Multiple Distributed Services - MDS
Transmitter
Earthstation on QNP received the data from Sydney.
Row grabber units then used the information from the signal from glebe and built a video signal which was sent to the unit behind the techs. Glen is holding the feed that goes to the microwave dish on roof.
This dish on top of QNP pointed to the MLC building in Brisbane.
Another dish existed at the MLC building, at the bottom of the tower. The signal was retransmitted by the MDS transmitters for the aerials situated between the banks of lights, on the side of the MLC weather beacon. The power out of the transmitters was about 10 watts. AAP had a prefab hut built on the roof which housed the electronics.
Receivers
Adrian holding Gridpack antenna to show the clients actual physical size. These antenna were powder coated 'white' and used outdoor.
The downconvertor here shown has a small antenna connected and you can see a coaxial cable leds off to a power supply and a Row Grabber modem. These unit were successfully used from Nevitts Stockbroking and other local sites.
M21 gridpack hanging off the QNP building March 2001. The power coating seems to have worked well. This antenna supplied the editorial staff of QNP with wire services.
Internal of MDS downconverter
Internal componets of the downconverter. These units were designed and manufactured at University of Queensland, before Codan in South Australia took over the production. The Brisbane tech was seconded to work on the production of 100 units.
Power injector
Power injector were used at the bottom of the cable run, They passed DC power 18Volts to the downconvertors. The signal from the down convertoer passed through the power injector onto the RGM or Music on Hold tuners.
Power injectors are also used for MATV ie: TV signal amplfiers
Lift music - a novel system
I was able to monitor the service at home by putting a gridpack antenna on the house. At the entrance of the house there was some equipment to listen to the quality of the music carried by the MDS transmitters. This then told you whether, the weather was interfering with the signal or equipment had failed.
Insides a of a purpose built box. The device is similar to an AM radio.
Layout MDS hardware for 'Music on Hold'.
Music on hold was delivered all over Brisbane. This is a site outside brisbane on the north side at Kalangah (23 Klms). You can see that we had to raise the antenna to a fair height. This installation use a M23 gridpack with a 10 metre extender pole from Hills Industries.
TV transmissions.
During the time of Expo 88, AAP carried on the MDS a Pay TV signal. The service was deleived to Hotel, Motels and Units in the CBD of Brisbane. The service was for the visitors to Brisbane with information on the city and the surrounds.