Mount Evelyn DX Report: A VISIT TO RADIO COOK ISLANDS MW TRANSMITTER SITE

Some serious corrosion of the transmitter mast
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A VISIT TO THE RADIO COOK ISLANDS

MEDIUMWAVE TRANSMITTER SITE

by Chris Rogers (Guest Contributor)

Although not a shortwave topic, I am sure many readers will be interested in this Radio Cook Islands report concerning their mediumwave transmitter. - Rob

There has been a lot of news lately on the internet about the impending closure of Radio Cook Islands medium wave service on 630 kHz, which will be replaced by an FM service on the main Island on the frequency of 101 MHz.

Whilst on a DXpedition earlier this month in Rarotonga, my long time DXing partner and friend Dave Headland decided to visit the mediumwave transmitter site located at Matavera about 5 kilometres from the main town of Avarua on the Island of Rarotonga.

After a phone call to Bluesky Telecommunications who look after the technical side of the Government run Radio Cook Islands a technician met us at the transmitter building and showed us through a rather run-down concrete building which had boarded up windows and had not seen any maintenance for a long time.

What we discovered inside was a very modern Nautel NX3 transmitter running at 2.3kw and there was also the remains of a gutted older Nautel AMPFET 5kw transmitter. Monitoring of the signal over there by us observed 2nd, 3rd and also 4th harmonics of the main signal frequency so it was obvious to us there are technical issues with the existing equipment that hasn’t been addressed for some time.

Inspection of the 105 metre MW radio mast that was a gift from the NZ government many years ago, also indicated extremely dangerous corrosion at the triangular base of the mast with rust almost 50% of the way through the structure, causing the evacuation and relocation of the students of the school where the mast towers over. Apparently, the last maintenance of the mast was in early 1990 and the salt air has clearly taken its toll. There is a delay in the closure of the MW service, and removal of the mast, as Bluesky telecommunications and contractors try and work out how to remove the mast safely, as there are no riggers on the island, nor large cranes.

When we first arrived in Rarotonga, Radio Cook Islands had an FM service on 88.8 MHz right around the island of Rarotonga located at three transmitter sites, strategically placed not to interfere with each other. During the week the frequency was changed to 101 MHz. This was probably implemented to avoid interference and confusion to listeners as there are many other low powered stations in the 88 MHz area.

The 101 MHz frequency allocation is an interesting choice because a vast majority of cars on the Island are Japanese “grey imports” that have Japanese radios installed in them which only cover the Japanese FM band up to 95 MHz and which will obviously impact listening to Radio Cook Island once 630khz leaves the air.

Whilst monitoring Radio Cook Islands after the frequency change, on-air announcements were heard advising the MW service at Matavera will be closing in a “week or two” and advising listeners to tune to 101 MHz. There was no mention of FM frequencies for the other 14 islands in the group whose residents will undoubtedly suffer the most from the loss of reception when the MW service is closed.

Unfortunately for MW DXers another Pacific MW service is closing and will shortly be part of mediumwave history.

(This article first appeared in the July 2019 issue of the Australian DX News)

My thanks to Chris Rogers for allowing me to reproduce this article here in the MEDXR blog.

73 and good DX to you all!

Rob Wagner VK3BVW