The Amateur Radio Experimenters Group
is please to announce that it will be supporting the WIA AGM & Convention weekend with a balloon launch. This launch will take place from Hahndorf Oval, as part of the “Come and Try Radio” activities day to be held on Sunday 21st May.
This event is aimed at promoting the many different facets of Amateur Radio and giving people the opportunity to learn about how to get involved. AREG will be manning two complete tracking stations at the event, one a fixed ground station and the other will be one of the chase cars decked out in the equipment we use to chase balloons in.
The main aim is to get more people interested in tracking the balloons!
Flight Payloads
The payloads are still being finalized, as the jet-stream has returned and there are concerns that the flight could be carried downrange much further than planned.
Balloon Repeater Frequencies
The balloon repeater will be heard on:
- INPUT: 145.775MHz with 91.5Hz CTCSS (+/- thermal drift of the receiver)
- OUTPUT: 438.850MHz (+/- thermal drift of the transmitter) – 0.8W into 1/4wave omni
NOTE 1: The VHF frequency has changed this flight to avoid harmonic issues with the Wenet imaging payloads
NOTE 2: The repeater is built out of a received designed to receive Narrow FM (12.5kHz bandwidth) not the usual 25kHz wideband FM that amateurs use. Please keep your deviation down so that you can pass through the repeater without it closing it’s mute.
To transmit to the balloon at the maximum range of 800km (once the balloon reaches 100,000ft ++) you should only need approximately 10-20W and an 2-4dB gain antenna.
Receiving the balloon at 400km range in a handheld environment should be achievable, but to hear the repeater at the maximum range of 800km you should expect to need a 10dB gain Yagi for a 0.4uV capable receiver and 2dB feeder loss
This setup is much the same as the LEO satellites but without the high speed Doppler shift.
PLEASE MAKE SURE YOU CAN HEAR IT BEFORE YOU TRANSMIT!
Other Balloon Payloads
Other payloads being flown on this flight will include:
- our standard 100bps 7N1 RTTY telemetry transmitter on 434.650MHz, and
- the Wenet imaging payload which will downlink on 441.2MHz at 115Kbit/s, and which will stream HD photos during the flight.
Images can be seen (here).
Tracking will again be available via www.habhub.org
Flight Time and Launch Location
If you would like to learn more about how to get involved in tracking the balloon, take a look at the following resources on the club website, or come on down to the launch on Hahndorf Oval. Preparations will begin around 1.00pm, with liftoff planned for 2.00pm. (See the location marked “Amateur Radio Come and Try Day”.
WIA AGM & Convention Special Event Callsign to be Net Control on the balloon repeater
The WIA AGM & Convention special event call sign VK5WOW and VI5WOW will be heard via the balloon repeater during the event. Contacts with VI5WOW and VK5WOW through the balloon will qualify for the award certificate.
Full details of the Convention 2017 award are available via www.wia.org.au/members/wiaawards/agm2017/