Note
QST, Sep 1966, inside back cover.
QST, Feb 1967, back cover.
QST, Feb 1968, p. 111.
The National 200 five-band transceiver was suitable for either mobile or home-station use. It featured complete coverage of the 80-10 meter bands and ran 200 watts PEP on SSB with a pair of 6JB6s. The National 200 also had CW and AM modes. A crystal lattice filter was used in its 5.2 MHz IF. The AC and DC power supplies were external.
Features
– Complete coverage of the 80 through 10 meter bands.
– 200 Watt PEP input on SSB, plus CW and AM.
– Separate product and AM detection plus fast-attack slow-release AGC.
– Crystal-controlled front end and single VFO for high stability, and identical calibration and tuning rate on all bands.
– Crystal lattice filter for high sideband suppression on transmit, and rejection of adjacent QRM on receive plus solid-state balanced modulator for "set-and-forget" carrier suppression.
– Operation from new low-cost AC-200 supply or from NCX-A or mobile power supplies.
– ALC.
– 45/1 planetary/split gear tuning drive.
– Automatic carrier insertion in AM and CW modes.
– Panel meter automatically switched to S-units on receive.
Specifications
– Frequency Range: With supplied crystals: 3,500 to 4,000 kHz, 7,000 to 7,300 kHz, 14,000 to 14,500 kHz, 21,000 to 21,500 kHz, 28,500 to 29,100 kHz. (Two additional crystals required for full 28,000–29,700 kHz coverage.)
– Power Input: 200 watts PEP SSB; 200 watts CW; 100 watts AM.
– R.F. Power Output (Nominal): 120 watts PEP SSB; 120 watts CW; 30 watts AM.
– Types of Emission: SSB (USB for 20, 15, 10 meters; LSB for 80 and 40 meters), AM, CW.
– Output Impedance Range: 40–60 ohms minimum, Pi-network.
– Frequency Determination: Single conversion, with pre-mixed crystal-controlled high frequency oscillators and tunable VFO.
– Operating Facilities:
(All modes) Full AGC and S-meter on receive.
(SSB) PTT or front panel manual operation on transmit with ALC, product detector on receive.
(AM) PTT or front panel manual operation on transmit with automatic carrier insertion, AM detector on receive.
(CW) Grid-block keying on transmit with automatic carrier insertion, product detector on receive.
– SSB Generation: Crystal lattice filter; 6–50 dB shape factor 2.2 to 1; Bandwidth 2.8 kHz at 6 dB; Center frequency 5.202 MHz. Solid state balanced modulator.
– Dial Calibration: 5 kHz; identical on all bands.
– Tuning Ratio: 45:1; identical on all bands.
– Frequency Stability: Nominal 1500 Hz in first 30 minutes after 5-minute warm-up; long-term stability nominal 400 Hz in room ambient conditions.
– Suppression: Carrier -50 dB; unwanted sideband -40 dB; 3rd order distortion products -30 dB at full output.
– Receiver Sensitivity: Nominal 0.5 µV for 10 dB S/N in SSB mode.
– Audio Output: Better than 2 watts; 3.2 ohms.
– Microphone Input: High Impedance (dynamic microphone recommended).
– Metering: Back-lit edge reading: PA cathode current on transmit; S-units on receive.
Rear Panel Controls: Antenna, Bias Adjust, Phones or Speaker, Key, Power Input, External ALC Input, Calibrator Socket, External Relay Control, Carrier Insertion, S-Meter Adjust.
Tube Lineup (16 total)
– 6BZ6 RF Amplifier
– 12BE6 Receiver Mixer
– 12BA6 1st IF Amplifier
– 12BA6 2nd IF Amplifier
– 12AX7 AM & Product Detector / First Audio Amplifier
– 6AQ5 Audio Output
– 6GH8 Microphone Preamplifier / Speech Amplifier & S-Meter Amplifier
– 12BA6 Carrier Oscillator
– 12BA6 Transmit IF / Balanced Modulator
– 12BA6 V.F.O. (Variable Frequency Oscillator)
– 6GH8 Crystal Oscillator / Pre-Mixer
– 6JD6 Transmit Mixer
– 6GK6 Driver
– 6JB6 (or 6GJ5) Final Power Amplifier
– 6JB6 (or 6GJ5) Final Power Amplifier
– 0A2 Voltage Regulator
Power Requirements: 700 V.D.C. at 300 mA, 280 V.D.C. at 200 mA, -80 V.D.C. at 10 mA, 12.6 V at 5 A.
Accessories: AC-200 power supply (operates from either 117 or 234 V.A.C., 50–60 Hz); XCU-27 100 kHz plug-in crystal calibrator.
References
See National's notes: QST, Sep 1966, p. 107.
See National's notes: QST, Oct 1966, p. 123.
Brief description. Electronics World, Dec 1966, p. 85.
Review. 73, Feb 1967, p. 104.
