Philips 650 a service manual 3

Page 1

TRADER " SERVICE SHEET

378

lhilips (>50 A 4-valve (plus rectifiori

AL: 5~banil supvrhct, which h.-
prmision for both an extension speaker
and a graniophone pick-up, a shortrwm'i-
range of Ii)7*5| iii, a cathode-ray tuning
indicator. and a switch for bringing this
PIfh'rIIp into circuit. lhc rooc' 'cr as {or
)de of IOU-100 V, 5orrooC
Rclazsc date : August, 1938.

a. N RF amplifier is included iii thr-

CIRCUIT DESCRIPTION
Aeriiil input is via coupling coils Ll

Supplement [0 TIM Wln'lasi' &
Electriuil Trailer, January 14, 1939

PHILIPS 650A

3-BA ND AC SU PERH ET

LlllILti L1[L|llL\ L4, CS7 (5), L5, 087
(MW) and L6. 037 (cm, which precede
first vaive (V1, Mullard EFS), a variahlm
iiiii low-noise liexode ope-iating as RE
amplifier. 01, via 54, shunts aerial circuit
mi VI \" and L\\' bands.

'l' Llueli~§9L undm'y R I" transformer
coupling by L7. L10. C41 (S\V). L8.
L11, G41 QIW) and L9, L12, G41 (LW)
hit-twat v1 and ortniie vahe (v2,
Mullald EK2) which operates as frequency
changer with electron coupling. Oscillator
grid coils L13 (5), L14 (MW) and L15
\IM") are tuned by C42 : parallel trimming
by 045 (S\\'), 046 (MW) (Ind C13, 047
(Mi), series tracking by 014 (SW),
015, C43 lMW) and C16, C44 iLW).
Reaction by coils L18 iSW). L17 (MW)
3an L18 (11W),

'lhiiil \ai\L 1V3, Mullard EFS) is an
Kl" pontode operating on radio with

med ms m intermediate iroquoncy
amplifier with tulldlrpnilldiy tuned-
secnndriry iron - cored transformer

couplings 09, L19, L20, Clo and (120,
L21, L22, C21 ; tuning is effected by
adiustment of iron cores.
Intermediate frequency 470 KC/s.
Diode second detector is part oi double
diode output pentode Vulx 0 (V4, Mullmd

in rectified output it. developed across
load resistances R13 and B22, the latter
operating also as manual volume control,
and passed vizt Al coupling condenser
C27 and grid stopper 3.25 to CG of
pcntodo section, which provides the
only AF amplification on radio Tone
compensation by R21, 025 across part
of 1122. Fixed tone correction by 029
in anode circuit Variable tone control
by R23. R24 and 028, also in anode
circuit. Provision for connection of
low impedance external Speaker across
secondary of output transformer T1.
Operating potential for the cathode
ray tuning indicator (121., Mullard mm) is
applied to its control grid from the
junction of the resistances R19 and R20,
which form a pOtEDtI'Ai divider across R22.
Special arrangements are made for
using a gramophonc piclrup. Sockets are
provided across 880, which is closed on
radio, between L20 and chassis, so that
when its plugs are inserted the pickA
up IS included in the grid circuit of V3,
\iliicli operates on grain as a triode AF
amplifier with its second grid as the
anode. R16, which on radio is the screen
iced resistance, becomes the anode load,
and 019, which on radio is the screen

(SW), L2 (MW) and L3 (IAN) to Single EBLI). .\iiilm frequency component bypass, becomes the AI coupling
/
R; m
SCALE
I
A
Kl)
\_.__\_
Si 957
H
52 Slé
C mi
53 SI7
s4
6
G 530 PU
._l RIS
SIB $2?
i .
TC7

Circuit diagram of the Philips 650A 3-band AC superhet.

EF8 noiseless RF hcxodc.

Mullard RedE type valves are used, V1 being the
the that the IF stages are adjusted by the variable iron cores of L19-L22. For

gramophone reproduction V3 operates as a triode AF amplifier, the second grid being used as an anode. R16 becomes
the anode load, and 019 the AF coupling condenser.

Page 2

Supp/CINE! m llw Hnelrxx (ll 3 7 PHILIPS
Fl [lradcnlulm 3114,1939 650A

Under-chass s
l view. The three
w a v e c h a n g e
switch units (1
[0 3) and (he
1' a d i 0 / g r a m
switch unit (4)
are shown in
detail overleaf,
as seen looking
in (h: directions
of the arrows In
this View 043
and 044 are
wire-wound pre-
set condensers.

condenser. S31 opens, 11nd S32 closes in COMPONENTS AND VALUES V 1
connect 019. to R22 ; 5339 1 Vzpentode Now. To ward l nil/1.4.110» 11111111; onlcr l (film:
Odo rum. 0PM to "1? (ho ing a rcplwcmcm 6/11szsz fmm, 2/;
Second 11111111: of v4 1111 1111111 v3 111 11, . . 111 l r) W
_ _ . 1 . g u _1 11117114111111. 1, 111111111 111111111 1,110.11 111 1,, , _
V111 0231 PmVldCS Dc potcnual lCh 5 full Muripllon mu! Yalrw. no! 11141 '1} LE 1 :32
developed across load rkslit-An(r R30 111,; mpmmfl MW! 01111111111; 111 \ 4 A\L 1111111» . 11 1111111115
and 1811 back 111111111111 11110111111111; 1111-1111 -. ,. 11:111-111.. .11....11,
as GB to RF (on all bands) and Ni V 111-0» 113': 1121:1311[31131111.111111 ' Cf
(uxcept on SW) Valves, glvlng automatic 7 7 111111111 AI" mupling 10 V1 1113111 1151 . l n 0.:
xolume Control. To render AVC Lo v2 . _ 111.1111» 1:7 13111 111. .111111111111-1111111111 1 11-111
inoperatwe on SW, 818 closes, while R~ t; 11w} :11;u~llw 1' 11111 t: 1 1 l1\(~d mm "0 ' ,1 £12
519 opens. Delay voltage is obtained R: V1 13:.)11L1111A1("e1(\1~1'11.11 111.1%le (11* 1 1 """ "MW 1 1; 11
[mm drop along mantances R27, R28 111 R5 \2 11111110119111 111l1a1r . ' 12 : 3.1151113111111111; " W"
V4 cathode lead to chassm. E; E \'2 1111111 1:13 11515111111 ,1. . 7 3 L : A151xdvll(:1:cl1 HT current 15 supphod by full- Maw m V; m ((111111111»11 1 52 t : 4111111111111 V1 11111111111. 1101111111
rectifying valve (V5 Mallard AZl)_ R1,, v_ 1 0% L11 "15,511,? 1 00 L E Acrial (xnuit l. W trim-11111 . 11111111111
Smoothing 11v nun-cored choke L24 and 1110 '~ W -"l l l1 1 343?" [EW'fm 111m ' 0.0331419
. . 1,, 1. .1311 . 11-111
clectrolyuc condensers 030 and 031. R \.111111111» 111111115 7,2? ['11 ~, RF 11.1111 \11_ ~ 111111111111 11-00111):
1m 1 1111051. 111111111, 11111 V1» 1:000 L1. : Rh 111111.. 11-1. 1\1 11111111111 . 11 111111111
R13 1 1111011: 1111 g1.1111 HT 12111111 1 .11 M 11.1115 51-1111111111311111111111 11-00041;
1m l (and pm. 1111111 1,0.111111 11 * 011-111111111-111111111.111111: . . 11 11111.1)
R11 (11111111111 11111111111 4 4 0" mm W "All -
R23 R", 1 v L111 0511 cm 1111 1 w 11.1111 7-
1'1 1 111111511111111111111 . 011111001
1 111.1111» t
. R17 ' v .. 1 1111 411 1 11111111111
C R24 T, 1118 l 1211-: 1;:1g11.111111111. 111111 . 1 511111111 C1»; 00000.1
lug 1 <.ouo,11oo #
20_ u. :21, a 5x1. R211 1 11. U1 11e111111z. (llndcr (WW) .1 :11 N,
-- LS R21 Parr-1r Lone «:olunnmlnr . some
2 :23 0 L 1 R2: 1111: v1 a1gnal 111111 111.111. \
111a111131m1u11111 ,mlrol .. 11,0111 . . .. . - WW
1.- _ 25 1 . 1 330,410; OTHER unwmhx >1 Values
C23 R24 - th 111 1111111111-111111-11111 1111 1 mo [0111115)
1125 1 \4 p1111o111 LG 511111.111 , 1,1»1111 * fl ""7 fl ~
_ 11211 \4 11111113111 (1; mmume 1.0uo,ooo At m1 5 cuuplina c1111 1 5 s
1127 17 14 1111111111 1111 111111 1 1 1111. mm: "MP." W 2)
m 5 \ R28 1 1111mm 1111-13. . l1 mu Am 17"", MW: 1'0" 1 111011
1/11 1129 no 11111» 11 up1111g,. 1.;3n,111111 1411-11115 11111111g11111 '1 o 05
[<30 V. A16 111mm 111111 . 1110111111: 29: we t,~'.l' '1 S 0
11 _ 1. .11 1111111 1 1; 1, , 1 1-11.11 . 311111131111 45111
-l\-§;-( 7.2 3 ° "7 11111 1 1<1r1m11s.sw pr1.C01| . 21;
iffi RI? 111111;.Mw 1111 1111 2210-11
RI? C HF ,_. W 1111' 11111 v1 [111.1011 . 1711-11
321 __ 34 K C17 1111 11111 SW ~11 1111 11-115
' 1w mn 5 n
1' R26 7 7 RI 1 1m 4511
C 011 urcuxlSW 11111111511011. V1111 low
230 T} 1-1 (7; 11111 111.1111 1» 111111 '11w 111111111; 11111 x 3
C25 7 C3 1111 11111 c11c1111 1 w 1111111511111 1911
11; , 8:211:21 :131'. 1':
_ 5 1 11311111111: pr: NJ": 11-11mm
C22 L h as 111 11 11111111111-111w 1111' 411.111 1111,1115 WI-1W W 11.111111 3*;
=. 1125 Rm (7 -\1 1: 11111 1111 111111111; . .. 11-1 .11 n 1111111 1 7 f
N7 (3 \2 1111111111 1111111111111 111111111 1 7'1
1 . ] 1.11 } 151 n 111111;!11111111 1.1111 11111 1111011111,: 1111 IF nan». 'lg'. . .1 7 l
L10 1.1g 1011111. 11 11.11.1111,; 1- " 1 M- 7 .1
V5 T2 c ,11. . __ 11-1 omkcr 51111111 11111 . .. 1 11
5» c1: \ 2 111.11, c 11111111 3 11 1.111115 HT wwmhvw gnkv 2800
E13 EM 1111111;1L;\(\N1l1x 111-11111111111111011114 01111111111111». 1 1 .1 643::
:4 1111111 1 1 11111117
(15 111mm 1m '. Irm ker 1111110. 48 0
1 cm 11.1-11111w1111111111111. 11111111141. 211.1 111 _\ 0 1
<:33'1' 1 AC (.17 (1 and x.- 1111111115 111» A 1 1111 LR: hmt 1 o 15
MA/Ns 11111.1 1;; .13 1. w 1 11 111 .11 H 11 100 n
. (x8 (.11 111111111111 0 1 . ("an 1'1
1 tn) 1 drrouvlnw (r Mia): >l v; AF 11111111 111 \4 11111.
i lfiupling (3mm 1 n "i » 11111115 )Wfltln 3, annuml 11.1.1
1. 535-» Lommum m 111:: [011mm