(d) Fixed Rate Ballast Equipment:(optional)
1 ea. orifice spinnerette, to give proper ballast flow
1 gallon ballast, compass fluid AN-C-116
1 ea. ballast reservoir (1 gallon capacity)
1 ea. filter 3' diameter, 325 x 325, phosphor bronze mesh
6 inches tubing (Tygon) 3/16" bore
Tracking of these flights was maintained by use of an SCR 658 radio receiver with a 400mc transmitter telemetering information from the balloon system. Information received through the telemetering circuit can be recorded on a standard weather station recorder, a recording oscilloscope of the Brush Development type or by any other convenient means.
Altitude of the service flights was determined by use of a modified radiosonde modulator, an olland cycle modulator (see p.68 , Section I, General, Technical Report 93.02(1)), or by computation from knowledge of the weight of the balloon system and volume of the balloon.
In order to keep balloon systems from floating in the air lanes, a flight termination switch was included in the circuit. This switch is a radiosonde modulator modified so that all contacts above 25,000 ft. are disconnected from the circuit. The pen arm rides on a shelf during ascent to about 30,000 ft. and then falls to the commutator (See Fig. 12).
Fig. 12
Flight Termination Switch