Appendices
APPENDIX 1. UNIT CONVERSION CHARTS
The following charts are listed to give a convenient method for comparing various common English and metric units to allow easy conversion from one unit to another. These comparisons are for common values of lengths, areas, volume, speed, and electric resistivity. Included also is a listing of several other miscellaneous unit comparisons.
Length Comparisons
To use this chart to compare (and thus convert) one unit to another, find the existing measurement in the From columnand then find the desired unit in the vertical headings (To). Where these two intersect will give you the conversion of one exsting unit (From) into one new unit (To). For example, if you have one inch and you need this in centimeters; find “1 inch” in the From column (4th line down) and go over to the vertical column labeled cm; and you find that 1 inch = 2.54 cm. Then, if you wanted to convert 25 inches (or any value of inches) into centimeters you would simply multiply 25 (or any given number of inches) by 2.54 for 63.5 centimeters.
The charts that follow are used in the same manner as the length comparison chart with the “From” in the left column and the “To” conversions listed in the following vertical columns.
Miscellaneous Unit Comparisons
| 1 fathom = 6ft | 1 liter = 1000cm3 |
| 1 yard = 3ft | 1 knot = 1 nautical mile/hr |
| 1 rod = 16.5ft | 1 mile/min = 88ft/sec = 60 miles/hr |
| 1 U.S. gallon = 4 U.S. fluid quarts | 1 meter = 39.4in = 3.28ft |
| 1 U.S. quart = 2 U.S. pints | 1 inch = 2.54cm |
| 1 U.S. pint = 16 U.S. fluid ounces | 1 mile = 5280ft = 1.61km |
| 1 U.S. gallon = 0.8327 British imperial gallon | 1 angstrom unit = 10−10 meters |
| 1 British imperial gallon = 1.2 U.S. gallons | 1 horsepower = 550ft-lb/sec = 746 watts |
APPENDIX 8. HOW TO USE SQUARE ROOT TABLES
The following table can be used to find the square root or square of most any number. Numbers from 1 to 120 can be read directly from the table. But what about a number such as 150? How can its square or square root be found? The secret to the use of this table is in the understanding of factoring. Factoring a number means to break the original number up into two smaller numbers, that, when multiplied together, give you back the original. For example, 150 is equal to 10 times 15. Ten and 15 are said to be factors of 150. If 10 times 15 is equal to 150, then the square root of 10 times the square root of 15 is equal to the square root of 150. Both 10 and 15 are listed on the square and square root table. The square root of 10 from the table is equal to 3.162. The square root of 15 is equal to 3.873; 3.162 times 3.873 is equal to 12.246426, which should be the square root of 150. You can test this number by multiplying it by itself. Thus, 12.246426 squared is equal to 149.97, etc., — very close to 150. (Small errors due to rounding will normally occur when using the tables.) The factoring procedure written out mathematically would then be:
Try another number now, say, 350. First, factor 350:
The square root of 350 must equal the square root of 35 times the square root of 10.
Go to the tables and look up the square roots of 10 and 35:
Multiply the square roots of 10 and 35, and you have found the square root of 350.
To check the accuracy of your calculations, multiply 18.706 by itself.
Again, very close to the original number.
Try one more number, this time 1,150.
The square root of 1,150 must equal the square root of 115 times the square root of 10.
Look up the square roots of 115 and 10 from the tables.
Multiply the square roots of 115 and 10, and you have the square root of 1,150.
To check the validity of this number, square it. It should be very close to 1,150.
APPENDIX 9. EXTRACTING SQUARE ROOT USING A CALCULATOR*
THE DIVIDE-AND-AVERAGE METHOD TO FIND SQUARE ROOTS
*This procedure is for use with calculators that do not have a square root key but do have a memory function. Most scientific calculators have a square root key function. On such calculators, the above result could have been obtained easily by entering the number 89 and pressing the square root key (usually indicated 
on most calculators).
APPENDIX 11. THE UNIVERSAL TIME CONSTANT GRAPH
How to Use This Chart
This chart can be used to graphically determine the voltage or current at any point in time for an RC or L/R circuit, during charging (or current buildup), or discharge (or current collapse).
The examples shown below illustrate the use of the chart.
1. Find the voltage across the capacitor shown in the circuit below, 1 second after the switch is thrown.
a. First find the circuit time constant
The voltage at any point along a charge or discharge curve may be calculated by using one of these two mathematical formulas:
b. Express the time (t) at which the capacitor voltage is desired in time constants.
Here you want the voltage after 1 second and the time constant is 2 seconds, so t = ½ (the time constant)or t = 0.5τ
c. Look at the chart, on the horizontal axis and locate 0.5 time constants.
d. Move up the vertical line until it reaches the appropriate curve (in this case the charging curve). Read from the vertical axis the fraction of the applied voltage at the time (here 39%).
e. At t = 1 second, the voltage across the capacitor equals 39% of 10 volts or
2. Find the voltage across the capacitor shown in the circuit below 2 seconds after the switch, S, is thrown. The capacitor is charged to 20 volts before the switch is thrown.
a. Find the circuit time constant
b. Express the time at which the capacitor’s voltage is desired in time constants. Here, 2 seconds divided by 0.5 seconds is 4; 2 seconds is 4 time constants for this circuit.
c. Look at the chart, locate 4 time constants on the horizontal axis.
d. Move up the vertical line until it reaches the appropriate curve (the discharge curve). Read the fraction of the original voltage from the vertical axis (2%).
e. At t = 2 seconds, the voltage across the capacitor is at 2% of the original voltage or is at 2% of 20 volts.
Remember that 5 time constants is required for a 100% charge (full charge or discharge for RC circuits, maximum or zero current for L/R circuits).
APPENDIX 12. PEAK, PEAK-TO-PEAK, AND RMS CONVERSION CHART
This chart contains factors to easily convert one ac value of a voltage or current to the other two types of values.
APPENDIX 14. COLOR CODES
PREFERRED VALUES FOR RESISTORS AND CAPACITORS
The numbers listed in the chart below, and decimal multiples of these numbers, are the commonly available resistor values at 5 percent, 10 percent, and 20 percent tolerance. Capacitors generally fall into the same values, except 20, 25, and 50 are very common, and any of the values can have a wide range of tolerances available.
| 20% Tolerance (No 4th Band) | 10% Tolerance (Silver 4th Band) | 5% Tolerance (Gold 4th Band) |
| 10* | 10 | 10 |
| 11 | ||
| 12 | 12 | |
| 13 | ||
| 15 | 15 | 15 |
| 16 | ||
| 18 | 18 | |
| 20 | ||
| 22 | 22 | 22 |
| 24 | ||
| 27 | 27 | |
| 30 | ||
| 33 | 33 | 33 |
| 36 | ||
| 39 | 39 | |
| 47 | 47 | 47 |
| 51 | ||
| 56 | 56 | |
| 62 | ||
| 68 | 68 | 68 |
| 75 | ||
| 82 | 82 | |
| 91 | ||
| 100 | 100 | 100 |
Most of the following color codes are standardized by the Electronic Industries Association (EIA). Although members are not required to adhere to the color codes, it is industry practice to do so where practical.
Chassis Wiring
In electronic systems wires are usually color-coded to ease assembly and speed tracing connections when troubleshooting the equipment. Usually the colors of the wires are in accordance with the following system.
| COLOR | CONNECTED TO |
| Red B + | voltage supply |
| Blue | Plate of amplifier tube or collector of transistor |
| Green | Control grid of amplifier tube or base of transistor (also for input to diode detector) |
| Yellow | Cathode of amplifier tube or emitter of transistor |
| Orange | Screen grid |
| Brown | Heaters or filaments |
| Black | Chassis ground return |
| White | Return for control grid (AVC bias) |
A-F Transformers
Blue — plate lead (end of primary winding)
Red — B+ (center-tap on push-pull transformer)
Brown — plate lead (start of primary winding on push-pull transformer)
Green — finish lead of secondary winding
