This report describes the development of a frequency-modulated VHF data transmitter, an HF frequency-shift keying low data rate transmitter and a dual-frequency HF command receiver. These units were designed for high altitude balloon control and data systems. An antenna for the data transmitter and a detector for FSK were also designed. (Author).

This report describes the development of a frequency-modulated VHF data transmitter, an HF frequency-shift keying low data rate transmitter and a dual-frequency HF command receiver. These units were designed for high altitude balloon control and data systems. An antenna for the data transmitter and a detector for FSK were also designed. (Author).