GV-66 PHOTOGRAMMETRIC ENGINEERING 
different transmission frequencies for adjacent Analyzers. In a four Analyzer 
set-up, for example, the first will beam its pulse on the 217.550 megacycle band, 
the second the 219.450 megacycle band; the third the 217.550 megacycle band 
again, and the fourth will use the 219.450 channel. Each receiver is equipped 
with a multivibrator type selector gate which locks out the 217.550 megacycle 
signal the instant the first pulse is received on the 219.450 megacycle band. 
  
Fic. 11. Dual channel pulse linking receiver. 
After a brief interval the device resets itself and is ready to lock out the 219.450 
megacycle band the instant it receives its first pulse from the third Analyzer on 
the 217.550 megacycle band. This pattern of operation repeats each time 
another Analyzer begins to track the target. 
For short and spasmodic flight 
test work, the enlargements of the 
Analyzer give quick and simple media 
for data reduction and computa- 
tion. Where a large volume of test 
work is being done, it is essential that 
accessory equipment be provided for 
data reduction. Just as aerial pho- 
tography requires stereo-planigraphs 
or stereo-plotters, so it has become 
necessary to develop a Data Reader 
for Flight Analyzer recording work. 
DATA READER 
Such a powered comparator Data 
Reader is illustrated in Figure 12. It 
incorporates a unique power-driven 
comparator stage with large projected 
image screen for selection, and iden- 
tification of the target to be meas- 
ured. At the same time a highly mag- 
nified projection of the image (30 X) 
is given on a small second screen 
powered comparator with Analog- where it may be very accurately posi- 
Digitator Output. tioned with respect to the cross hair 
  
FrG. 12. Fairchild Data-Reader. A