Crossnumber Puzzle
August 1958 Popular Electronics

August 1958 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.

In many ways a crossnumber (aka cross number or cross figure) puzzle, which is an intersecting grid of numbers, is more challenging than a standard crossword puzzle, which is an intersecting grid of letters. John Comstock created a few of these crossnumber puzzles for Popular Electronics back in the early days of the magazine. If you have never tried creating a crossword puzzle, especially one that uses only technical terms and has many interconnected squares in the grid, then you cannot appreciate the frustration it can be. The nice thing about creating a crossnumber puzzle versus a crossword puzzle is that every number is a valid "word" and it is therefore never a problem to find a clue to go with it. For example, any random number can be the answer to a clue that expresses it as the series or parallel combination of resistances, capacitances, or inductances.

Here is another Crossnumber puzzle from the April 1959 issue of Popular Electronics. 

Crossnumber Puzzle

By John A. Comstock

Like to work crossword puzzles? Then you have a treat awaiting you. Here is something new - a crossnumber puzzle. Instead of filling in words, you fill in numbers ... "electronic" numbers. Read the clues and see how well you can do.

Across

1. Upper frequency limit of broadcast band: kc.

4. Amount of wattage that equals 1 hp.

6. Number of degrees phase shift through capacitor.

7. One kilowatt: watts.

8. Impedance of common ribbon-type TV twin-lead.

11. Common record player speed: rpm.

12. Value of resistor color-coded brown, grey, violet, red.

13. TV line scanning frequency used in U. S.

15. TV field frequency.

16 Total resistance of two 5 -ohm resistors in series.

18 Last TV channel in u.h.f. group.

20 Foot -second velocity of sound waves in free space.

22 The year Edison demonstrated transverse of electrons between hot filament and cold plate in vacuum.

26 Amount of power that can be dissipated by two 15 -ohm, 50- watt resistors in series.

27 Ripple frequency output of single-phase full -wave rectifier: cps.

28 Hot resistance of 110 -volt, 50 -watt light bulb.

29 First TV channel in u.h.f. group.

30 Velocity of electromagnetic radiation in free space: mph.

Down

1 The year in which E. H. Armstrong first demonstrated his system of FM broadcasting.

2 Wavelength of 500 -kc. signal: meters.

3 Common commercial power line frequency in U. S.

5 Total capacitance of two 20 -pfd. capacitors in parallel.

7 The year Marconi sent wireless messages.

9 Intermediate frequency of some superhets.

10 International distress frequency: kc.

11 Intermediate frequency of many superheterodyne AM receivers.

14 In FM, frequency deviation that corresponds to 100% modulation: number of kc.

16 Upper limit of commercial FM broadcast band: mc.

17 Number of volts from 12 -volt battery.

19 Velocity of radio wave traveling in free space: meters.

21 The year E. H. Armstrong first demonstrated superheterodyne circuit.

23 Lower frequency limit of commercial FM band: mc.

24 Seventh harmonic of 360 kc.

25 Upper limit of TV v.h.f. Channel 13: mc.

27 Number of degrees phase shift through transformer.

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Here are other electronics-themed crossword puzzles from vintage electronics magazines (RF Cafe Crosswords here):

Posted March 27, 2024
(updated from original post on 10/3/2017)