Search RFCafe.com                           
      More Than 18,000 Unique Pages
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
Please Support My Advertisers!
 
  Formulas & Data
Electronics | RF
Mathematics
Mechanics | Physics
 About | Sitemap
Homepage Archive
        Resources
Articles, Forums Calculators, Radar
Magazines, Museum
Radio Service Data
Software, Videos
     Entertainment
Crosswords, Humor Cogitations, Podcast
Quotes, Quizzes
   Parts & Services
1000s of Listings
Software: RF Cascade Workbook | Espresso Engineering Workbook
RF Stencils for Visio | RF Symbols for Visio
RF Symbols for Office | Cafe Press
Aegis Power | Alliance Test | Centric RF | Empower RF | ISOTEC | Reactel | RFCT | San Fran Circuits
Anritsu Test Equipment - RF Cafe

Axiom Test Equipment - RF Cafe

Innovative Power Products Cool Chip Thermal Dissipation - 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

KR Electronics (RF Filters) - RF Cafe

What's Your EQ?
August 1961 Radio-Electronics

August 1961 Radio-Electronics

August 1961 Radio-Electronics Cover - RF Cafe[Table of Contents]

Wax nostalgic about and learn from the history of early electronics. See articles from Radio-Electronics, published 1930-1988. All copyrights hereby acknowledged.

Three new "Electronics Quotient" (EQ) puzzles await your solving, these from the August 1961 issue of Radio-Electronics magazine. The first, "A Lighting Problem," is fairly simple. You'll need to think out-of-the-box to figure out what is in-the-box. If I got it, you can get it. The second puzzler, "Resistor Mixup," is yet another variation on a common attempt to throw the reader off by configuring the connections in a nonconventional manner. By the way, you might remember to use the same technique to assess actual schematics when attempting to figure out what is going on in a "real" circuit. It seems to me whenever not enough EQs are received from readers, Jack Darr, of R-E's "TV Service Clinic" column fame, is solicited for one of his TV troubleshooting challenges. Being in the prehistoric Vacuum Tube Age (~1906-1966), his circuits nearly always involved tubes and complex analog waveforms. Anyone born after about 1970 may skip this problem ;-)

What's Your EQ?

We've been swamped! Each day the post office delivers so much mail for our EO column that we've had trouble keeping up with it. We're happy to learn so many of our readers are interested in the puzzles, but we just won't be able to answer any individual letters. We will publish any interesting solutions we receive.

Our black box problem this month is a little different, it has two black boxes instead of one. And the TV stinker is a little more difficult than usual.

Send us more problems on the engineering level - we have plenty of TV and general ones, $10 and up will be paid for each one accepted. Write to EQ Editor, Radio-Electronics, 154 West 14th St., New York 11, N, Y.

Answers to July puzzles are On page 75. Answers to this month's puzzles appear next month.

A Lighting Problem - RF CafeA Lighting Problem

Two boxes are connected by a single wire. A lead runs from each box to an ac source. On the first box are mounted two bulbs; on the second a single-pole, three-position switch. In the first position of the switch, the red bulb glows; in the second, the blue one glows, and in the third position, both bulbs light. What is the simple circuitry in the two boxes that performs this bit of "magic"?

 - Charles B. Randall

 

Resistor Mixup

Resistor Mixup - RF CafeThis apparently simple problem in resistance becomes more confusing as you study it. Find the effective resistance of this circuit.

- Fred W. Blakeley

 

Yuletide Effect

Yuletide Effect - RF CafeSymptoms: Horizontal oscillator in a Truetone 2D1235A squegged, and made "Christmas trees" all over the place. No high voltage at all. Tubes and all parts OK.

Clues: If horizontal oscillator coupling capacitor is disconnected from horizontal output stage, output stage can be driven to full output, plenty of high voltage and brightness, by using external horizontal drive pulse from tester. If horizontal output is driven in this way to bring boost voltage up, horizontal oscillator then puts out perfectly shaped, locked-in-sync waveform. If the two are re-connected, waveform at horizontal output tube grid looks like drawing - almost as if a color burst were being added to the slope of the waveform - and whole thing won't work.

Hint: The oscillator and output stages will work separately and all parts are good, but the two won't work together.

- Jack Darr


Quizzes from vintage electronics magazines such as Popular Electronics, Electronics-World, QST, Radio-Electronics, and Radio News were published over the years - some really simple and others not so simple. Robert P. Balin created most of the quizzes for Popular Electronics. This is a listing of all I have posted thus far.

RF Cafe Quizzes

Vintage Electronics Magazine Quizzes

Vintage Electronics Magazine Quizzes

Vintage Electronics Magazine Quizzes

Solutions

A Lighting Problem

Yuletide Effect (solution) - RF CafeThe switching is accomplished by an arrangement of rectifying diodes. In position 1, the positive pulse from the ac generator is passed through the single wire into the box with the bulbs. This pulse is accepted only by the rectifier hooked up in the same polarity and blocked by the other rectifier, the resulting current flow lighting the red bulb. In position 2, the opposite occurs and the blue bulb lights. In position 3, pure ac is passed into the first box and both bulbs light, one from the position pulse and the other from the negative pulse.

Resistor Mixup

Answer: Actually all the resistors are connected in parallel. Therefore, the effective resistance is 8 ohms .

Yuletide Effect

The 80-μf electrolytic capacitor in the output of the B-supply filter is defective. It had an extremely high power factor, coupled with a severe loss of capacitance, although there was no perceptible hum in the sound. This allowed the horizontal oscillator to receive peaks or pulses probably fed back through the boost in some way and caused it to break into sporadic oscillation on each cycle. This broke up the time-constant circuits in the yoke, etc., and stopped the output stage from functioning properly.

KR Electronics (RF Filters) - RF Cafe
withwave microwave devices - RF Cafe

Cafe Press

Werbel Microwave (power dividers, couplers)