Power - Triode ·Triode
Directly heated amplifier triode developed for critical audio-frequency applications where low microphonics are important. Rated for 15 W plate dissipation, it combines power-triode capability with construction intended to reduce mechanically induced signal disturbance.
The 1602 is a three-electrode vacuum tube designed primarily for audio-frequency amplification in applications where microphonic noise must be strictly minimized. Originally designated as the 10-Special, this triode features a filamentary cathode and is capable of operating as either an audio-frequency (A-F) power amplifier or a radio-frequency (R-F) power amplifier.
The 1602 is constructed with a directly heated filamentary cathode. The filament is designed to operate on either alternating current (AC) or direct current (DC) power supplies.
The tube is housed in an S17 glass bulb and utilizes a medium 4-pin bayonet base. The physical dimensions of the envelope are constrained as follows:
The base pins are designed to fit a standard four-contact socket, such as the UR-542A.
When viewed from the top of the socket, the pin connections are arranged as follows:
The 1602 is characterized by a moderate amplification factor and low interelectrode capacitances, which are critical for maintaining stability and performance in both audio and radio-frequency circuits.
The 1602 can be operated under several distinct service classes. The maximum ratings and typical operating points vary significantly depending on the application.
In A-F power amplifier service, the 1602 can be operated in either Class A or Class B configurations.
Under Class A conditions, the tube operates with continuous plate current and a negative grid bias.
Typical Class A Operating Point:
For Class B service, the maximum ratings are averaged over any audio-frequency cycle of sine-wave form:
For high-frequency transmitter and amplifier applications, the 1602 is rated for Class B Telephony, Class C Telephony, and Class C Telegraphy.
These ratings apply to carrier conditions per tube for use with a maximum modulation factor of 1.0:
These ratings apply to carrier conditions per tube for use with a maximum modulation factor of 1.0:
These ratings apply to key-down conditions per tube without modulation. Modulation that is essentially negative may be used if the positive peak of the audio-frequency envelope does not exceed 115% of the carrier conditions:
The 1602 is specifically designed for applications where microphonic disturbances must be minimized, making it highly suitable for sensitive preamplifier and driver stages in audio systems.
For high-frequency operation above 6 megacycles, special operating precautions and circuit adjustments are required to ensure stable performance and prevent damage to the tube. The 1602 shares operational and installation characteristics with the type 801 tube, which can be referenced for general installation practices.
The 1602 is a low-microphonic, directly heated amplifier triode featuring a 7.5 V, 1.25 A filament and an amplification factor of 8. It is designed to deliver reliable performance in both sensitive audio-frequency systems and radio-frequency power amplifiers. With a maximum plate voltage rating of up to 450 V and a plate dissipation limit of up to 15 W depending on the class of service, the 1602 offers a robust and versatile solution for Class A, Class B, and Class C applications. It is housed in an S17 glass envelope with a standard medium 4-pin bayonet base.
Medium 4-contact bayonet 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
Published maximum ratings and characteristic values promoted from the approved source.
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.
HeaterVoltageNominal
7.5 V
Nominal
HeaterCurrentNominal
1.25 A
Nominal
Maximum Plate Voltage
450 V
Maximum Plate Dissipation
15 W
Maximum Frequency
6 MHz
Published full-rating frequency guidance
Amplification Factor
8
Typical