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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February 1930 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 Brunswick Panatrope was billed as the world's first all-electric phonograph (as opposed to the mechanical crank-up models), combined with an AM radio. It was designed with the assistance of RCA, many of whose components were integrated into the unit. A video of a restored Panatrope is embedded on the page below the data sheet.
In this receiver a radio-record switch, Sw2, cable and input transformer, T4, are used, in order that the low-impedance of the pick-up may be matched with the relatively high input impedance existing in the primary of T1. Referring to the parts layout sketch, units TC1, TC2, TC3 and TC4 are trimmer condensers in shunt to the tuning condensers but not shown in the schematic circuit. This receiver is in three sections: The R.F. chassis, the "SPU" (socket-power-unit) chassis and the dynamic reproducer. Field current for the latter is supplied by the SPU. Note that operation of the receiver should not be attempted unless either the field coil of a dynamic or a 600-ohm resistor is connected across the terminals for the two "field" leads; this resistor must be capable of carrying 100 ma. To facilitate service, the RF. chassis and SPU chassis are bolted to a single mounting board which, in turn, may be removed from the cabinet by removing retaining bolts at the rear of the mounting board...
Restored Brunswick Panatrope
Posted June 9, 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.