of
tronic
equipment
frequency. Oscillator circuits
other electronic circuits.
coils of wire wound
the
various
wind-
find
in
elec-
tronic
equipment
take out.
a
type
of
the
rectifier.
AC
F
U
L
L-W
AVE
RECTIFICATION
mwm
a
volts with
to
smooth
out
the
pulsations
in
volts. These types
required.
1-13
parts;
symbol
shown
below
is
the
a
metal
support
side. To his
elements are
As
a
result,
the
B+
voltage
is
very
regulation. Regula-
put voltage
Be-
diode. These electrons passing through
the
Ionized
the tube,
there is
15
passes through the tube, the voltage drop across the tube
is still
drop as the
tube is constant at
the
if a
FILAMENTS
to heat
1. Only
one-half of
25K
resistor.
4.
The
—
cathode
(filament)
the
full-wave
does
the
same
job
station,
first half-cycle the transformer's AC voltage makes the upper diode
rectifier plate positive so that
it conducts and, as a result,
current
flows
conduct.
plate
of
the lower
connected
together.
is
so, two separate rectifier tubes can be put together into one
envelope so
plates
tube.
like this.
is
the
other
and this
one
in series with the fila-
ment, therefore has pulsating
in
a
the
load,
of the input.
DC
output
from
a
to the schematic diagram, just imagine the two
end
units
make sure
simple job.
You
3
volts
AC
remove the
current through
through
This voltage takes
on the shape
of
a
full-wave
rectifier
peak
value.
current to
the various
duplicated by
of the
resistance the
the condenser
discharge
the
next
when you
total voltage
volts
same
resistor.
Suppose
increased
25V,
in
electronic
a
By
increasing
the
wire
through
the diameter of the
made.
Chokes
does
just
a
little
better
job
of
filtering
than
the
current
flowing
through
despite
choke
er
than
because of
as
used are res-
they will
conden-
AC
input
of
the
choke
is
voltage
When a bleeder is connected directly
across
the
the bleeder is
current through
a
series
the
circuit
supply.
The
single
-section
choke
input
filters
con-
of
the
dropping
resistor,
you
maximum
current
(40
-
from the power formula
is a
resistor of
4750 ohms
special
able is
through
the
AcTn
ne
lead
to
their
voltage into
change
a
small
Common-Core
program:
to
make
Electricity
the
cost
of
training
Every
page
has
been released
Power
Amplifiers,
The
a
pair
manufactured
in
the
parts (cathode, grid,
powerful
signal
a
kept
and tends to attract
grid
at a
lower value
of plate
voltage if
grid; in
zero is called
produce cut-off.
In
a
be
cut-off
con-
structed)
and
times
creases,
age
from
-10
120
volts
volts on
the grid
4
with respect
is much smaller
greater
than
that
across
the
provides
a
the B+
negative
voltage
with
ground, the
bleeder
through
Rl,
plate
and ground is negative
the cathode resistor. Using
plate
and
plate.
2-42
plate.
Now
series between the plate and
the
used at higher fre-
the
be attracted to
is because
the
screen
voltage,
almost
Screen
Voltage
20
CO
6
ei
ft
15
10
Grid
V
oltage
3. When
an
amplifier,
the input
input is
a
simple
the
next
tube
and
B+,
second
tube
the
fying
a
wide
range
capacitor
the
grid
resistor
becomes
less
and
less
as
amplified. This
itor should be
capacitance that exists
At
low
Thus,
the
that
a
tube
along
with
the
into
the
the
plate
currents
rents.
The
current
flow
in
produced by an
produced by
then
will de-
Primary
turns
you
maximum power output and
load
loudspeaker
and
it
wish to
supply the amplified audio power. You may be thinking that it
would be
recall that
is usually in
pedance
was
used
as
would
result.
impedance matching
voice coil.
coil of wire,
gap
the
microphone.
types
magnetic
field.
The
electromagnetic
type
uses
a
field
nent
magnet
made
cone are pushed
grid be-
the output
voltage of
Common-Core
program:
to
make
Electricity
the
cost
of
training
Every
page
has
been released
Power
Amplifiers,
The
(includes
Colpitts)
it
should,
are
used
portions
of
the
picture.
do its
job. Therefore
is
to
de-
wave,
an
in-
The
charging and
proper
wave.
across
voltage,
leaves
the compensating
voltage
but
from
a properly
that the
output is
crease in the
amount of distortion.
This method of
the
flat
fed
Wave
Wave
a
radio
from the antenna,
or you may
audio frequency
amplification is not
amplifier
tune
a
the
resonant
you understand
this, it
frequencies
its resonant
capacitor will
capacitance of the tuned
frequency.
variable capaci-
louder than
to
the
loudspeaker
together.
Then,
the
On the
other hand,
of
a
another set
you
can
mount
turn the
and has
the same
units. This is
same capacity. These
of
an
RF
microvolts.
You see
single-
stage
amplifier.
When
se-
lectivity
frequencies
at
once.
Output
Output
elec-
trons
contact
circuit
at
you will very
flow
through
sudden pulse
grid circuit.
re-
sistor,
the
plate
of
flow
back
through
the
on the
to flow for
surge
the
LC
circuit.
The
tickler
in
the
cur-
rent
begins
to
flow
plate of
grid capacitor is
are
means
oscillating. This
plate current
suddenly drops
B-C,
where
vibrate so
in
RF
ground
potential.
This
produces
three
more
variations
are
ex-
of
the
power
put
into
on the same
I
Entirely
different
types
principles from
circuit.
Besides,
different principle
from conventional
at
the accelerator.
first
and
deliver
a
kick
to
By
the
back
from
the
catcher
quencies
other
ultra-high
frequency
SERIES
FEED
which
wide band of frequencies.
Common-Core
program:
to
make
Electricity
the
cost
of
training
Every
page
has
been released
Power
Amplifiers,
The
in
any
to listen
called
a
 buffer
amplifier.
Oscillator
Signal
i=>
Amplified
Signal
The
RF
signal
final power
intelligence.
However,
the
changed so that it
interpreted
as
having
any
meaning.
In
range
can
receive
MCW.
MCW
transmission
is
used
trans-
mitter
front
panel
age
not
its cut-off
the cycle.
Thus the
beyond cut-off.
The tube
methods
will
keep
the
bias is
from the
commonly
used
than ground and therefore
signal on grid.
the grid, the
during
the
tends to stabilize the
As a
not
vary
and, therefore, is
sometimes called  automatic
in transmitters makes
use of the
of this type of bias is that it develops a
voltage whose
the input signal. If the input
sig-
nal
the
as
therefore
doesn't protect the tube when there is no signal on the grid. If
the
oscil-
be driven positive.
to
grid positive, grid-leak bias
combina-
tion
or
the
generated
fre-
The
operation
of
the
IPA
by-pass capacitor,
than to
any RF
load
C-9
to
the
IPA
be tuned to twice
in this
case the
IPA
breaking
raises the
carrier frequency
while permitting
the oscillator
C-ll couples
radiated by the
R-6
grid signal
i
The
center
tap
of
the
transformer
is
connected
to
ground
through
the
RF
choke
to
keep
the
RF
current
from
flowing
frequency.
THE
TRANSMITTER
current.
maximum.
maximum. This second
induced
voltage
brightest when
to
coupling must
plate
the
tuning
coils
are
out
plate voltage
the
correct
a sensitive DC
neutralizing
final
100 watts,
as a
as
a
doubler,
generator
to
the
point
of
application.
to
convey
RF
power
from
in the
energy
put
into
the
wall,
the forward
you will
observe that for a given wavelength back from the end, the
react-
ances
are
opposite
to
each
lines
and
It is obvious from the above diagrams that the terminal
conditions at
 
open terminals of the Lecher wire
and
moved
flected short
the bulb comes back
original brightness. Soon another point is reached where the short
reflects
a
short
across
The number
WAVES
learn about a few of the many applications of
transmission
offer
It can therefore be
the
line.
W
Two-wire
transmission
line
to trans-
sion
lines.
Single
Wire
simple
method
maintained at
by
and
the line
a
conductor is
for
standing waves
types of
pickup devices.
a
half
wave-
length
network.
quarter-wavelength short-circuited
always oscillate
at the
resistor
which
produces
this
of
the
on
in ampli-
rection, at the same frequency
as the antenna
must be a
half
as
long
as
a
preferred
at
longer than
can
be
made
of
tubing
which
is
self-supporting.
the elec-
at
resistive
for
is
capaci-
tor
to
cancel
the
radiation
which
point
of
ground surfaces so
appreciably
from
that
is
reflected
purposes since
they will
actually
reflected
once
again
refracted
flection
wave
radio
silence
(no
signals)
called
can return
to earth,
varies depending
and
the
back
sion is
a  space wave.
enemy
craft
wave are usable,
presence
RF
current
meter.
A
through
to
picks
up
RF
end. Observe
that the
bulb is
the
line
a
quarter
wavelength
from
the
used
for
or voice. Code transmission
and off
When a transmitter
the carrier frequency,
MCW
signal,
must
be
broadly
tuned
carrier and the
wide
a
a
CW
advantage of
You will
sheets.
MCW
and
voice
transmission.
connected
no
current
signal.
the key is
opened, the screen
series with the
in accordance
the
RF
carrier
wave.
A
block
diagram
following
the
elec-
screen
(Point
A).
When
the
the trapezoid
of the electron
voltage is.
At time
transmitter output
represent
a
graph
of
the
the
modulating
voltage
will
same condition of
RF
do
so
peak and trough points
in
the
more
than
twice
manner
controls
PA
505
Kt
/_L\
Common-Core
program:
to
make
Electricity
the
cost
of
training
Every
page
has
been released
Power
Amplifiers,
The
of
hostilities
and
:
er the tuning.
trans-
mitters,
many which
strike the
to have good
sets'/
IN
THE
BEGINNING...
5-11
while the other
a
an
overall
survey
of
localized
the
electromagnetic
This voltage causes a
to which
erated
been listed,
for
both
and installing an
which absorb
antenna
antenna
shown
below
have relatively large
and
produce
greater
the
the
man-
ufacture
Perhaps you
resistance, determines both
low.
Another
Unless RF
Q
of
a
coil.
ing resonant
of
the
TRF
receiver.
If
a
one
is accomplished
of four
radio
receiver
may
differ
considerably
deeper bass
radio
receiver.
review
briefly
picked
the
radio
receiver.
of the
rectified by
the detector and
DC
the
other,
audio
ulate the radio
headphones.
economy.
noise.
no
amplification.
crystal with
a wire
de-
Diode detectors are
tuned circuit
signal
cycle.
preceded
by
one
RF
position,
to
oscillate.
detector.
The
ceding
RF
and
capacitor
acts
ometer
across
the
tickler
coil
controls
.001-
mfd
AF
amplifier
stage.
COMPONENTS
FUNCTIONS
. 01-mfd
of
RF
amplifier
stage.
tube
increased
by
placing
an
RF
amplifier
stage
RF amplifier stage, the
second
station
broadcasting
that it will
at
a
higher
are identical, the total
capacity,
the
and
capacitor is
justed for perfect tracking at the low frequency end of
the band.
it
possible
to
vary
or out
fixed frequency, the
receivers
is
456
kc,
although
kc
and
as
high
as
12,
000
kc
possibility
gain. The
500K
of
the
amplifier which
first
AF
the
main
consideration
power
amplifier
previous
put
constant
despite
variations
at
developed
by
the
AVC
circuit
to
the
control
flow of
rectified signal
Rj
is
AVC
line
to
accordance with
of mod-
strength
which
show
up
of
total capacity
of the
with
the
to
the
100K
coil act
as a
IF amplifier.
and First
the first audio
output, you inject a
the
the instruction
until the standard receiver
than that
various
test
modulated
RF
out-
put
fies
the
trouble source. If
there is a
from
it,
step—
five
senses.
Once
inspection
does
not
take
long—
in
about two minutes you should be able to see the trouble
if it
that even
find
a
trouble
imagine another
trouble which
equipment
on,
which
'scope. Signals
permanently
connected
to
The
signal
towards the
other similar equipment
signal amplitude
to the 'scope vertical
lem
by
using
signals into
various parts
of the
last stage
signal into that
the
checked.
the
example,
checked
to
this section and
of detectors will
signal
is
connected
to
there is trouble in
end
of
the
being that
the IF
finally
on the 'scope.
This method will localize the trouble in any one of these three circuits
the is a
job for the
RF
local oscillator. The
of
the
incoming
RF
To
accomplish
oscillator trimmer
end.
a.
course
in
Basic
Electronics.
Looking
back
on
and
installing,
5-19,
5-20
receiver,
5-1
superheterodyne
receiver,
5-71
oscillating,
5-51
regenerative,
5-45
which
AC-DC
1-
94,
1-95
5-36
AF
and
5-79
the
superheterodyne
receiver,
5-72
Audio
power
amplifiers,
what
they
do,
5-33
Band
pass,
3-37
Band
tube,
3-30
trimmer,
5-30
tuning,
3-25
RF amplifiers, 3-28,
3-4
Superheterodyne
at high frequencies,
Common-Core
program:
to
the
cost
of
training
Every
page
has
been released
Power
Amplifiers,
The