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Technical Specifications
- 20" CPT - JCTEL A48JSK61X
Other 20" Colour Picture Tube Types
 •
Electrical Data
• Optical Data
• Mechanical Data
• Bulbs
• Ratings
• Sagittal Heights and Mounting Lug Height
•
Electrical Data
| Electron Gun |
Unitized (one piece) triple aperture
electrodes centre beam (Green), side beam (Blue, Red) |
Heater Current at 6.3 volts |
680mA |
| Focus Method |
Electrostatic |
Focus Lens |
Bi-potential - Uni-potential
Uni-potential - Bi-potential |
| Convergence Method |
Magnetic |
Deflection Method |
Magnetic |
| Deflection Angles (Approx.):
Diagonal |
90 deg. |
Direct Interelectrode Capacitance
(Approx.) Grid No.1 to all other electrodes |
12 pF |
| All cathodes at all other electrode |
15 pF |
Grid No. 3, 5 to all other electrodes |
5 pF |
| External conductive coating
to anode |
2000 max. pF,
1500 min. pF |
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- |
•
Optical Data
| Light Transmission at Centre(Approx.) |
52.5% |
Screen on Inner Surface of
Face Plate |
Aluminized, Tricolour, Phosphor-Stripe,
Black Matrix Type Stripe Screen |
| Phosphor (three separate phosphor,
collectively) |
P22-New Rare-Earth (Red) Sulphide(Blue
& Green) Type |
Arrangement |
Vertical Line Trios |
| Spacing between centre of adjacent
Stripe trios (Approx.) |
Horizontal-0.82 mm (0.032 in.)
Vertical-0.64 mm (0.025 in.) |
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• Mechanical Data
Overall Length : 430.9 ± 6.5 mm (16.96
± 0.26 in.) Minimum Useful Screen Dimensions (Projected) :
| Diagonal |
480.0 mm (18.90 in.) |
Horizontal axis |
404.4 mm (15.92 in.) |
| Vertical axis |
303.3 mm (11.94 in.) |
Area |
1194 cm² (185 sq.in.) |
| Base Designation |
B10-277 |
Bulb Contact Designation |
Record Small Cavity Cap. (JEDEC
No. J1-21) |
• Bulbs
| Funnel |
EIAJ-JF510AF01 |
Panel |
EIAJ-JP510AD11 |
| Pin Position Alignment |
Pin No. 9 and No.10 Aligns Approx.
with Anode Contact |
Implosion Protection |
Banded Type with Mounting Lugs |
| Weight (Approx.) |
13.5 kg (29.7 lbs) |
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• Ratings
a. Maximum and Minimum Rating, (Design- Values)
:
Unless otherwise specified, voltage values are for each Gun and values
are positive with respect to Grid No.1
| Anode Voltage |
27,500 max.V
20,000 min. V |
Total Anode Current: Long-Term
Average |
1,000 max. uA |
| Grid No. 3, 5 (Focusing Electrode)
Voltage |
8,200 max. V |
Peak Grid No. 2 Voltage Including
Video Signal Voltage |
1,000 max. V |
| CV*: Positive Bias Value |
400 max. V |
CV*: Positive Operating Cut-off
Value |
200 max. V |
| CV*: Negative Bias Value |
0 max. V |
CV*: Negative Peak Value |
2 max. V |
| Heater Voltage (AC or DC) |
6.9 max. Vrms
5.7 min. Vrms |
Surge of Heater Voltage (within
100 /m sec) |
9.5 max. Vrms |
| PHCV**: Heater negative with
respect to Cathode |
200 max. V |
PHCV**: Heater positive with
respect to Cathode - AC component |
200 max. V |
| PHCV**: Heater positive with
respect to Cathode - DC component |
0 max. V |
Peak Heater-Heater Voltage
(Operating with pulse of F. B. T.) |
22 max. Vo-p |
NOTE: * CV
= Cathode Voltage **PHCV = Peak Heater-Cathode Voltage
b. Equipment Design
Ranges :
Unless otherwise specified, values are for each Gun and Voltage Values
positive with respect to Grid No. 1.
For anode voltages between
20,000 and 27,500 volts:
Grid No. 3, 5 (Focusing Electrode) Voltage |
26.6% to 29.8% of Anode Voltage. |
| Grid No. 2 and Cathode Voltages
for Visual Extinction of undeflected focused Spot |
See CUT-OFF DESIGN CHART |
For anode voltages between
20,000 and 27,500 volts:
Grid No. 3, 5 (Focusing Electrode) Voltage |
26.6% to 29.8% of Anode Voltage. |
| Maximum Ratio of Cathode Voltages,
Highest Gun to Lowest Gun in any Tube (With Grid No. 2 at 425
Volts and Cathode Voltage Adjusted for spot cut-off) |
1.25 |
| Grid No. 3, 5, Current |
-15 to + 15 uA |
| Grid No. 2 Current |
-5 to + 5 uA |
c. Examples of Use
of Design Ranges :
Unless otherwise specified, values are for each Gun and are positive
with respect to Grid No. 1.
| Anode Voltage |
25,000 V |
| Grid No. 3, 5 (Focusing Electrode)
Voltage |
6,650 to 7,450 V |
| Grid No. 2 Voltages when circuit
design utilize cathode voltage of 160 volts for visual extinction
of focused spot |
460 to 820 V |
| Heater Voltage (1) : Under
operating condition |
6.3 Vrms |
d. Limiting Circuit Values
:
High-Voltage Circuits :
In order to minimize the possibility of damage to the circuit caused
by a momentary internal arc, it is recommended that the high-voltage
power supply and the Grid No. 3, 5 power supply should be of the limited
energy type.
| Grid No. 3, 5 Circuit Resistance |
30 Max. mega ohms. |
| Low-Voltage Circuits : Effective
Grid No.1 to cathode Circuit resistance (each Gun) |
0.75 Max. mega ohms |
•
Sagital Heights and Mounting Lug Height
X Dimension is 434.2 mm and Y Dimension is 336.8 mm.
Tolerance of the Mounting Lug holes will accommodate mounting screws
up to 8.5 mm in diameter when positioned on the true centre of the
hole. |
