TM 11-5840-281-35/1
by the gating action of amplifier transistor Q3901.
wideband video (used with the narrow transmitter pulse)
This is accomplished by the azel relay gate (0- volt
is taken from diode detector CR301 (fig. 2-15) in the
during azimuth scan) which cuts off amplifier transistor
seventh i-f stage. The narrow- band video (used with the
Q3901 and allows the -3-volt collector voltage to be
wide transmitter pulse) is taken from detector CR302 in
applied to the grid of cathode follower tube V3903B.
the eighth i-f stage. The video selected by bandwidth
g. Intermediate-Frequency Amplifier AM-S39/TPN-
relay K301 (wideband or narrow-band video) is coupled
8 Circuit (Fig. 7-7 and 7-40). The delay signal from the
through cathode-follower tube V309 to the video
sum channel is coupled to transformer T301 of
amplifier. Intermediate Frequency Amplifier AM-
Intermediate-Frequency Amplifier AM-3339/TPN-8. The
3339/TPN-8 is stagger-tuned for a selective bandpass of
four windings of transformer T301 are connected as an
7 or 2 MHz, with a gain of approximately 80 db.
auto- transformer to match the low impedance input to
h. Intermediate Frequency Amplifier AM-3339/TPN-8
the grid of first stage amplifier V301. The cathode bias of
Circuit (Fig. 7-7 and 7-39).
h. Intermediate Frequency Amplifier AM-3338/
tube amplifiers V301, V302, and VS03 is controlled by
emitter-follower transistors Q301, Q302, and Q303. The
TPN-8 receives its i-f signal from difference channel
base of each transistor i returned to a voltage divider
Intermediate Frequency Amplifier AM-S337/TPN-8.
between -35 and +35 volts. The grid of amplifier V304 is
(1) The gain of log Intermediate Frequency
returned to WIDE BAND IF GAIN ADJ control R336. The
Figure 2-15. Intermediate Frequency Amplifier AM-3339/TPN-8 wideband narrow-
band video circuit, simplified schematic.
2-19
Previous Page
