Quantcast Second 500-Kc If. Amplifier V502


Click here to make tpub.com your Home Page

Page Title: Second 500-Kc If. Amplifier V502
Back | Up | Next

Click here for thousands of PDF manuals




Information Categories
.... Administration
Food and Cooking
Nuclear Fundamentals


Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
500-Kc If. Filter FL901
TM-11-5820-222-35 Radio Sets AN/VRC-24 and AN/TRC-68 Manual
First Audio Amplifier V504

+125-volt dc supply through the plate load
and R518. The audio signal is coupled from
w h i c h consists of rf choke L501 and re-
t h e junction of resistors R518 and R517
s i s t o r R504. Screen grid voltage is sup-
through resistor R538, diode CR503, and
capacitor C522 to the grid circuit of first
p l i e d through a voltage divider network
a u d i o amplifier V504. Capacitor C524
that consists of resistors R503 and R507.
grounds the cathode of detector CR501 for
C a p a c i t o r C519 decouples rf from the
audio and rf voltages. Resistor R538 and
+125-Volt dc supply. The output of V501 is
capacitor C521 filter rf components from
coupled through capacitor C502 to the grid
the audio signal. Jack J508 is a test point
of V502.
for measuring avc delay bias plus dc bias
d e v e l o p e d by detector CR501 across re-
35. Second 500-Kc If. Amplifier V502
s i s t o r s R516, R517, and R518. Resistor
R532 prevents test equipment from loading
The second 500-kc if. amplifier stage is
the detector circuit.
identical (except for reference symbols) to
c. The audio and dc voltage developed
first 500-if. amplifier V501 (para 34),
a c r o s s the diode load (R516, R517, and
and provides a second stage of amplifica-
R518) is also applied through resistor
t i o n to the 500-kc signal. The output is
R 5 1 5 to the control grid of squelch am-
coupled through C503 to the control grid
plifier V801 (para 42) and to the control
of V503.
grid of broadband cathode follower V802A
(para 63). The series circuit that consists
36. Third 500-Kc If. Amplifier V503
of capacitor C528 and L503 is resonant at
500 kc and provides a low-impedance path
The third 500-kc if. amplifier is similar
for the 500-kc if. components to ground.
to the two previous stages (para 34 and
35). Jack J505 is provided for injecting test
38. Series Noise Limiter CR503
signals for troubleshooting. Resistor R510
provides cathode bias for V503, and capac-
itor C509 is a bypass capacitor for rf.
a. The audio signal applied to the anode
C a p a c i t o r C506 is a low-impedance path
of diode CR503 is a varying dc negative
for rf signals between the screen grid and
w i t h respect to the cathode of detector
cathode. Plate voltage is supplied through
C R 5 0 1 . The applied signal is approxi-
resistor R512 and the primary of output
mately 63 percent of the total audio signal
transformer T501. Screen voltage is sup-
a c r o s s the diode detector load (resistors
p l i e d through voltage dropping resistor
R516, R517, and R518). The negative end
R511. Capacitors C527 and C510 and re-
of the diode detector load (junction of re-
sistor R512 decouple rf from the +125-volt
sistors R515, R516, R519, R529, and R532)
dc supply. The output of V503 is developed
is connected through a filter that consists
across the primary of output transformer
of capacitor C523, resistor R519, and
s e r i e s noise limiter diode load resistor
R520 to the cathode of diode CR503.
37. Detector CR501
b. T h e l o n g t i m e - c o n s t a n t o f r e s i s t o r
R519 and capacitor C523 causes a negative
bias voltage at the cathode of diode CR503
a. The secondary of transformer T501
that is fairly constant. This cathode volt-
is connected across detector diode CR501
age is more negative than the varying
through rf filter capacitor C520. Resistor
negative dc applied to the anode of CR503;
R539 is connected across the secondary of
the diode conducts and produces a voltage
T 5 0 1 to improve the frequency response
drop across load resistor R520 which re-
of the transformer.
produces the varying audio signal. Sharp
b. Detector CR501 demodulates the 500-
kc input and produces an audio signal
negative peaks of noise, which drive the
anode instantaneously more negative than
across detector load resistors R516, R517,

Privacy Statement - Press Release - Copyright Information. - Contact Us

Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business