. QST . er, and the tuning range of Ci was approxi-mately 40 kc. With C2 set at maximum, the band-sot had to be set about 300 kc. higher, and therange of Ci was about 300 kc. On 40, the band-set was adjusted about 200kc. higher, C2 at minimum, and the tuning rangewas about 40 kc. With C2 at maximum, theband-set was about 250 kc. higher, and the rangeslightly over 300 kc. On the 20- and 10-meter bands, the band-setadjustment was only slightly different thannormal. On 20, the bandspread range of C\ couldbe varied from about 30 kc, with Ci at minimum,to about 300 kc. with C2 at maximum. The range
. QST . er, and the tuning range of Ci was approxi-mately 40 kc. With C2 set at maximum, the band-sot had to be set about 300 kc. higher, and therange of Ci was about 300 kc. On 40, the band-set was adjusted about 200kc. higher, C2 at minimum, and the tuning rangewas about 40 kc. With C2 at maximum, theband-set was about 250 kc. higher, and the rangeslightly over 300 kc. On the 20- and 10-meter bands, the band-setadjustment was only slightly different thannormal. On 20, the bandspread range of C\ couldbe varied from about 30 kc, with Ci at minimum,to about 300 kc. with C2 at maximum. The rangeon 10 was about 2 Mc. with C2 at minimum,and with C2 set at about half capacitance, theentire band was covered. This simple band-scannercan be thrown together in afew minutes. The ball-bearingcapacitor driven by the clockmotor is mounted, with itsshaft in line with that of themotor, on a scrap of alumi-num. The range-adjusting ca-pacitor, C2, is suspended fromC\ on stiff leads connecting itto the July 1955 19 A Tripler for the 1215-iyic. Band Crystal-Controlled Output with 420-Mc. DriveBY RUSSELL W. ROBERTSON.* W6DQJ • Most of the work done so far on 1215Me. has been with oscillator-type rigs,which leave much to be desired in theway of stability and efficiency. Here is asolution in line with more modern tech-niques: a tripler that can be driven witha low-poMered 420-Mc. stage. NOW that the design of stable equipment forthe 420-Mc. band is fairly well standardized,experimentally inclined hams are thinkingof going higher in frequency. Most of the workdone so far on 1215 Mc. and higher bands hasl)een with oscillator-type transmitters. This canbe fun, but experience has shown, as on all lowerbands, that if we are to accomplish any real goodit must be with something more stable and reUa-l)le in performance. Choice of tubes for use as frequency multipliersor ampUfiers is limited enough at 420 we go to 1215, there is practically nochoice at all. The lighthouse
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectradio, bookyear1915
