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
Copper Mountain Technologies Vector Network Analyzers - RF Cafe

Copper Mountain Technologies Vector Network Analyzers - RF Cafe

ConductRF VIDA67 RF Cables - RF Cafe


everythingRF AI Artificial Intelligence Client - 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

Johanson Technology Hi-Q Porcelain Capacitors - RF Cafe

Clarion De Luxe Models AC-280 and 25-280, 12-Tube Superheterodyne
Radio Service Data Sheet
September 1932 Radio-Craft

September 1932 Radio-Craft

September 1932 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.

For many years now I have been scanning and posting Radio Service Data Sheets like this one featuring the Clarion De Luxe Models AC-280 and 25-280, 12-tube superheterodyne radio receiver. There are still many people who restore and service these vintage radios, and often it can be difficult or impossible to find schematics and/or tuning information. Unfortunately, an extensive Internet search did not turn up any examples of the Clarion Model 280.

Clarion De Luxe Models AC-280 and 25-280 12-Tube Superheterodyne

One of the newest of Transformer Cor-poration of America's "Clarion" line of radio sets is the De Luxe Model 280 superheterodyne, listing for less than seventy dollars, which incorporates a number of interesting circuit variations with which the Service Man must acquaint himself; these new circuit "kinks" are evident by reference to the schematic circuit.

The component characteristics are as follows: Resistor R1, manual volume control, 0.75·meg.; R2, tone control, 0.1-meg.; R3, 500 ohms; R4, R8, 10,000 ohms; R5, 0.1-meg. ; R6 1. meg.; R7, ¼ meg.; R9, 8,100 ohms: R10, 1,000 ohms; R11, 300 ohms. The field coils measure 400 ohms each; choke Ch., 400 ohms.

In the second-detector stage two type '27 tubes are used in double diode con-nection. In this circuit the detectors are used as ordinary two-element rectifiers of the R.F. signal fed to their control-grids, which arc connected in push-pull. The plates are connected in parallel, the audio component dividing into two paths.

Automatic volume control is secured through the pulsating D. C. (rectified R.F.) drop across R7. The higher powered stations with strong R.F. carriers when tuned in cause greater pulsating D.C. to flow from the detectors' plate-cathode, through R7, to ground; thus, the drop across R7 is in-creased.


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.

 

Posted

KR Electronics (RF Filters) - RF Cafe