SABA SCHAUINSLAND T240 AUTOMATIC CRT TUBE PHILIPS A61-120W

TELEVISION CRT TUBE PHILIPS A61-120W

QUICK REFERENCE DATA

61 cm (24in)direct viewing television tube with metal backed screen
and reinforced envelope. A separate safety screen is not required.
Suitable for use in receivers with push—through presentation. This
tube is fitted with a ring trap base.

Deflection angle 110 deg

Focusing Electrostatic
Light transmission (approx.) 42 %
Maximum overall length 370 mm

This data should be read in conjunction with GENERAL OPERATIONAL
RECOMMENDATIONS — TELEVISION PICTURE TUBES

HEATER

Suitable for series or parallel operation

Vh ’ 6.3 V

Ih 300 mA

The limits of heater voltage and current are contained in ‘General Operational
Recommendations — Television Picture Tubes.

Note - applies to series operation only

The surge heater voltage must not exceed 9.5V r.m.s. when the supply is
switched on. A current limiting device may be necessary in the circuit. to
ensure that this voltage is not exceeded.

OPERA TING CONDITIONS

Va2+a4 _ 20 20 kV

Vag (focus electrode control range) 0 to 400 0 to 400 V

V 400 500 V
211

Vg for visual extinction of focused raster -40 to -77 -50 to -93 V
*Vk for visual extinction of focused raster 36 to 66 45 to 80 V

*For cathode modulation, all voltages are measured with respect to the
grid.

SCREEN (metal backed)


Fluorescent colour White
Light transmission (approx.) 42 %

FOCUSING (Electrostatic)

The range of focus voltage shown in !Operating Conditions’ results in opti-
mum overall focus at a beam current at 250pA.

DEFLECTION (Magnetic)

Diagonal deflection angle 110 deg
Horizontal deflection angle 98 deg
Vertical deflection angle 81 deg

The deflection coils should be designed to provide a pull—back of 4 .0mm on
a nominal tube .

CAPACITANCES
cg_au 7.0 pF
ck_an 5.0 pF
°a2+a4-M 1500 to 2300 pF-(-
°a2+a4—B 600 PF

EXTERNAL CONDUCTIVE COATING

This tube has an external conductive coating, M, and in accordance with
the General Operating Recommendations this should be connected directly
to pin 5 and not to chassis. The electrical connection to this coating must
be made within the area specified on the tube outline drawing. The capaci-
tance of this coating to the final anode is used to provide smoothing for the
e.h.t. supply.

RING TRAP

For flashover protection of the receiver, parallel spark gaps are included
for all the electrodes in the base of this tube, and the common connection
is made to pin 5. These spark gaps are intended as part of a system for
full flashover protection. A direct connection must always be made from
pin 5 to chassis, and the external conductive coating returned to chassis
only via pin 5, using short leads. Any electrode supplied directly from a
high energy source (such as the h.t. line) should be provided with a series
resistor.

RASTER CENTRING

See note under this heading in ‘General Operational Recommendations —
Television Picture Tubes‘.

Centring magnet field intensity . 0 to 800 A/ In

Maximum distance of centre of
Vcentring field from reference line 57 mm

Adjustment of the centring magnet should not be such that a general reduc-
tion in the brightness of the raster occurs .

REFERENCE LINE GAUGE

J .E.D.E.C. 126. For details see ‘General Operational Recommendations-
Television Picture Tubes‘ .

  MOUNTING POSITION

Any. The tube socket should not be rigidly mounted’ but should have flex-
ible leads and be-allowed to move freely. The bottom circumference of the
base shell will fallwithin a circle of: 40mm diameter which is centred on
the perpendicular from the centre of the face.

This tube is fitted with a pin protector in order to avoid damage to the
glass base due to bending of the base pins whilst handlingthe tube.

It is advisable to keep this pin protector on the base until it can be replaced
by the socket after installation of the tube in any equipment’.

RATINGS (DESIGN CENTRE SYSTEM)

Va2+a4 max. (at la2+a4 =0) (see note 1) 20 kV I
Va2+a4 min. 13 kV
+V max. 1.0 kV
a3
-V max. 500 V
a3
V’ max. 700 V
a1
V min. 350 V
a1
—vg(pk)b max. (see note 2) 400 V
-Vg max. (see note 3) 150 V
tIa3 max. 25’ pA
tlal max. 5 uA
Vh_k (see note 4)
Cathode positive
d.c. max. 250 l V
pk max . 300 V
Cathode negative
d.c. max. 135 V
pk max. 180 V
Rh_k max. 1 .0 M9
Zk_e max. (f=50I-lz) 100 kn
R max. 1.5 M52
g—k
Zg_k max. (f= 50}hz) 500 k9