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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 World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a nice lady's voice announced "You've Got Mail" when a new message arrived...

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Kennedy "Model 826B" Combination Receiver Radio Service Data Sheet
February 1931 Radio-Craft

February 1931 Radio-Craft

[Table of Contents]

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Craft, published 1929 - 1953. All copyrights are hereby acknowledged.

I don't usually read through all of the text included with these Radio Service Data Sheets, but I did see at the end of this one where instructions are given for increasing the sensitivity of the units. Capacitor value increases are made in the dynatron oscillator circuit, which is the beat frequency oscillator (BFO) in the received signal path. Why wouldn't that have been incorporated in the factory-built radio? My guess is that the tuning process would take more effort than a typical owner would be willing to tolerate. I could not locate a photo of the Model 826B.

Kennedy "Model 826B" Combination Receiver

With the "Model 826B" broadcast receiver , the Colin B. Kennedy Co., South Bend, Ind., pioneers the field of mass-produced "combination-wave" radio receivers The long-wave chassis, covering the regular broadcast band (and a bit more), tunes from about 195 to 550 meters, and is "Model 26;" the short-wave chassis, "Model 34," tunes over three wave-length bands of 15-25, 25-50 and 50-100 meters, each band being switch-selected. The two chasses, in a Model 826 cabinet, comprise the Kennedy "Model 82613" receiver; the latest diagram of connections appears below. The receiver has a tone-control (R8-CI7).

The following modifications for increasing the sensitivity of the "Model 826B" receiver are recommended only to the experienced Service Man, and are to be applied with care: Change C13S to .04-mf., and shunt the old 0.25-mf. unit across C14S. Replace C22 by a .002-mf. unit. The shielding of the oscillator output wire must be grounded to the chassis. A good ground connection must be used for the combination set. Tube variations will be more evident in a set of this nature and, for best results, it is ad-visable to try several of each type.

All shielding must be fastened tightly The shielded coil at the rear center of the base is L2S; midget condenser C2S is on its shield top.

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 227 Radio Service Data Sheets as of December 28, 2020.

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Kennedy "Model 826B" Combination Receiver Radio Service Data SheetFebruary 1931 Radio-Craft

Kennedy "Model 826B" Combination Receiver

Kennedy "Model 826B" Combination Receiver Radio Service Data Sheet
February 1931 Radio-Craft