Appendix
Useful Information
Abbreviations of Units
| Unit | Abbreviation |
| ampere | amp. |
| ampere-hours | amp.-hr. |
| centimeter | cm. |
| centimeter-gram-second c.g.s. | |
| cubic centimeters | cm.^3 |
| cubic inches | cu. in. |
| cycles per second | ~ |
| degrees Centigrade | °C. |
| degrees Fahrenheit | °F. |
| feet | ft. |
| foot-pounds | ft.-lb. |
| grams | g. |
| henries | h. |
| inches | in. |
| kilograms | kg. |
| kilometers | km. |
| kilowatts | kw. |
| kilowatt-hours | kw.-hr. |
| kilovolt-amperes | kv.-a. |
| meters | m. |
| microfarads | [Greek: mu]f. |
| micromicrofarads | [Greek: mu mu]f. |
| millihenries | mh. |
| millimeters | mm. |
| pounds | lb. |
| seconds | sec. |
| square centimeters | cm.^2 |
| square inches | sq. in. |
| volts | v. |
| watts | w. |
Prefixes Used With Metric System Units
| Prefix | Abbreviation | Meaning |
| micro | [Greek: mu]. | 1 millionth |
| milli | m. | 1 thousandth |
| centi | c. | 1 hundredth |
| deci | d. | 1 tenth |
| deka | dk. | 10 |
| hekto | h. | 1 hundred |
| kilo | k. | 1 thousand |
| mega | m. | 1 million |
Symbols Used for Various Quantities
Quantity Symbol
capacitance C
conductance g
coupling co-efficient k
current, instantaneous i
current, effective value I
decrement [Greek: delta]
dielectric constant [Greek: alpha]
electric field intensity [Greek: epsilon]
electromotive force,
instantaneous value E
electromotive force,
effective value F
energy W
force F
frequency f
frequency x 2[Greek: pi] [Greek: omega]
impedance Z
inductance, self L
inductance, mutual M
magnetic field intensity A
magnetic flux [Greek: Phi]
magnetic induction B
period of a complete
oscillation T
potential difference V
quantity of electricity Q
ratio of the
circumference of a
circle to its diameter
=3.1416 [Greek: pi]
reactance X
resistance R
time t
velocity v
velocity of light c
wave length [Greek: lambda]
wave length in meters [Greek: lambda]m
work W
permeability [Greek: mu]
Square root [Math: square root]
Table of Enameled Wire
| No. of | Turns | Turns | Ohms per |
| Wire, | per | per | Cubic Inch |
| B.& S. | Linear | Square | of |
| Gauge | Inch | Inch | Winding |
| 20 | 30 | 885 | .748 |
| 22 | 37 | 1400 | 1.88 |
| 24 | 46 | 2160 | 4.61 |
| 26 | 58 | 3460 | 11.80 |
| 28 | 73 | 5400 | 29.20 |
| 30 | 91 | 8260 | 70.90 |
| 32 | 116 | 21,000 | 7547.00 |
| 34 | 145 | 13,430 | 2968.00 |
| 36 | 178 | 31,820 | 1098.00 |
| 38 | 232 | 54,080 | 456.00 |
| 40 | 294 | 86,500 | 183.00 |
Table of Frequency and Wave Lengths
W. L.—Wave Lengths in Meters.
F.—Number of Oscillations per Second.
O. or square root L. C. is called Oscillation Constant.
C.—Capacity in Microfarads.
L.—Inductance in Centimeters.
1000 Centimeters = 1 Microhenry.
| W.L. | F | O | L.C. |
| 50 | 6,000,000 | .839 | .7039 |
| 100 | 3,000,000 | 1.68 | 2.82 |
| 150 | 2,000,000 | 2.52 | 6.35 |
| 200 | 1,500,000 | 3.36 | 11.29 |
| 250 | 1,200,000 | 4.19 | 17.55 |
| 300 | 1,000,000 | 5.05 | 25.30 |
| 350 | 857,100 | 5.87 | 34.46 |
| 400 | 750,000 | 6.71 | 45.03 |
| 450 | 666,700 | 7.55 | 57.00 |
| 500 | 600,000 | 8.39 | 70.39 |
| 550 | 545,400 | 9.23 | 85.19 |
| 600 | 500,000 | 10.07 | 101.41 |
| 700 | 428,600 | 11.74 | 137.83 |
| 800 | 375,000 | 13.42 | 180.10 |
| 900 | 333,300 | 15.10 | 228.01 |
| 1,000 | 300,000 | 16.78 | 281.57 |
| 1,100 | 272,730 | 18.45 | 340.40 |
| 1,200 | 250,000 | 20.13 | 405.20 |
| 1,300 | 230,760 | 21.81 | 475.70 |
| 1,400 | 214,380 | 23.49 | 551.80 |
| 1,500 | 200,000 | 25.17 | 633.50 |
| 1,600 | 187,500 | 26.84 | 720.40 |
| 1,700 | 176,460 | 28.52 | 813.40 |
| 1,800 | 166,670 | 30.20 | 912.00 |
| 1,900 | 157,800 | 31.88 | 1,016.40 |
| 2,000 | 150,000 | 33.55 | 1,125.60 |
| 2,100 | 142,850 | 35.23 | 1,241.20 |
| 2,200 | 136,360 | 36.91 | 1,362.40 |
| 2,300 | 130,430 | 38.59 | 1,489.30 |
| 2,400 | 125,000 | 40.27 | 1,621.80 |
| 2,500 | 120,000 | 41.95 | 1,759.70 |
| 2,600 | 115,380 | 43.62 | 1,902.60 |
| 2,700 | 111,110 | 45.30 | 2,052.00 |
| 2,800 | 107,140 | 46.89 | 2,207.00 |
| 2,900 | 103,450 | 48.66 | 2,366.30 |
| 3,000 | 100,000 | 50.33 | 2,533.20 |
| 4,000 | 75,000 | 67.11 | 4,504.00 |
| 5,000 | 60,000 | 83.89 | 7,038.00 |
| 6,000 | 50,000 | 100.7 | 10,130.00 |
| 7,000 | 41,800 | 117.3 | 13,630.00 |
| 8,000 | 37,500 | 134.1 | 18,000.00 |
| 9,000 | 33,300 | 151.0 | 22,820.00 |
| 10,000 | 30,000 | 167.9 | 28,150.00 |
| 11,000 | 27,300 | 184.8 | 34,150.00 |
| 12,000 | 25,000 | 201.5 | 40,600.00 |
| 13,000 | 23,100 | 218.3 | 47,600.00 |
| 14,000 | 21,400 | 235.0 | 55,200.00 |
| 15,000 | 20,000 | 252.0 | 63,500.00 |
| 16,000 | 18,750 | 269.0 | 72,300.00 |
Pronunciation of Greek Letters
Many of the physical quantities use Greek letters for symbols. The following is the Greek alphabet with the way the letters are pronounced:
| a | alpha |
| b | beta |
| g | gamma |
| d | delta |
| e | epsilon |
| z | zeta |
| ae | eta |
| th | theta |
| i | iota |
| k | kappa |
| l | lambda |
| m | mu |
| n | nu |
| x | Xi(Zi) |
| o | omicron |
| p | pi |
| r | rho |
| s | sigma |
| t | tau |
| u | upsilon |
| ph | phi |
| ch | chi |
| ps | psi |
| o | omega |
Table of Sparking Distances
In Air for Various Voltages between Needle Points
| Volts | Distance | |
| Inches | Centimeter | |
| 5,000 | .225 | .57 |
| 10,000 | .470 | 1.19 |
| 15,000 | .725 | 1.84 |
| 20,000 | 1.000 | 2.54 |
| 25,000 | 1.300 | 3.30 |
| 30,000 | 1.625 | 4.10 |
| 35,000 | 2.000 | 5.10 |
| 40,000 | 2.450 | 6.20 |
| 45,000 | 2.95 | 7.50 |
| 50,000 | 3.55 | 9.90 |
| 60,000 | 4.65 | 11.8 |
| 70,000 | 5.85 | 14.9 |
| 80,000 | 7.10 | 18.0 |
| 90,000 | 8.35 | 21.2 |
| 100,000 | 9.60 | 24.4 |
| 110,000 | 10.75 | 27.3 |
| 120,000 | 11.85 | 30.1 |
| 130,000 | 12.95 | 32.9 |
| 140,000 | 13.95 | 35.4 |
| 150,000 | 15.00 | 38.1 |
Feet per Pound of Insulated Magnet Wire
| No. of | Single | Double | Single | Double | |
| B.& S. | Cotton, | Cotton, | Silk, | Silk, | Enamel |
| Gauge | 4-Mils | 8-Mils | 1-3/4-Mils | 4-Mils | |
| 20 | 311 | 298 | 319 | 312 | 320 |
| 21 | 389 | 370 | 408 | 389 | 404 |
| 22 | 488 | 461 | 503 | 498 | 509 |
| 23 | 612 | 584 | 636 | 631 | 642 |
| 24 | 762 | 745 | 800 | 779 | 810 |
| 25 | 957 | 903 | 1,005 | 966 | 1,019 |
| 26 | 1,192 | 1,118 | 1,265 | 1,202 | 1,286 |
| 27 | 1,488 | 1,422 | 1,590 | 1,543 | 1,620 |
| 28 | 1,852 | 1,759 | 1,972 | 1,917 | 2,042 |
| 29 | 2,375 | 2,207 | 2,570 | 2,435 | 2,570 |
| 30 | 2,860 | 2,534 | 3,145 | 2,900 | 3,240 |
| 31 | 3,800 | 2,768 | 3,943 | 3,683 | 4,082 |
| 32 | 4,375 | 3,737 | 4,950 | 4,654 | 5,132 |
| 33 | 5,590 | 4,697 | 6,180 | 5,689 | 6,445 |
| 34 | 6,500 | 6,168 | 7,740 | 7,111 | 8,093 |
| 35 | 8,050 | 6,737 | 9,600 | 8,584 | 10,197 |
| 36 | 9,820 | 7,877 | 12,000 | 10,039 | 12,813 |
| 37 | 11,860 | 9,309 | 15,000 | 10,666 | 16,110 |
| 38 | 14,300 | 10,636 | 18,660 | 14,222 | 20,274 |
| 39 | 17,130 | 11,907 | 23,150 | 16,516 | 25,519 |
| 40 | 21,590 | 14,222 | 28,700 | 21,333 | 32,107 |
International Morse Code and Conventional Signals
TO BE USED FOR ALL GENERAL PUBLIC SERVICE RADIO COMMUNICATION
A dash is equal to three dots.
The space between parts of the same letter is equal to one dot.
The space between two letters is equal to three dots.
The space between two words is equal to five dots.1
A.-
B -...
C -.-.
D -..
E.
F..-.
G —.
H....
I..
J.—
K -.-
L.-..
M —
N -.
O —
P.—.
Q —.-
R.-.
S...
T -
U..-
V...-
W.—
X -..-
Y -.—
Z —..
Ä (German).-.-
Á or Å (Spanish-Scandinavian).—.-
CH (German-Spanish) ——
É (French)..-..
Ñ (Spanish) —.—
Ö (German) —.
Ü (German)..—
1.——
2..—
3...—
4....-
5.....
6 -....
7 —...
8 —..
9 ——.
0 ——
Period......
Semicolon -.-.-.
Comma -.-.-.
Colon —...
Interrogation..—..
Exclamation point —..—
Apostrophe.——.
Hyphen -....-
Bar indicating fraction -..-.
Parenthesis -.—.-
Inverted commas.-..-.
Underline..—.-
Double dash -...-
Distress Call...—...
Attention call to precede every transmission -.-.-
General inquiry call -.-. —.-
From (de) -...
Invitation to transmit (go ahead) -.-
Warning—high power —..—
Question (please repeat after...)—interrupting long messages..—..
Wait.-...
Break (Bk.) (double dash) -...-
Understand...-.
Error........
Received (O.K.).-.
Position report (to precede all position messages) -.-.
End of each message (cross).-.-.
Transmission finished (end of work) (conclusion of correspondence)...-.-
International Radiotelegraphic Convention
LIST OF ABBREVIATIONS TO BE USED IN RADIO COMMUNICATION
ABBREVIATION QUESTION ANSWER OR REPLY
Prb Do you wish to communicate I wish to communicate by means by means of the International of the International Signal Code. Signal Code?
QRA What ship or coast station is This is.... that?
QRB What is your distance? My distance is....
QRC What is your true bearing? My true bearing is....
QRD Where are you bound for? I am bound for....
QRF Where are you bound from? I am bound from....
QRG What line do you belong to? I belong to the... Line.
QRH What is your wave length in My wave length is... meters. meters?
QRJ How many words have you to send? I have... words to send.
QRK How do you receive me? I am receiving well.
QRL Are you receiving badly? I am receiving badly. Please Shall I send 20? send 20....-....-. for adjustment? for adjustment.
QRM Are you being interfered with? I am being interfered with.
QRN Are the atmospherics strong? Atmospherics are very strong.
QRO Shall I increase power? Increase power.
QRP Shall I decrease power? Decrease power.
QRQ Shall I send faster? Send faster.
QRS Shall I send slower? Send slower.
QRT Shall I stop sending? Stop sending.
QRU Have you anything for me? I have nothing for you.
QRV Are you ready? I am ready. All right now.
QRW Are you busy? I am busy (or: I am busy with...). Please do not interfere.
QRX Shall I stand by? Stand by. I will call you when required.
QRY When will be my turn? Your turn will be No....
QRZ Are my signals weak? You signals are weak.
QSA Are my signals strong? You signals are strong.
QSB Is my tone bad? The tone is bad.
Is my spark bad? The spark is bad.
QSC Is my spacing bad? Your spacing is bad.
QSD What is your time? My time is....
QSF Is transmission to be in Transmission will be in alternate order or in series? alternate order.
QSG Transmission will be in a series of 5 messages.
QSH Transmission will be in a series of 10 messages.
QSJ What rate shall I collect for...? Collect....
QSK Is the last radiogram canceled? The last radiogram is canceled.
QSL Did you get my receipt? Please acknowledge.
QSM What is your true course? My true course is...degrees.
QSN Are you in communication with land? I am not in communication with land.
QSO Are you in communication with I am in communication with... any ship or station (through...). (or: with...)?
QSP Shall I inform...that you are Inform...that I am calling him. calling him?
QSQ Is...calling me? You are being called by....
QSR Will you forward the radiogram? I will forward the radiogram.
QST Have you received the general General call to all stations. call?
QSU Please call me when you have Will call when I have finished. finished (or: at...o’clock)?
QSV Is public correspondence being Public correspondence is being handled? handled. Please do not interfere.2
QSW Shall I increase my spark Increase your spark frequency. frequency?
QSX Shall I decrease my spark Decrease your spark frequency. frequency?
QSY Shall I send on a wavelength Let us change to the wave length of... meters? of... meters.
QSZ Send each word twice. I have difficulty in receiving you.
QTA Repeat the last radiogram.
When an abbreviation is followed by a mark of interrogation, it refers to the question indicated for that abbreviation.
Useful Information
Symbols Used for Apparatus
alternator
ammeter
aerial
arc
battery
buzzer
condenser
variable condenser
connection of wires
no connection
coupled coils
variable coupling
detector
gap, plain
gap, quenched
ground
hot wire ammeter
inductor
variable inductor
key
resistor
variable resistor
switch s.p.s.t.
" s.p.d.t.
" d.p.s.t.
" d.p.d.t.
" reversing
phone receiver
" transmitter
thermoelement
transformer
vacuum tube
voltmeter
choke coil
Definitions of Electric and Magnetic Units
The ohm is the resistance of a thread of mercury at the temperature of melting ice, 14.4521 grams in mass, of uniform cross-section and a length of 106.300 centimeters.
The ampere is the current which when passed through a solution of nitrate of silver in water according to certain specifications, deposits silver at the rate of 0.00111800 of a gram per second.
The volt is the electromotive force which produces a current of 1 ampere when steadily applied to a conductor the resistance of which is 1 ohm.
The coulomb is the quantity of electricity transferred by a current of 1 ampere in 1 second.
The ampere-hour is the quantity of electricity transferred by a current of 1 ampere in 1 hour and is, therefore, equal to 3600 coulombs.
The farad is the capacitance of a condenser in which a potential difference of 1 volt causes it to have a charge of 1 coulomb of electricity.
The henry is the inductance in a circuit in which the electromotive force induced is 1 volt when the inducing current varies at the rate of 1 ampere per second.
The watt is the power spent by a current of 1 ampere in a resistance of 1 ohm.
The joule is the energy spent in I second by a flow of 1 ampere in 1 ohm.
The horse-power is used in rating steam machinery. It is equal to 746 watts.
The kilowatt is 1,000 watts.
The units of capacitance actually used in wireless work are the microfarad, which is the millionth part of a farad, because the farad is too large a unit; and the C. G. S. electrostatic unit of capacitance, which is often called the centimeter of capacitance, which is about equal to 1.11 microfarads.
The units of inductance commonly used in radio work are the millihenry, which is the thousandth part of a henry; and the centimeter of inductance, which is one one-thousandth part of a microhenry.
Note.—For further information about electric and magnetic units get the Bureau of Standards Circular No. 60, called Electric Units and Standards, the price of which is 15 cents; also get Scientific Paper No. 292, called International System of Electric and Magnetic Units, price 10 cents. These and other informative papers can be had from the Superintendent of Documents, Government Printing Office, Washington, D. C.
Wireless Books
The Admiralty Manual of Wireless Telegraphy. 1920. Published by His Majesty’s Stationery Office, London.
Ralph E. Batcher.—Prepared Radio Measurements. 1921. Wireless Press, Inc., New York City.
Elmer E. Bucher.—Practical Wireless Telegraphy. 1918. Wireless Press, Inc., New York City.
Elmer E. Bucher.—Vacuum Tubes in Wireless Communication. 1919. Wireless Press, Inc., New York City.
Elmer E. Bucher.—The Wireless Experimenter’s Manual. 1920. Wireless Press, Inc., New York City.
Frederick Collins.—Wireless Telegraphy, Its History, Theory, and Practice. 1905. McGraw Pub. Co., New York City.
H. Dellinger.—Principles Underlying Radio Communication.
Signal Corps, U. S. Army, Washington, D. C.
M. Dorsett.—Wireless Telegraphy and Telephony. 1920. Wireless Press, Ltd., London.
A. Fleming.—Principles of Electric Wave Telegraphy. 1919. Longmans, Green and Co., London.
Charles B. Hayward.—How to Become a Wireless Operator. 1918. American Technical Society, Chicago, Ill.
G. D. Robinson.—Manual of Radio Telegraphy and Telephony. 1920. United States Naval Institute, Annapolis, Md.
Rupert Stanley.—Textbook of Wireless Telegraphy. 1919. Longmans, Green and Co., London.
E. W. Stone.—Elements of Radio Telegraphy. 1919. D, Van Nostrand Co., New York City.
L. B. Turner.—Wireless Telegraphy and Telephony. 1921. Cambridge University Press. Cambridge, England.
Send to the Superintendent of Documents, Government Printing Office, Washington, D. C., for a copy of Price List No. 64 which lists the Government’s books and pamphlets on wireless. It will be sent to you free of charge.
The Government publishes; (1) A List of Commercial Government and Special Wireless Stations, every year, price 15 cents; (2) A List of Amateur Wireless Stations, yearly, price 15 cents; (3) A Wireless Service Bulletin is published monthly, price 5 cents a copy, or 25 cents yearly; and (4) Wireless Communication Laws of the United States, the International Wireless Telegraphic Convention and Regulations Governing Wireless Operators and the Use of Wireless on Ships and Land Stations, price 15 cents a copy. Orders for the above publications should be addressed to the Superintendent of Documents, Government Printing Office, Washington, D. C.
Manufacturers and Dealers in Wireless Apparatus and Supplies
Adams-Morgan Co., Upper Montclair, N. J.
American Hard Rubber Co., 11 Mercer Street, New York City.
American Radio and Research Corporation, Medford Hillside, Mass.
Brach (L. S.) Mfg. Co., 127 Sussex Ave., Newark, N. J.
Brandes (C.) Inc., 237 Lafayette St., New York City.
Bunnell (J. H.) Company, Park Place, New York City.
Burgess Battery Company, Harris Trust Co. Bldg., Chicago, Ill.
Clapp-Eastman Co., 120 Main St., Cambridge, Mass.
Connecticut Telephone and Telegraph Co., Meriden, Conn.
Continental Fiber Co., Newark, Del.
Coto-Coil Co., Providence, R. I.
Crosley Mfg. Co., Cincinnati, Ohio.
Doolittle (F. M.), 817 Chapel St., New Haven, Conn.
Edelman (Philip E.), 9 Cortlandt St., New York City.
Edison Storage Battery Co., Orange, N. J.
Electric Specialty Co., Stamford, Conn.
Electrose Mfg. Co., 60 Washington St., Brooklyn, N. Y.
General Electric Co., Schenectady, N. Y.
Grebe (A. H.) and Co., Inc., Richmond Hill, N. Y. C.
International Brass and Electric Co., 176 Beekman St., New York City.
International Insulating Co., 25 West 45th St., New York City.
King Amplitone Co., 82 Church St., New York City.
Kennedy (Colin B.) Co., Rialto Bldg., San Francisco, Cal.
Magnavox Co., Oakland, Cal.
Manhattan Electrical Supply Co., Park Place, N. Y.
Marshall-Gerken Co., Toledo, Ohio.
Michigan Paper Tube and Can Co., 2536 Grand River Ave., Detroit, Mich.
Murdock (Wm. J.) Co., Chelsea, Mass.
National Carbon Co., Inc., Long Island City, N. Y.
Pittsburgh Radio and Appliance Co., 112 Diamond St., Pittsburgh, Pa,
Radio Corporation of America, 233 Broadway, New York City.
Riley-Klotz Mfg. Co., 17-19 Mulberry St., Newark, N. J.
Radio Specialty Co., 96 Park Place, New York City.
Roller-Smith Co., 15 Barclay St., New York City.
Tuska (C. D.) Co., Hartford, Conn.
Western Electric Co., Chicago, Ill.
Westinghouse Electric Co., Pittsburgh, Pa.
Weston Electrical Instrument Co., 173 Weston Ave., Newark, N. J.
Westfield Machine Co., Westfield, Mass.
Abbreviations of Common Terms
A...............Aerial
A.C.............Alternating Current
A.F.............Audio Frequency
B. and S........Brown & Sharpe Wire Gauge
C...............Capacity or Capacitance
C.G.S...........Centimeter-Grain-Second
Cond............Condenser
Coup............Coupler
C.W.............Continuous Waves
D.C.............Direct Current
D.P.D.T.........Double Point Double Throw
D.P.S.T.........Double Point Single Throw
D.X.............Distance
E...............Short for Electromotive Force (Volt)
E.M.F...........Electromotive Force
F...............Filament or Frequency
G...............Grid
Gnd.............Ground
I...............Current Strength (Ampere)
I.C.W...........Interrupted Continuous Waves
KW..............Kilowatt
L...............Inductance
L.C.............Loose Coupler
Litz............Litzendraht
Mfd.............Microfarad
Neg.............Negative
O.T.............Oscillation Transformer
P...............Plate
Prim............Primary
Pos.............Positive
R...............Resistance
R.F.............Radio Frequency
Sec.............Secondary
S.P.D.T.........Single Point Double Throw
S.P.S.T.........Single Point Single Throw
S.R.............Self Rectifying
T...............Telephone or Period (time) of Complete
Oscillation
Tick............Tickler
V...............Potential Difference
Var.............Variometer
Var. Cond.......Variable Condenser
V.T.............Vacuum Tube
W.L.............Wave Length
X...............Reactance
Notes
1 period denotes Morse dot, hyphen denotes Morse dash
2 Public correspondence is any radio work, official or private, handled on commercial wave lengths.