Operating instructions
-:
l-..riil'.ll
o\-OFF
su'itch
5102
can be
used
: ì :r
iitt
.lteaker
circuit and
permit
opera-
'.
r.
,,:
iirt.
reeeiver
rvith
headsets
only.
,.
\',,ltuge
fol
avc
is
developed
across
a
por-
::,,n,,1
the rliocle load in
the circuit
of V6. This
i','.ti,ge
is
t'ed
to
i-f
amplifier
tube
V4 and r-f
:,nr1'liher
tubes
V1 and V2, when
PHN.-C.\V.-
\I'lT-t'AL. su'itch
52
is in
the PHN.
position.
F,,i' all other
positions
of 52, the
avc
\roltage
is
groundecl.
r.
Fol
reception
of continuous \vaves
(switch
52
in
C.W.
position),
the triode section
of tube
\-7
lLrnctions
as
a
bfo
at a frequency
of
151.66
kc.
-1
to 1.167 kc. The
third harmonic
of the
oscillator
output
(455
kc
r-3.5
kc) is
coupled
to second i-f
amplifier tube V5, where it mixes
ri'ith
the i-f signal to
produce
an audio tone
in
the detector
portion
of V6. The bfo tube
is
op-
erative also when switch 32 is set at
NET
or
CAL.;
it is inol;.1'atir-e
onl;.
for the PHN.
set-
ting
of 52.
g.
F or
checking
the calibration
of the
re-
ceiver
dial, the
triocle section
of V5 functions
as a crystal-controllecl
oscillzrtor
at a
funda-
mental
frequency
of 200 kc,
The
output of
the
oscillator
(200
kc
and
the harmonics)
is
radi-
ated within the receiver.
The signal-s
are
picked
up by the r-f
section
of the receir,er, amplified,
detected,
and beat with
the
bfo
to develop
a
beat note
every 200 kc
on the dial. The
crystal
calibration
oscillator is disabled
when
FHN.-
C.W.-NET-CAL. switch
52
is in
any
position
other than
CAL.
It,.
For monitoring
purposes,
a-f amplifler
V6 is disabled,
the sidetone signal
of
a trans-
mitter may
be connected
to the receiver
audio
section, and
the audio
output of the receiver
may
be coupled
to the remote location.
HEADSET
NAVY TYPE
cw-49507.4
A.V.C VOLTAGE TO
I
ST
R-F.2D
R-F.AND
I ST I.F AMPLIF|ERS IN
PHN.
POSlTION OF S
-4.2VDC
II5 V AC DRY
6v
DC EATTERY
|
2
V
DC
24
V
DC
Figure 23.
Radio Receiaer R-174lURR, block cliagrunr,,
lLowl
IourPUil
-
s4
|
HIGH
I
I
I
I
I
I
I
a
I
I
I
{
I
I
'41
lSPEAKldl\
@@
ò IUZ
fM 295-24
DEîECToR,
A-V-C,
AND
A.F AMPLIFIER
V6
tu5
POWER
SUPPLY
PP.3O8,/URR
MON ITORIN G
INPUTCIRCUIT
38
AGO 3134.