The Grim Facts on Short-Wave Broadcasting
September 1969 Electronics Illustrated

Stanley Leinwoll wrote a couple articles about shortwave broadcasting for the September 1969 edition of Electronics Illustrated magazine. "They're Taking the Guesswork out of Scatter Communications" discusses advances (at the time) in ionospheric scattering of shortwave radio signals, and also this one entitled "The Grim Facts on Short-Wave Broadcasting." This is another example of the old adage of how the more things change, the more they remain the same. Frequency crowding was then and is now a continual challenge for operators in non-privileged bands (spectrum purchased for private, military, government, or commercial use, e.g., cellphone carriers). Mitigation techniques include narrowing of channel bandwidth (via improved modulation techniques or improved transmitter / receiver spectral requirements), decreased transmit power levels, modification of usage regulations, and allocation of new spectrum (either by reallocation of existing bands or opening new bands at the top of existing bands). These issues are not unique to the U.S. or even western Europe; they are problematic for nearly all regions, except for maybe in Siberia, the middle of the African continent, or at the poles. I captured a Google Street View image of the International Telecommunications Union (ITU) headquarters building then (1969) and now (2013). Not much has changed.

The Grim Facts on Short-Wave Broadcasting

Watch it - Your short-wave receiver may soon be gathering dust!

By Stanley Leinwoll

Talk to a ham licensee and the first thing he'll complain about is the decreasing space available on the ham bands. He has lost quite a bit of the spectrum over the last few years and he's anxious about the future.

Most short-wave listeners, however, seem to live in a land of milk and honey. As they tune in stations all over the globe they seldom question what the future will bring. Local conditions are blamed for interference and, of course, increased transmitter power would take care of a lot of things. Or would it?

Truth is, time is running out for short-wave broadcasting. Unless something is done pronto by the powers that be, your SW receiver soon may sound like a voice scrambler in Operations at the Pentagon. A traffic jam is building up all over the spectrum that will soon make your Sunday afternoon drive look like a breeze.

Unfortunately, unlike cars, most radio waves don't travel in the nice, neat patterns found on the highway charts of a city planner.

Directional antennas are a help but radio propagation dictates that a good deal of energy will always spread to areas where it isn't wanted. And the more transmitters in a given area, the more likely that interference will be severe.

Geneva. Of course, this problem isn't new. September marks the tenth anniversary of the Geneva Radio Conference where representatives from almost 100 countries made the first attempt to bring law and order to the management of international high-frequency broadcasting.

Up until this conference very little had been done to plan the flow of radio transmissions throughout the world. At Geneva, a revolutionary new procedure - described in Article X of the Geneva Radio Regulations of 1959 - was drafted which brought some stability to international broadcasting at a time when it appeared headed towards complete turmoil.

However, the conditions which led to the enactment of Article X have continued to worsen. The number of transmitters operating in the high-frequency bands has increased to the point where congestion is extreme. During certain hours some bands are overloaded by a factor of three. Thus, interference is at an unprecedented level. To make matters worse, these man-made problems will intensify since the number of frequencies available for short-wave broadcasting will soon decrease due to lower sunspot numbers. As a result, the international bands are going to become progressively less useful as a medium for communication.

Under the terms of Article X the year is divided into four seasons that are determined by propagation conditions (November to February is the winter season. March and April are spring, May to August is summer, and September and October are the fall). All member countries of the International Telecommunication Union (ITU) are required to submit their program schedules for each season six months in advance. The International Frequency Registration Board (IFRB), a division of the ITU, is responsible for publishing these schedules two months before they are implemented. Fig. 1 shows a page from the schedule for March 1969.

The whole schedule consists of 206 pages, covering all SW bands from 6 to 26 mc. Besides publishing schedules, the IFRB undertakes a technical examination of them and recommends changes that will eliminate or reduce harmful interference. The schedules are also examined by the management experts of countries engaged in international broadcasting. These people attempt to find solutions for potential interference problems.

The Article X procedure brought order to short-wave broadcasting because it provided an advance look at schedules so that changes could be made. But this has its limitations. In Fig. 1, Angola (AGL) is shown operating on 6175 kc. The station has never appeared on this frequency, though it has been listed on numerous schedules. Unfortunately, since some nations are under the erroneous impression that the IFRB schedule can serve as a framework for their future plans they pad their schedules. A second problem is that some countries do not even notify the IFRB about their plans. The schedule often does not show a country occupying a frequency that it is actually using. Consequently, the IFRB schedules contain errors which are unnecessary;

Recent Developments. During the years following the Geneva Conference the number of hours of daily broadcasting increased from 9500 in 1959 to 17,000 in 1969. Many channels are now occupied by two or more broadcasters, with sometimes as many as four countries broadcasting simultaneously. This is serious and yet the trend continues. Broadcasters are using not only more transmitters, but greater power as well. It's been estimated that at the present rate of expansion there will be a 20 per cent increase in the broadcasters now operating when the next minimum in the sunspot cycle is reached.

As sunspot activity passes from maximum to minimum the amount of useful spectrum space decreases by as much as 50 per cent. Since the maximum of the current sunspot cycle was reached several months ago spectrum space will be on the downswing in the months (and years) to come, forcing more and more broadcasters to crowd into the bands that remain. You can bet your last dollar that the combination of increased broadcasting and worsening propagation conditions will produce a situation bordering on chaos.

Look at the Future. Though the outlook appears bleak there are a number of steps which can be taken to improve conditions:

• At the present time representatives of the VOA, the BBC, RFE, Radio Liberty, Radio Netherland, Radio Germany, Radio Canada and the FCC (which represents private U.S. stations such as Radio New York Worldwide) meet six times a year to coordinate their schedules before they are submitted to the IFRB for publication. These conferences are an informal extension of the Article X agreement and offer no long-term solution. However, they do assist these broadcasters in working out some of the conflicts that arise in their schedules. For instance, representatives have learned that sharing frequencies (which at first may have looked technically impossible) will work under certain conditions. Also, changing the characteristics of an assignment (such as target area, hours of operation, transmitter power, etc.) can make conflicting assignments more compatible.
  
  By extending such conferences to other regions broadcasters in other parts of the world could work out similar arrangements among themselves. This would not solve the problem of overcrowding on an international level, but it might result in an improvement in conditions at the grass roots.
• Several broadcasters make considerable use of the short-wave bands to send programs to bases closer to target areas. The relays then transmit the programs to the intended audience. Crowding often results from the use of these feeder frequencies for transmissions to distant relay stations. If relay operations were transferred to other services such as cable satellite or commercial high-frequency channels a significant step toward alleviating congestion will have been taken.
• Approximately 50 per cent of short-wave broadcasts are intended for domestic consumption. Extensive short-wave home service networks exist in the Soviet Union and in many Latin American countries. A panel of communication experts which met in Geneva some years back, reported that crowding in the high-frequency bands would be reduced if the domestic services were transferred either to MW or FM. There has been some improvement as several countries have begun a move toward domestic VHF networks, but it has been too slow a process to produce meaningful results. Acceleration of this program, perhaps with financial assistance from the ITU, would benefit everyone.
• Presently Communist countries attempt to prevent reception of Western broadcasts by jamming some programs. To combat the effects of jamming, the West uses multiple frequencies to carry the same program material in the hope that at least one channel will get through. This puts added strain on spectrum space. So an end to any form of jamming would free many of these frequencies.
• In the final analysis, the future effectiveness of short-wave broadcasting depends on making more frequencies available. This appears to be the only practical long-range solution. Of the 27,000 kc available, only 2150 kc are allocated to international broadcasting (see Fig. 2). This amounts to 8 per cent of the high-frequency spectrum.

During the past ten years communication satellites have become a reality, cable facilities have expanded and the use of ionospheric and tropospheric scatter circuits has increased significantly. Since these sophisticated methods of transmitting information will continue to replace HF services, the concept of making more spectrum space available to SW broadcasting is now more feasible.

At the Geneva Radio Conference of 1959 there was considerable pressure from smaller countries to expand the broadcast bands. The Article X agreement was a compromise arrived at after strong opposition to expansion was voiced by the major broadcasting powers. It appears that Article X must be modified.

There is no radio conference scheduled in the immediate future. A space conference and maritime conference will be held in Geneva in 1971 and 1973, respectively. The earliest possible date for a radio conference appears to be 1975. and the earliest date for possible expansion, to be late 1976 or 1977. The question is, will it be in time to save international broadcasting?