Specialized - Cathode Ray ·CathodeRay
Direct-view cathode-ray picture tube documented by manufacturer data for type 16JP4; available extracted technical detail is limited, so the description remains conservative.
The 16JP4 and 16JP4A are direct-view, round glass cathode ray picture tubes designed primarily for television receiver applications. These tubes feature magnetic focus and deflection, a unipotential cathode, an external conductive coating, and require an external double-field ion trap magnet.
The two designations are electrically and mechanically identical, with the sole distinction being the faceplate treatment: the 16JP4A incorporates a grey filter faceplate to enhance picture contrast under ambient light conditions, whereas the standard 16JP4 utilizes a clear faceplate.
The 16JP4 and 16JP4A are built using a round glass bulb construction. The physical envelope and mechanical dimensions are specified as follows:
The tube structure includes an external conductive coating. When grounded, this coating forms a capacitor with the internal anode, which can be utilized for high-voltage ripple filtering. The approximate capacitances are:
| Parameter | Value |
|---|---|
| Cathode to all other electrodes | 5 µµF |
| Grid No. 1 to all other electrodes | 6.5 µµF |
| Maximum external conductive coating to anode | 2,000 µµF |
| Minimum external conductive coating to anode | 750 µµF |
The screen utilizes a sulfide-type phosphor designated as Phosphor No. 4. Its optical performance parameters include:
The 16JP4 and 16JP4A utilize a small shell duodecal 5-pin base with a 12N basing arrangement. The pin connections, viewed from the bottom of the tube base, are allocated as follows:
The operating limits of the 16JP4 and 16JP4A are established under the Design Center rating system. Operating the tubes beyond these limits may impair performance or cause permanent damage.
For standard television receiver operation, the typical electrical operating points and associated magnetic component requirements are defined as follows:
The 16JP4 and 16JP4A are 16-inch round glass, direct-view television picture tubes featuring magnetic focus, magnetic deflection (60-degree deflection angle), and a unipotential cathode. They operate with a standard 6.3 V, 0.6 A heater and require an external double-field ion trap. The tubes are identical except for the grey filter faceplate on the 16JP4A, which provides approximately 66% light transmission at the center to improve contrast. Under typical operating conditions, the anode is operated at 11,000 V, Grid No. 2 at 250 V, and Grid No. 1 bias is adjusted between -33 V and -77 V for spot extinction. The design center maximum anode voltage is rated at 14,000 V, and the maximum Grid No. 1 circuit resistance is limited to 1.5 Megohms.
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
11000 V
Maximum Grid2 Voltage
410 V
Typical Grid2 Voltage
250 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.
MAGNETIC FOCUS 8 DEFLECTION
8 mA
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DEFLECTION
6 degrees
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC ANODE
11000 V
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
250 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC FOCUSING COIL CURRENT (APPROX.j
115 mA
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC ION TRAP CURRENT STANDARD CULL #108 (APPROX.) — value 1
108 mA
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
DC ION TRAP CURRENT STANDARD CULL #108 (APPROX.) — value 2
120 mA
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
MAXIMUM 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.
MAXIMUM DC GRID #2 VOLTAGE — value 2
41 V
Published CRT datasheet value; multiple values on a row represent the source table's separate conditions/limits.
MAXIMUM GRID #1 VOLTAGE
1 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.