A New Series of helpful ideas and tricks for the Amateur Operator
Now showing on VK3RBO
Touch Tone Commands can be
entered via VK3RBO Phone Repeater
*01# Colour Bar and Tone for 10 minutes
*02# Colour Bar only for 10 minutes
*20# Local Camera on Specimen Hill
What you need to receive VK3RBO ATV
The easiest way to receive VK3RBO is to get hold of an old Austar 'MDS' antenna sometimes called a grid pack. These are usually available around Bendigo or try the re-cycle centre at Eaglehawk. There are various manufacturers and styles of down-converters so keep a look out. If you are getting desperate you could try Graeme VK3JGL who usually has a few recovered units lying around.
Inside the antenna is a PCB dipole, Gasfet amplifier, local oscillator, mixer and power regulator, to operate all this it is required to apply between 9-18 volts to the centre of the coax. This is done by using a 'power inserter' available from most antenna suppliers or you can make your own.
Once this is done try pointing the antenna towards the transmitter and put your television into search mode.
The output of the antenna will fall into what is called the 'cable ready' portion of your TV tuner. Most TV's produced in the last few years are described as 'cable ready' which means they will tune the 'gap' between the VHF TV band and the UHF TV band.
Examples of Common Gridpack Antennas
2415 Mhz - Local Osc (1951Mhz) = 464Mhz ( your TV has to tune this Frequency)
What you need to transmit to VK3RBO ATV
Most people start by building a small transmitter board kit of around one watt and experiment with these. There are a number of kit suppliers both in Australia and overseas. Locally you can contact Mini-Kits Australia who supply both transmitters and amplifiers. A good antenna is required and a good quality coax cable.
All that is needed to activate the repeater is a 1250Mhz FM transmitter modulated with a Television signal. The repeater responds to sync pulses contained in the TV signal needed to key the transmitter.
TV Signals can be derived from video cameras, computers and pattern generators.
Down The Track
If there is enough interest in the ATV repeater it is proposed to have other frequencies and modes as receive inputs, an updated micro PC controller and user selected test patterns. All it needs is interest from local Amateurs.