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What's Your EQ?
April 1962 Radio-Electronics

April 1962 Radio-Electronics

April 1962 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.

Here is another triplet of mystery circuit configurations for you to cogitate upon, if you are inclined to cogitate upon such things. The first one is not too much of a challenge, so don't over-think it. Number two: Fuggetaboutit, unless you were a television repairman back around 1962 when this "What's Your EQ?" feature appeared in Radio-Electronics magazine. Just reading the description makes my head hurt. Of course this would pose no difficulty for Mac McGregor. Last but by no means least is the dreaded "black box" problem. I usually do not fare too well on these. I have the reference Black Box No. 3 issue posted, but haven't added the images yet. My simplistic solution is to say there is a constant current source in the black box, but that is not the inventor's intention. Can you guess his solution? Bon chance.

What's Your EQ?

What's Your EQ (Electronics Quotient) ?, May 1962 Radio-Electronics - RF CafeIt's stumper time again. Here are three little beauties that will give you a run for the money. They may look simple, but double-check your answers before you say you've solved them. For those that get stuck, or think that it just can't be done, see the answers next month. If you've got an interesting or unusual answer send it to us. We are getting so many letters we can't answer individual ones, but we'll print the more interesting solutions (the ones the original authors never thought of). Also, we're in the market for puzzlers and will pay $10 and up for each one accepted. Write to EQ Editor, Radio-Electronics, 154 West 14th St., New York, N. Y.

Why the Decrease?

Knobs 1 and 2 are continuously variable from A to B. Set knob 2 at A as shown, and rotate knob 1 from A to B. The output will increase.

Now set knob 2 at B and rotate knob 1 from A to B. The output decreases!


- Henry P. Houton


Too-Automatic Tuner

Symptoms: Automatic tuner changes stations, turns volume up or down, turns set off, etc., all by itself! Horizontal hold off quite a bit. Very fine lines on screen. Customer has turned horizontal hold control quite a bit out of range. Set is a Zenith 16C21Q.

Clues: As soon as set warms up, automatic tuner takes off and may do anything at all. Cutting it off with selector switch on back allows set to work normally, outside of horizontal hold being away off frequency.

Hint: When picture was locked in by restoring horizontal hold control to normal, automatic tuner worked perfectly. Is auto-tuner intermittent or what?


Black Box No. 4

In this variation of Black Box No. 3, which appeared in the September 1961 issue, any number of cells may be connected to the box as shown. Whether the cells are connected in series or in parallel, the current will be the same. What is in the box?

- Douglas A. Gammage

Quizzes from vintage electronics magazines such as Popular Electronics, Electronics-World, QST, 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


April Solutions

Why the Decrease?

Let's look inside.


Too-Automatic Tuner

This chassis uses an ultrasonic automatic tuner circuit, operating around 45 kc or so. When horizontal hold was thrown off frequency, either the fundamental or a harmonic, radiated as sonic waves by the flyback or yoke, got into the input of the automatic tuner, which is a microphone at the front of the chassis! Turning the horizontal hold control would cause the auto-tuner to react on one of its functions, depending upon the frequency being generated by the horizontal output at the time!


Black Box No.4

The black box contains a resistor equal to the internal resistance of one cell, as shown in the figure. When the cells are in series, the current is equal to the total voltage divided by the sum of the resistances of each of the cells plus the resistor in the box. With the cells in parallel, the voltage of one cell is applied to the resistance in the box plus the resistance of one cell divided by the number of cells. Try it with a couple of examples!



Posted June 19, 2024

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