3.
301
TELEPULSE CODING UNIT
General Description
In the Telepulse Coding Unit, (Figure. 12) the ground level
radiation intensity from the detector is measured by vacuum tube
voltmeter bridge which drives a strip chart recorder and is also
converted to a periodic, time-modulated, constant-amplitude pulsetrain for radio transmission.
This type of signal is suitable for
transmission by both telephone lines and radio.
The instrument is
powered by 115 volts at 60 cyoles.
An auxiliary unit, the Junction Box, contains a control to permit
either voice communication or telemetering over the plane radio
tranamitter.
3.2
Circuit Description
The Unit is divided into four subsections:
3) Comparator, and 4) Power Supply.
1) Bridge, 2) Converter,
The circuit diagram is shown in
Figure 13.
302.1
Bridge
In the bridge section, the ground level radiation signal from the
detector is emplified by a balanced D.C. amplifier, V-1 (a one volt
full soale sensitivity).
It drives a strip chart recorder (Esterline-
Angus Model AW) end the meter on the control box of the "Top Hat"
airborne detector,
The radiation intensity corresponding to the
current indicated it can be obtained from the calibration curves
given in Figure 5 or three decade chart paper (Esterline Angus type
1273) may be used and the intensity read off directly.
= 27 =
The voltage