Dominica Amateur Radio Club Inc. WWW.J7HAMS.COM

Repeater Network History

The Dominica Amateur Radio Club owns, operates and maintains a number of repeaters which are situated on various mountains around the island. The functions of the repeaters are to enhance communications over long distances, particularly rugged terrain, as in Dominica.
Since VHF and UHF communication are "line-of-site", the range between two stations can be determined by the terrain. Any obstruction such as a hill or mountain could block communication between two stations particularly portable or mobile stations. A repeater placed on a high point sees for miles, and stations with limited power and antennas can still be picked up by it, and signals re-transmitted over long distances.

The Club owns four (4) mountain-site repeaters and one (1) Club station which are located as follows: · Morne Au Diable - Vielle Case, Morne Anglais - Giraudel, Morne Haut Jean - Salisbury, Morne Fraser - Castle Bruce, Morne Au Diable.

After much discussion about establishing a repeater system which would provide island-wide coverage, we finally made the practical step of cutting our way to the top of Morne Au Diable.

Morne Au Diable is the most Northerly peak on the island of Dominica, the summit being at 2850 ft.. From the top of this mountain, the view is astounding and islands such as Guadeloupe, the Saints, Marigalante and Deserade are just some of the islands which can be seen from that point. When at the top of the mountain, beneath the feet, lay the town of Portsmouth, villages of Pennville, Vielle Case, Thibaud, Paix Bouche, and in the distance is a vue of the East and West Coasts with the majestic Morne Diablo in due south.

The first trip was made by Clement James (J73CI) and Wayne Abraham (J73WA), who had seen on a map of Dominica a track to the top of the mountain. No one had been there since the passing of Hurricane David and some parts of the trail had almost disappeared beneath the vegetation. Above 1800 ft., these two Amateur Radio Operators found a steep section and wondered whether they had made the right decision. After several hours of cutting grass however, they came within five minutes of the top. Due to time constraints and other engagements, they had to turn back and head home.

The following week, these same two Operators returned to the mountain and this time, with an additional crew of Aaron Blaize (J73BA) and Werner Henry (J73JH) they resumed cutting grass along the trail and within ten minutes, were at the summit. While there, some initial tests were conducted with a 5/8 mobile whip to determine the suitability of the site and these tests proved to be very positive.

On the third visit to the mountain, there was a much larger crew which cleared the summit. Batteries were found, which were buried by decaying vegetation. The crew was later informed that the batteries were left there by Jacques Cousteau, the famous underwater explorer who had been conducting some sort of a survey. On that trip, a repeater antenna was taken up to the summit and more tests were carried out with one Amateur Radio Operator (J73CD) driving through the Pond Casse to Melville Hall road. The crew was very happy with the results of these tests.

Another visit was paid to Morne Au Diable with a contingent of twenty-four (24) Scouts from the Mahaut and Vielle Case troops who assisted the other members of the Club in carrying up all the necessary equipment to establish a Solar Power VHF Repeater at the summit.

Morne Anglais

The Dominica Amateur Radio Club was looking for a repeater site to the South of the island and had explored Morne Micotrine/Macaque. This mountain was found to be very cloudy and not suitable for solar. Amateur Radio Operator Kelvin Southwell (J73SK) made a trip to Morne Anglais and reported that the climatic conditions were much milder there. He also did some initial tests and was able to work the repeater in St. Vincent. The DARC then decided to take a closer look at that mountain for a suitable repeater site.

A contingent of Amateur Radio Operators consisting of Clement James (J73CI), Aaron Blaize (J73BA), John Michel (J73MH) and Sevrina Bell, a guide, made their way to the top of Morne Anglais and were very excited to find that it would be a very suitable site for the South repeater. There were fantastic views from this mountain of the Capital Roseau beneath their feet, and the villages of Pichelin, Bellevue Chopin, Grandbay, Tetemorne, Pointe Caribe, the Roseau Valley and others were visible from the top.

There was one complication - they were in the prestigious Trois Pitons National Park. It was not too long after that trip, that there was a Communications Exercise carried out by the Office of Disaster Preparedness on the island. The result of that exercise demonstrated that the high frequencies failed to provide dependable communications between Dominica, Barbados and the other islands, Barbados being the home of the Caribbean Disaster Emergency Response Agency (CDERA).
That situation was used to present a case to the Government for permission to establish a site within the Trois Pitons National Park. While in negotiations with the Government, a Tropical Storm was developing out in the Atlantic. The then Permanent Secretary in the Ministry of Communications and Works gave the Club verbal permission to establish a site on the mountain and indicated that the paperwork would be processed at a later date. The DARC immediately went back up to Morne Anglais and established a small solar-powered Digipeater (Packet radio node). This was the first time that Amateur Radio Operators were able to maintain contact with Barbados via this digital node. It also enabled them to talk (by typing text) to other islands such as St. Kitts, Guadeloupe, among others.

Later, after sourcing equipment and more solar panels, the Amateur Radio Operators established a Voice Repeater at the site and made their first contact on voice with Barbados, St. Vincent, St. Lucia and a few other islands.

Morne Haut Jean

There was a need to communicate within some parts of the interior of the island and along the West Coast, which neither the North or South repeaters covered. Again Amateur Radio Operators Clement James (J73CI) and Wayne Abraham (J73WA), in studying maps of the island, began their search for a suitable site. While driving around the island, Mr. James (J73CI) noticed that his altimeter went up to as much as 2700 feet when climbing into the heights of Salisbury. Messrs James and Abraham therefore looked carefully at that area on the map and noticed that the road went very close to a peak of a mountain called Haut Jean. They immediately agreed to meet in the village of Salisbury and then drove to the highest point on road, and then walked for ten minutes up to the summit. To their surprise, there was a fantastic and panoramic view of the surrounding area. Tests indicated that it would be a suitable site and so they were faced with the challenge of finding out who the owner of the land was and how they could secure permission to use it for a repeater site. After making inquiries, they found out that it was owned by one Mr. Norry Vidal of Salisbury. They sought and finally contacted the gentleman and after discussions, Mr. Vidal expressed his willingness to allow them to use the site to establish a repeater.

It was not long after, that a crew of Amateur Radio Operators visited the site and established a repeater (remote base) there.

Morne Fraser

Ulrich Esprit (J73UE) and Joseph Guiste (J73JT) both Amateur Radio Operators in the village of Castle Bruce to the East of the island, expressed a desire to establish a repeater in their village to facilitate communications there. The Dominica Amateur Radio Club was again faced with the challenge of finding a suitable site for the repeater. An initial trip was made to the Morne Fraser site to explore and clear it. The second trip to that mountain entailed carrying up all necessary equipment to establish a repeater. At the end of that day, the Fraser repeater was fully functional and the Operators were amazed at some of the areas it covered.

Maintenance of Repeater Systems

Maintaining the repeater systems entails keeping the vegetation on the mountain cleared so that it does not over-shadow the solar panels, checking the water in the batteries, ensuring that water does not enter the storage compartments housing the repeaters, keeping the antennas and cabling in good condition and rectifying failures to the repeaters.

Linking Local and Regional Repeaters

For more versatile communication, a link between all the different repeaters was the answer. Though there were repeaters which covered every part of the island, they were not all connected together. A first link was established between the North and the South repeaters, using UHF radios. Subsequent to that, a UHF Hub repeater was established at the south site and it did the job of linking not only the local repeaters, but created an opening to link regional repeaters, St. Lucia being the first of those to be linked, and recently St. Kitts. The DARC is hoping that in the very near future, Barbados will be linked. Barbados is presently awaiting some equipment to expedite the process. Klaus Rung (VE3KR) from Canada had been working with NORTEL and made several visits to various islands in the Caribbean. He thought it would be interesting to link the islands and spoke of his idea to Amateur Radio Operators in St. Kitts. At that same time, Clement James (J73CI) of Dominica had also been speaking with Operators in St. Kitts. The St. Kitts Operators then introduced Mr. Rung to Mr. James and on a subsequent visit to Dominica, the two met. At that meeting, Mr. Rung shared some of the plans he had drawn up with Mr. James and suggested ways in which a system of linked repeaters could be created. The two gentlemen then went on to implement those plans.

Internet Repeater Link Project (IRLP)

The IRLP system was started by Dave Cameron (VE7LTD) in Vancouver, British Columbia. It is a system whereby VHF and UHF repeaters can be connected to each other via the internet and which greatly enhances the range of communication to a global field. One is able, with this system, to stay anywhere in Dominica on a VHF or UHF radio and dial up using DTMF, any other repeater in any part of the world that is part of that system - examples in our greater neighborhood being Antigua, Aruba, Barbados, Bermuda, Curacao, Grenada, Grand Cayman, Jamaica, Puerto Rico, Sint Maarten, St. Thomas and Trinidad.

This system is an ever-expanding network and now includes the USA, Canada, Australia, New Zealand, South Africa, Korea, Ireland, United Kindom, Sweden, Italy, Mexico, Belgium, Japan, Chile and India. It has been a source of much excitement for Amateur Radio Operators both here and abroad, but it is also a very versatile tool to be used for emergency communication. Preferably, a high-speed connection on a personal computer with a special board purchased from IRLP, allows one to interface a radio or repeater with a personal computer. Tones received by the radio are sent via the internet to a central system, which then connects the Operator to the appropriate repeater dialled, and presto!, that Operator is getting out on a repeater in Canada, the United States or other such region.

Conclusion

In conclusion, the survival and development of these systems are dependant on an on-going education programme for prospective Amateur Radio Operators and a vibrant Membership Chairman to maintain an active membership of the Dominica Amateur Radio Club, keeping in mind the main objective of the Club which is to provide an emergency communication service. The Dominica Amateur Radio Club members are ready and willing to participate in various activities, exercises and any emergencies that may arise at any given moment in support of the public.

 

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