Philips 584 a service manual

Page 1

Service Engineer Supplement to The Broadcaster

)5.

August, 1935

Circuil.-The combined first detector
oscillator valve, FC4 met. (V1), is preceded
by a. special aerial filter and band-pass
coupling. Bias is partly by cathode resistance
alld partly from A.V.C. Oscillator tuning is
in the grid circuit of the triode element.

The following coupling is a band-pass I.F.
transformer (frequency 125 kc.).

The IF. valve, VP4A met. (V2), is also
biased by cathode resistance and A.V' ., and
is followed by a second hand-pass I. . tfans-
former.

The second detector is a. diode, ZD4A met.
(V3), of which only one anode is used. Both
DC. and A.C. components of the rectified
carrier are utilised, the D.C. providing
A.V.C. to V1 and V2.

Coupling to the next valve is by resistance
capacity filter with the potentiometer volume
control forming the diode load.

The L.F. valve, SP4 met. (V4), is re-
sistance capacity coupled to the output valve,
a PM24M. This is of the directly heated
type, and is biased by R7 in the common
heater centre tap lead.

Tone compensation and control are pro-
vided in the anode circuit. and the speaker
is the usual permanent-magnet type.

Mains equipment consists of transformer,
full-WBVP, type 1821, rectifier, a choke in the
positive H.T. lead, and electrolytic conden-
sets.

Special Notes.-Pilot lamps are type No.
BOMX, and the pilot lamp panel can be
removed for replacement by slackening
the two left-hand screws and removing the
one right-hand screw.

Owing to the fact that the tuning dial and

VALVE READINGS

Valve. Type. Electrode. Volta Ma.
1 FCA met. (7). . anode . . 230 1.25
aux. grid. 73
2 VP4 A met (5) anode . . 280 .3
aux grid . . 73
3 2D1NA(5) .. .. -
4 or; met (5) . anode . , 140 .36
aux. grid. . 73
5 P152404 (5) . . anode . . 210 26.0
1:.ng 227 4

Diode only. '3,

PHILIPS MODEL 5822
SUPERHET

indicator are in the top of the cabinet, this
set appears more complicated thauyigreally
dis. , . _, , c,

A band drive is
are carried out the
to removingthe ch s.

The tuning indicator meter is connected in
the HT. lead to V1 and V2. '

d, and if instructions
no: difficulty attached

is immaterial which way round these are con-
nected), 227 volts and 210 volts.

Removing Chassis.-Unsolder the earth

Remove the knobs (grub screw, two on large
knob); remove four screws from underneath
and slip the driving band from the drum
in front of the gang condenser.

Ease the chassis backwards and free the
pin on the driving band from the hole in
the condenser drum.

If the chassis must be removed completely,
unsolder the leads to the speaker and to the
pilot lamps and tuning indicator, marking
them carefully.

General Noam-Alignment of circuits.

The tuning on the LF. circuits is sharp, and
accurate tuning to 125 kc. will be facilitated

COND EN SERS
Purpose. Mfd.
1 H.T. smoothing . . . . 32*
2 um. smoothing .. .. . . 32
8 Decoupling aux. grids . . . . 1
4 HIP. smoothing .. .. .. .6
5 V1 cathode lay-pass . . . . .05
6 v4 cathode by-paas . . . . 25
7 V5 bias resistor by-pess . . .225
15 Tracking on 030. . . . . .0009
16 Trecking on one. . . . . .00181
13 Band piss coupling on MW. . . .025
19 Band pass coupling on L.W. .025
(series).
20 Across tuning indicator . . . . .1
26 Decoupling A.V.C. . . . . .
27 LJ'. coupling v¢ to V5 .. .o
23 Tune compensating, v5 node .002
29 LJ. coupling from diode .01
30 HF. by-pess from diode . . .0002
31 HI. by-pass new diode . . .0001.
92 v2 cathode by-paes . . .1
34 Tone control circuit . . . . .032
Code No. 28, 180, 011.

Quick Tesls.-Between the two terminals,
on the speaker transformer and chassis (in

wire from the case of the speaker transformer.

An inclined liming scale at the lap of the

cabinet is embodied in the Philip: 584A,

although the control: are below the speaker
opening.

by connecting temporary resistances of 10,000
or 15,000 ohms across the coils.

Win the LF. transformer by injecting
125 kc. to grid (top) of F04 with set switched
to the dung waveband and R1 shortrcircuited
(see diagram).

To trim H.F. and oscillator sections, turn
condenser to minimum and switch to the
medium waveband. Leave the 10,000 ohm
resistance across the primary of IFT]. and
remove the short circuit on R1. Inject on
225 m. for M.VV. and on 900 m. for L.W. ,

Condenser Driving Mechanism.-The fric-
tion drive is mounted on a plate fixed to the
chassis by three screws. For adjustment or
removal, the two grub screws on the collar
of the drum should he loosened. .

Replacing Chassis-Lay the chassis
half-way inside the cabinet and engage the

- RESISTANCES

R. Purpose. Ohms.

1 V1 oec. rid leak 50,000
2 germs .0. to grid . . 84 01"???)

4 0 tags dropp ng aux. s. . ,

5 V1. cathode his: . . . . . . 200

6 V4 cathode bias . . 6,400

7 V5 his! . . . . ' 800

8 v1 grid decoupling 10,000 ,
9 v4 grid leak .. 1 Me:
10 v4 anode coupling .52 Meg

11 v5 dleak .. ..
12 vagasubmmu .. ., .MMag

13 . A.V.C. decoupling . . 1 Meg
' 14 H.172 stopper 0'0 diode 25 Meg
15 v.0. .. .. .. .. .5 Meg
16 V2 cathode bias . . . . 640
17 Tone control circuit (Van) 64,1300

18 Tons control circuit

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A milioe super-bet.
the 5844. incorporate:
n'x values, including an
acted: on a single
diode. The first L.F.
amplifier is actually on
HF. Mode

1

Page 2

August, 1935

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The compounds in the 584A an all special Philip: productions and (and themselvcs (a compact construction. Care should be taken not to

gin on the driving band in the hole in the

ide chassis into position and replace the

eaEiug Contact plate under the left-hand

The 5.0.3
just intro-
duced by
G.E.C. for
the coming
season.

VALVE READINGS

V. Type. Electrode, Volts. M.A.

1 V324 met (4) . lnods .. 110 1.5
screen . . 60

2 VP21 met (7) . anode , . 44 2
nuxgrld. 60

a PT2 (5) . anode ,. 106.5 4
120

unhgrld
I The average not current is 9 m.u.

7' RESISTANCE

IL. Puryose. Ohms
1 :Volume control ptl'. . . 50,000
2 " " series with in (min. bias)

5 t 2 grid leak . . . .

I V2 Anode coupling

5 Pm of bins pix. .. 3.6
6 Pitt of bins 361. . .

7 V3 grid stub leer. . . . . . 99,000
a Decoupling v1 gnd . . .. 33,000
D Bin-l ptr. of V2. . . . . . 2 may

CONDENSERS
. Purpose. Mid.

1 Series um! . . . . . . .003

2 Decoupling V1 grid . . . . .005

5 V2 grid reservoir . . . .0001

6 Reaction , . . . .0005

7 V1 screen lay-pass . . . .25

8 LF. feed to LF. transformer . . .1

0 V3 luode compensating , . .002 .
10 Across hinagtr. . . . . . . 50 (20V.)
11 Angling E. . tron". secondary .005
14 H. . blocking in motion circuit .005
ll Dew-mun: earls! can . . . . .005

displace the bare wires.

rear corner, so that it touches the screen
in the bottom of the cabinet.

Replace holding screws and knobs and,
after resoldering the esrthing lead (and

others, it these have been disconnected), slip
the driving band over the pulleys. The ten-
sion spring allows adequate freedom for this
operation.

G.E.C. BATTERY 5.0.3

Circuit-The H.F. valve, VS 24 met.
(V1), is preceded by a. tuned secondary aerial
transformer. the volume control bein a
potentiometer across the aerial coil w ich
also acts as a. control of bias. The following
coupling is a tuned secondary H.F. trans»
former with reaction.

The detector valve, VP21 met. (V2),
operates as a. leaky-grid detector and has
reaction applied to the HI. transformer by
means of a. differential condenser. Coupling
to the next valve is by auto-coupled trans-
former. ,

The output valve, PT2 (V3), has a grid
stabilising resistance and is tone compensated
by a condenser between anode and chassis.
The speaker is a permanent-magnet moving-
coil type.

Switching is in both the L.T.- and the

main H.T. + leads. The Ill-lead is fused
with a 5.5 volt, .15 amp flashlsmp bulb.

Quick Tests.-These are best carried out
by makinfi! the routine valve test: (see table).

Specia Notes.-The battery is type
No. B8120.

H.T. +, red, is the 120 v. topping, and
H.T.+, blue, is the 60 v. tapping.

Bias is obtained by means of the resist-
imcdes R5 and R6 in the common negative
654 .

Removing Chnsis.-Iull ofi the knob:
and remove three screws from underneath.
For quick tests the Clea/t holding the speaker
leads should be undone or, if it is necessary
to remove the chassis entirely, the plugs,
should be removed and the earthing lead
unsoldered.

(Continued on next page.)

HT+EO

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Re TV _J
r-use HT-

The 5.63 uliiius a Weight and orthodox circuit which include: refinements sad: as a

difennh'ai reaction conlml.