The Wrangell sentinel., 1936-12-04
CBy c. ". De Remer)

How you. with your cooperation, can help eliminate radio interfer-. ence and the more thoroughly en-. joy radio entertainment.
 How you can make your own ra- dio sound better. and everyone else. too. by just a few simple things right in your own home that will only take You a moment and will pay you a thousand fold in return with hours of beautiful radio re- ception is the purpose of this ar ticle in which l shall try to cov- CT the various phases of radio recep- ton, radio, interference, what aus es interference, the simple methods of it's elimination in every home in the town of Wrangell, and what the City Council is doing to help eY- cry citizen to have perfect recep ton for any program, regardless of time of day or night the reception is desired: in their proper sequence.
 What Produces Radio
 In the first place slight knowledge of what takes place when music, talk. or any other sound is sent over the air, is not out of place here. It will show why the problems of in terference which we will cover later are really problems because We per init them to be such.
 When a radio transmitter is turn ed on, it sends forth. into the already heavily charged air, a powerful surge of electrical energy, of a def mite length of wave form, which is of a definite speed and number per second of time. Each wave form is complete in itself, and they fol- low upon each other so long as the power is turned on at the trans hitter. (This is what you hear when you turn on your radio and tune a station position but don't hear a program of music, talk, etc, but just a low hiss). These wave forms altogether are called the carrier, and can be pictured as track car rying a train, or a water pipe car rying water to various parts of the city.
 Radio Carrier
 And while the carrier is ever pres ent while the power is turned on; the same as the pipe is always there regardless of whether 1t is full of water or not; or as the track is al- ways lying where placed, tho car rying trains only at certain times when necessary: You see the track and water pipe, so can you hear the radio carrier. When the water is turned into the pipe it is carrying that water, the same as the track is carrying the train when the train runs. There is no actual music or other noise heard until it is super imposed upon the electrical charge cast into the air by whatever source creates it. This being true. then ev- erything that tends to create .elec- rical surges in the air, that are not tuned to a definite wave le1s th, causes interference to ALL radio re- ceiyers. as this type of electrical surge will be received all over the scale of any radio receiver. These surges are caused by food mixers, electrical motors, that have a seg-
 
 vacuum cleaners, oil burners. any type of machinery that uses this type of motor for motive power, K ray apparatus, welding cathodes, re- frigerators, toy electric trains, cash registers, etc. In fact anything that makes an electrical spark when it makes or breaks the circuit.
 ToJi,, T ;ob4 n1nba Mavooa
 When you turn on your electric lights in the house and when you turn them off, it causes small sparks that are heard for miles on every radio receiver that is turned on. An electric light globe, whose life is almost finished will, during the last few hours of it's life cause untold electrical noises by the slow burning of the filament, which when red hot causes the light to be reflected which it creates.
 Sewing machines are a great source of noises. Electrical signs an- other. And one of the worst is that caused by the engines in automobiles and small boats as their constant sparkling will be heard when noth- ing else will go through. Two loose wires, swinging in the air, both car rying electrical energy will cause small statical charges of energy to be shot off into space. Each and ev- eryone can be eliminated by filter ing the cause, or eliminating it's use less existence.
 So then it follows that whatever makes radio entertainment also causes interference and are both one and the same thing, except that the interference is untuned, or un- measured, uncontrolled while the ra- dio waves are measured, and control led to definite wave length. For in- stance, interference is heard all ov-