Philco 37 Service Bulletin

308A
OFFICIAL RADIO SERVICE MANUAL
Supplement No. 5
PHILCO RADIO & TELEVISION CORP.
Service
PH
Bulletin-No.
RSA. U.S.
LCO
PAT.
Orr
141
Model 37
The Philco Model 37 is a five tube battery operated
superheterodyne receiver.
This model contains the new Philco type 15 r.f. pentode
l_
tube as detector oscillator, a type 32 screen grid inter-
mediate frequency amplifier, a type 32 screen grid second
i.
% I
'
lir'
%, e
BALLAST
32
SOCKET
(..
1-
, . ,
detector, a type 30 first audio, and the new type 19 push
SPEAKER
DETECTOR
-
- F
pull (class B amplifier) output tube.
SOCKET
Volume equal to that of most A.C. receivers and economy
32
in B battery operation are highly important features of
the circuit. Unlike most receivers, the heavy B battery
F F
G P
30
1ST AUDIO
I.F.
1S971
P' F
current drain, necessary to produce loud volume, is present
only when such volume is actually coming through the
speaker. At all other times, the current drain is small.
The filaments are supplied from the Philco Dry A bat-
..
i...
;
' '
15
G 19
DETECTOR
OUTPUT
OSCILLATOR
i
F
' ,,
F
tery. The chassis is equipped with an automatic voltage
regulator tube which affords constant A voltage to the set
throughout the life of the battery. The filament current
drain from the A battery is 720 milliamperes.
The plates are supplied from standard Philco 45 B
F-Filament
SG-Screen Grid K-Cathode
CG-Control Grid
batteries. At 135 volts, the B battery current drain varies
between 8 and 12 milliamperes.
Fig. 1-Tube Sockets, Under Side of Chassis
The intermediate frequency of the superheterodyne
Caution.-Never connect the chassis to the power supply
circuit in this model is 175 kilocycles.
unless the speaker is connected and all tubes are in place.
Table 1-Tube Socket Data
Tube
Filament
Plate Screen
Control
I
Cathode
1
Type Circuit
Volts
F to F
Volts
P to F
Grid Volts
SG to F
Grid Volts
Volts
CG to F
K to F
15
32
32
30
19
Det.-Osc.
I.F.
2nd Det.
1st Audio
Output
1.9
1.9
1.9
1.9
2.0
120(P to K)
120
2.0
110
120/Plate
60(SG to K)
60
45
..
..
2.5(CG to K) 5.5
I
2.5
..
2.5
..
.
.4
..
.
.4/Grid
I
Table 2-Resistor Data
No. in Figs.
Resistance
Color
3 and 4
(Ohms)
Body Tip Dot
® @
4
0
0
® ® 0
0 ®
1,000
2,900
6,000
25,000
51,000
99,000
490.000
Brown
Red
Blue
Red
Green
White
Yellow
Black
White
Black
Green
Brown
White
White
Red
Red
Red
Orange
Orange
Orange
Yellow
10
.5 puti
.1c
al
.5 112125 TT
=
3t
MFOL.15
I
tri
.52`
Mal_
T
.--
01
:..,_
.11111_
6
3
T
GROUND TO CAN-v- ----=
Fig. 2-Internal Connections Filter Condenser Bank