Philco 200 User manual

PH·ILCO
REG.U.tl.PAT.or,.
Service Bulletin,... No. 201
Model 200
Philco Model 200 is a superheterodyne radio
receiver designed especially to deliver high fidel-
ity reproduction of broadcasts. The audio
response of this model extends from 30 to 7500
cycles. This is made possible partly by the design
of the R. F. and I. F. circuits, which are so
arranged that by means of a set of variable
resistances in the I. F. circuits the tuning can
either be broadened to take in the high fidelity
transmissions which cover more than a single
channel, where conditions permit; or sharpened
when necessary and when full high fidelity cannot
be used to advantage. The design of the audio
circuit, speaker and cabinet and the use of a
special "Sound-Diffuser' consisting of a scienti-
fically arranged group of sound-radiating vanes,
also contribute greatly to the high fidelity result.
The Selectivity-Fidelity Control is the most
important adjustment in this receiver. To oper-
ate this control properly requires a thorough
understanding ofits functions and its relationship
to the performance of the set. Broad tuning in
the R. F. and I. F. circuits is required for the
passage of a broadcast signal without any
tendency to lose the higher audio frequencies
contained in the side bands. This condition is
obtained when the selectivity-fidelity control is
Tube Socket Voltages
Det. 1st 2d Shadow- Ori- Out-
Circuit R.F. Osc. I.F. I.F. meter A.F. ver put Rect.
Control
--- - - -- -- - --
TypeTube 78 6A7 78 78
Test Points 37 75 42 42 5Z3
42
-- --- ---- -- - --
F to F ......... 6.3 6.3 6.3 6. 3 6. 3 6.3 6.3 6. 3 5.0
- --- - - -- -----
PtoK ...... 225 210 210 220 63 110 225 335 350•
-- --- - - -- - - - -
SGtoK ....... 80 (G3&5-K) 73 76 225 335
73 ... 335 ...
--- - - -- - - -- -
KtoGnd ..... 3 8 8 4 0 0 0 0
0 ..
--- - - -- - - -- --
CGtoK ....... 0.2 0 0.2 4 0 0.2 35
... 35
--- -- - -- - - - -
6A7-GltoK .. 22.0
-
6A7-G•to K .. 90.0
turned to the extreme right hand position. In
this position, maximum fidelity and minimum
selectivity will be obtained. This setting will
enable the audio amplifier and speaker to repro-
duce the widest possible range of audio fre-
quencies, but should only be used when no
broadcasting station within the range of the
receiver is operating on a channel within ten
kilocycles of the station being received. As the
control is turned toward the left, the selectivity
is gradually increased with an attendant gradual
decrease in response to the higher frequencies.
With this control in the left hand position, the
tuning will be extremely sharp.
Model 200 uses the following tubes: Type 78
R. F., type 6A7 detector-oscillator, two type 78
I. F., type 37 Shadowmeter control tube, type
75 2d detector-1st audio, type 42 driver, two
type 42 output tubes used as triodes and a type
5Z3 rectifier. The interm ediate frequency (I. F.)
is 175 kilocycles and the power consumption is
130 watts. The Model 200 will receive broad-
casts from 540 to 1720 kilocycles, which includes
all standard broadcasts and some of the police
broadcast frequencie s. This model is for use on
alternating current (A. C.) only.
Power Transformer Data
Terminals A.C. Volts Circuit Color of Leads
1-2 120 Primary White
3-5 780 Plates of 5Z3 Yellow
6-7 5.0 Filament of 5Z3 Blue
8- 10 6.3 Filaments Black
4 ... Center Tap of 3-5 Ye!low-Green Tracer
9 ... Center Tap;'of 8-10 Black-Yellow Tracer
Use Fig. 1 when testing voltages as per table above.
The above voltages were obtained using a high resistance D. C. voltmeter for plate, grid and cathode tests, and an A. C. voltmeter for filaments. Line voltage 115
dial at 55, volume control at maximum, fidelity control at middle position. •p to ground.
Philco Model 025 Circuit Tester is recommended for making these tests.
TYPE37 TYPE15
SHADOWMETERCONTROLZ"'DE1,jSTA.F.
Fig. 1-Tube Sockets (Viewed from Underneath)
philcoradio.com

! ~I I c1,:
/ [: II
/ ,~; ~!-©
1
\O~tl'f
i?@
1o n.~ ~Ofl
1.F.=115KC.
Fig. 2. Schematic Wiring Diagram.
NOTE: An8000ohm resistor, 33-3016 (Gray-Black-Red ) is added across the 2000 ohm section or @
<o o~@
-I" '°i.1.
:; -.,..
~
!
@-T
'"0
;.,
Q0,
(P
w
r.n
~
""I
-<
....
r')
~
t:o
C:
-
-
~
.-t-
....
=
z
?
w
=
....
philcoradio.com

No. on
Fig. 3. Bottom
View of Chassis
Diagram Descr;ption Part No.
(D Resistor (10,000 ohms) (Brown-Black-Orange). 33-1000
@ Antenna Transformer.. . . . . . . . . . . 32-1420
@ Tuning Condenser Assembly..... . ... 31-1217 .
G) Compensating Condenser (Ant .).... . . •. . . . . . . • . . . Part of@
@ R. F. Transformer........ . . . . . . . . . . . . . 32-1421
@ Compensating Condenser (R. F.) . .... ....... ......... Part of@
G) Resistor (500 ohms) (Flexible; Green-Black -Brown) ..... 6977
<pCondenser (.05 Mfd. Tubular).. . . .. ......... . . . . 30-4020
® Condense r (.02 Mfd. Tubular) .. . .................... 30-4113
@ Resistor (100,000 ohms) (White-Whit e-Orange). 6099
@ Condenser (.03 Mfd. Tub ular)... . . . . . . . . . . . 30-4025
@ Detector Transformer .... .. .. . . . . . . . . . . . . . 32-1422
@ Resistor (10 ohms Flexible Wire-Wound).... . .. 33-3139
@ Compensat ing Cond enser (Det.). . . . . . . . . Part of @
@ Resistor (50,000 ohms) (Green -Brown-Orange) .... . .... 5868
@ Condenser (.00041 Mfd. Mica)....... 30-1000
@ Compensating Condenser (Osc. L. F. ) . ..... . .. .. ...... 04000R
@ Condenser (.00015 Mfd . Mica).... . .... 30-1033
!Compensating Condenser (Osc. H. F.) .. . . . . . . •. . . . . . . Part of@
Compensating Condenser (1st I. F. Pri.) ..... . ..... . . . . Part of@
A Condenser (.000235 Mfd. Mica) . ..... . ... . .. .• ....... 30-1037
@ First I. F. transformer •••• •• . •. . . . 32-1403
@ Compensat ing Condenser (1st I. F. Sec.). . . . . . .. . . . Part of@
@A Condenser (.000045 Mfd . Mica).... . . . . . . . . . . . . . . . 30-1034
@ Compensating Condenser (1st I. F . Tertiary) .......... 04000A
@A Condense r (.00011 Mfd. Mica).... 30-1035
@ Fidelity-Se lectivity Cont rol (Wire-Wound Resistors)
(2000, 8775, 8775 ohm) .. .. . .. .. . . .. .. . .. 33-5070
@A Resistor (1 Meg.) (Brown-Black -Green). . .... 33-1096
@ Resistor (400 ohms Flexible Wire-Wound).. .. . . .. .. 33-3016
~ Condenser (.! Mfd. Tubular). . .... . ... ..• ..... 30-4122
@ Oscillator Tran sformer ....... ...... .. . . . . . . . •. . 32-1423
@ Resistor (25,000 ohms) (Red-Green-Oran ge) .. . .. . ..... 4516
@ Resistor (2 Megs.) (Red-Black-G reen).. . .... . . 33-1025
@) Compensating Condenser (2d I. F. Primary) . .... • .... Part of®
@)A Condenser (.000235 Mfd. Mica). . ... . . . . . . . . . 30-1037
@ 2d I. F. Transform er........... .......... . .. .. . .. 32-1403
@ Compensating Condenser (2d I. F. Sec.). . . . . . . . . Part of ®
@A .Condenser (.000045 Mfd. Mica).... . . . . . . . . . . . . . . 30-1034
@ ·Compensating Condenser (2d I. F. Tertiary)... 04000A
@( Condenser (.00011 Mfd. Mica) ..... ........... 30-1035
@ Resistor (1,000 ohms) (Flexible Wire-Wound). 33-3017
@ Condenser (.05 Mfd. Tubular). . . . . . . . . 30-4020
@ Resistor (1,000 ohms) (Brown-Black-Red). 5837
@ Condenser (.05 Mfd. Tubular)....... 30-4123
@ Compensating Condenser (3d I. F. Primary). . Part of @)
@(Con denser (.00015 Mfd. Mica).... 30-1041
@) Third I. F. Transformer.. .. . . . .. .. 32-1404
@ Compensat ing Condenser (3d I. F. Tertiary)......... 04000X
@A'.Condense r (.00025 Mfd. Mi ca)....... . ...... . . . . . . 30-1038
@ Compensating Condenser (3d I. F. Secondary) .. .. , . . Part of@)
@A'.Condenser (.000235 Mfd. Mica) ........ . . . .... . .... .. 30-1037
@ Resistor (2 Mega.) (Red-Black -Green) . ... . ....... .. .. . 33-1025
@ Condenser (.00015 Mfd. Mica). . .. . . . . .... .. . . .... 30-1033
@ Resistor (2 Megs.) (Red-Black-Green) . . .. . .. , . •.. .. ... 33-1025
~ ~~:::::~~5- ~ fd..Tubular) :::::::::::::::::: . . !~!~~~
@ Pilot Lamp (Shadowmeter) .. . . . ... . ..... . . . ....... .. Part of@
List
Price
S0.20
.60
8.25
.45
.20
.35
.30
.20
.30
.90
.20
.20
.35
.45
.35
.35
1.25
.35
.15
.35
2.50
.20
•20
.35
.45
.20
.20
.35
1.25
.35
.15
.35
.20
.35
.20
.35
.35
1.25
.20
.35
.35
.20
.35
.20
.35
2.50
Ne. on
Dia~ram Description PartNo.
@ Filter Coil (10 K. C.).. 32-7261
@ Compensat ing Condenser (10 K.C. Audio Filt er Trap
Circuit) ... .. 04000B
@ Condenser (.00015 Mfd. Mica) 30-1033
@ Condenser (.00015 Mfd. Mica) 30-1033
@) Resistor (100,000 ohms) (White-White-Orange).. 6099
@) Condense r (.02 Mfd. Tubu lar). 30-4113
@ Resistor (.5 Meg.) (Yellow-White -Yellow).... . .. 6097
@) Conde nser (.25 Mfd. Metal Case). . . . . . . . . 4264
@) Resistor (100,000 ohms) (White-White-Orange) ... 6099
® Audio Transformer....... . . . . . . . . . . . . . . 32-7057
@) Output Transformer (On Speaker) 32-7247
@) Voice Coil and Cone Assembly (U-7 Speaker) 36-3321
@) Field Coil and Pot Assembly (U-7 Speaker) 36-3088
@ Condenser (Electro lytic- !, !, 2 Mfd.) .... 30-2080
@ B. C. Resisto r (Wire-Wound--4750 ohms, 3000 ohms) .. 33-3138
@) Condenser (.0001 Mfd. Twin - Bakelite Block) . . .... 8035-P
@ Resistor (70,000 ohms) (Violet-Black -Orange) ......... . 33-1115
@ Condenser (.03 Mfd. Tubula r). . . . . . . . . . . . . . . .. 30-4025
@ Volume Contro l (500,000 ohms Tapped at 100,000) and
@)
@
@
®
@
®
@
@
®
®
@
®
@
@)
@
@
@
@
@)
On-Off Switch.. . .. . .. . .. .. .. .. . . . . .. . . 33-5071
Condenser (.01 Mfd . Bakelite Block). . . . . . . . . . . . . 3903-G
Resistor (1 Meg.) (Brown-Black-Green) 33-1096
Resistor (500,000 ohms) (Yellow-White-Yellow).. 6097
Resistor (1 Meg.) (Brown-Black-Green) 33-1096
Resisto r (70,000 ohms) (Violet-Black-Ora nge)... . . 33-lll5
Resistor (15,000 ohms) (Brown-G reen-Orange). . . 6208
Resistor (20,000 ohms) (Red-Black-Orange)........ 6650
Bass Compensator..... . . . . ... .
Condensers (In Bass Compensator) ............ . ..... .
Condenser (.03 Mfd. Tubular) . . . . .... .. . • .•..
Condenser (.09 Mfd. Bakelite Block) ..... . , .• , ..
30-4196
Part of@
30-4025
4989AR
Condenser (Electrolytic-8 10 Mfd.) .. .
B. C. Resistor (10, 110, 130 ohms) 30-2046
...... .. 33-3137
Resistor (51,000 ohms) (Green -Brown-Oran ge)
Resisto r (15,000 oh1ns) (Brown -Green-Oran ge) ....
Filter Choke .... ................ . . . .
Condenser (.25 Mfd. Bakelite Block) ..
Condenser (Electrolytic-8 Mfd .).
Power Tran sformer, 115 volts 60 cycles .. . ..
115 volts 25 cycles
4518
5718
32-7056
6287-S
30-2011
@ Condenser (.015 Mfd. Twin Bakelite Block) .
... •• 32-7258
32-7259
3793-K
6608
4989N
@) Pilot Lamp (Station Selector)
@ Condenser (.09 Mfd. Bak elite Block) .... . . . .
@) Resistor (13,000 ohms) (Brown -Orange-Oran ge)...
®) Condenser (.001 Mfd. Tubular).
Four Prong Socket .... .
Fiv e Prong Socket ... .. .
Six Prong Socket ..
Seven Prong Socket ......... . . . . . . . . ... . . .
Speaker Socket.
Dial Assembly . .
Dial Scale. ... ... .
Knob (Large).. . .. . .... . .. . .• . ..
Knob (Small) ..... .
Chassis Mtg. Screw ......... .
Chassis Mtg. Foot (Rubber). • . ..... . . . . . .. .. . .
Chassis Mtg . Foot (Steel) ...... .
Chassis Mtg . Foot Plate
Tube Shield ............. . ............... . . . .... .
A. C. Cord and Plug Assembly
3766
30-4201
7544
75460
64!7C
27-6005
4957
31-1255
.. 27-5049
27-4051
27-4052
W!388A
27-4116
29-1983
27-7497
28-1107
.. L-943A
list
Price
$0.85
.25
.35
.35
.20
.30
.20
.60
.20
2.75
2.10
1.75
8.00
1.85
.45
.25
,20
.30
1.50
.25
.20
.20
.20
.20
.20
.20
.75
.30
.35
1.85
.30
.20
.35
2.20
.40
1.40
7.25
11.25
.40
.09
.35
.20
.25
.10
.11
.11
.11
.10
.60
.25
.10
.10
.40C
.05
.03
.35C
.IO
.60
philcoradio.com

Adjusting Compensating Condensers in Model .200
The quality performance of this receiver depends to a great 5. Readjust the 3rd I. F. primary padder @ for maximum
output. Do not touch the grid padder @ again.
extent upon provid!ng a wide channel through the R. F. and
I. F. stages to permit the passage of a broad cast signal without
cutting of the side bands.
In order to produce this wide tuning band the set must be
carefullf _andaccu:ately adjusted. Th ese adjustments will be
m_orecriti cal than m the conventional radio, and the procedure
will be somewhat more complicated.
In making the adjustment;s, it is necessary to use an unmodu-
lated signal generator. The PHILCO Model 048 Set Tester
or.the Model 024 Signal Generator can be readily ada:pted for
th1~purpo se by the installation of a single-pole double-throw
switch,_and ~n add!tional grid lea~ resistor, as shown in Figure
4. This switch will adapt the signal generator for either a
modulated or an unmodulated signal.
Figure4 Adaplationof SignalGeneratorCircuitfor Use In MakingAdjustments
on Model200.
LocationsofAdjustingCondensers.
With an unmodulated signal, it is not possible to obtain an
indication of output by means of the usual form of output
meter. An indirect. indication can be obtained, however,
thr?ugh t~e automatw volume ~ontrol system by connecting
a high resistance voltmeter haVlng a scale reading of 0-5 or
0-10 volts across the R. F. cathode resistor (i;, shown in the
wiring diagram Fig. 2. This connection can be made conven-
iently through the use of leads equipped with test clips. With
this arrangement, maximum output at the second detector
will be indicated by a minimum reading of the meter, and vice
versa. In other words, the action will be just the opposite of
an output meter used to measure audio frequency voltage at
the power output stage. With no signal applied to the receiver
the bias voltage indicated by the voltmete r, will be approxi~
mately 3 volts. This voltage will be redu ced by the application
of a signal to the R. F. or I. F. input circuits.
I. F. ADJUSTMENTS
After preparing the unmodul ated signal generator and con-
necting the voltmeter as directed, proceed as follows:
1. Set the receiver tuning dial at its extreme low frequency
position. Remove the grid clip from the cap of the 6-A-7
detector oscillator tube, and connect the signal generator
antenna lead in its place. Connect the ground lead from
the signal generator to the ground terminal of the chassis.
Adjust the signal generator frequency to exactly 175
K. C. Turn the fidelity control of the receiver all the way
to the left.
2. Adjust the 6 I. F. padd ing condensers @, @, @, @, @
and @ (see Fig. 5) in the tops of the 3 I. F. cans, for
maximum output (minimum meter reading), starting with
the compensato r or~padder at the front of the chassis, and
contin uing ;with the adjustments toward the rear of the
set. During these "adjustments, th e output of the signal
generato r should be regulated to maintain a voltmete r
3.
4.
reading of approximately 2 volts.
Connect a 250 Mmf. Condenser from the plate of the 2nd
I. F. tube to ground. This will increase the voltmete r
reading to approximately 2.5 volts.
Readjust the 3d I. F. secondary padder @ for maximum
output.
September, 1934
6.
7.
8.
1:urn the fidelity selectivity control all the way to the
right.
Adjust the 1st & 2nd I. F. tertiary padders @ and @ for
MINIMUM output (maximum voltmeter reading).
Lea:v!ng ~he ~delity selectivity control in the right hand
pos1t!on, tt will be found, upon varying the frequency of
the signal generator, that two definite dips will appear in
the voltmeter reading-one at 167 K. C. and another at
182 K. C. These dips in the voltmeter reading indicate
peaks in the tuning curve. The amplitude of these peaks
should ~e equal; that is, the same voltmeter reading should
b_eob~amed at both 167_K. C. and 182 K. C. Any varia-
t10ns m these two readmgs can be corrected by a slight
readjustment of the 3rd I. F. primary padder @. If the
peak at 167 K. C. is higher than the one at 182 K. C., the
primary padder will have to be turned out. If the reverse
is true, the capacity of this padder must be increased. In
a?)'. ~ase, the yoltmeter readings must be made equal by
d1v1dmgthe differences through readjustment .
.tl. F. ADJUSTMENTS.
The R. F. portion of the receiver is adjusted as follows:
9. Replace the grid clip on the detector-oscillator tube and
connect the antenna terminal of the signal generator to
the a~1;enna terminal of the chassis. Turn the fidelity
select1v1tycontrol all the way to the left and set the receiver
dial at 1,500 K. C. The same type of output indication
is employed as in the I. F. adjustments.
10. Adjust the signal generator for a frequency of 1500 K. C.
Adjust the "oscillator" padding condenser @ and the
"detector" padding condenser @ for maximum output
and in the order mentioned. Regula te the signal generator
output control to maintain a voltmeter reading of 2 volts
as before.
11. Turn in padder © (R. F.) until the voltmeter reads 2.5
volts and then adjust padder © (ANT.) for maximum
output.
12. Readjust padder © for maximum output . Do not touch
padder © again.
13. Set the receiver dial and the signal generator at 600 K. C.
Adjust the "oscillator low frequency " padder @ for maxi-
mum output. As the R. F. tuning is rather broad there
will be a considerable range on the dial that will give'about
the same output when the oscillator L. F. padder is adjusted
for maximum. The padder must be adjusted at the
middle of this range. This point may be determined with
accuracy in the following manner: Starting with the usual
voltmeter reading of 2 volts, slowly turn the receiver dial
toward the low frequency end and, at the same time,.
readju st the padder @ for maximum output until a point
is reached where the maximum output is indicated by a
voltmeter reading of 2.5 volts. Note carefully the exact
dial reading at this point. Follow the same procedure
while turning the dial in the opposite direction until the
outpu t reading decreases to the same value. Set the dial
at the exact center of these two points and readjust padder-
@ for maximum output.
14. Adjust the 3d I. F. tertiary padder @ to give mtnimum
width in the shadow tuning meter in the receiver. This·
padder is reached from rear of chassis.
ADJUSTMENT OF 10 K. C. FILTER
The 10 K. C. filter in the audio circuit will rarely require
readjustment. As the proper adjustment of this padder (@
on diagra m) requires an accurately calibrated audio oscillator ,
it should be reset only in the event that it has been tampered
with or in cases where it has become necessary to replace one
of the elements of this filter. An emergency adjustment of
this filter can be made in the following manner:
15. Connect the signal generator to the control grid of the type•
6-A-7 tube, leaving the grid clip in place,
16. Disconnect the voltmeter from resistor (i; and connect an
output meter to the plates of the power output tubes in
the usual way.
17. Set the receiver dial at 550 K. C. At this point, the oscil-
lator in the receiver will be tuned to 725 K. C. The
adjustment of the signal generator (switch in unmodulated
position) to approximately this same frequency will cause
an audible'.beat note"to'be heard in the speaker. By means
of the signal' generator tuning control,':reduce the fre-
quency of this beat not e until zero'beat is reached, at which
point the output meter reading will decrease to 0. Turn-
ing the receiver dial in either direction will gradua lly
increase the frequency of the audible note so that at 540
or 560 K. C. a 10.000 K. C. note will be heard. At either
of these points, the padder @) should be adjusted for·
minimum reading of the output meter.
Printed in U. S. A.
philcoradio.com