Note on the Measurement of Radio Signals

A portable compact measuring unit for incoming signal strengths has been worked out, capable of measuring from 3.5 microvolts per meter up, at 23,500 cycles, and giving satisfactory results. The measurements are made by a primary comparison with a locally generated emf. by means of a highly selective receiving unit and a 600-ohm artificial line box especially made for this purpose. The method is equally applicable to other frequency ranges and should be especially convenient at the higher radio frequencies where the absence of static allows of meter comparisons and the use of the double detection method of reception. This latter method allows of a fixed filter adjustment for all frequencies and is very flexible.