The system uses an electrical pressure transducer to position modulate an audio tone according to the water level, the record being received ... Following a few early troubles the installation has operated satisfactorily during the past winter. ... 08 feet. Photographs of the transmitting and receiving equipment are shown in figs. 1-6 attached. Because of the inaccessible ... In order to provide zero, full 104 An Unattended Radio Telemeter For Lake Levels 104/- J R Leslie and G M Keyser.