Tuning Head VH-11

Watkins Johnson Company, Gaithersburg (MD)

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  • Year
  • 1970 ?
  • Category
  • Radio module post 1925 (not a part, not a key)
  • Radiomuseum.org ID
  • 364599

Click on the schematic thumbnail to request the schematic as a free document.

 Technical Specifications

  • Number of Transistors
  • Semiconductors present.
  • Semiconductors
  • Main principle
  • Wadley-Loop principle (including dual superhet); ZF/IF 21400 kHz; none
  • Wave bands
  • Wave Bands given in the notes.
  • Power type and voltage
  • Powered by external power supply or a main unit.
  • Loudspeaker
  • - - No sound reproduction output.
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: Tuning Head VH-11 - Watkins Johnson Company,
  • Shape
  • Chassis only or for «building in»
  • Dimensions (WHD)
  • 3 x 3.12 x 15.25 inch / 76 x 79 x 387 mm
  • Notes

  • The Type VH-11 Tuning Head is designed to operate as a plug-in module with the Types 205 and 205-2 Receivers. The VH-11 tunes the frequency range of 30 to 60 MHz and provides a 21.4-MHz IF output for the receiver. The tuning head can be manually or
    electrically tuned depending upon the operating mode of the 205 Series Receivers. A front panel tuning knob and tape dial are provided for use in the manual tuning mode and a tuning voltage range of +10.3 to -10.3 volts from the receiver will tune the unit from the low band limit to the high band limit.

    The tuning head consists of a voltage tuned RF amplifier 
    and local oscillator, mixer, IF amplifier, and circuits to shape the tuning voltage input from the receiver to provide a linear volts versus frequency tuning curve for the unit. In addition to the 21.4-MHz IF output, buffered local oscillator output and a five wire code are provided for operation of the accessory DRO-308 Counter, DRX-308 Digital Readout Extender. and VM-105 Marker Accessory. Additional jumper wires in the VH-11 select the appropriate IF bandwidths for both the PAN and SECTOR operating modes of the 205 Receiver.

    Specifications

    Tuning Range: 30-60 MHz

    Input Impedance:  50 ohms, nominal

    Input VSWR:   4:1, maximum

    Noise Figure:  6 dB, maximum

    Gain x Noise Figure Product:  30, ±3 dB

    IF:   21. 4-MHz

    3rd Order Intercept Point:  ≥ -10 dBm

    Image Rejection:  80 dB, minimum

    IF Rejection:  30-40 MHz, 70 dB minimum
                        90-60 MHz, 85 dB minimum

    Gain Control Range:  30 dB, minimum

    RF Bandwidth:   3 MHz, minimum

    Local Oscillator Radiation:  2 µV, maximum

    Local Oscillator Output Level:  50 mV, minimum, across 50 ohm

    Tuning Voltage Low Band Edge:  +10V High Band Edge  -10V

    Linearity (volts versus frequency):  1% of tuning band

    Tape Dial Accuracy:   ±2% of the operating frequency
     

  • Net weight (2.2 lb = 1 kg)
  • 3.5 lb (3 lb 8 oz) / 1.589 kg
  • Mentioned in
  • - - Manufacturers Literature (Instruction Manual for Type VH-11 Tuning Head, Watkins-Johnson, p/n C/200/4/18/74/HED)
  • Literature/Schematics (1)
  • - - Manufacturers Literature (Receiving Equipment Condensed Catalog, Watkins-Johnson, May 1970, pages 4-5)
  • Author
  • Model page created by Pius Steiner. See "Data change" for further contributors.

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