Philips 462 a schematic

Page 1

PHILIPS 462A

Horizontal Ali-rain! mlzlr' super/wt m
moulded cabirirl with mixed scale ,' ware
range: 16.2;52. 190-575, 800' 00
metres; for AC only, Made by Philips
Elm-(rim! Lnl.. Cut/my Hausa, Slmflerbury
Avenue, Lon/Ian, WCZt

Circuithriode-heptode frequency changer V1
is followed by a similar valve V2 in which the
heptode portion is an [F amplifier and the triode
porlion an audio amplificrt

A double-diode-pentode V3 is the signal rectifier.
AVC and output valve, HT is by a full-wave
directly heated rectifier V4.

Aerial Circuit.70n SW aerial is connected
through 51 to primary L1 of aerial coupling trans-
former, On MW and LW :1 band~pass circuit is
used and the aerial is connected (through 51) to
aerial coils L3 and L4. 55 shorts out LA for MW
operation. The band-pass tuned circuit consists of
L5, L6 tuned by VCl, with L7, L8 tuned by VC2.
and also L9, L10 and capacitors C3 and C4. 53
and S4 are closed on MW only. T1 is SW trim-

selects the aerial tum-t1 circuits, and CS is grid
coupler,

AVC is applied to grid of V1 on all wavebands
through R2. Cathode is at earth potential.

Screen voltage of V1 is obtained from R] and
decoupled by C(L L18, C25, primary of IFTl, are
in the heptode anode circuit of V1.

Oscillator is connected in a tuned anode parallel-
fed circuit. S7 selects the oscillator tuned circuits
L13 (SW), L15 (MW) and L17 (LW) to Oscillator
unodc through coupling capacitor C7t VC3 is
oscillator tuning capacitor, and R3 is anode lead
resistor. T5 (SW), T7 IMW), T9 (LWy are trim-
mers, and T6. C9 (MW), T8 (LW) are pudding
capacitors, 58 and S9 short circuit unnamed
tuned circuits.

The grid feedback circuits consist of L1], L12
T4 (SW), L14 (MW) and L16 (LW), and 56 switches
these to oscillator grid, C8 is grid coupllng
ca citor, and R4, C8 provide self-bias for osmllator
grid.

IF Amplifier : 470 Kc. L19. C16. the secondary
of lFTl. feeds the signal to heptodc grid of V2.
AVC is applied to grid through R16 and decoupled
by C19. Cathode is at earth potential

Screen voltage is obtained from R5 undvtle-
coupled by C11. 1.20. C27. primary oleTZ. is m

mer; T2 and T3 MW bandrpass trimmers. $2 the heptode anode circuit of V2. . , .
Vl-ECHZI v2~ECH21 vs-EBLZI v4 inst DIAL .iofi'figagefififg;
()6 TG $240v. s o A 265v. A265v. LA M 95 the diode anodes
0A I15vi 585m Tum, 590v. AC AC of V3, fed from
4m 5m 9 3'61 6 AVG 0 L21, C28, second-
G 5 . ary oilFTZ.Diode
A2240vr A240v. A245v. ' 1133451128 angR 10-
mn IG bmu [G 32mg (1 p ts_s orte cut
COV. c ov my 6 3 32A on radstoobygwttchr
H H H H H H D.C. V [3 ug . ut on

Contd, an next page

HESISTORS
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CAPAC TORS
( Wltlr

lZ pi Lemmic
10 pt Ceramic
.01 Tubulal mm
.039 Tubular 100 v
220 pt Ceramic

.047 Tubular 400 v
470 pt Ceramic
.. 82 pt Ceramic

, 330 pt Mica
., 27 pt (mmrc

. .047 Tubular 400 v
5,6 pr Ceramic

.047 Tubular 400 v
.022 Tubular 400 v
.01 Tubular 100 w
.. .047 Tubular ton v
,. 82 pi Ceramic
x .. .0039 Tubular 400 v

bwtu#=o=c~i0urbw)441

«arm

19 ., ,047 Tubular 100 i
20 . .001 Tubular 400 i

21 .. .022 Tubular 1400 v

22 ., 250 Elccrmiuic 12 t

33 :_ 2;}Eiccrm1yiic Jim

25 . rwiurs unknown.

It: . LMnunled inside

27 . rcans or lFTl .ind

28 , )lFTZ

INDUCTORS Phili s 462A has an

S;

b'~tJ-c~i>oe4:\méwn-

exterior scale, ol

i313"; which drive details
ar. below
TOP PULLEVY"
3»: MCONDENSER
~ li / ATMAXIMUM
:07 1 \2/ lt>osmo~
0 : room/M
5 ~- 425M/M-'
5 CONDENSER a: OM/M
>7 AND SCALE DRIVE 440MN4>
55 LI AE WAVECHANGE SW1TCH LII
22 (Tau itt .2) T '5" 33
. .7 -
35 5657
. 350
Very low 55 59 v E
5| vca, I 1.17
53 c7 Ll3 us
55 VIEWED FROM VOLUME ANCHORVNG

CONTROL END 01: INVERTED cuAsgg racs

-_L

OCTOBER. 94 7

Page 2

TRIMMING INSTRUCTIONS

Philips 462A-Continued

l Trim in Order

gramophone is brought into circuit across R10 by Anni: Signal .is Si'ued Tune . siuied For Max

earihing oi ihe radio section of the receiver at Below i Recehei' in Output
f 7* _, #_____,_ R. , _
{,gfigsflfflg and M by 510 PU 5 Onnemd I) 470 K: in cmumil 200 metres 0 niv 1.20. him

L 21 Damp

AVG-C12 feeds signal from anode V2 in second gm] II VI W mi

, . . <1 4 I9. T LIK.
diode anode V3. RF! is the diode load : R16 ihc pm! E [[20, (Baum
AVC iced resistor. Delay bins for AVC diode is i i LIX. Trim I 19

W7- 7 "WW, *1? , W, W
2) See m." mm in cenJ 5
1r: or dial pIaic cu-
insides will] miirk inl
ceiilre nf cabinet.
Turn gang In max.
and ndiusl pnimer m.
line up wixh 225 mark:

on (he sw scale l i

from R20.

AF Amplifier (lriodc scciion at V2) -~CIS feeds
the signal from R10 to iriode grid. R12 is me
grid rcsisior. Negative bias for grid is obtained
from R20 through RI} CI6 IS decoupling
capacitor. Ncgaliie feedback from the LS speech

Continuad an pug: viii

Below, mains'tap adiunmencs and chassil diagram
_I£V___l_g§1 IASV 200v 220v 245v
l5 -

__l,,,,,
H I78 M0 in nrenal i 15.9 metre» i ii T; nm 5
sucker Iiu dummy i lupprox) naI irnm mini-
i
i

aerial mum
TI

L30 7
Repeat <3)

T T3 T7

6) 550 Kc as aha-v:
7) 375 K: as above

8| I60 Kc as above

L3. 545 metres hi T6 Repcal(5)

son inelres i T9

875 metres l TS Repeat 47)

L32 Damp circuius by connecting 80 pF capaclmr across the
- g-windinus as indicaicd.

(bi

TESTER

and Capacity.
0 RANGES : 5, 25, 125. 250 and 1,000 volls.
l,10,i00md LOOOMiliiamps. 150 in 50.000 chin:
and 75 Mlgohms. ~02 to I6 Microfarads.
O DwuriOmni-Rung-Curr-niTransIormorgiving
range: on A.C.oi10, 25, 50,125 and 250 ampons,
"in secondary curroni being 1 ampere.

EVERETT EDCCUMBE

Manufacturers of all kinds of indicating
and recording electrical instruments.
Phncometry experts.

Colindale Works, London, N.W.9

ALL-PURPOSE

MULTl-RANGE TESTING SET
FOR A.C. AND D.

Measures: Volt: -- Ampereu - Ruin-nu

C.

e IFTI lz®4
V3 0 ® 0
a 5 @.@® a; .

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TONE 2Irrz C25 8 ANGE
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699533331. vca vcz VCI J
L272 L28 can: Lzoumr W TUNING
.. L2lupplr

VTJEJJTH @Zfi

ONIOFF
TO MAINS SWITCH VOLUME 0 _ OI
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WORK

Exporreol
+0 all
Counrries
in ihe

World

.1 FEW pm
at SERVKSOL .
Iris" (IF 7v M/

SERVISOI. LTD. séukflivxi phasifvmooi 7.

OCTOBER. 1 947