GENERAL RADIO TYPE 583-A Output Power Meter Instruction Manual
1 INTRODUCTION.
1.1 PURPOSE
1.2 DBSCRIPTION
2 OPERTION
To measure the power that a circuit can deliver into a given impedance, atmplyconnect the circuit output terminals to the Jots ..
put-Power Meter input tenn inala, set the load impedance to the desired value, and detennlne the power output from the meter indication and the meter MULTIPLIBR (DECmBLS) switch setting.
The Output Power Meter can also measure the internal impedance of tbe circuit under test, s nice that impedance equals the impedance into which maximum power is delivered.
You may want to know the loss ln a transformer working from a source. In such an application, determine the maximum output from the source, then lnsen the transformer between tbe source and the Output·
Power Meter a.Dd detennlne the maximum output from the transformer. The erected the two readings on the db(upper) select. ells the loss in the transformer.
3 ACCURACY OF MBASURBMBNT
3.1 GBNBRAL
The Output-Power Meter is not intended to be a precision instrument, and tbe uses for which it ts unusually do not justify precision methods. It combines convenience and wide range wth a reasonable deg-ree of accuracy, and permits high accuracy over a some what smaller range.
3.2 POWER ERROR
The error In lull-scale power reading does not exceeds decibel between ISO and2SOO cycles, nor does itexc:eedl.S decibels •t 20 and 10,000 cycles. The average error at 30 and 5000 cycles is 0.3 decibel Somewhat larger errors occur at the high and low ends of the useful frequency range. At 20 and 10,000 cycles the average error Is 0.6 decibel.
3.3 IMPBDANCB ERROR
Between ISO and 3000 cycles the Impedance error does not exceed 7 percent. The average error at 30 and 5000 cy· clews ts 8percent. At frequency extremes the Impedance error increases, and the average error at 20 and 10,000 cycles is 20 percent.
Figure 3 shows power output pilonce agaJJlst load resistance for a generator with an intimal impedance of SOO ohms. An analysis of the to this curve shows that errors are neg· ltgt. blew over most of the range.
3.4 WAVBFORM ERROR
The copper oxidic retailer type meter used ln the Instrument is calibrated in nns values for · tags. and non sinusoidal voltages may cause errors, since the meter ts not a true rms instrument. The degree of error depends on the magnitude and phase of the harmonics present, and will be small with wave· funs normally encountered tn communications.
3.5 REACTANCE ERROR
The Output war Meter Is designed to work out of a resistive impedance, and wool be subject to error when used in measurements on a highly reactive source. Unless the reactance enlarge enough 10 act matert.ally tM power factor of the Internal Impedance of the circuit under test, this error i.e negUglble.
3.6 DIRBCT·CURRBNT ERROR
When the current flowing through the Output· Power Meter has a d-e component, a slight error may occur. An error of from 2 to 3 percent results under the following circumstances:
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GENERAL RADIO TYPE 583-A Output Power Meter [pdf] Instruction Manual TYPE 583-A, TYPE 583-A Output Power Meter, Output Power Meter, Power Meter, Meter |