National's NC-190 is the latest in the new "National Blue" series. It's a 10 tube double-conversion general coverage receiver that demonstrates all of the knowhow and engineering experience you would excpect from National-The oldest manufacturer of amateur and short wave recivers in the United States.

We've done quite a remarkaable job with the '190-we built the finest amateur receiver possible for the price incorporating practically every feature necessary for reliable, interference-free reception, and then added our exclusive Dial Selector-the result-a receiver with maximum Ham band performace, and with the flip of a knob, the only receiver on the market with calibrated foreign broadcast bandspread. We thereby retain the performance of a receiver designed for amateur communications and simultaneously provide the short wave listner with a receiver that solves two big problems:

1. Identifying an unknown foreign broadcast station by his frequency.

2. Locating a known foreign broadcast station by frequency.

The NC-190 is a modern attractively styled receiver with tremedous advatages for its owner:

  • Double conversion for rejection of unwanted "images" and spurious signals.

  • Dial Selector for instant choice of foreign broadcast or amateur bandspread calibration.

  • 60:1 bandspread tuning ratio with built-in National vernier means easier tuning than any other two-dial general coverage receiver, regardless of price.

  • Five separate main tuning ranges mean uncrowded high frequencey calibration.

  • Sensitiviy better than 1 microvolt for 10 db S/N ratio.

  • Variable IF Selectiviy with National's Ferrite Filter for optimum selection of receiving bandwidths to meet any condition.

  • Voltage-regulated oscillators, 1/8" steel front panel and sturdy oscillator components for maximum electrical and mechanical stability.

  • SSB reception with calibrated upper/lower sideband BFO control, separate product detector and SSB/CW automatic gain control.

    6BZ6 RF Amplifier
    6BE6 HF Converter
    6BE6 2nd Converter
    6BA6 IF Amplifier
    6BA6 IF Amplifier
    12AX7A Product det-BFO
    6T8 AM Det, ANL, AGC, Audio Amp.
    6CW5 Audio Output
    5Y3GT Pwr Rect.
    OB2 Voltage Reg.

    Calibration: Bandspread dials calibrated every 20 KC or better on all bands below l0 meters. The l0 meter amateur and 11 meter Citizen's Band is calibrated every 50 KC.

    Main Tuning Ranges International Broadcast Bandspread Amateur Bandspread
    540-1600 KC 13 Meter Band (21.5-22.1 MC) 10 Meters (26.6-30.0 MC)
    1.6-4.0 MC 16 Meter Band (16.4-18.0 MC) 15 Meters (21.0-21.5 MC)
    4.0-10.0 MC 19 Meter Band (14.6-15.4 MC) 20 Meters (13.8-14.5 MC)
    10.0-20.0 MC 25 Meter Band (11.7-12.0 MC) 40 Meters (6.9-7.5 MC)
    20.0-30.0 MC 31 Meter Band (8.6-10.0 MC) 80 Meters (3.5-4.0 MC)
    49 Meter Band (5.9-6.3 MC)

    Image Rejection: Double conversion above 4 MC assures optimum image rejection on all bands, eliminating unwanted "ghost" responses on the higher frequencies. NC-190 first IF: 2215 KC, second IF: 230 KC.

    Stability: The use of a I/8" steel panel, I/16" steel chassis, ceramic coil forms and rugged oscillator components assure excellent mechanical stability. All oscillators are voltage regulated, which minimizes frequency changes as a result of voltage variations.

    Sensitivity: Better than 1 microvolt for 10 db S/N ratio. Two highly selective tuned circuits effectively couple signals to the low noise 6BZ6 RF stage and the 6BE6 mixer stage. An antenna trimmer is included for optimum matching of the front end circuits to any type of antenna.

    Selectivity: National's high frequency Ferrite Filter, operating at 230 KC, achieves remarkable selectivity at a relatively high intermediate frequency. 6 db bandwidths of 600 cycles for single signal CW reception, 3 KC for SSB and crowded AM phone conditions, and 5 KC for clear channel speech and music reception are selected from the front panel. The use of the Ferrite Filter also minimizes the secondary images characteristic of receivers using very low last I F's.

    Detection: An excellent diode detector is used for AM reception, while a separate true triode product detector provides undistorted SSB and CW reception.

    Automatic Gain Control (AGC): AGC operation is available for both AM and SSB/CW signals, allowing effortless tuning of any type of signal under widely varying signal input conditions.

    Noise Limiters: A high performance series gate noise limiter circuit may be inserted at will during the reception of AM signals. Typical of National's famous noise limiters, the NC-190 limiter takes out pulse and ignition type interference almost completely, but distortion of the wanted signal is so low as to be unnoticeable. During SSB/CW receiving conditions, IF limiting effectively removes impulse noise, again without observable distortion.

    Audio Amplifier: The high gain audio amplifier in the NC-190 is capable of producing more than a full watt of high quality audio output at the 3.2 ohm speaker terminals. Hum and noise are more than 40 db below the signal level.

    Muting provisions: Two alternate muting systems are incorporated in the NC-190. The relay terminals at the rear of the receiver are shorted when the "Stdby-Rec" switch is placed in the "Rec" position. These terminals may be used to operate an external circuit. The NC-190 may be controlled externally by placing the switch in the "Stdby" position and then shorting two terminals in the calibrator socket at the rear of the set to activate the receiver.

    Power supply: The NC-190 full-wave transformer type power supply utilizes three filter capacitors to remove all hum and ripple from the 150 volt B+ output. This B+ voltage is available at the "calibrator" socket at the rear of the set along with the 6.3 V. A. C. filament supply. The use of only 150 volt B+ assures low operating temperatures, with resultant improved stability and prolonged tube life.

    Crystal calibrator: The accessory XCU-109 crystal calibrator provides strong 1 MC marker signals throughout the tuning range of the NC-190 to assure accurate dial calibration on all bandspread ranges. The XCU-109 plugs into the rear of the receiver, and may be controlled by a frontpanel switch.

    Dial Selector: National's exclusive Dial Selector rotates the bandspread dial scale so that a separate set of calibration markings may be employed for either amateur bands or the popular foreign broadcast bands. Operated by simply pulling out the Dial Selector knob and rotating one-half turn until a detent snaps into place, the Dial Selector permits calibration accuracy on the foreign broadcast bands equal to the excellent amateur band calibration characteristic of all National general coverage receivers. No other two dial general coverage receiver manufactured today has this feature, and the short wave listener using other equipment must rely on the necessarily rough main tuning calibration or on an arbitrary logging scale on the bandspread dial.

    Tuning ratio: The NC-190 utilizes a built-in miniature National Velvet Vernier in the bandspread drive, affording a total drive reduction to the bandspread capacitor of 60.'1. For this reason, the NC-190 is a general coverage receiver with the tuning ease of a ham-band-only set, making SSB signals as easy to tune as regular AM. The NC-190 has the greatest drive reduction of any general coverage receiver on the market, regardless of price.

    Calibrated BFO control: The NC-190 BFO control is calibrated directly in kilocycles each side of zero beat, allowing the operator to easily reset the BFO for optimum performance. In addition, the BFO is calibrated for upper and lower sideband selection, taking the guesswork out of SSB BFO adjustment.

    S-Meter: The NC-190 S-meter is a modern edge-reading meter calibrated in 6 db steps from S-1 to S-9 and to 80 db over S-9. Zero-adjust is controlled by a potentiometer at the rear of the chassis, and the NC-190 S-meter operates on all modes of reception, including CW and SSB.

    Bandwidth Selector: True variable IF selectivity is incorporated in the NC-190, and three discrete bandwidths may be selected by the front-panel "kilocycles" control. 600 cycle single signal CW, 3 KC SSB, and 5 KC AM bandwidths may be instantly chosen to fit any receiving requirement.

    Flip Foot: National's Flip Foot allows adjustment of the NC-190's operating angle to meet the individual's preference--tilted up for table-top use, or level for applications above normal eye level.

    NTS-3 speaker: The matching NTS-3 speaker incorporates its own Flip Foot so that the speaker may be tilted up, leveled, or set on its side to match the proportions of the NC-190.

    Power Requirements: 105-125 volts AC, 50-60 cycles, 75 watts.

    Dimensions: 8 3/4" high, 15 3/4" wide, 9" deep.

    Shipping Weight: 28 pounds.

    Price: 219.95 am. net.

    Accessories: XCU-109 crystal calibrator, $20.95. NTS-3 matching speaker, $19.95.


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