast reception) down to approximately 500 Hz for CW .
Detectors:
AM Mode: Dedicated vacuum tube diode detector.
CW / SSB Modes: Separate combination triode product detector and BFO circuit for reduced distortion and optimized beat-note tuning.
Automatic Gain Control (AGC): Active across all modes, including AM, SSB, and CW.
Rear-apron high-impedance tuner output jack providing detected audio from either the diode or product detector to feed an external hi-fi amplifier (selected via the Function switch).
Tube Lineup (6 total)
– 6BE6 (High-Frequency Converter / Mixer)
– 6BA6 (First IF Amplifier)
– 6BA6 (Second IF Amplifier / Q-Multiplier Stage)
– 6T8 (Triple Diode / High-Mu Triode: AGC, Detector, ANL, and Audio Stage)
– 6AW8 (Triode / Pentode: Product Detector / BFO and Audio Output Stage)
– 6X4 (Full-Wave Power Rectifier)
Power requirements
105–125 VAC, 50/60 Hz, 49 watts
References
Review: QST, Apr 1962, p. 53.
Brief description. Popular Electronics, Jul 1962, p. 92.
Review: CQ, Sep 1962, p. 38.
