Here is a relatively low cost balloon 2m transmitter

https://www.argentdata.com/catalog/product_info.php?products_id=134

Thanks Calvin

Ham radio operators have a particular need for a transmitter shield that can work on 144-148 mhz (the 2m band). The reason is that we have a worldwide network of receiving stations that can receive digital positional information and then transmit it into a world wide map

see

http://aprs.fi (scroll to your nearest big city and look at all the things being tracked)

We also have a frequency in this band which is monitored by the International Space Station and can forward packets of data received by radio into the APRS network.

Putting that aside we have a amateur radio operator here in Melbourne VK3YT (Andy) who has been building small helium filled balloons with onboard transmitters.   He recently had an onboard 434.500 mhz transmitter sending ssdv pictures and data.

This is probably the sort of transmitter he was using

http://www.robotshop.com/en/rf-link-transmitter-434-mhz.html

It puts out 25 mw of power which is hardly anything. But up in the sky with clear line fo sight, that signal can be heard for vast distances, especially with a well designed antenna. Andy used just 10mw and was heard by repeaters and gateways 100 kilometres away.

cheers Peter 

Hi all

I'm an Amateur Radio operator and many of us have extended our hobby into sending up pico balloons. These are small balloons with very a light payload with a small microcontroller and transmitter for tracking purposes. Its a growing part of our hobby but at this stage it appears that the hardware is being built form scratch by most people.

The Tinyduino could be good for this purpose because its light, doesn't use much power and you can get a gps module for it.

But the missing link is a smaller transmitter module ideally for 434 mhz or one for vhf/uhf with the frequency user definable. As things stand a user would probably need to interface the tinyguino to something like this

https://www.sparkfun.com/products/retired/8946

If you could develop a small transmitter module it could be really useful for doing stuff like making gate openers as well. You embed the transmitter in a remote control housing and the receiver can drive the gate.

cheers
Peter VK3PB