13 March 2002 First DATV (qpsk) transmissions in Belgium

Thanks to the cooperation of the Adacom group I could start the first DATV transmissions in Belgium.Since I wanted to do DATV experiments before I went to Spain ,they send me the MPEG-2 Endoder,the Baseband board and lent me their devellopment sample of the IQ modulator/HF amplifier.
Pitty enough I had not sufficient time to measure the output power,so the figures mentioned are best guess.
The borrowed HF amplifier had an output power of abt 10-20 mW and the next amplifier(designed by Philip/ON7IZ)supplied abt 500 mW.
The final amplier was made with the wellknown Mitsubishi module M57762 and delivered abt 8 Watts by driving the module on 1247 mHz with low power.
Later measurements showed that there were relative high "shoulders",mainly caused by driving the 500 mW stage with too much power.

My antenna is made with two 35 elements Tonna Yagi's that are mounted above each other giving abt 17 db gain.

The Adacom kit worked with a SR of 6000 and a FEC of 1/2.There were two channels ,each having a bitrate of 3000 kb/s.You can have a look here
at the parameters I used at the time.
Also actif were two Teletext pages and a (no-standard) testcard.

The camera was a Sony TVR900 and for sound I used the two camera microphones,giving stereo sound.

The first "viewer"was Ellen/ON1AVC.The distance from my qth Dilbeek near Brussels to the town of Herent is 37 km and the signal had to go straight
across the town of Brussels.My output was abt 8 Watts.Ellen reveived picture and sound B5 on her Nokia 9800 digital receiver.The receiver showed a S/N of 8 db.I forgot the type of antenne she used.

The second OM was Stefan/ON7WE who lives abt 20 km from here.The output power was 500 mW.Picture and sound were B5.His Humax 5400
showed a Signal Level of 27 % and a Quality Level of 70 %.I do not know the antenna he used.

The third OM was Walter/ON4BCB.Distance 40 km and his antenna was a 15 elements Yagi having a gain of abt 12 db.On his Nokia 9800 the S/N was
8 db.On his Spectrum Analyzer was de -6db bandwidth 6.76 mHz.At noise level abt 8 mHz.Picture and sound were B5.Even with a 3 db attenuator in front
of the final amplifier they were still B5.

All om's used a RF amplifier in the antenna mast.

It was the pitty that I could'nt do more experiments since we left two days later for Spain.There I exercized with the software and made several Teletext
pages.
I did also test transmissions (EA5FIN)over abt 500 mtr distance  with groundplane antennas's and 15 to 500 mW output with good results.

There have been several updates since so please check the download page from Adacom regularely.

                                                                                                                                                                                               12-03-2003