1996 - 2016
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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July 1933 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.
Here is General Electric Model K-40-A Radio Service Data Sheet as featured in a 1933 edition of Radio-Craft magazine. As mentioned many times in the past, I post these online for the benefit of hobbyists looking for information to assist in repairing or restoring vintage communication equipment.
*Impossible to measure on ordinary voltmeter; on 25 cycles the voltages will be lower than those on 60 cycles. Voltages are measured to cathode. These figures are for set adjusted to maximum volume; line potential, 115 V., 60 cycles A.C., or D.C.
Note the use of a voltage doubling connection of rectifier V4; on A.C. the power output is greatly increased. Undistorted power output on A.C., 0.55-W.; on D.C., 0.15-W. Power consumption, 50 W, at 115 V, A.C. Since the frequency range is 540 to 1,710 kc., it is possible to receive police broadcasts on wavelengths below 200 meters.
Check power line characteristics and the position of Sw. 2 before connecting the set to the power line; disconnect the set before touching the chassis.
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 156 Radio Service Data Sheets as of December 6, 2016.