A Linear Radio Frequency Field Intensity Meter

Abstract

In this paper the construction of a linear and stable signal strength meter is described for accurate study of radio signal strengths. A simple d.c. amlplifier has been designed for being used along with a communication receiver. Type BC 348 Q. Overlapping linear ranges are provided in this meter enabling comparison of readings taken on successive ranges. The calibration curves are linear in the range of variation usually met with. A suitable micro ammeter of range 0-60 microampere A with 60 divisions is used as an indicator. This instrument measures radio frequency voltages from 5 microvolts to more than 1.5 volts. The error in measurement of varying radio fields is less than 10% for recorded observations and less than 15% for visual observations. The modification of this circuit for actuating a pen and ink recorded is also described. This instrument can also be used as an r.f.. microvoltmeter.