RF Cafe Software
About RF Cafe
1996 - 2022
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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January 1936 Radio-Craft[Table of Contents]
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Radio-Craft was published from 1929 through 1953. All copyrights are hereby acknowledged. See all articles from Radio-Craft.
The RCA Victor Model C9-4 is a 9-tube, 3-band superheterodyne console model radio made in the mid 1930s. A Radio Service Data Sheet for it appeared in the January 1936 issue of Radio-Craft magazine. The image to the left was found on the RadioMuseum.org website. FM broadcasting was not in common use yet, so only AM bands and some shortwave bands were available. In fact, 1936 was the year that frequency modulation (FM) inventor Edwin H. Armstrong first demonstrated his newfangled concept that largely solved the noise problem.
Before aligning this set, use tuning wand to be sure alignment is required. I.F. is aligned at 460 kc., by means of an oscillator. Use an output indicator or an oscilloscope. Adjust trimmers C29, C30, C24, and C25 in that order. Align band A at 1,720 kc., by adjusting C20, C10 and C3 to produce maximum output.
Tune oscillator to 600 kc., adjust receiver to resonance. regardless of dial setting, and adjust C19. Recheck C20. Band B is aligned at 6,132 kc., by setting test connections oscillator at this frequency and turning receiver station to this setting.
Posted December 5, 2016
Radio Service Data Sheets
These schematics, tuning instructions, and other data are reproduced from my collection of vintage radio and electronics magazines. As back in the era, similar schematic and service info was available for purchase from sources such as SAMS Photofacts, but these printings were a no-cost bonus for readers. There are 185 Radio Service Data Sheets as of April 12, 2017.