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IET Output Power Meter 1840-A

IET Output Power Meter 1840-A; General Radio (ID = 2518468) Equipment
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IET Output Power Meter 1840-A; General Radio (ID = 2518468) Equipment
General Radio: IET Output Power Meter 1840-A [Equipment] ID = 2518468 920x448
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For model IET Output Power Meter 1840-A, General Radio Company; Cambridge (MA):
From Gen-Rad
Country:  United States of America (USA)
Manufacturer / Brand:  General Radio Company; Cambridge (MA)
alternative name
Year: 1962 Category: Service- or Lab Equipment
Wave bands - without
Power type and voltage No Power needed
Loudspeaker - - No sound reproduction output.
Power out
from Model: IET Output Power Meter 1840-A - General Radio Company;
Material Metal case
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

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.

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

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)

Model page created by Alberto Sanna-Alonso. See "Data change" for further contributors.

All listed radios etc. from General Radio Company; Cambridge (MA)
Here you find 216 models, 197 with images and 84 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.