Data set 01
1950 Sylvania
Published operating points and test conditions from this source.
SECTION 1
Pentode
Other
Plate Voltage
250 V
Screen Voltage
100 V
Voltage Pentode - Sharp Cutoff (single) ·Pentode
1232
Sylvania triple-grid amplifier pentode with published operating characteristics and interelectrode capacitances. Manufacturer data establish conventional signal-amplifier service without sufficiently explicit evidence for a stronger functional category.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- 8-V
- Socket code
- -
- Base pins
- 8
- Nominal heater
- 7 V / 480 mA
Description
1232 — High-Mu Triple-Grid Loktal Amplifier
The 1232 is a high-transconductance triple-grid amplifier tube designed for use in television receivers and high-frequency amplification circuits. Featuring a compact Loktal construction, the tube provides robust shielding and physical locking, making it highly suitable for demanding high-frequency applications.
Construction and Physical Characteristics
The 1232 is housed in a T9-G glass bulb and utilizes an 8-pin Loktal (8-V) base. The Loktal design ensures a compact form factor, excellent shielding, and a secure mechanical lock in its socket. The tube is designed to operate in any mounting position.
Internally, the 1232 is a triple-grid tube that shares similarities with the type 1231. However, the 1232 incorporates additional internal shielding. To accommodate this extra shielding, both the physical construction and the electrical characteristics of the tube have been specifically adjusted.
Heater Ratings
The 1232 can be operated under nominal or specific active operating conditions. The heater is designed for either alternating current (AC) or direct current (DC) operation.
- Nominal Ratings: 7.0 V at 0.48 A. Under AC service, this nominal 7.0 V rating corresponds to a standard 130 V line supply.
- Active Operating Conditions: 6.3 V at 0.45 A.
Electrical Characteristics and Operating Points
The 1232 is characterized by high mutual conductance relative to its operating current. Typical operating parameters and maximum ratings are defined as follows:
Typical Operating Conditions
| Parameter | Value |
|---|---|
| Heater Voltage | 6.3 V |
| Heater Current | 0.45 A |
| Plate Voltage | 250 V |
| Suppressor Grid Voltage | Connected to cathode |
| Screen Grid Voltage | 100 V |
| Control Grid Voltage | -2 V |
| Plate Current | 6.0 mA |
| Screen Grid Current | 2.0 mA |
| Internal Resistance (Approximate) | 800,000 Ω |
| Mutual Conductance (Transconductance) | 4,500 µmhos |
| Grid Voltage for Cathode Current Cutoff | -6 V (approximate) |
Maximum Dissipation Ratings
- Maximum Plate Dissipation: 1.5 W
- Maximum Screen Grid Dissipation: 0.2 W
Interelectrode Capacitances
When measured with a standard tube shield, the direct interelectrode capacitances of the 1232 are:
| Connection | Capacitance |
|---|---|
| Grid to Plate (Maximum) | 0.007 µµF |
| Input: Grid to (Heater + Cathode + Screen + Suppressor + Shield) | 9.0 µµF |
| Output: Plate to (Heater + Cathode + Screen + Suppressor + Shield) | 7.0 µµF |
Applications
The 1232 is primarily designed for television amplifiers and other high-frequency applications requiring high mutual conductance. Due to its high mutual conductance per milliampere, the tube is exceptionally well-suited for receiver circuits featuring a wide range of high-frequency (RF) amplification. In these designs, the antenna system should be configured to prevent the application of excessive RF voltages to the control grid (Grid No. 1).
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- 8-V
- Socket code
- -
- Base pins
- 8
- Nominal heater voltage
- 7 V
- Nominal heater current
- 480 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
8-V - Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
1 physical section, each with unique specifications.
Section 1
Pentode
X-ray radiationInterelectrode capacitances
- Plate resistance
- 800000 Ω
- Transconductance
- 0.0045 S
- Max plate dissipation
- 1.5 W
- Max screen dissipation
- 0.2 W
Sylvania 1232 loctal eight-pin shielded triple-grid RF/TV amplifier pentode. Nominal heater specified as 7.0 V 0.48 A, with 6.3 V 0.45 A in operating-characteristic tables (7 V nominal relates to 130 V mains service). Typical pentode conditions: anode 250 V, screen 100 V, control grid -2 V, anode 6 mA, screen 2 mA, gm 4500 µmhos, plate resistance ~800 kΩ. Maximum anode dissipation 1.5 W and screen dissipation 0.2 W already stored. Additional internal shielding, capacitances and short loctal electrode leads characterize this type.
Source-dependent data
Operating conditions by source
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.