Radiowaves Special Feature: The Radio 4U Story

THE RADIO 4U STORY


Chapter Five


The basic design was a desk top with two turntables at the far end; in between was the mixing unit and plenty of writing / working space in front.

I knew from previous experience how much DJs like to fiddle with sound control buttons, putting too much bass on their voice with the intention to sound butch. The result of those practices is usually a dull mumble on the receiver’s end.

No chance for those bad habits at Radio 4U: I bought a straight forward mixer from the shelf and expanded it to have two studio microphones and two record players attached. Two further channels were switchable for a) cassette drive one or reel to reel, and b) cassette drive two or telephone .

Back in 1987 mobile phones were still very expensive, and even though the Telecom transmitter was within view on top of the next hill the service used to be very unreliable. This yuppyish feature was the most expensive single item within the Radio 4U operation.

I also knew how terrible DJs are when it comes to reading meters in order to keep the right volume level. To overcome this obstacle, I pre-adjusted the mixer inputs permanently (fiddle free zone) and led the mixer output through a built in limiter and equalizer before feeding the very first stereo encoder in the north-west. The limiter and equalizer were all manufactured by Willy, and the encoder was even designed by him. All the jocks had to worry about was to open the right fader at the right time.

However a few experts were allowed to play: the Aiwa cassette player had a secret speed control button; and I can assure you that some rather funny trailers and links were produced with this facility. This had nothing to do with station policy to play the silly, then current, chart hit ‘Star Trekking’ at double speed to make it sound even sillier.

Special thought was given to the microphone facility. Do you know the echo sound or even feed backs of pirate radios just because the studio monitors are left on? Not so at Radio 4U. They were switched by the mic fader as well as a tape recorder upstairs for ROTs (recording of transmission). By recording all voiceovers I was in full control of whatever went on the air. None of the Donegal operators ever bothered that much about security and nobody has that tight station policy about dos and don’ts…

Of course, the microphone fader operated an ‘On Air’ light too. It was a bit small so Marie suggested that I should attach a further warning sign to it. You should have seen her face when she saw this little tiny typed note (smaller than the light itself) next time she came up to the cottage.

A reasonable headache was the question of a telephone. When I asked Telecom Éireann how long it would take to get a line, I was told that I would be given an answer to this question only within three months, provided I’d apply for a phone in the first place. Some people in the area actually waited ten years to get a telephone. I had a business to run and so my only option was to call British Telecom Mobile Communication for a portable radio phone. Asked for when I would need it my reply was “Yesterday”, so it was delivered the next morning.

Back in 1987 mobile phones were still very expensive, and even though the Telecom transmitter was within view on top of the next hill the service used to be very unreliable. This yuppyish feature was the most expensive single item within the Radio 4U operation.

On Monday (01.06.1987) and Tuesday I started to tackle a remarkable bit of RF engineering: the Radio 4U transmitter. Willy supplied me with two transmitters (don’t laugh!), a 35 watts and a 10 watts FM unit, as emergency reserve.

As I mentioned before, to supply a city like Derry one would require at least 250 watts transmitter power. Now, if you give a 35 watts transmitter signal on an omnidirectional aerial (eg dipole) you will receive 35 watts ERP (effectively radiated power) in all directions from your antenna.

Radio 4U was planned as a city station and therefore I could afford to restrict the signal to a small beam directed at Derry. Considering the distance between the transmitter and the city, a 45 degrees beam was sufficient.

Radio waves work quite similarly to electric light. If you put a mirror behind a light bulb you restrict the light to just one direction but double its brightness. You can achieve the same effect with radio waves by using directional antennas. Radio 4U’s was a nine element Yagi antenna reaching 45 degrees with a gain of transmission power times 12. Accordingly, the effective radiated power of Radio 4U’s first transmitter was 420 Watts. (35 W X 12 = 420 W ERP)

Only Willy could come up with such an idea!

Besides the obvious low cost transmitter, there were some more advantages with this system, such as: low wear and tear of the equipment, and extremely low running costs (£2 for electricity per month compared with £48).