Radio Furaha Iringa

on new Antenna mast with 2000 Watts!
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STL Antenna got a llonger antenna mast

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so we have to increase the cable length!

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Arriving at the new transmitter site

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New antenna mast

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and the ground staff

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STL cable needs to be connected!

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Old transmitter site

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The antenna needs to be tuned to te frequency

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and its length to be adjusted

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All 4 Antennas!

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The antenna is on top of the antenna mast, much higher than before!

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All studio staff is helping to put in the new power cable

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The new 2000Watts power amplifier

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Protos is putting the 4 amplifier modules each producing 500 Watts of RF

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Switching everything on

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On air on 97.6 MHz with 2000 Watts full stereo!

 

 


On Tuesday 5th of March Martin came from the Lutheran Radio Centre in Moshi and we showend him the new Power amplifier.
We brought it up imeadetly to the transmitter site.
The next moring we were very busy to extend the cable of the STL at the diocese, since Fundi Macha had helped to increase the length of the antenna pipe of the STL.
After getting the STL on air again we drove up to the tansmitter side again in the afternoon. We had to connect the STL receiver cable here as well and complete the antenna earthing. Fundi Macha had already moved tho hole of antenna structure from the other antenna mast to the now one of TTCL. He also had moved all the antenna cables and mounted een the STL receiving antenna nicely on the new antenna mast.
Then we continued inside the transmitter shelter. Radio Furaha is sharing it with the microwave links of TTCL, the GSM phone, some Internet providers and another 2 radio stations. They have rented their space plus electricity even with diesel back up in case it fails.
We connected the ground using a thicker earth cable. The STL antenna cable and the transmission cable got grounded outside the building. Inside the cables got grounded again together with the power stabilizer, the UPS and transmitter/ amplifier.
We also replaced the 1.5mm electricity cable with a 6 square one to carry the new 6 kW load.
Then we assemled the power amplifier and connected everything placing all in their rack.
The amplifier had to be adapted for the transmitter. We fed the transmitter with the multiplex signal to ensure real stereo operation and set the transmitter to receive the signal correctly. Then the level had to be properly adjusted.
Unfortunaltely the antenna system did not work. So we returned the next days trouble shooting. We checked the antenna cable with a dummy load. We checked each antenna one after another. All behaved similar bad giving an SWR higher than 3. We measured the frequency response courve of the top antenna, which is really free and far from any mast construction. But the response had been bad all over the FM band. We swithced off the other FM station operating close by. But no change! Then we realized that the antenna had not been tuned at all the first time when it got installed by Samueli.
It was still in its packing condition! After adjusing according to its instructions it gave a perfect match! Connecting again all newly tuned antennas using the combiner gave a good picture again. Then we checked the frequency response of the cavity filter. Unfortunately it was a bit off the frequency, but we had not been able to adjust it, because the adjusting screwa had been to tight. So we just left it and tested the hole antenna system again. And- it worked well!!
The SWR could even be lower if the cavity filter could be adjusted a little bit, but as it is it is fine as well!
We adjusted the maximum power for 2000 Watts and the drive power to 70 Watts as given in the manual.
It had a real moving moment when we listened to the German Choir singing in the big Cathedral "Lets Thank God ..." (This was Radio Furahas only very wide stere CD )

In the Evening we were invited home of the general secretary of the diocese together with the staff of Radio Furaha for the dinner celebrating the new chance on air with 2000 Watts.
We got reports as far as Chimala of listerners listening to the station. Evaluation of all programmes was planned for the next week after getting feedback from the listerners.