Spectrum Management - From the Early Years to the 1990s

by Laval Desbiens

Our Radio Trouble Hunters

GOVERNMENT SERVICE - AND YOU

The story of the radio sleuths' campaign to make the air safe for listeners-in

By Norman Reilly Raine
Published in MacLean's Magazine, November 1, 1927

Few CANADIANS know it, but it is a fact, nonetheless, that Canada was the first country in the world to enlist the radio sleuth in the public service. Canada was the first country in the world to recognize the necessity of protecting the radio listener from interference, and Canada still is the only country which maintains an organized corps of radio sleuths for that purpose.

And what is a radio sleuth? Precisely what the name indicates - a detective whose sleuthing concerns radio. And what does he do? Well, he can and does make things very uncomfortable for the radio fan who thinks he can hide an unlicensed radio set where no one can find it. But his main function is to see that Canada's 200,000 or more radio listeners get the programs from the Dominion's seventy-five broadcasting stations and the programs from foreign stations with a minimum of interference.

Suppose for instance, that you own a One Dial Super Ten and that you are listening to a dance orchestra at BXY. The music is coming through clearly when, suddenly, there's a raucous buzz and a noise akin to the shrieking of half a dozen band saws. You twist your dials and fume and fret without result: still the ripping and tearing continues. Finally, you give up in disgust, muttering "Interference." And that's where the government radio sleuth comes in. It's his job to find out what's causing all the racket and to devise some means of stopping it. That buzzing sound may be coming from the house next door or its origin may be a mile away, hidden in the tangle of wires that traverse a great city. No matter. The radio sleuth must trace it to its source.

How does he do it? Like any other good detective, largely by a process of deduction and elimination. With this difference, however, that where the ordinary detective relies largely on his own powers of shrewd observation, the radio sleuth employs the aid of some of the most sensitive electrical devices known to modern science.

Scattered over the Dominion from end to end, the Radio Branch of the Department of Marine and Fisheries has close upon fifty inspectors who devote all or part of their time to this kind of sleuthing. In addition, the Branch operates a fleet of interference motor cars which are really travelling radio laboratories. Each of these is fitted with two super-heterodyne receivers, a three-tube portable receiving set and other electrical apparatus. Manned by two men, each car patrols a given district searching for that which causes the radio fan to tear his hair in impotent rage.

The service has been in operation upwards of three years. The first car commissioned covered about 4,000 miles on its maiden trip and cleared up interference in some thirty towns and villages. Since that time, the work has been extended until, today, there are few parts of Canada that are not served by these sleuths of radio science.

Running Down the Whoops

BY FAR the most of the trouble in the reception of radio programs is due to what the radio engineer calls inductive interference. Suppose for example, that there is a defective connection in the electric light circuit leading into your house. Likely as not, this defective connection will give rise to surges of electrical energy which will flow through the lighting circuit and in so flowing will give rise to radio waves which will be picked up by your antenna, just as any other radio wave is picked up. The result is that tearing, ripping or buzzing sound that often makes reception of a program impossible.

One of the most troublesome cases encountered by the Branch occurred some time ago in Ottawa. There were reports of interference from all over the city, and from Hull across the river. The noise sometimes was intermittent, sometimes constant, and was of such volume as to totally destroy enjoyment of programs. The inspector set out with a portable receiver and discovered interference radiating with great strength in the vicinity of a street railway sub-station. Tests at this and similar stations were made, but without result. One complainant had reported that the noise recommenced with the switching on of the city lighting system, but this was not definite. However, tests with the lighting system were carried out, and the co-operation of radio fans secured to report results. They were nil.

During several days following, the inspector, with power officials and a lineman, patrolled the streets of Ottawa and Hull, day and night, testing at various points where the strength of the interference seemed greatest. They finally confined their activities to a point in the vicinity of the Chaudiere Interprovincial Bridge, nearly two miles away from complainants' sets. The inspector worked until two in the morning testing in this spot. The following day he returned, having previously located five points of maximum interference. These he tested, a lineman climbing poles and tapping with a hammer to detect loose gear, shaking wires and so on, while the inspector listened in underneath. The source, a small automatic switch with badly burned blades, eventually was located when wires lead in from the switch were shaken. The blades were burned so badly that contact was intermittent instead of continuous. Most of the time they vibrated, causing severe sparking which was the cause of the interference. What had puzzled the inspector most was the fact that sometimes the blades would burn together for a short time, thus eliminating the noise. The switch was replaced, the trouble ceased and fans throughout the entire district were jubilant...

A Mechanical Bloodhound

WHEN a complaint of interference is received by the Branch, and the inspector cannot at once locate the trouble, he patrols the vicinity with his portable set. This set is equipped with a direction-finding coil which points to the spot from which the greatest interference emanates. Often it is necessary to penetrate to places impossible of access to the test car - in the country districts across fields, and in cities, within buildings and so on. Here, the little portable set proves very valuable.

Upon one occasion, complaints were received from a certain locality in Toronto, of intermittent interference, and as no one could furnish a clue to its source, an inspector set forth with his portable set. He localized the racket and the direction-finder pointed to a building. Then the interference ceased. The inspector waited for it to continue and while so doing saw a friend leave the building. In the course of the subsequent conversation, the friend remarked that he had just been having his tooth cleaned. As he spoke, the interference resumed its song. Another patient had taken the chair, and the trouble was found to lie in the dentist's electric drill. He was willing to have a condenser installed, and the trouble stopped.

Vacuum cleaners, electrically driven sewing machines, violet ray sets for home use, battery chargers, electric irons, even defective curling tongs, can cause annoyance to your neighbours for two or three houses around. The electric clippers used by your barber cause a buzzing in sets many houses away and of course makes him unpopular with his radio fan customers. Oil-burning furnaces are not nice neighbours, for sparks from the ignition system, when set in operation even for the few seconds necessary to get the furnace underway, cause the neighbourhood to tear its hair and when there are eight or more on the street, as one inspector encountered, it ceased to be a joke.

It is possible by means of an appliance called a surge trap, to imprison the surges which give rise to the kind of interference about which we have been talking and make them expend their energy before they reach the listeners' sets. It is precisely as though a trench were dug in the path of a stream of water to trap it before it could reach the point of spread. Surge traps and condensers, which serve the same purpose, generally are cheap and easy to install. Sometimes the owner of interference- emitting apparatus is willing to have these condensers or surge traps installed at his own expense, glad to save his neighbours annoyance. But if he happens not to be a radio listener, he may object to an expenditure which is to benefit others. Government inspectors spend considerable time visiting owners of trouble-causing apparatus, and by the exercise of a lot of tact induce them to install these preventives. Some of the larger surge traps cost thirty dollars, exclusive of the cost of installation, but in many cases the use of them reduces sparks in motors and lessens depreciation, and it is in the interest of the owners to have them put in.

On one occasion, considerable annoying interference originated, as the inspector discovered, in a street railway generator. He informed the company that the direct cause of the interference was an intermittent fault in the winding, which should be seen to, and the coil rewound. The generator already had been running in this condition for three days.

The company gave many thanks and continued to run the generator as it was. In a short time the motor burned out and stopped, but too late. Instead of having to rewind one coil, as at first, it was necessary to rewind one hundred. Frequently, radio shows up faults in apparatus that cannot be detected in any other way, and a number of the larger plants are using portable sets as adjuncts to their business.

Checking Up on Bloopers

The average fan, if told that he personally was responsible for some of the bizzes, whoops, buzzing and ululation that cause him congestion of the temper, would not be polite in his repartee. What? Call my set a blooper! No such thing! Yet, if he be the owner of a regenerative set, he is quite likely to be a source of intense asperity on the part of his neighbours, for, due to the easy oscillation of such sets, said oscillation can force itself upon the antenna, and from there leap away into the air in the form of radio frequency waves that sweep with an appalling whistle upon an unoffending receiving set perhaps a mile away. The whistle changes its pitch as the blooper's dials rotate, and so does the patience of the recipient.

But there is a remedy even for the blooper. An extra tube placed ahead of the detector will keep the whistle home 'o'nights, and promote the set into the tuned radio frequency class. The inspector has no legal power to compel a blooper to restrain its exuberance, but a heart-to-heart talk with the owner thereof often works wonders, for not many fans know just what the inspector's powers are - and it might be unsportsman-like to tell you.

Government inspectors develop an astonishingly accurate faculty for picking out the cause of interference by its sound. A certain definite type of trouble has the same or approximate sound always, and it is interesting to follow the thought process of one of the Sherlock Holmes of radio as he approaches a town. His car is running along easily. The window is open and his headphones are clamped on. He hears a bird-like chirping.

"Aha" says he. Electric wires running through trees somewhere, and if he wishes, in a very short time he can find out just where. A little later a hard buzzing hits his eardrum. "Defective primary cut-out," he mutters. A clicking and scratching send him hunting for a live wire hitting an insulated guy-wire. He hears a high, hard whine and reflects upon the poor guy in the dentist's chair. A racket intervenes that sounds like a cross between a soft murmur and an intense buzzing. Sounds funny, but there is such a noise. The inspector raises his head and peers about for a flour mill in the town ahead, for he knows that what he has heard is a flour bleacher. Oil furnace buzz and an X-ray machine will transmit a soft, mushy sound that will blanket an area for eight blocks, With this faculty of classifying sounds by their origin developed to expertness, it makes for time-saving and prevents the wild goose chasing that formed so joyous a diversion for the inspector of the early days.

Interference sometimes shows as much ingenuity in evading and fooling the radio sleuth as real criminals dodging the police. Faults on power lines play Puckish trick, dots and dashes like the Morse' code and actually forming letters have given rise to the suspicion that an amateur transmitter was causing the interference, but in the end have turned out to be low power lines swinging together in the wind. This type of interference often travels for miles along the power wires, and stops when the investigator thinks he has reached the source and recommences when he has moved away.

There is much to learn regarding interference and its causes, and the game of detection is full of surprises. Some time ago, at Milton, Ontario, interference was so great that it spoiled reception in the entire town. The investigators traced the interference along the power line to a point over four miles away, and there found a piece of iron wire lying across one of the power wires, but not making contact with any other wire or the ground. The current through that wire, so small that it would not light a pocket flashlight, sent back for more than four miles a surge greater than might have been caused by huge arcs of thousands of amperes used in electric furnaces.

On the other hand, inside a metal building at Shawinigan Falls, housing four electrical furnaces each taking thousands of amperes, it was possible to hear a broadcast concert through a three-tube portable receiver and loop aerial, and very little interference was met with. It is difficult to tell the cause, or the effect, as the case may be. It has been noticed that when a street car has been coasting downhill, taking hardly sufficient current to keep the lights going, the radio interference often is excessive. The same car, going uphill and drawing heavy current, and arcing at the trolley so vividly that the sky is illuminated, has disseminated very little trouble to the listener.

The interference inspector works in all weathers, and at all hours. Sometimes he is able to immediately locate the source of the trouble--then again, he may be engaged for weeks in patient investigation and experiment before settling the difficulty. His efforts to locate the interference may be out of all proportion to the cause. Hawkesbury, Ontario, was blanketed intermittently for some time, and three times the inspector investigated, only to have the trouble cease after he arrived.

It was the middle of winter and the roads were all deep in snow. Eventually, however, he got there when the trouble was active, so, attaching an exploring coil to his set, he entered the local power house and hooked the coil to each of the power lines in succession until he found the guilty one. The ensuing chase took him out along the power line for seventeen and one-half miles, through gale and snow and drifts, until he found the cause of the trouble - a piece of hay wire lying over a high tension wire and swinging in the wind.

It is difficult to work in cities during the day when the roar of traffic makes it almost impossible to keep trace of the interference among a multiplicity of sounds. But long after the interference-baffled fan has retired, disgusted and angry to his pillow, wondering for a sleepy moment why the government doesn't do something about it, the inspector patrols the streets in his car or with his portable set, sometimes until six o'clock in the morning, endeavouring, when other obstructions are not so heavy, to run down the sources of various weird rackets that have been reported to him.

Keeping Tabs on the Broadcasters

There is another important base of this protection of the radio-listening public and that is the monitor system. While the fan is sitting at his set enjoying a program, a government monitor, equipped with a calibrated receiving set, also is listening in to every station transmitting and broadcasting, to make sure that they are keeping on their proper wave lengths. A station off its band is immediately notified by telephone or telegraph. If it is a Canadian station, and adjustment is not made, disciplinary action follows. United States stations pirating Canadian allotments are reported to Washington.

Monitoring is done by the inspectors in the various districts, and if a listener in Calgary or Winnipeg or any other Canadian point finds his enjoyment broken by the transmitting of Morse from some ship or shore station off its wave, he can communicate with the nearest inspector and complain, certain that the complaint will be followed up and a repetition avoided. If a foreign vessel sends its dots and dashes whining across the ether outside of its allotted band, the country of its registry promptly hears from Ottawa, and when the vessel returns home, it is warned not to repeat the offence. An ardent small boy amateur decides to try his hand at transmitting and spends a hugely joyful hour launching his pip-squeaks into the night ozone. Next day, that scared small boy is apt to face an outwardly grim but inwardly sympathetic Federal Government inspector, who will give him a good talking to and some good advice also. If the boy is bright, he will control his feelings and grasp the opportunity to get some useful pointers.

Monitoring, primarily, is for the purpose of shooing trespassers into the proper pastures and making the air safe for democracy. The work the radio sleuths have accomplished is quite capable of speaking for the value of the service our government renders, but it is interesting-and pleasant-sometimes to hear the opinions of those outside our boundaries. A recent number of Radio Broadcast, an influential United States magazine in the field of radio, published an editorial which summarizes the work of the Department of Marine and Fisheries. It reads: "Our northern neighbours have succeeded in managing their radio affairs with a competence in marked contrast with our own methods. The Radio Branch of the Department of Marine and Fisheries provides, at cost, equipment to suppress radiation from electrical apparatus which interferes with broadcast reception. It aids in locating interference and advises remedies, and the Interference Service of the Canadian Government is the only one like it in the world, and a remarkable example of Government co-operation."

by Laval Desbiens