Laboratory Jottings

Radio Record, Volume III, Issue 42, 2 May 1930, Page 30

Laboratory Jottings

R.C.A. 221

A MALGAMATED Wireless (Aust.), Ltd., have introduced a new valve on to the New Zealand market, and a sample has found its way into our laboratory. The arrival of this valve is timely, as it has been designed to meet the requirements of the dry cell "A" battery type of receiver. Following are the technical features of the valve: Filament current, .06, at 6 volt, .056 at 5 volts.

Plate resistance, 10.000, 9000, 850 ohms, Amplification factor, 9. The performance of the valye as detector and amplified was good. It can be used in the last stage of a 2valve amplifier properly biased with quite good results. Its place, however, is as first or second audio in a larger set, or a radio amplifier. It is a sensitive detector, and oscillates freely. The figures quoted above show that although it requires only a ldw filament consumption the plate is quite low. ‘

Plate voltage, 150 max. Filament voltage, 5.5-6. Plate voltage .. 45 90 185 180 Grid bias ...... 4.5 9 10.5 Plate cur, mas. 15 2 2.5 3 _