Philips 555 597 a u service manual

Page 1

TRADER "

SERVICE SHEET

4O

2 mm 5

The Philips 555A (or 555U) table press-
buiton receiver. The 597A and 59'iU
models are consoles.

A is i! 3-talve (plus

Ill: Iliilips
rectifier) 3rl A( table superliet
with mechanical din-ct action press»

button timing for six stations The 5551'
lH similar, liut is fitted with a Converter
for use on DC mains.

The 507A and 597 air the console
versions, which were issued prior to the
table models

Divergencies of the various models we
given in vols 3 and 4 overleaf.

Thi- AC models are suitable for use on
1007250V, jOrlOO( mains; the DC
models in for 200.250 V or may \r
mains, according to the type oi converier
fitted

Supplemeni w The Wireless ii
Electrical Trader. May 27, 1939

PHILIPS 555A

597A, 555U

Lliirs Sow/in Shari was prepared on it
535A model.

Rl'lmse dates: 555/1, 1553!], Norsemlicn
i i38 ,' 597A, 3 y I. August, 1038,

CIRCUIT DESCRIPTION

Aerial input on MW and LW is Via
coupling coils L2, L3 to mixed coupled
mud-pass alter. Primary toils L4, L5
:i'e tuned by 028 ; secondaries L10, L11
by C30; coupling by coils L6, L7 and
mnrlensers C3, 04. IF filtEIIng by L1,
C26 ; image suppression by, C1. On S\\',
input is no coupling coil L8 to single
lllflFd rircuit L9, 030.

First Valve (V1, Mallard EKZ) is an
actode operating as frequency changer
with electron coupling. ()sCillator grid
ioils L12 (SW), L13 (MW) and L14 (LVV)
:i'e tuned by 031; parallel trimming
1W 082 (MVY) and 033 (LVV); series
Hacking by 09 (MW) and 68 (LVV'),
Reaction by coils L15 (SW). L18 (MW)
ind L17 (LVV).

Second valve (V2, Mullaid E139) is
ii VariableAmu RF pentode operating as
litermediatc frequency amplifier with
riined~primary tuned secondary (rans-
Tiller couplings 034, L18. L19. 035
mid 036, L20, L21. 037.

Intermediate irequency 128 Ram.

Diode second detector is part at double
IilOdl peritode output valve (V3, Mullaril

AND 597U

EBLIJ. Audio frequency component in
R'Ctified output is developed acros.
load resistances R12 and the mzmual
volume control R15, which forms part
01' the diode load, and passed \ia 018 and
stopper 216 to CG of pentode section.
I]? filtering by 016 and 019. Provision
inr connection of grainophone pick-up
across R15, 017. Operating potential
for cathode my tuning. indicator (Tl.
Mullald EMI) is obtained from junction
01 resistances 313. R14, which form U
potential divider across R15. Variabil-
tone control in pentode anode circuit bi
R18. 020, 12.19 and fixed tune correction
by 021, also in anode circuit. Provision
for connection of low impedance external
speaker across secondary of Output
transformer '11

Second diode of V3. fed from V2 anode
via. 015, provides DC potential which X>
developed across load resistanCe 3,23
Lind fed back through decoupling circuits
as GB to FC (except on SW) and I}-
\'alves, giving automatic volume control
Delay voltage is obtained from drop
alongr resistances R20, R21 in V3 cathodi.
lead to chassis,

HT current is supplied by full-fl\t
rectifying valve (V4, Mullard A21).
Smoothing by irOIIrCOI'fld choke L23 and
large capacity wet electrolytic mn-
densers 022 and C28.

H8

El.

CH

«in

Page 2

Under-Chassis
View, Diagrams
of the two wave-
change switch
units are in Cu].
6 overleaf. 815,
518 are ganged
with the volume
A c o n t 1' 01 R 1 5 .
C33 is a spiralled
wire adjustable gpfAKER
condenser. LEADS

DISMANTLING THE SET

Removing Chassis; AFirst remove the
two right-hand control knobs from the
{rent of the cabinet and the hakelite
uscutcheon which they hold in place.
lhen remove the remaining knob from
the front of the cabinet and one from the
side (grub screw inside cabinet). Remove
the II. holder [knurled screw) and scale
lamps from their brackets inside the
cabinet: Slacks!) the fixing screw in the

Circuit diagram
of the Philips
555A- The 597A
cunsole is almost
identical (5:):
col. 3 overleaf),
while the U V
m n d e l s a re

similar except
for the addition
of the DC to AC
converter units

(sec col. 4 over-
leaf).

Supplymmr In My wiry/cm d2
Elmrical Trader. 34111'27, 1939

Sl5 Sl6

SOCKETS SOCKETS

spring-loaded pointer drum bogs, hohl
the drum, slip the wire «lrivc cord from
the flat hook on the drum and allow tlw
spring to mm the drum ilmwly unm tlw
tension is leleahed; remove u seumil
wire drive cord from the \vavttbmnl
indicator plate; umnldcr the two mm
tram the Lonnectmp, pdnel on the Spktlkll'
and the two wires from the tag scrcwul
to the screening on the base of the cabinet
Now remnm the luur bolts [uith \Vaslmh)
holding the vhassxs to the bottom of the
cabinet, when the chassi~ may he \uth-
drawn from the mhmetv

Why» refill/15mg, note that Una Ila,
washer and one spring washer are httvrl
on each of the mo nglitihzunl control
~pindles between the cuntlul knob and
the bakelite est-utcheon plate, lhl-
yellow rnhlxrrrruverwl lenll lrom the firm
(if the cabinet and the bare Wm- from
the chassis shouhl be connected to tlu-
tag screwed tn the Stirronlllg in the ham ml
the cabinet and the speaker leads bltnuhl
be connected as: follows, numbering from
top to bottom ' t and 2 joinml tngotllcr
yvllu lr-ml rmm T1; 3 mil livul fum-
T1.

Removing Speaker.7'lu rmymm tlli
\In-nkvl {Him the mum, it n m»
neceswiy n. romuw the (hams s; then
ilacken the square mm nml lot nun
holding the ilIl'Kl flamp~ to the S}? Ikr
{tame and the sub hullle, ulmn the ~pt'nki-
may be withdrawn ll lhk ('lnmptx ml-
wry vllerl TYIllnil 11/1»?! whmmn tlil
slllitll comm-ting pullkl \lmuhl 1w wt llw
right at the \peulimg zlml thl: lczul:. um
neuterl .H \'l(llllli1l nhow

COMPONENTS AND VALUES

\' n l. t
l R. \1pt~mu<:» k" \ u [in l\(|(lL' ( l: qmmw
h", v. mm. H w» «tint
R4 \n (w u [Mm-r
w: \. rw u. whim

L H .. .
(m 4m ml MW m1! Vi n-m-

V; W mule HT («in
u Hl' n-od n-qzumu

Part V; new] (linill Imul
1.1. Ci. iced potential (lludrr v

\umtlieimm mmtml
lam manna.- limvumllul

AYC lmrdecuuplln: .i
)3; AW llunli hm

lnmgr NW N"
MW and LW mum;

Una umuii I, u when
(lw llllliil \l\\' lmilu-v

x
(mulling m \ 3 «

* nupling tr, \ Jim-um

mu m vnrl {lllk' \Mnl- wmnl

m wmzlmmum
,

\ . nrlluh M m- H-

1l1\\llll MW um IH
14 w mu [mm m \mlnyl

4 Old/mun, 711 mm

PHILIPS 555A, 597A.
SSSU AND 597U

\ an.»
4mm

:tum,

mm»
mm
lfMLDOU
whim
\zo
100,000
;,.u>twm
yaw um.

3m; .m.
mom,
mm mm l

an om.
llm l
tho l

4
.'.oUu, 5mm.
:(mrumm

\.'|lr[o-.

(ull

.. mum;
nlmuoxlm

Irumml
n 0',
0 mm;
()Ullohh
m. '35
u-m
0 m
U'lh
n m
t. n:
"0:100.
n my,»
:5 n
001
in «mm
was

1) mm]
i» own:
4. 004qu
0 00005