Philco 39-25 Reference manual

• • • • • • • • • • • m,d,d. 39-25,ComL121
SERVICEBULLETINNo. 303 for members ol
RADIO MANUFACTURERS SERVICE
A PHILCO Service Plan
SPECIFICATIONS
TYPE OF CIRCUIT: A. C. operated; superheterodyne circuit
with two tuning ranges, covering standard br.oadcast (540
K. C. to 1720 K. C.) and short wave (4.9 M. C. to 18.0 M. C.)
frequencies; Automatic Volume Control : and pentode output.
The receiver is designed io operate from a "Philco Safety
Aerial," part No. 40-6371. This aerial system should be used
to obtain maximum performance from the receiver.
POWER SUPPLY: Voltage-115 volts . Frequency 50-60 cycles.
Power consumption 45 watts.
INTERMEDIATE FREQUENCY: 470 K. C.
TUNING RANGES: 540 K. C. to 1720 K. C.; 4.9 M. C. to 18.0
M. C.
PHILCO TUBES USED: !-6A8G, !st detector and oscillator ;
1-78, I. F.; 1-75, 2nd detector, Automatic Volume Control,
and !st audio; 1-41, Output; and 1-84, Rectifier.
TUNING MECHANISM: Pulley and cable drive for Manual
tuning. Electric Push-Button for Automatic tuning.
CABINETS: Types "T" and "XF."
OUTPUT·41
211V
VOLTAGES MEASURED FROM SOCKET
CONTACTS TO CHASSIS -
DETOSC.
6"8G
..,..r-UgV
( Ill 0K
IIC.P.IJIV... O •
esu·
'-..!Jt'
•v ZIIY
g
2HV UY . 2ND DETAVC .
IST AUDIO· 7!,
REcT-a\v _A
25
v
~
+
UV ¥
UV.
1.F 78
Fig. 1. Socket Voltage--Undenide of Chaasis
The voltages indicated by arrows were measured with a Philco 027 Circuit
Tester. which contains a sensitive voltmeter. Volume Control at minimum-
Tuning Condt:nser set for no signal -- line voltage 115 A. C.
Adjusting Push-Button Tuning to Stations
These detailed instructions have been prepared to make sure
the correct procedure is followed in setting the stations on the
Philco Electric Push-Button Tuning models. The work requires
the use of a Philco Model 077 Station Setter and a part l\o .
27-7059 Insulated Screw Dri-..er.
(A) Select ·eight of the most popular stations received in the
locality and remove their call letters from the call letter sheets
supplied. Place the call letters in the windows above the buttons,
making sure that each respective button covers the frequency of the
station for which it is to be used. The frequency range of the
circuits are as follows :
Circuits
1 and 2
3 and 4
5 and 6
7 and 8
Frequency Range
540 to 1030 kilocycles
670 to 1160 kilocycles
900 to 1470 kilocycles
1170 to 1600 kilocycles
These numbers are stamped on the unit as seen from the rear .
Looking at the front of the cabinet the numbers read from left
to right.
(B) Connect the aerial and ground to the "ANT" and "GND"
terminals of the receiver.
(C) Turn the receiver Tuning Range Selector to position two
("Manual Tuning") and tune the receiver to the station to be set
on the first button .
(D) Plug the output leads of the Station Setter into the "High"
and "Gnd" jacks, and turn the output controls to maximum.
Turn the modulation control to "Modulation Off." Connect the
output lead of the Station Setter to the "ANT" and "GND"
terminals of the receiver and tune to the frequency of the station
being received. As the indicator is slowly tuned through the
frequency of the station there will be two points at which a high
pitched swish will be heard, one ahove and 011ebelow the frequency
of the station. When the indicator is on the frequency of the
station, minimum high pitched swish will be heard.
(E) Set the modulation control of the Station Setter for
"Modulati on On.'' The modulat ed signal of the Station Setter
will then be heard through the receiver.
(F) Turn the receiver Tuning Range Selector to pos1t10n one
(Automatic Tuning) and push in the first button . Using the
Part No. 27-7059 Insulated Scre;v Driver, turn the number 1
"OSC'' screw until the modulated signal of the Station Setter is
tuned in to maximum volume. Then adjust the number 1 "ANT"
screw for maximum signal.
(G) Remove the output lead of the Philco Station Setter from
the "ANT'' terminal of the receiver and turn its indicator off the
frequency of the station. The program of the desired station will
then be heard on the receiver.
(H) \,Vith the volume of the receiver low. slowly turn the
number 1 "OSC" back and forth until maximum output is
received. Repeat the same procedure for the number l "AXT"
screw.
After setting up the first station. the same procedure given
under (C) to ( H) is used for the other stations.
Copyright 1938, Philco Radio and Television Corp.
philcoradio.com

Page 2
©oscTRANS .
PHILCO Service Bulletin
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75 ·
No. 303
OUTPUT
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NOTE
~S INDICATE POSITION Of SWITCH
WAfERS FROM REAR or CHASSIS,
!!OTTOM VIEW.
ALL SWITCHES SHOWN IN POSITION No .I
PUSHBUTTQl\f .
SOLID AREA INDICATES RING AT REAR OF
SWITCHWAFER
SHADED AREA INDICATES RING AT FRONT OF
SWITCH WAFER
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t t t f ·,, I~ °T
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2
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DIRECTION OF ROTATION
FROM REAR OF SWITCH
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Fis. z.Schematic Dlacram, Model 39-25, Code 121
...........,
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philcoradio.com

No. 303 PHILCO Service Bulletin Page 3
0
0
Fie. 3. Part Locations, Underside of Chaui1
REPLACEMENT PARTS-MODEL 39-ZS, CODE IZI
• 0
0 oo
ScNIII. Part Sch- .
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
2,
30
31
32
33
34
35
36
37
38
39
40
41
De1crlptlo11
Antenna Transformer (short wave) . . . . .... . .... , .. . . .. .
Antenna Tran sfor mer (broadcast) ..... . .. . .
Tubular Condenser (.OS mf.) . ... ... ...... . .. . .. ... .... . .
Tuning Condenser Assembly .. ..... ...... .. .... . ..•... .. .
Dual Padder U nit ...... . . . . ....... . . . .. . . •. . . • . . . ..... .
Oscillator Transformer ... . ... . . . .. . .. . .. . . . . . , . ..... . . .
Con dens er (250 mmf. , mica ) ...... . . . .. . . . .. . .... . .. •.. ..
Condenser (4500 mmf. , mica) ..... . . . ...• ... . . .•..... .
Resi stor (51,000 ohms, ½ watt ) . .. . .. ......•. . .. .• ... .. . .
Conden ser (370 mmf., silver plated mica) ... . . .. . ... . . .. .. .
Condenser (370 mmf. , silver plated mica) ........ • ... . . . .. .
1st I. F. Tr ansfor mer Assembly .. . ..... . .. • ..•.. .. .. . . ..
Condenser (.1 mf., tubular ) ... ....... ..... ...• . .. . .•... .
Resi stor (32,000 ohms , ½ watt) .. . ...... . .. . .. . . . . .... .. .
Resist or (3000 ohms , ½ watt) ... .... . .... . •..... . . .... ..
Resist or (5000 ohms, ½ watt) . ..... ....... , .. , . . .. .. ... .
Electrolytic Condenser (16 mf., 250 V.) ....•.. . ..•..•.....
Elect ro lytic Conden ser ( 16 mf. , 250 V.J ......... . . ....... .
Condenser ( ll O mmf., mica) .............. .. . .. ...•. . . ..
2nd I. F. Transformer Assembly ..... . . ..... . . . ,. .. . . . .. .
Resistor (51,000 ohms, ½ watt ) .. . ... .. .. . . . . • .. •.. ......
Volume Contr ol (500,000 ohms) .. .. . .. . ...... ..... . . ... .
Condenser (.05 mf. , tubular) ... . .... . . . . . . . . . . . .. . .. . .. .
Resist or ( 1 meg. , ½ watt ) . .... . . . .. ... . , . . .. .. . .. . ... . .
Resist or (2 megs., ½ watt ) . . .... . • . . •.. . .........•.....
Condenser (.0 5 mf.. tubular) ...... .. . • . .. ..... .. ...... . .
Condens er (.003 mf. , tubular) . .... . . . . ... .. . . . . . ... . ... .
Resist or (4.0 megs., ½ watt) .. . . ..... • ...... . ... .. .. . ...
Condenser (2 50 mmf. , mica) ..... .... ....... ....... •.. ...
Condenser (.0 1 mf., tubular) . ..... . . .. . . . •. ..... . . .... . ..
Resistor (70,000 ohms , ½ watt) .... . . . . . •.. • . . ... ... . .. .
Resistor (750,000 ohms, ½ watt). . . . . . . ....•... .. . . .. . .
Output Trans former .. . ... . .. . . . .. . .. . , . , .. , . , , .. , ... . .
Voice Coil and Cone Assembly
(for "T " Speaker, part No. 36-1439) ..... • . . . .. •. .. ..
(for "XF " Speaker , part No . 36-1437) ..... . .•..• . . ...
Condenser (.03 mf., tubular) . .. .. ....... . ..... . . . . ... .. .
Condenser (.006 mf., tubular) . . ........ . ... . .. . . . . .. .. . .
Tone Control and On-Off Switch .... .. ... , ... .. • .... . .. .
Condenser (.01 mf.-.01 mf ., bakelite) ... . .......•... .. .. . .
Power Transformer ... . , , ... . ......... . .. . . .. . , . ...... .
*Field Coil for Speaker , part No. 36-1439
*Field Coil for Speaker, part No. 36-1437
Electrolytic Condenser (8 mf., 400 V.) .... . . .... •.. . • . .. .
No.
32-3027
32-3026
30-4519
31-2267
31-6255
32-3028
30-1032
30-1109
33-351339
30-1110
30-1110
32-3018
30-4455
33-332339
33-230339
33-250339
30-2331
30-2331
30-1031
32-3030
33-351339
33-5289
30-4444
33.510339
33-520339
30-4518
30-4469
33-540339
30-1032
30-4572
33-370339
33.475339
32-7978
36-4087
36-4088
30-4449
30-4445
42-1443
3903-DG
32-7976
30·2330
No. Description
42 Resistor (280 ohms, wire wound) .... . . •.... . . .. . . ... ... .
43 Res istor ( 70 ohms, ½ watt) . .. .... . ..... .•... ... . .. .. ..
44 Push -Button Swit ch ... .. . . .. ·.... . .... •.... . .. . . .. .•...
45 Compensa tor Strip Assembly . .... . ... .. .. . .. • ..... .• . ....
45A Compensator, No. 1, 540-1030 K. C...... . ............... .
451 Compensat or, No. 2, 540-1030 K. C...... .. . . .. .• .. ... . ...
45C Compensat or, No. 3, 670-1160 K. C. ........ . .. • .. . .. . . ...
45D Compensator, No. 4, 670-1160 K. C.. . ... .. . . •. . ........ . .
45E Compensato r, No . 5, 900-1470 K. C. . ... ... . .. . . ..• .. . : ...
45F Compensator, No. 6, 900-1470 K. C. ....... • . . . . . . ...•.. . .
45G Compensator, No. 7, 1170-1600 K. C.. . . .. .... .....• ... ...
45H Compensator, No. 8, 1170-1600 K. C. .... . .... . . . . . ... ... .
46 Electric Tuning Coil Assembly (complete) .. . ..... • .......
46A Osc . Coil, No. 1, 540-1030 K. C... .. .. . ..... .. .. ........ .
461 Osc . Coil, No . 2, 540-1030 K. C. . . .. . . . .. . . . .. .... . .. . .. .
46C Osc. Coil, No. 3, 670-1160 K. C. .. .. . ... .. . . ... ... . . . . .. .
46D Osc. Coil, No. 4, 670-1160 K . C....... . . . .•..... .• .... . ..
46E O sc. Co il, No. 5, 900 -1470 K. C...... • . .• . .. . .. • . .. .. . ...
46F Osc . Coil, No. 6, 900-1470 K. C. .. ........ . . . ......... .. .
46G Osc . Coil, No. 7, 1170-1600 K. C... .. . . •.... ... ... . ..•.. .
46H Osc. Coil, No . 8, 1170-1600 K. C. ...... • . . ... .... . . .. . . ..
47 Range Switch . .. .. . .... .. . ... . ... . . . .. .•.. .. .... ......
48 Pilot Lamp .. . .. .. ....... ........ .. .•... . ...... . .. . ...
Bezel Assembly .. ... . .. .. .. . . .. .... . • ...• . .• .. . . .... . ... .. ..
Bezel Gasket . ...... ... •.. .. ....•. .. . . ... . • ......•... ... . ...
Bezel Sctew .. ........•.. .• . . .. . .. .. ... . ..•.. • . ..• .. • . . • . ...
Cab le (speaker) ... .. . . ..... . . .. .. .. . • ..• ..... .. .. .. ........
Cable (power) . ..... .. • . .•. .. . .. ..... .. ... . . . . .• . . ... . .. .. ..
Dial Scale . .... ... . •........... . ..... . ... .. .. ... ... . ...... . .
Dial Spring ... . . .... .. . . .. . .. , . . • .. • ... . .. . . .• . ............
Dial Pointer .......... .. ......... • . . .. ..•..• . . • . ..... . ..•...
Dial Drive Cord Assembly . . .. ... ........ . •..• .. ....... • . ...
Dial Drive Spring ..... . . . .. .. . . .... .. .. . ... . • . ..... ... • ....
Dial Tuning Shaft Assembly . . .•.. . • . . . . .... • ... .. . .. ... ....
Dial Tuning Drum .. . . . ........•.. . .. . ... ..... . ....•..... ..
Knob ... . . . . ........ .......... .... . .. .•... . .... . . . . •. . .. ...
Socket (5 Prong) . .. .... . .. .• . . .... .. . .. . ..•. . . . . ... .. .. ... .
Socket (6 Prong) .. .... . .........•. .... ....... .•. .• . . . ......
Socket (7 Prong) .. ..... . . . . .. . ......... , ..... . . . . .. ....... .
Pilot Lamp Socket Assembly .. .. .... ... . .. . . . . . •.. . .. . . . .. .. .
Pushbutton ... . .. . . . . .. .........• ........ . • .. . .. • .. . . ... . . ...
Speaker (T Cahinet) ... . ... . .. • . ...... ....... . • .. .. ... .. . . .
Speaker (XF Cabinet) . . .. . ... .. ..•....... . • .. ... .. .. •. .... .
• Replace Speaker .
Part
No.
33-128431
33-070339
42-1446
31-6256
31-6274
31-6274
31-6276
31-6276
31-6278
31-6278
31-6280
31-6280
32-3031
32-3042
32-3042
32-3042
32-3042
32-3041
32-3041
32-3041
32-3041
42-1445
34-2210
40-6365
27-9175
W-1834
41-3443
L -2778
27-5403
28-8908
28-5941
31-2269
28-8913
31-2260
31-2281
27-4332
27-6035
27-6036
27-6099
38-9607
27-4759
36-1439
36-1437
philcoradio.com

Page 4 PHILCO Service Bulletin
Alignment of Compensators
EQUIPMENT REQUIRED: (1) Signal Generator; Philco
Model 077 Signal Generator which has a fundamental fre-
quency range from 115 to 36,000 K. C. is the correct instru-
ment for this purpose . (2) Output meter, Philco Model 027
Circuit Tester , incorporates a sensitive output meter and is
recommended. (3) Philco Fiber Handl e Screw Driver, part
No. 27-7059, and Fiber Wrench, part Nu. 3164.
OUTPUT METER: The Philco 027 Output Meter is connected
to the plate and cathode terminals of the Type 41 tube. Set
the meter to use the 0-30 volt scale. After connecting the
output meter adjust compensators in the order as given below.
Signal Generator
Operations Output Dummy
in Order Dial
Connections Antenna Setting
to Receiver (Note A)
1 6A8G Grid .1mf. 470 KC
2 Ant. Ter. lOOmmf. 18.0 MC
3 Ant. Ter. IOOmmf. 1550KC
4 Ant. Ter, IOOmmf. 580 KC
5 Ant. Ter . IOOmmf. lSS0KC
□ ~o
~
0
Fl.-. 4. Location• of Compenaators
Receiver
Adjust
Dial Control
Setting Settings Compensators
in-Order
580 KC Vol. Cont. (20A) (12B)
max, (12A)
18.0 MC Vol. Cont. (4B)
max .
lSS0KC Vol. Cont. (5) (4A)
max .
580 KC Vol. Cont. (SA)
max .
lSS0KC Vol. Cont. (5)
max.
No. 303
Special
Instructions
See Note B
NOTE A-The "Dummy Antenna " consists of a condenser connected in series
with the signal generator output lead (high side). Use the capacity as
specified in each step of the above procedure .
NOTE 8-DIAL CALIBRATION: In orde r to adjust the receiver correctly
the dial pointe r mu st be aligned to track properly with the tuning con-
denser. To adjust the dial proceed as follows : With the tuning condenser
closed. set the dia1 pointer on the extreme left index lin e at the low fre ~
quency end of the sca le.
PHILCORADIOSwillgiveoriginalqualityperformanceONLY
when Genuine PHILCOREPLACEMENTPARTS are used.
June 1938
PBILC:O RADIO AND TELEVISION CORPORATION
Puts and Service Division
Philadelphia, Pa.
Printed in U.S. A.
philcoradio.com