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Tho powor qutput valvo is a LQlGT/G bcam
power :unpliJier. Hore
the
audio
signals
rocoived
by the
grid through C24
arc
:unpliliod and impressed
ictoss
the
primary
of
the output
transformor
TT.
In the
.PNJA
the
socondary
ol
this transformer
supplies the inductd audio frequoncy sign•ls to the
hoadphones
th,ough
the
audio
socket CCI.
In
the
PNLB tho
mnsformor
£.eds oither
the
earphonos or the loudspeaket, as
dot'ecminod
by
tho
sott,ng
of a DPDT Toggle switch, S7, connected to its output
tecminals. This
sv.•itch
i,
mounted on tho
front
panel,
above
the filament
rheostat,
and is
marked
..
SPEAKER-PHONES'-.
The ovec•II arnplilication of the roceiver is controlled
by
the panel
control
design1red VOLUME,
This
i, a dual control consisting of
RI I
and
Rl7. The functions have already bttn described.
The seloctic,n of any desired fr«jueocy within the range of
the
receiver
is made by a
three
gang
tuning
condens<r which tune> the
r-f and
detector
transfo,me,
ciccuits to the desired f1«ju<ncy, and as previously stated, the
oscillator socondary
10
a
frequoncy
455 kc higher. Tho gang condoruor is
adjusted by the tuning dial mountod on tho front panel, the scale of
which
is calibrated
in
megacycles. The only othec controfs neces5.try foe operation
of
lhc
receiver
arc
the control$ maiked VOLUME and the PHONll-C.\X/,
switch.
The
r-f
detector
and
oscillator transformcis arc wound on high grade,
low
loss
bakclitc formers,
the
sccondarios being space-wound, The
trans•
formers arc
impregnated with
a
non•hygroscopic bakclite varnish, baked and
waxed. These
precaution,
servo to prevont
losses due
to
excess humidity,
and
provide goo<! stability under 111 climatic conditions.
Tho
j.[
transfonncts
arc
likewi,c impregnated but use litz .,•iro coils on fish p•p~r formers.
TI,e
BFO
u2nsformer uses
duo-latcul wound
coils on
a
ba.kclitc
former,
all
being
similarly treatod as tho r-f and i,f coils. For adjustment all
r•f
and i-f tran>•
former, use high grade powdered
iron
core,, which ue sealed
in place
bcforo
the «juipmont
IS
shippe<I.
The following
is
a tabulation of tho
Technictl
Specifications and
Ratings
of
the
receiver s«tion of the Trinsmitter•Rcceiver.
VALVES:
1-RVC IPlGT/G
-
R-F Amplifier.
1-RVC JA7GT/G
-Conv,rtor.
1-RVC LP5GT/G
-'
J.f Amplifier.
1
-
RVC LH)GT /G
-
Dcteclor, AVC and Audio.
1
-
RVC
1G4GT/G
-llfO.
I
-
RVC 1Q5GT/G
-Powe,
Output.
FREQUENCY RANGE: 3 mog,cydes
to
6 megacycles.
INTERMEDIATE
FREQUENCY:
455
kilocyclts,
ANTENNA INPUT: High impedane<
.matched
to
rod
anttnna up
t•
¼
wavc•ltngth long
.
antcnn:i or wire
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