. QST . al, using chokeinput and a transformer rated at 600 or 750 , 200 to 300 ma. Adjustment After checking the crystal oscillator to makesure that it is functioning properly, the VFOshould be checked and its tuning range adjustedto cover the desired range of frequencies. SettingCi to minimum capacitance, C2 should be ad-justed until the oscillator is heard at 4000 kc,or a few kc. higher. Then, with the bandswitchin the 80-meter position, and the milliammeterreading grid current to the 807s, Cg should beset at midscale (Ci still at minimum capacitance)and the slug in Lo adjusted for max
. QST . al, using chokeinput and a transformer rated at 600 or 750 , 200 to 300 ma. Adjustment After checking the crystal oscillator to makesure that it is functioning properly, the VFOshould be checked and its tuning range adjustedto cover the desired range of frequencies. SettingCi to minimum capacitance, C2 should be ad-justed until the oscillator is heard at 4000 kc,or a few kc. higher. Then, with the bandswitchin the 80-meter position, and the milliammeterreading grid current to the 807s, Cg should beset at midscale (Ci still at minimum capacitance)and the slug in Lo adjusted for maximum 807grid current. Then Ci should be adjusted untilthe oscillator signal is heard at 3200 kc, andCe readjusted for maximum grid current. If thislast adjustment requires an increase in thecapacitance of Cq, the tuning range of the 80- (Continued on page 120) Rear view of the 150-watttransmitter, showing arrange-ment of components on topof the power-supply and ex-citer chassis (see text). September 1955. • ^ecAmc€ii ^afUc^ — Ripple on the Scope Pattern IT IS well known that a perfect single-tone single-eideband signal consists of but a singleradio frequency. When such a signal is displayedon the face of a scope being swept horizontallyat an audio-frequency rate, the pattern is ahorizontal band having perfectly smooth andstraight upper and lower edges. It is identicalwith the pattern of any unmodulated carrier. If the suppression of the other sideband orthe carrier is not complete, the edges of thepattern show a ripple. Assuming that the carrieris completely suppressed, the relationship be-tween the desired and undesired side frequenciescan be represented by the phasor ^ diagramshown in Fig. 1. AB represents the amplitude X \ Fig. 1 — The mechanism I by which the undesired side / frequency makes a ripple on the desired side frequencyof an signal. Other pos-sible spurious components areneglected in this drawing, butcan be included if their rela-tive amplitu
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
