IET Output Power Meter 1840-A

General Radio Company; Cambridge (MA)

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  • Year
  • 1962
  • Category
  • Service- or Lab Equipment
  • Radiomuseum.org ID
  • 320468
    • alternative name: GenRad

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

 Technical Specifications

  • Wave bands
  • - without
  • Power type and voltage
  • No Power needed
  • Loudspeaker
  • - - No sound reproduction output.
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: IET Output Power Meter 1840-A - General Radio Company;
  • Shape
  • Portable set > 8 inch (also usable without mains)
  • Dimensions (WHD)
  • 305 x 90 x 170 mm / 12 x 3.5 x 6.7 inch
  • Notes

  • The IET 1840-A measures audio-frequency power into any desired load.  This model formerly was manufactured by GenRad (General Radio).

    Its important uses include the measurement of:

    • *Power output of oscillators, amplifiers, preamplifiers, transformers, transducers, and low-frequency lines.
    • *Output impedance, by adjustment of the load, to yield maximum power indication.
    • *Frequency-response characteristics of amplifiers, transformers, and other audio-frequency devices.

    This instrument basically is a multi-tapped audio-frequency transformer with a fixed secondary load. Its two front-panel switches connect eight identical primary windings and six secondary taps in various combinations to provide a total of 48 different primary impedances.

    The maximum power rating can be extended for any given impedance with the use of simple T-network attenuator, design data for which are supplied with the instrument.

    Power Range:
    0.1 mW to 20 watts in five ranges, 40 Hz to 20 kHz; maximum rating is reduced by up to 50% (at 25 Hz), depending on impedance selected.

    An auxiliary dB scale on the meter reads from -15 to +3 dB, referred to 1 mW.

    Impedance Range:
    0.6 Ω to 32 kΩ in two ranges; yielding 48 individual impedances spaced approximately 2 apart.

    Accuracy
    Impedance:
    at 1 kHz, ±6% max, -0.5% avg;
    70 Hz to 2.5 kHz, ±7% above 10 kW;
    70 Hz to 5 kHz, ±7% below 10 kW;
    at 20 Hz, -15% max, -8% avg;
    at 20 kHz, ±50% max, ±12% avg
    When impedance is specified, accuracy applies at full-scale on all ranges and impedances at 1 kHz;
    when frequency ranges are specified, accuracy is at full-scale at ranges ≥20 mW at the specified impedances.
    When a frequency limit is specified, accuracy is at full-scale at all impedances

    Power:
    at 1 kHz, ±0.3 dB;
    50 Hz to 6 kHz, ±0.5 dB;
    30 Hz to 10 kHz, ±1 dB;
    at 20 Hz, -1.5 dB max, -1 dB avg;
    at 20 kHz, -5 dB max, ±1.5 dB avg.

    Waveform Error:
    Meter will indicate true rms with as much as 20% second and third harmonics present in the input signal

  • Net weight (2.2 lb = 1 kg)
  • 4.9 kg / 10 lb 12.7 oz (10.793 lb)

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