Transmitter Operations - Reminiscences
|The picture shows my brother in law Robert, myself, Mr. Yong and Cindy Yeo...|
When I joined the BBC in 1962 at Daventry there were just the two overseas relay stations for BBC World Service transmissions, at Cyprus and at Tebrau on the southern tip of Malaya. At Daventry we had a special huge array, an HRRS 8/6, and two transmitters in parallel on 17.79 MHz that was used mainly for feeding Tebrau with programme. For political reasons, after Singapore split from the Malaysian Federation, the Tebrau station closed and a new station was built at Kranji on Singapore Island.
In those days I never dreamed that I would one day visit the area at the other end of that beam! Even travel to Europe in those days seemed only for the rich! A few years ago I was able to visit my brother-in-law Robert (G4BWB) who was living in Hong Kong at that time and was able to visit the BBC relay station there not long before it closed.
Robert has now moved to Singapore where he is a TV producer and he invited my wife and me to visit him and his family. In 2001 we went out there, taking in Dubai and Hong Kong on the way to see if there had been any changes since our last visit.
We arrived in Singapore in mid-November for a 2 week stay with Robert and his family. I had already contacted Kranji by e-mail and they had kindly offered to let me visit the station during our stay.
I must admit that before my first visit to Hong Kong I had assumed that it was totally covered with buildings, as this is the impression given by all the tourist photos. I was surprised to find how much countryside there is in the territory. I had the same impression about Singapore and a casual visitor to the island would tend to agree, as there are large areas of high rise apartment blocks, apparently covering every inch of the island.
Once again, my impression was proved wrong. I telephoned Kranji to arrange a time for my visit and they warned me that I might have difficulty finding them and gave me detailed instructions, as they doubted that even a local taxi driver would know where they are! The address of the station gives the impression that there are many other buildings along the road. However, consulting Robert's street directory revealed that it was in the middle of a blank page, with only one other building shown.
There is an excellent Mass Rapid Transit (MRT) rail system in Singapore and one of its stations is Kranji. Robert and I set off on the MRT and as the train approaches Kranji you can indeed spot the red and white towers of the radio station over to the West, looking as though it would be only a short walk to reach it. However, the map reveals that in the way is the large Kranji reservoir.
We eventually managed to hail a taxi and sure enough the driver had never heard of the place. With the aid of the map I was able to direct him, which involves driving north to the coast, with its views of Johore Baru across the strait, then crossing over the dam at the reservoir and then heading south down a lonely road surrounded by green countryside. In fact it could almost be an English country road were it not for the banana and palm trees!
Eventually a small sign on the left proclaims 'BBC Far Eastern Relay Station' and a narrow track winds past a radio station owned by the local Singapore radio authority and then ends abruptly at the gate of the BBC station.
We were greeted by Mr. Yong Wui Pin, the operations manager who took us to his very pleasant air conditioned office and introduced us to the two charming ladies who look after the administration there. Cindy Yeo told us that she had been there almost since the station had opened and she invited us to sign the visitors book. They seemed genuinely pleased to see visitors and I was quite surprised to see that my name was the first entry in the book for 2001. Obviously, given their location, they do not get many people passing by! In fact, the previous signature in the book was that of Mark Byford, the World Service boss, so we were in illustrious company.
Mr. Yong then showed us first around the stores and workshop areas, all nice and cool and air-conditioned. I was amused to see lots of familiar RS Components boxes in the workshop, they get everywhere!
It was quite a contrast when we went out into the transmitter hall. Here it was very hot, even though our visit coincided with the 90 minute period when the station is shut down for maintenance. To me, apart from the heat, it was a moment of great nostalgia! Way back in 1963 I was transferred from Daventry to Woofferton, the station located near the Welsh border, which at that time was primarily a Voice of America relay station and was just in the process of having its 50 kW RCA transmitters replaced by then brand new 250 kW Marconi BD272 units.
Nearly 40 years later, it was a bit of a shock to step into the sender hall at Kranji to see almost a replica of Woofferton, with those Marconi units still giving sterling service. The BBC has always called its short wave transmitters 'senders' for long forgotten reasons and at Kranji they are numbered Senders 102, 103 etc..
The BD272 units need manual wave changing, which in practice means they need to be closed down for 15 minutes at a minimum to manually remove some very large, heavy (and hot!) coils, insert ones for a different band and then tune up the sender on its new frequency. The final anode coils for the 41 & 49 metre band are very impressive, the antenna coupling coil is a single turn over a metre in diameter and made of tubing about 12 cms. across - quite a beast! Doing a rapid wave change at Woofferton in cool England made you sweat profusely, I can imagine in the heat of Kranji, you rapidly lose some weight!
Power for the station is supplied by the local electricity authority and is transformed down to 11,000 volts to supply the anodes of the two BY1144 triode valves in grounded-grid configuration in the final stage of each sender. At full power these draw 26 amps. anode current, so some quite serious power is being consumed. The senders use high level modulation, which means they need something in excess of 125 kW of audio to give 100% modulation. This is provided by two more BY1144 valves in class B configuration. This means that the current they draw varies wildly with the modulation, thus the current being drawn by the station is not constant, particularly if all the senders are carrying the same programme. I remember that in the town near to Woofferton, all the lights in the houses flickered in time with the modulation and when the Greenwich Time Signal 'pips' were broadcast at the top of the hour, you could check your watch by your house lights!
The sender hall is raised above ground level and when we went out of the hall we found ourselves on a balcony overlooking the antenna farm. I soon realised the reason for not going down into the field, the lush tropical vegetation is infested with some very nasty snakes - not a problem I had at Woofferton! Mr. Yong told me that crocodiles had also been spotted in the area. Thus their 4 antenna rigging staff had to take great precautions when going out to their tasks in the field. All the antenna switching is done by air operated switches remotely controlled from the building, which must be a great relief to the staff!
Although the station is now operated by Merlin, the station still has a BBC 'feel' to it and I was interested to learn that the station operates on a three shift system with similar hours to that worked at the UK stations. Day shift is I think 09.00 to 17.00, evening shift is a short one until 23.00 and the night shift is the long one until 09.00. This used to be quite a good system, well liked by most staff, as it meant on evening shift you had most of the day free and could still be in bed by midnight.
BBC World Service in English is available for local listeners on 88.9 MHz FM, the programme feed for this is received at Kranji but is fed on to a site located with all the other domestic transmitters in the centre of the island.
I asked if they receive many reception reports at Kranji from Short Wave Listeners and was told that they are forwarded to Bush House, London. I mentioned that while I was working on Ascension Island I used to answer reception reports personally, but I am not sure if this will have any effect at Kranji !
Interesting smells coming from the kitchen announced that it was nearing lunch time for the staff, so we bade our farewells to our hosts and suggested we phone for a taxi. Mr. Yong said that taxi drivers would never find the place, so he very kindly drove us to Kranji MRT station. A fascinating visit, full of nostalgia for me, with grateful thanks to the very friendly staff who took time out to show us around.
Having now seen the Hong Kong and Kranji relays, I must now persuade my wife that we need to visit Thailand next!