The old good times – Tropical Bands in review

Lecture by Anker Petersen  held on the 16th of August 2003
at the EDXC Conference in Königstein, Germany.


As one of the founders of the European DX Council (EDXC) it is a great pleasure for me to be here in Königstein  this weekend. It is nice to see that the EDXC is still much alive after 36 years of existance. It is also nice that its many  active member clubs on shift have been able each year to organize an Annual EDXC Conference where we can meet and discuss current issues. My thanks to Dr. Harald Gabler and the Rhein-Main-Radio-Club for inviting us once more to a Conference here in Germany.

To throw the theme for this Conference : ”DX-ing in the digital future” in relief, Harald Gabler asked, if I could talk about the old good times before the digital age and give a review of the broadcasting on the Tropical Bands.
I will try not to be too nostalgic, but rather look closely on the past and future development of this broadcasting.

Let me first remind you that the Tropical Bands include the 60, 90 and 120 metrebands on shortwave. The International Telecommunication Union (ITU) has allocated these bands for domestic broadcasts in principle to countries located in the Tropical Zone between the Tropic of Cancer on 23 degrees north and the Tropic of Capricorn on 23 degrees south. This is to give them a safe heaven where they are not supposed to be disturbed by strong international broadcasters.

In many developing countries, radio is still the primary medium and much more widespread than TV. In Nigeria, for instance, with a population of 130 million, today there are about 24 million radio sets, but only about 7 million TV sets. Printed newspapers play only a minor role in countries where more than 50% of the population are illiterates.

In a few countries, however, the term Tropical Zone has been subject to a wide interpretation. The former Soviet Union, for instance, declared in 1959 that ”it reserved the right to use the broadcasting assignment existing in the bands between 3.950 kHz and 27.500 kHz in the USSR in accordance with the needs of this country” ! Many of you will remember some of its many, strong stations on the 60 metreband like Kiev on 4940 and Petrozavodsk near St. Petersburg on 5065 kHz. Even Yakutsk in Siberia on 62 degrees north was broadcasting on several frequencies. They could be heard here in Europe each winter when Yakutsk had temperatures down to minus 50 degrees Celsius, - but obviously it was their ”Tropical Winter”.

To DX-ers, these Tropical Bands were – and still are – very interesting, because so many stations in exotic countries can be heard, often with good reception. About 80% of the active stations can be heard here in Europe under the right propagation conditions. I began to listen to the Tropical Stations back in 1959 when I bought a small shortwave receiver with the 60 metreband for 85 Danish Kroner which equals to 12 Euro today.

(Slide 1: My first DX on 60 meters)

Here you see the first stations I identified.

Quite nostalgic, isn’t it ?  None of these stations exist any longer on shortwave today.
But there are still some other stations which can be heard on the Tropical Bands. That raises these questions:

How many have disappeared  ?
Where have they gone ?
and when will the last stations disappear ?
That is what I will try to analyze during the rest of my talk.

Since 1959, listening to the domestic broadcasting stations on the Tropical Bands has been the favourite part of my DX-hobby! Furthermore, during the past 20 years I have visited a lot of tropical countries in Central and South America, the Caribbean, Africa, Asia and the Pacific.

But my own DX-experiences are not sufficient for a thorough analysis to this forum. It has to cover the stations worldwide, monitored on a regular basis, also those which cannot be heard in Denmark due to propagation limitations.

Tropical Bands Survey and Domestic Bands Survey.

Fortunately for this analysis, the Danish Shortwave Club International can provide documentation on this broadcasting from the past 30 years. Back in 1972 another Danish DX-er, Mr. Carol Feil and I decided that the Club with its members in more than 40 countries should publish an annual list called the Tropical Bands Survey – the TBS.  It was a frequencylist covering all active broadcasting stations between 2.200 kHz and 5.800 kHz and their schedules. It has been published every year since 1973, edited by various members of the Club living in Denmark, Germany, the Netherlands and Argentina. Some data from these annual surveys will be used for my analysis.

In 1999, however, our publication was expanded to cover all active domestic broadcasting stations on shortwave from 2 to 30 MHz . Then it changed name to the Domestic Broadcasting Survey – the DBS which I now am editing.

Let me show you small extracts from these surveys published in June 1973 and May 2003 covering the frequency spectrum  4.775 – 4.780 kHz, just for comparison.

(Slide 2: Excerpts from TBS and DBS)

The key words in the policy for our publications are ”active stations” which means that they should be up-to-date and only contain stations which have been reported heard by DX-ers during the past 12 months. All other stations are moved to an attachment of deleted stations. A few ones of these may be reactivated later on.

On the slide you see an activity  Code to the left where A means Regular, B Irregular and C  Sporadic, as deemed by the Editor. Furthermore the DBS has been expanded with a column to the right called ”Last log” indicating the last month during which the station has been heard.  This is a useful feature for the DX-er who tries to identify a station.

Of course the information in the DBS has to be as correct as possible. Therefore it is necessary to recheck official schedules and reports from DX-ers, because from time to time they contain typing errors, or are outdated.

The task for the editor is therefore, throughout the year until the next publication, to check the bands himself and follow the loggings from our members around the world. For each station in the list, a note is taken of the months when it has been heard. Furthermore loggings are followed in as many printed and internet DX-publications as possible. Nowadays the network of DX-ers around the world is very extensive via the internet, so a station can hardly appear on the Tropical Bands without being discovered and reported by DX-ers somewhere within a week or so.

Trends in Tropical Broadcasting

With this systematic registration of broadcasting stations on the Tropical Bands each year, it is possible to make some statistics on how many frequencies were active in each part of the world and compare these numbers.

I have selected the Tropical Bands Surveys published with 12 years intervals in 1973, 1985 and 1997, and the Domestic Broadcasting Survey from 2003. For each of these four years I have then counted the number of active Domestic Broadcasting stations between 2.200 and 5.800 kHz. This also includes the frequencyspectrum between the official bands, because some stations are broadcasting there as well. International broadcasters, Clandestine and Pirate stations are not included in these statistics.

(Slide 3: Active domestic transmitters)

This slide shows the number of active frequencies used by stations in various parts of the world for domestic broadcasting. During this period of 30 years, most of the countries have had the same, downgoing development in the use of the tropical bands for broadcasting. At the bottom line you see that the total number has steadily fallen from 1106 in 1973 to 363 - or one third - in 2003.  All these numbers answer my first question: How many have disappeared ?

I will now comment on some of the countries and try to answer the next question: Where have they gone ?

Five months ago I visited the smallest independent nation in Africa, São Tomé e Príncipe, which is also one of the most poor countries. I saw the remains of the former tropical band transmitter of Rádio Nacional de São Tomé e Príncipe broadcasting on 4807,5 kHz with 10 kW. Some of you may even have heard it around year 1980. The transmitter was provided and maintained by Portugal when the islands still were a colony. But at the independence in 1975 the Portuguese left the islands, and because no other nation did support, the transmitter and antenna were never maintained properly. According to our Tropical Bands Surveys, the station was regularly heard until mid 1982, but only sporadically the succeeding three years. During a storm in 1985 the antenna broke down and the shortwave transmitter has been off the air since then. In March 2003, I saw the remains of the transmitter building and the broken antenna which still are there! The U.S. has leased the site and now operates the VOA Pinheira relay station from there, but also the mediumwave transmitter of Rádio Nacional on 945 kHz. I think this is typical for many of the developing countries. Because of lack of money or knowledge – or both – they are only able to run shortwave transmitters until these fall apart, unless they get support from abroad.

From Ghana a DX-er, Charles Wompiah, reported this spring that the transmitter of the Ghana Broadcasting Corporation – Radio One, broadcasting mostly in African languages on 4915 kHz, had been off the air for two months due to a breakdown of the old valves. It came back only because valves were cannibalized from the Radio Two transmitter which broadcast daytime on 6130 kHz and at night on 3366 kHz  all in English. Radio Two has not been heard since April. This is a typical example of an old shortwave transmitter installed right after the independence by a foreign contractor who no longer exists, and all spareparts in the meantime have been used up.

Our Scottish member, George Brown, experienced something similar when he visited Radio Vanuatu in the Pacific in November 2001. They use a two channel 10 kW transmitter tuned to 4960 and 7260 kHz, normally switching frequency around local sunrise and sunset. During the visit one channel developed a fault, and the other one had to be used all the time. The other standby transmitter on 3945 kHz was out of service because of shortage of spare parts to make it operational. DBS monitoring indicate that 3945 and 4960 kHz have been off the air since then, while 7260 kHz is regularly heard.

In Ecuatorial Guinea, Chinese engineers recently has provided and installed a new transmitter for Rádio Nacional, Bata which used to be heard around 5004 kHz. Last month China also accepted to give an intensive maintenance course this autumn in Beijing on the new equipment to a number of Ecuatorial Guinea technicians. The government had bought an electric generator to keep the radio regularly supplied with energy, because the commercial power is unstable, as in most other developing countries.

In Southern Africa it is the same story. Lesotho National Broadcasting Service of 4800 kHz was off the air for some months last winter, because they were awaiting transmitter spare parts.

The two transmitters of the Namibia Broadcasting Corporation on 3270 and 3290 kHz used to be heard well here in Europe until about a year ago. Then the modulation deteriorated and the signals disappeared. In April I read in the press that the Namibian Prime Minister Theo-Ben Gurirab had told the National Assembly that a cash injection of 66 million Namibian Dollars was urgently needed to get the broadcasting back on the air.

Let me jump down to Indonesia which always has been a popular target for DX-ers. Back in 1973 it was the country in the world with most stations broadcasting on the Tropical Bands – no less than 171. Many of these were private, low powered and irregular. But most of these and of the Government owned Radio Republik Indonesia stations have disappeared from the Tropical Bands, maybe because of transmitter problems, but rather because they have been replaced by Mediumwave or FM. In this vast country, today there are at least 600 mediumwave transmitters and 625 FM transmitters, but less than 20 Tropical Bands transmitters !

When I visited Guatemala in Central America last November, I noticed the same. Only seven stations still broadcast on shortwave, but the whole country is fully covered by FM-stations. In the old colonial city of Antigua,  25 kilometres west of Guatemala City, I counted no less than 90 stations on the FM-band ! So in that country the need for stations on the Tropical Bands is diminishing and quickly approaching zero. Mr. Wayne Berger at Rádio Cultural has disclosed that the transmitters on 3300 and 5955 kHz are only kept on the air to please DX-ers!  Another regular Guatemalan station, Rádio K’ekchi’ on 4845 kHz which broadcasts to the Quiché speaking Indians, was off the air for four months last year, but the reason for that was a very unusual one: The transmitter site was occupied by a group of homeless squatters !

One of our Italian members, Massimo Cerveglieri, has just been on holidays in the neighbour country Honduras where he only found 4 stations active on the tropical bands. One rarely heard was HRET, Rádio Buenas Nuevas in Puerto Lempira on 4960 kHz. A few years ago they installed a solar and windpower generating system as their power supply, but that appeared to be too small to operate the 500 watt transmitter and studio equipment. Their back up diesel generator is expensive in fuel costs. Furthermore they have an increasing problem in lack of operating funds from local churches and underwriters, so they cannot pay enough to attract qualified personnel to their own staff.

In 1995, I visited  the station Emisora Gran Colombia in Quito, Ecuador, together with DX-Editor Richard McVikar from HCJB. I asked what had happened to the shortwave transmitter on 4911 kHz which used to be heard in Europe. The station manager told us that the coverage by their mediumwave transmitter on 610 kHz was sufficient to reach their audience in and around Quito, so there was no longer a need for the broadcasts on 60 meters – and by the way, the elderly engineer who was the only one who was able to operate this transmitter, had died! In 1973 no less than 47 stations in Ecuador were active on the Tropical Bands. Today it is only 13, and most of these are very irregular.

The country with most stations on the Tropical Bands today is Peru with 53 frequencies in use! On the slide you can see that during the past 30 years there has only been a minor decrease from 78 stations. This country is probably one of those which will stay longest on the Tropical Bands. But it must be added that many of these stations are not on the air on a daily basis and several are replaced by new stations each year.

The Japanese DX-er Takayuki Inoue Nozaki (TIN), has visited the Andes countries many times, and he reported  from Bolivia 2½ years ago, that the small, privately owned commercial broadcasters on shortwave have ceased existing. This was due to the decrease in profits made by selling airtime for commercial advertisements and personal messages. New commercial broadcasting enterprises bristle on FM which replace shortwave and mediumwave. Religious organizations seem to buy up many of the old commercial AM transmitters.

The huge country of Brazil also needs shortwave to broadcast to its people in the rural and rainforest areas while  FM has taken over in the more densely populated areas. But the big networks have their own satellite systems, and with those, it is no longer economically impossible to transmit programmes to small, rural FM-stations which can relay them to the surrounding area. Consequently the use of Tropical Bands is also on decline in Brazil even though around 50 stations still can be heard.

Let me close with a look at another popular DX-country, Papua New Guinea. This country is very difficult to hear in Europe, but we have members and other DX-ers in the Philippines, Japan, Australia, New Zealand and on the west coast of North America who regularly report about the broadcasting situation. On the middle of the slide you can see that their number of broadcasting stations seems to be stable since they got new transmitters in the early eighties. But that is not true! These transmitters which mostly are on 90 meters, have big problems and I have made a more detailed study of loggings of their broadcasts during the past 24 months which is shown on the next slide.

(Slide 4: Papua New Guinea)

On the left side you have the frequencies of each of these regional stations which all use 10 kW. At the bottom on 4890 kHz, however, is the 100 kW transmitter located in the capital Port Moresby. Each of the letters to the right indicates the first letter of a month where the particular station has been reported heard by a DX-er. On top you see that this graph goes from July 2001 until June 2003.

Some stations are very stable like the two at the bottom which have been heard nearly daily. But other stations were very irregular. In some cases I found out the reasons from press reports:

On 3245 kHz Radio Gulf in Kerema was off the air from May 2000 till October 2001 due to lack of fuel for their power generator. Obviously they have not invested in large enough fuel storage capacity to avoid such problems.

On 3260 kHz Radio Madang was closed in May and June 2001, because the electricity bill was not paid!

On 3345 kHz Radio Northern was off  for 29 months until June 2002, because of a fire at the station.

On 3355 kHz Radio Simbu was off from July 2001 till March 2002, because of transmitter repair.

On 3395 Radio Eastern Highlands has been off for 2½ year, because of financial constraints. However, the Eastern Highlands Provincial Government found money to get the station operational up to the local elections in July 2002! It is remarkable that all stations, except Radio East Sepik on 3335 kHz, were operational during the elections, but about eight of these disappeared again shortly after for some months.

The future

My final question was: When will the last stations disappear from the Tropical Bands?

From the total figures on the  previous slide I have made a graphic which is shown here:

(Slide 5: The future trend)

You see that the curve of the total number of active transmitters is going very steadily downwards. I suppose that this trend will continue and when I prolong it beyond 2003, it will hit ZERO around year 2014. So it is my guess that after that year there will no longer be domestic broadcasting on the Tropical Bands.

It raises two further questions:

1.     What shall the Tropical Bands DX-ers do after 2014 ?
        I will suggest DX on Mediumwaves where there still is a lot to hear.

2.     Which radiostations will take over the Tropical Bands when the Domestic Broadcasters have left ?
        Our longtime member in Sri Lanka, Victor Goonetilleke, expects more international broadcasters, but as a dedicated radio amateur himself, he also hopes that hobby radio will be allowed on certain frequencybands. I am afraid that this Conference is not the right forum to discuss this question. Victor attended the EDXC Conferences in Stockholm, Sweden in 1984 and in Rebild, Denmark in 1995, and he asked me to forward his greetings to all of you.

To sum up:

(Slide 6: Conclusions)

We are approaching the end of the Era of Domestic broadcasting on the Tropical Bands !
The technical standard of a large part of the transmitters on the Tropical Bands is poor. In more developed countries they are being replaced by  FM-networks and it can be feared that the trend will continue to go downwards and the stations will all have left around year 2014.
However, you can still hunt for and maybe get QSL’s from 363 Domestic Broadcasting Stations on the Tropical Bands, before it is too late. Fortunately the interfering broadcast and utility stations are also disappearing. So do not give up your Tropical Bands DX-ing! It is just a matter of switching on your receiver and tune in to these frequencies at the right times!