Search RFC: |                                  
Please support my efforts by ADVERTISING!
Serving a Pleasant Blend of Yesterday,
Today, and Tomorrow™

Vintage Magazines

Electronics World
Popular Electronics
Radio & TV News
QST | Pop Science
Popular Mechanics
Radio-Craft
Radio-Electronics
Short Wave Craft
Electronics | OFA
Saturday Eve Post

Formulas | Data

Electronics | RF
Mathematics
Mechanics
Physics


Calvin & Phineas

kmblatt83@aol.com

Archive | Sitemap

Resources

Articles | Radar
Cogitations
Magazines | AI
RF Museum
Software | Videos
Radio Service
Tech Notes

Entertainment

Crosswords
Humor | Podcasts
Quotes | Quizzes
Tech Comics

Parts | Services

1000s of Listings


About RF Cafe

Software: RF Cascade Workbook | RF Symbols for Office | RF Symbols & Stencils for Visio | Espresso Workbook
Please Support My Advertisers!
Aegis Power | Centric RF | RFCT
Empower RF | Reactel | SF Circuits

Alliance Test | Isotec
Exodus Advanced Communications Best in Class RF Amplifier SSPAs

Innovative Power Products (IPP) Directional Couplers - RF Cafe

Amplifier Solutions Corporation (ASC) - RF Cafe

everythingRF AI Artificial Intelligence Client - RF Cafe

Werbel Microwave power dividers, couplers - RF Cafe

Please Support RF Cafe by purchasing my ridiculously low-priced products, all of which I created.

RF Cascade Workbook for Excel

RF & Electronics Symbols for Visio

RF & Electronics Symbols for Office

RF & Electronics Stencils for Visio

RF Workbench

T-Shirts, Mugs, Cups, Ball Caps, Mouse Pads

These Are Available for Free

Espresso Engineering Workbook™

Smith Chart™ for Excel

Copper Mountain Technologies Vector Network Analyzers - RF Cafe

General Electric Models G-105 and G-106
Radio Service Data Sheet
December 1938 Radio-Craft

minimum height spacer

December 1938 Radio-Craft

December 1938 Radio Craft Cover - RF Cafe[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.

General electric G-106 Vintage Radio (raddiomuseum.org) - RF CafeGeneral Electric engineers were really thinking 'outside of the box' when designing the 1938-vintage Model G-106 console radio. In addition to its stylish wooden cabinet, the 13-station, piano-keyboard-like 'Touch-Tuning' tuning scheme employed a motor-driven variable resonant tank circuit. No doubt the sound of a motor spinning inside was a major selling point for hooking techno-audiophiles of the era. There are some good photos of a restored GE Model G-106 console radio on the RadioMuseum.org website that includes details of the tuning mechanism.

General Electric Models G-105 and G-106

 - RF CafeGeneral Electric Model G-106·receiver featuring automatic program selection, Beam-a-Scope antenna, and touch-tuning. The pushbuttons are in the form of piano keys.

10-Tube Superhet.; 3-Bands (540-1,575 kc.; 1,575-5,700 kc.; 5,700-18,000 kc.); "Beam-a-Scope" built-in antenna; 13-Station Touch-Tuning System; Push-Pull Output; A.V.C.; Power Output (max.) 13 W.; Automatic (time clock) Program Selection (Model G-106 only)

Alignment Procedure. I.F. Alignment with Oscilloscope

Condenser gang at minimum capacity vertical input to ground and junction at R-25, R-12, and R-17. Adjust trimmers in order mentioned for a single . curve of maximum amplitude. . The resulting curve on the "Normal" position is shown in Fig. 2A. The expanded curve taken with tone control at "Treble 1" is shown in Fig. 2B.

Alignment Procedure. I.F. Alignment with Meter

Condenser gang at minimum capacity- output meter connected across voice coil volume control at maximum input as low as practical.

Mechanically adjust dial pointer to first line at left-hand end of dial scale with condenser gang fully meshed.

Connect output meter across voice coil - antenna switch turned to counter-clockwise position.

 - RF CafeAdjust; trimmers in order listed for maximum-output.

Adjust padder for maximum output in vicinity of 580 K.C. while rocking gang condenser.

Touch-Tuning

Figure 1 shows a simplified schematic of the control circuit and the following cycle of operation may be traced very easily. When a key is depressed. it completes the 23-volt circuit through the button making contact with the contact segment (CT) and energizes one winding of the motor. The other winding on the motor is energized through the condenser C51. The direction of rotation of the motor is dependent upon whichever half of the contact segment (CT) that the station button first energizes. When voltage is applied to the motor, the rotor is pulled further into motor field. and engages its rubber cone hub with the dial drive wheel which in turn rotates the gang condenser and contact segment (CT). This operation continues until the insulated segment (1) breaks the station button circuit to the contact segment and removes voltage from the motor. The inertia in the tuning system drives the insulated segment past the station button and makes contact with the other half of the contact segment. This ener-gizes the other winding of the motor and causes the motor to reverse. The brake on the dial drive wheel· does not allow the tuning

 

 

Posted May 17, 2017


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 255 Radio Service Data Sheets as of April 30, 2025.

ConductRF Precision RF Test Cables MAESTRO - RF Cafe