Specialized - Cathode Ray ·CathodeRay
P4 television picture tube using magnetic focusing and magnetic deflection, approximately 60-degree scanning, and an external double-field ion trap for beam correction.
The 16HP4 and 16HP4A are direct-view cathode ray picture tubes designed for television receiver applications. These tubes feature a round glass construction, magnetic focus and deflection, and require an external double field ion trap. The two designations are identical in their electrical and mechanical specifications, with the sole exception of the faceplate: the 16HP4A incorporates a grey filter faceplate to improve contrast under ambient light, whereas the standard 16HP4 does not.
The 16HP4 and 16HP4A are built with a round glass envelope and feature a unipotential cathode. The tubes are designed with an external conductive coating that, in combination with the internal anode, forms a capacitor. This capacitance helps in filtering the high-voltage anode supply.
The screen utilizes Phosphor No. 4, which provides a white fluorescent and phosphorescent color with medium persistence. This phosphor is optimized for black-and-white television reproduction. The faceplate has an approximate light transmission of 70 percent at the center. The standard raster size produced on the screen is 10 1/4 inches by 14 1/2 inches.
Both focusing and deflection are accomplished magnetically. The nominal deflection angle of the tube is approximately 60 degrees. To prevent screen damage from heavy ions, the electron gun design requires an external double field ion trap magnet.
The physical dimensions and mechanical layout of the 16HP4 and 16HP4A are highly standardized to fit television chassis of their era.
The tube uses a Small Shell Duodecal 5-Pin base (designation B5-57) with a 12N basing arrangement. The high-voltage anode connection is made via a recessed small cavity cap (designation J1-21) located on the side of the bulb. The J1-21 contact aligns with pin position #3 within a tolerance of ± 10 degrees.
The pin connections, viewed from the bottom of the base, are as follows:
| Pin Number | Connection |
|---|---|
| Pin 1 | Heater |
| Pin 2 | Grid No. 1 (Control Grid) |
| Pin 10 | Grid No. 2 (Screen Grid) |
| Pin 11 | Cathode |
| Pin 12 | Heater |
| Cap | Anode |
The operating limits and typical characteristics of the 16HP4 and 16HP4A are defined under the design center rating system.
These ratings represent the maximum safe operating limits for the tube:
Under typical operating conditions, the tube is set up with the following parameters:
The focusing coil current of 110 mA is specified for a standard focus coil #109 (or equivalent) under the condition that the combined Grid No. 1 bias voltage and video signal voltage are adjusted to produce a highlight brightness of 20 foot-lamberts on a 10 1/4" by 14 1/2" picture size. For this setup, the distance from the reference line to the center of the air gap on the focus coil must be exactly 3.25 inches.
The direct interelectrode capacitances of the tube are influenced by the external conductive coating:
The 16HP4 and 16HP4A are 16-inch round glass, magnetically focused and deflected television picture tubes. Operating with a standard 6.3 V, 0.6 A heater, they are capable of displaying a 10 1/4" by 14 1/2" raster using a white-emitting Phosphor No. 4 screen. They require an external double field ion trap and a standard focusing coil to achieve a sharp, focused spot. With a maximum design-center anode rating of 14,000 Volts and typical operation at 12,000 Volts, these tubes represent a classic example of early-1950s television display technology, distinguished primarily by the grey filter faceplate option on the 16HP4A variant to enhance viewing contrast.
Small-shell Duodecal 5-contact CRT base
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
CRT-specific anode/focus/deflection ratings retained as parameters rather than mapped to ordinary plate/screen fields.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Maximum Anode Voltage
14000 V
Typical Anode Voltage
12000 V
Maximum Grid2 Voltage
410 V
Typical Grid2 Voltage
300 V
DeflectionAngleApproximate
60 degree
FocusingMethod
Magnetic
DeflectingMethod
Magnetic
PhosphorNumber
4
FluorescentColor
White
Persistence
Medium
Data set 02
Published operating points and test conditions from this source.
NAGMETIC FOCUS 6 DEFLECTION
6
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
EXTERNAL DOUBLE FIELD ION TRAP — value 1
1
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
EXTERNAL DOUBLE FIELD ION TRAP — value 2
1
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
EXTERNAL DOUBLE FIELD ION TRAP — value 3
2
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DEFLECTION ANGLE (APPROX.)
60 degrees
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC GRID #2 VOLTAGE — value 1
2 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC GRID #2 VOLTAGE — value 2
3 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC GRID #1 VOLTAGE A — value 1
1 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC GRID #1 VOLTAGE A — value 2
33 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC GRID #1 VOLTAGE A — value 3
-77 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC ION TRAP CURRENT STANDARD COIL #108 (APPROX.)
108 mA
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
SIGNAL VOLTAGE ADJUSTED TO PRODUCE A XI GXLIGXT BRIGHTNESS OF 20 F00T LAMBERTS ON a 10 1/4" BY — value 1
10 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
SIGNAL VOLTAGE ADJUSTED TO PRODUCE A XI GXLIGXT BRIGHTNESS OF 20 F00T LAMBERTS ON a 10 1/4" BY — value 2
1 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
SIGNAL VOLTAGE ADJUSTED TO PRODUCE A XI GXLIGXT BRIGHTNESS OF 20 F00T LAMBERTS ON a 10 1/4" BY — value 3
4 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
14 1/2" PICTURE SIZE. GIST ANLE FROM REf ERENCE LINE TO CENTER OF aIR GaP ON FOCUS COIL SH aLI BE — value 1
14
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
14 1/2" PICTURE SIZE. GIST ANLE FROM REf ERENCE LINE TO CENTER OF aIR GaP ON FOCUS COIL SH aLI BE — value 2
1
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
14 1/2" PICTURE SIZE. GIST ANLE FROM REf ERENCE LINE TO CENTER OF aIR GaP ON FOCUS COIL SH aLI BE — value 3
2
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
MAXIMUM OC GRID #2 VOLTAGE — value 1
2 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
MAXIMUM OC GRID #2 VOLTAGE — value 2
4 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
MAXIMUM GRID #1 CIRCUIT RESISTANCE
1 mA
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.