Low-Frecuency Receiving Ecuipaent (cont).
RF sreaaplifier:
ASCOP, Motel APA-2, I$-db gain, 2.5-2d mise
figure
;
Receiver:
Naticnal 500, with coawerter; sensitivity
0.1 micrcwolts at 50 obms; 10-db ovoise figure
Recorders:
Miller, paper oscillograph, with 230-cps
galvanseters; Ampex 600, with FM recording
aaplifiers, 13.5-ke center-frequeacy; direct
recorders, 20~ to 100-kc response
High-Frequency Receiving Equipment.
.
antenna:
Belix, 7-turn, 15-db gain, 27° beam width
RF a=plifier:
RCA 4-1056 traveling wave tube, 32-2b gain,
7-db aoise figure
Receiver:
Polarad Model RB, sensitivity, minus 60 dba,
8-db noise figure
Power divider:
Admittance, Namco Corporation Model C3-3,
3-db splic
Recorders:
Miller; Ampex 600
Measurable Range of Attenuation.
A calculation incorporating antenna
gains, path attenuation, preamplification, receiver sensitivity and noise,
and transmitter power produced the following results:
Frequency
7-1.6
Rance Measurable
225 ax
35 db
1500 mc
ko db
Transaitter Positioning
The Sandia MIDOT system! was used to track the 222-mc and 224-ec transmitter missiles on both Teak and Orange.”
The MIDOT system functions in a
manner similar to the Michelson light interferometer.
Two high-gain helical
antennas, separated a measured oumber of wavelengths at the received frequency, are fed into a single summing point (T connector).
The single output
of the T goes to an ASCOP milticoupler, then to a Nems-Clarke receiver, and
thence to a Miller paper oscillograph recorder.
A oll] occurs at the suming
®
fn
Met
=
In addition to the above referenced report! which gives a complete description of the MIDOT systes, further information appears in Chapter 9 of
this report.
p27