1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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April 1959 Popular ElectronicsTable of Contents
People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Popular Electronics was published from October 1954 through April 1985. All copyrights are hereby acknowledged. See all articles from Popular Electronics.
Here is a rather unique type of crossword puzzle that uses numbers rather than words. It appeared in the April 1959 edition of Popular Electronics. The software that I use to create the RF Cafe crossword puzzles each week has the ability to create such a puzzle, but I have never made one because it would take a lot of time to build a clue / answer file to be drawn upon for input. Maybe some day I'll do it, though.
by John A. Comstock
1 Year Fleming invented diode vacuum tube.
3 This quantity multipled by r.m.s. value of a.c. voltage will give peak voltage.
6 Slow record player speed.
5 Difference frequency in kilocycles produced by mixing 1000·kc. signal with 50·kc. signal.
9 Quantity by which peak value of a.c. voltage is multiplied to obtain r.m.s, value.
12 One-half kilowatt expressed in watts.
13 Output frequency in kc. of transmitter having crystal frequency of 2017.5 kc. and two doubler stages.
14 Lower limit of u.h.f. frequency band expressed in megacycles.
15 Large-size hi-fi woofer.
17 Very slow record speed.
18 Year tetrode (screen-grid) vacuum tube was developed. in reverse.
20 Mid frequency in megacycles of TV Channel 6 when lower frequency limit equals 76 mc.
21 Total resistance of two 44-ohm resistors connected in series.
22 Upper frequency limit in mc .. of super-high-frequency band.
24 Voltage drop across 20-ohm resistor when current flow is 10 amperes.
25 Number of feet in 12 yards of hookup wire.
26 Mid frequency of TV Channel 2 when upper channel frequency limit is 60 mc.
27 Actual filament voltage rating of 6-volt vacuum tubes.
28 Popular-size TV screen.
30 Heater voltage of 35Z5 vacuum tube.
31 Separation in megacycles between TV sound and video carrier frequencies.
32 Number of zeros represented by letter K in stating resistor values.
33 Cycles in one megacycle.
34 Total voltage drop in series circuit when applied voltage equals 50 volts.
1 Degrees of phase shift in voltage fed back to produce
degeneration in amplifier circuit.
2 TV aspect ratio; ratio of picture width to height.
4 Year Lee de Forest invented triode.
5 Voltage drop across 90-ohm resistor when current flow equals 112 amperes.
7 Tape recorder slow speed in ips.
10 Wavelength in meters of 400-kc. signal.
11 Fast record player speed in rpm (approx.).
14 Electrical degrees in one cycle of alternating signal.
16 In resistor color code, number represented by green,white and yellow.
17 Year pentode was developed.
19 Electrical degrees in one alternation of sinewave signal.
23 Capacitance reactance of 1.0 ufd. capacitor at frequency of 60 cps.
24 Express 0.00271 henrys in microhenries.
27 Convert 650,000 watts to kilowatts.
29 Amount of capacitance in farads that will store 100 coulombs of electricity when applied voltage equals 1.0 volt.
30 This number means "the end."
31 Grade of solder often used in electronics work.
Posted December 27, 2013