. QST . 470 ohmsfor each triode section). This circuit is identical to that usedby Longerich and Smith, except that coupling is em-ployed rather than direct coupling and the series-resonatedcoil in the cathode is replaced by a resistor. The noise figureof the cathode-coupled amplifier is in general sjmewhatbetter than the grounded-cathode pentode amplifier. Thiscircuit is, however, inferior to the grounded-cathodegrounded-grid triode circuit in both noise figure and stability(, the so-called Wallman circuit ^ or cascode ampli-fier 3). Also, the lower available power gain of the g
. QST . 470 ohmsfor each triode section). This circuit is identical to that usedby Longerich and Smith, except that coupling is em-ployed rather than direct coupling and the series-resonatedcoil in the cathode is replaced by a resistor. The noise figureof the cathode-coupled amplifier is in general sjmewhatbetter than the grounded-cathode pentode amplifier. Thiscircuit is, however, inferior to the grounded-cathodegrounded-grid triode circuit in both noise figure and stability(, the so-called Wallman circuit ^ or cascode ampli-fier 3). Also, the lower available power gain of the grounded-plate triode means that contributions of third-stage noiseare correspondingly greater. — Jack Belrose, ex-VE7QH-VE3BLW 1 Valley and Wallman, Vacuum Tube Amplifiers, p. 664(McCiraw Hill Radiation Laboratory Series). 2 Shimizu, Modified Wallman Circuit with VoltageFeedback, Electronics for Communication Engineers, p. 28(McGraw Hill, 1952). 3 The Radio Amateurs Handbook, p. 366 (1954). 126. Submarine, heck! Its supposed to be an airplane!^ Trade-ins are not always what they seem, either. Thats why it will pay you,as it has thousands of others, to rely on the one and only Surprise trade-inpolicy popularized by Walter Ashe. For real satisfaction and money saving,trade used (factory-built) test or communication equipment today. Wire,write, phone or use the handy coupon. ECCO 10 METER TRANS-RECEIVERDesigned for spot frequency use for emergency, CD,and net operation. Completely self-contained includ-ing batteries. Transmitter uses 20 meter frequency receiver has regenerative loaded 36 antenna. Carbon mike input. Vzwatt input to final. With 5 tubes. Less mike, head-phones, crystal, and batteries. MODEL HT-2. Net $ Crystal (specify frequency). Net $ (2-M30 B, 1-2F A). Net $
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
