This is a proposal for a small uplink (ground to balloon) radio system:

Ground Station:

• 70cms (434MHz) Ham RADIO transmitter running 10W FM into
• 10dbi yagi
• PC
• packet radio TNC - or soundcard software TNC (such as AGWPE or TrueTTY)

Balloon System:

• Good quaility 434MHz “licence exempt” type NBBFM module
• Single PIC chip decoder based on N0QBH “simpler” code

Although the N0QBH decoder does not use DSP techniques the expected preformance should be quite good given the channel is running over FM.