. QST . detector!We were using it in a regenerative (but nonoscil- oscillating detector was substituted. Althoughthe original objective of single-signal receptionhad to be given up, the resultant receiver turnedout to be a husky little gentleman in everyother respect. The over-all gain was enough torattle the daylights out of a pair of high-im-pedance headphones, the stability was good,and the receiver will stack up well againstanything in its price class ($.35) or slightly that the inherent modesty of the authorhas been demonstrated, lets get down to details. The Circuit While few
. QST . detector!We were using it in a regenerative (but nonoscil- oscillating detector was substituted. Althoughthe original objective of single-signal receptionhad to be given up, the resultant receiver turnedout to be a husky little gentleman in everyother respect. The over-all gain was enough torattle the daylights out of a pair of high-im-pedance headphones, the stability was good,and the receiver will stack up well againstanything in its price class ($.35) or slightly that the inherent modesty of the authorhas been demonstrated, lets get down to details. The Circuit While few will argue about the sensitivity ofan autodyne detector, anyone who has workedwith one knows that the loading is critical, andan antenna swinging in the breeze may pullthe frequency. Then, too, the regenerationcontrol setting may need changing as one tunesa band. Using an autodyne detector at a low fixedfrequency obviates these shortcomings but dic-tates a superheterodyne type of receiver. By 12 QST for. rATiTI /N Fig. 1 — Schematic diagram ofC, _ 140-,iMf- milsft variable (Hammarlund IIF- C2_15.^f,f. midget variable (Hammarlund HF-15).1{, _ 10 000-ohm 2-vvatt wire-v>oiind potentiometer (Clarostat A43-10K).Li 1-2, L3, —B & W No. 3016 Mmiductor, l-uuh diam., 32 turns per inch, No. 22 v> — 12 — 26 turns. L3— 8 turns. , I,, 21 turns, separated from /.a by one (remo\e<l) turn. limiting the frequency range of the receiver totwo consecutive amateur bands and using an half the frequency difference l)etvveen thetwo bands, it is possible to change bandssimply by tuning the input circuit to the onel)andor the other. For example, with the high-fiequencv oscillator tuned to Mc, and thei f at 1700 kc, the receiver responds to eithera signal ( - = ) or a ( - = ), depending upon thetuning of the mixer grid circuit. It is a convenientarrangement that pernuts building a bandspreadtwo-band receiver w
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
