RF Cafe Software
About RF Cafe
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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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 American-Bosch model 430T is a 5-tube, 3-band superheterodyne table 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.
Adjustment of this set is accomplished in the usual manner, with volume control on full and tone control in the center or treble position. A series condenser of at least .25-mf. must be connected in the high side of' the oscillator test leads to act as a blocking condenser. With the oscillator set at 450 kc., align trimmers 4 and 5, then 7 and 8 for best signal. Set wave-band switch in broadcast position. Align dial pointer at maximum mark beyond 540 kc. point with gang fully closed. Set oscillator at 1,500 kc., turn set dial to same point and adjust 13 to maximum.
Connect oscillator to antenna through a 200 mmf. condenser and adjust 13 and 17 to best output. Set dial and oscillator at 550 kc., and adjust trimmer 15 at the same time changing the set gang condenser for best output. Readjust 13 and 17 with oscillator and condenser set at 1,500 kc, The police band is aligned with the center knob on the left-hand position, the wave-change switch being left in the broadcast position. Set dial at 1,500 kc. (this is position for reception of 2,400 kc.). With oscillator set at 2,400 kc., tune in signal with station selector and set 19 to best position.
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 177 Radio Service Data Sheets as of February 17, 2017.