November 1965 Popular Electronics
Table of Contents
Wax nostalgic about and learn from the history of early electronics. See articles
from
Popular Electronics,
published October 1954 - April 1985. All copyrights are hereby acknowledged.
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1965 was near the beginning
of the transition from vacuum tubes (plasma state) to semiconductors (solid state). If
you are not familiar with tube circuits, when deciding what type of mathematical operation
is being performed by each circuit, mentally replace the tube with a FET or a BJT. The
tube plate becomes the transistor drain or collector, the cathode is the source or emitter,
and the control grid is the gate or base, respectively. Don't worry about biasing. Circuits
A, D, and I should prove to be the easiest. Circuit F is pretty obvious if you look at
the input and output waveforms shown. Anyone familiar with analog power supplies will
breeze through circuits B and G (hint: count the number of charge storage components).
For the others, ignore that there is a squarewave shown at the input since the function
is not dependent on a squarewave to work. For circuit H, mentally reposition the bottom
tube above the other and have the B+ line point upward, then figure out what happens
as each turns on. It was common to draw B+ lines pointing downward whereas in transistor
circuits they normally point upward or sideward. Think of the two tubes in circuit E
as parallel resistors changing value (point B+ upward). Circuit C takes a bit of work
(hint: the circuit is a detector). Circuit J is the toughest of all, but if you get the
other 9 correct, only one possible answer remains from which to choose - that's how I
scored 10:10.
Electronics Math Quiz
By Robert P. Balin
Many basic electronic circuits can and do perform mathematical operations ranging
from elementary arithmetic to integral calculus. See if you can identify the electronic
circuits (A-J) below which perform the mathematical operations (1-10) at right.

1) Add ____________
2) Count ____________
3) Differentiate ____________
4) Double ____________
5) Divide ____________
6) Integrate ____________
7) Ratio ____________
8) Square ____________
9) Subtract ____________
10) Triple ____________
See answers below.
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.
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-
Elementary
Radio Quiz - December 1947 Radio-Craft
- Hi-Fi
Quiz - October 1955 Radio & Television News
- Electronics Physics
Quiz - March 1974 Popular Electronics
- A Baffling Quiz
- January 1968 Popular Electronics
- Electronics IQ
Quiz - May 1967 Popular Electronics
- Plug and Jack
Quiz - December 1967 Popular Electronics
- Electronic
Switching Quiz - October 1967 Popular Electronics
- Electronic
Angle Quiz - September 1967 Popular Electronics
- International
Electronics Quiz - July 1967 Popular Electronics
- FM Radio
Quiz - April 1950 Radio & Television News
- Bridge Circuit
Quiz -December 1966 Popular Electronics
- Diode Function
Quiz - August 1965 Popular Electronics
- Diagram Quiz,
August 1966 Popular Electronics
- Quist Quiz - November
1953 QST
- TV Trouble Quiz,
July 1966 Popular Electronics
- Electronics History Quiz,
December 1965 Popular Electronics
- Scope-Trace Quiz,
March 1965 Popular Electronics
-
Electronic
Circuit Analogy Quiz, April 1973
-
Test Your Knowledge of Semiconductors, August 1972 Popular Electronics
- Ganged Switching
Quiz, April 1972 Popular Electronics
- Lamp Brightness
Quiz, January 1969 Popular Electronics
- Lissajous Pattern Quiz, September 1963 Popular Electronics
- Electronic
Quizoo, October 1962 Popular Electronics
- Electronic Photo Album Quiz, March 1963 Popular Electronics
- Electronic Alphabet Quiz, May 1963 Popular Electronics
- Quiz: Resistive?
Inductive? or Capacitive?, October 1960 Popular Electronics
- Vector-Circuit Matching Quiz, June 1970 Popular Electronics
- Inductance
Quiz, September 1961 Popular Electronics
- RC Circuit Quiz,
June 1963 Popular Electronics
- Diode Quiz, July
1961 Popular Electronics
- Electronic Curves Quiz, February 1963 Popular Electronics
- Electronic Numbers Quiz, December 1962 Popular Electronics
- Energy Conversion Quiz, April 1963 Popular Electronics
- Coil Function
Quiz, June 1962 Popular Electronics
-
Co-Inventors Quiz - January 1965 Electronics World
-
"-Tron" Teasers Quiz - October 1963 Electronics World
- Polarity Quiz
- March 1968 Popular Electronics
-
Television
I.Q. Quiz - October 1948 Radio & Television News
- Amplifier Quiz
Part I - February 1964 Popular Electronics
- Semiconductor
Quiz - February 1967 Popular Electronics
- Unknown
Frequency Quiz - September 1965 Popular Electronics
- Electronics
Metals Quiz - October 1964 Popular Electronics
- Electronics
Measurement Quiz - August 1967 Popular Electronics
- Meter-Reading
Quiz, June 1966 Popular Electronics
- Electronic
Geometry Quiz, January 1965 Popular Electronics
- Electronic
Factor Quiz, November 1966 Popular Electronics
- Electronics
Math Quiz, November 1965 Popular Electronics
- Series Circuit
Quiz, May 1966 Popular Electronics
- Electrochemistry
Quiz, March 1966 Popular Electronics
- Biz
Quiz: Test Your Sales Ability - April 1947 Radio News
- Electronic
Analogy Quiz, November 1961 Popular Electronics
- Electronic
Coupling Quiz, August 1973 Popular Electronics
- Electronics Analogy Quiz, August 1960 Popular Electronics
- Audio Quiz, April
1955 Popular Electronics
- Electronic Unit
Quiz, May 1962 Popular Electronics
- Capacitor
Circuit Quiz, June 1968 Popular Electronics
- Quiz on AC Circuit Theory, December 1970 Popular Electronics
- Magnetic Phenomena Quiz, February 1962 Popular Electronics
- Electronics Geography Quiz, April 1970 Popular Electronics
- Electronic
Menu Quiz, August 1963 Popular Electronics
- Electronic Noise Quiz, August 1962 Popular Electronics
- Electronic Current Quiz, October 1963 Popular Electronics
- Electronic Inventors Quiz, November 1963 Popular Electronics
- Resistor Function
Quiz, January 1962 Popular Electronics
- Electronic Measurement Quiz, January 1963 Popular Electronics
- Vacuum Tube Quiz,
February 1961 Popular Electronics
- Kool-Keeping Kwiz, June
1970 Popular Electronics
- Find the Brightest
Bulb Quiz, April 1960 Popular Electronics
-
Where Do the Scientists Belong? - Feb 19, 1949 Saturday Evening
Post
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Math Quiz Answers
1 - H Amplifiers which have their load resistors in series produce an
output signal proportional to the sum of the in-phase input signals.
2 - F A step counter produces an escalated output which varies exponentially
with the number of pulses it receives. It can be used to count the number of pulses it
receives, and as a frequency divider by allowing it to trigger another circuit, say at
every 2nd, 3rd ... 7th step, as desired.
3 - I A differentiator circuit produces an output whose instantaneous
values are proportional to the rate of change of the input voltage waveform.
4 - G A voltage doubler produces a d.c. output which is approximately
equal to twice the r.m.s. value of the a.c. input voltage.
5 - D A voltage divider provides an output which is in the same proportion
to the applied voltage as the divider resistance is to the total resistance.
6 - A An integrating circuit provides an output voltage which is approximately
proportional to the time integral and potential of the input voltage.
7 - J In a ratio detector circuit, the variations of audio frequency output
signals have the same ratio as the variations of the applied FM radio frequency signals.
8 - C A triode square law detector produces an output signal which is
proportional to the square of the input signal.
9 - E A differential amplifier produces an output signal whose amplitude
is proportional to the difference between two in-phase input signals.
10 - B A voltage tripler circuit produces a d.c. output which is approximately
equal to three times the r.m.s. value of the a.c. input voltage.
Posted April 25, 2018
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