Philco 810PA Service Manual

l-tF-
PHILCO
TRANSITONE
SERVICE
B
ROADCAST
AUGUST,
I935
POLICE
AUTO
RADIO
-
MODELS sIOPA,
sIOPB
AND
sIOPV
THERE
are
two
new
types
of
Philco police auto radio
Receivers, each
designed
to
meet
the
special
requirements
of
this
-
particularl5'rigorous
service:
The
Model 810PY,
a
variable tuning
Police
Receiver
-
and the Models 8l0PA and
pB,
crystal controlled,
lixed
frequency lteceivers, the
Del-uxe Police
Auto
Radio.
HOUSING,
All are
single
unit
Receivers, housed
in
PLATING,
containers
ll
inches
long by
7a/"
inches
FINISH wide
by 7
inches
deep. All
corners
are
rounded,
the
chassis, housing
and
covers
are
all
steel
anil are plated to
prevent
rusting. They
are
given an exterior
black
wrinkle
finish.
MOUNTING
The
Receivers
are
furnisl"red
u'ith
metal
BRACKETS mounting brackets. One bracket is
bolted
to
the
inside
of
the
dash,
the other
bracket
is
fastened
to
back
of the
Receiver. The
Receiver
bracket
engages
on the
dash bracket and
is
fastened
by a
single
small screw. This
makes
the installation and
removal
of
the
Receiver
a
simple,
rapid operation. The
Receiver
may
be
installed
with
the tubes
upright or
inverted,
depending on
the
location of the
Receiver
in
the
car,
CONTROL The
volume control and
(in
case
of
810
SHAFTS,
PV) the tuning control shaft, the "A"
CONNECTIO\|g
battery
a.nd
the
antenna
connectors
are
located on one end
of
the housing. The
sl.rafts
are the
rapid
coupling
type
with the
locking gland nut at the
Recei-ver
end.
The
"A"
battery
ancl antenna
connections
are
the
quick,
detachable bayonet
locking type,
with
fuse placed in
the "A"
lea.d-
75
Tube-First A. F. Amplifier with
..Q"
Control.
4l
Tube-Power Output
Stage.
84
Tube-Full
Wave Rectifier.
A. V.
C.
Both the
R.
F.
stage
and the
first
detector
oscillaior modulator
stage
have
full
auto-
matic
volume
control
supplied by the
diode
detector.
In
addition
to
this, the Receivii
also
iras a
,.e,'
or
carrier relay circuit.
The function
of this circuit is
io
,,Q"crRcurr:"#lt""J:,tJ",":";'T*.H.""":;il,J"n.S..,""i$
the
air.
The conect
values
of
the resistor netu'ork hive
been
determined and
used
for
satisfactory city
operation where
it
is
desirable
to
exclude street car
noises,
etc.-A
switch
is
pro-
vided on the face of
the Receiver
to
open
or
close
this
cir'cuit,
since, when
in
remote
sections
of t6e territorv,
where
the
police.transmitter signal
might be u."y **ok, slight
ad-
ditional sensitivity can be
obtained with
"the
.'e..
cirEuit
cut
out.
This
"Q" circuit
should
not
be
confused
with the
con-
vential
squelch
circuit. The
..e"
relav circuit
operates
on
a
carrier
field strength equivalent to
approximatelv-B
microvolts
in
the antenna. A
carrier
below this^sirength is
almost
always
of
insufrcient.strength
to give satisfactory'reception,
especialiy
in
noisy
locations.
FLoATTNG
rhe
Receiver
chassis
is
shock mounted
with- 3J"T?Yit
*"1"1"0?Y;J"ir""li"J'?tul1ffi;iJ#fff?;
CHASSIS
AND in the
housing, actually floating
on live
SpECIALAUDIObetteT ariiculation." The iuclio and
the
CONDENSER
.rubber
bushings. The tuning
condenser
is
speaker
circuits
are
especially
designed to
lil<euise
ruhher
mounted.
give the
best reproduction
of
the voice fiequeniies.
fh"
R.-
h TL^ ^^-r^-^^- r--:..^
ceiver and
speaket are
capable
of
delive'ring
eonsiderably
CONDENSER The
condense"
qly" gear .ratio (M"9,"_1
greater
""airio.La
o"tp"i t'iru"-t.-;"";ily';FqJ;;:*"-t
DRIVE
SIOPV)
is
16:1. This eliminates practically
all
back lash and due to the mechanism PowER
The power supply is self
contained and
is
us.edr..preve.nts
the.
tuning
conclenser
from
detuning
frgm
suPPLY
not
p'olarized. Trr', R"""i,r""
can be installed
vibration- This high gear
ratio
also makes
accura.te
tuning
i"- *y -"u" without
reversing battery
connections.
philco,s
much
,€ag&r'
full-w"ave Vibrator
1-o"""irl-u"- tir"1-J-qiu"t.r, of a
million
CONTROL
A
steering column control
unit, with il-
in
successful
operation
during
the past three years) is
used.
*:-
'=f'rrei"
moads
.ii-iinouf-lee"-u.rd
J""-irr"
most
modern
810PV) is
used'
poliie
Receivers
oltainarte.
They
represent the
best designing,
SUPERHETERO-
A
superheterodyne
circuit
is
used
for t5e
engineering and production
skili
in
-the
industry.
DYNE RANGE 8IOPV,
also the
8l0PA
and
PB.
The fre-
slopv
DRiFi-
?1".*"{#'"i1ff$r*"
*41":."r.t;9.J"*
rhe co'
*i"di,l,F;.,;t*ilt["ilffi:,tead
or
terminars
in
one
band. The
oscillator and
LF.
circuits are
especialli
9"
l\g:'
T,he color
scheme
of
the
leads
is
given
in
Figures
designed
to
reduce
frequency
drift
to
a minimum.
The'Morteli
I
and
2.
RANGE
81opA
::1":t i:3 it"t?3;"llf"f":3;fi;:l"t:l
*;;
fr
reppcegre3r^f,
are ei,er ,€c€ssar'
reprace
the entire
coir
AND 8loPB
J." iL.ii"rr"i i."qu*n"y
witbin the
limitrs
asse-bly
3:-1621 fo1,t!e.
first
l.F.'stage'-ana
l2-tlzz for
the
of
the regular police 6and, i.e.
the
-Model
PA
covers
from
second
Ij F.
stage'
Neither the coil nor
the padilers will
be
CR'STAL
-
1575
K.i. to l?50 K.C.
ancl
the Moclel
furnished separately. Order
only by
the
above
numbers.
8l0PB
covers
frorn
2100
K.C. to
2500 K.C.
CONTROL
"n
"ivstat
controlled oscillator
circuit
is
PLATE---ErirFl------\
/,-tBtrieR-GRID
employed
in
the.Model "etOp,{
and 810PB. The crystal
con-
l- -{'!=
J
trol
n'aturally
lLolds
_the
oscillator on the
required
irequency,
i .J't
f
and
is
responsible,
in^a_large
m-easure,
for-the
greafly
im-
6*
^.o
I
-).f__l,ue.*_uoouno
proved performance
of
this
Receiver.
Frcunn
I-PART No.
32-1621 (f
st
L
F.
Transformer)
^.;.
ii fUng
The tubes
used
in
the
8l0PV
and 8l0pA
"i ':aYilttY
-
and_810P8
are:
o*"-uFEf).mc
;'
[i,It1n;tr'll,T"1;*,"19lff1;l'irft"";3r
with
AVC
tlF
f
I
",**
Et@*-*
u-..^"
.ji!;:5i:.,H;ffi::I-L,scuratorryIooulator.wrthA.v.(j','o.ol-).ffiB:''
75
Tube-Second Detector and
"Q"
Relay
Stage.
Frornn
2-PART
No.
B2-1622
(znd
I.
F.
Transformer)