NJ7P SQL Tube Database Query

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34
Remote Cutoff Pentode

EIA Base & Outline

Substitute Data

Preferred Substitutes ......................... 1A4
Substitutes ................................... 1B4 32
Source ........................................ RCA R-10 - 1932

34
Remote Cutoff Pentode

Substitute Data

Preferred Substitutes ......................... 1A4
Substitutes ................................... 1B4 32
Source ........................................ RCA RC-13 - 1937

Application

Source ........................................ RCA R-10 - 1932
The '34 is a super-control pentode recommended for use primarily as a radio-frequency amplifier and intermediate-frequency amplifier in battery-operated receivers employing the '30, '31. '32, and/or '33 where economy of filament current drain is important.

The '34 is very effective in reducing cross-modulation and modulation-distortion over the usually range of signal voltages without the use of antenna potentiometers or auxiliary volume control switches. This super-control characteristic makes the tube uniquely adaptable to the r-f and i-f stages of receivers employing automatic volume control.

The use of a suppressor is an important feature of the '34. In comparison with the usual type of screen grid tube operated under similar conditions, the '34 has a much higher plate resistance and a considerably increased range of voltage swing. Furthermore, a high value of mutual conductance is maintained.

The suppressor is connected inside the tube to the filament. During operation of the tube, the suppressor eliminates the secondary emission effects which limit the voltage swing permissible in the usual screen grid tube at low plate voltage, that is, at a plate voltage approximately equal to the screen voltage. The suppressor in the '34, therefore, makes possible efficient operation of this tube at a relatively low plate voltage. This may be greater than, equal to, or slightly less than the recommended screen voltage.

Mechanical Data

Source ........................................ RCA R-10 - 1932
Bulb .......................................... S-14
Base Type ..................................... Medium 4-Pin
EIA Outline ................................... 14-01
EIA Base ...................................... 4M
Top Cap ....................................... Small Metal
Mounting Position ............................. Vertical

Source ........................................ RCA RC-13 - 1937
Bulb .......................................... ST-14
EIA Outline ................................... 14-2

Electrical Data

Source ........................................ RCA R-10 - 1932
Filament Voltage .............................. 2.0 DC V
Filament Current .............................. 0.06 A

Direct Interelectrode Capacitances (approx)

Pentode
Source ........................................ RCA R-10 - 1932
Input ......................................... 6.4 pf
Output ........................................ 12.8 pf
Grid to Plate ................................. 0.020 pf

Pentode
Source ........................................ RCA RC-13 - 1937
Input ......................................... 6.0 pf
Output ........................................ 11.5 pf
Grid to Plate ................................. 0.015 pf

Maximum Ratings (Design Center Values)

Pentode
Source ........................................ RCA R-10 - 1932
Plate Voltage ................................. 180 V
Grid No. 2 Voltage ............................ 67.5 V
Cathode Current ............................... mA
Grid No. 1 Circuit Resistance
Fixed Bias ................................. Ω
Self Bias .................................. Ω
Bulb Temperature (At Hottest Point) ........... °C

Characteristics and Typical Operation

Class A Amplifier
Plate Voltage ................................. 67.5 V
Grid No. 2 Voltage ............................ 67.5 V
Grid No. 1 Voltage ............................ -3 V
Amplification Factor .......................... 224
Plate Resistance (approx) ..................... 400K Ω
Transconductance .............................. 560 µ
Plate Current ................................. 2.7 mA
Grid No. 2 Current ............................ 1.1 mA

Class A Amplifier
Plate Voltage ................................. 135 V
Grid No. 2 Voltage ............................ 67.5 V
Grid No. 1 Voltage ............................ -3 V
Amplification Factor .......................... 360
Plate Resistance (approx) ..................... 600K Ω
Transconductance .............................. 600 µ
Plate Current ................................. 2.8 mA
Grid No. 2 Current ............................ 1 mA

Class A Amplifier
Plate Voltage ................................. 180 V
Grid No. 2 Voltage ............................ 67.5 V
Grid No. 1 Voltage ............................ -3 V
Amplification Factor .......................... 620
Plate Resistance (approx) ..................... 1M Ω
Transconductance .............................. 620 µ
Plate Current ................................. 2.8 mA
Grid No. 2 Current ............................ 1 mA

If you are uncertain about the EIA designator for a particular tube please use the "Index" button to list all the tubes in the database. You can click on the designator for the closest tube.

(c) 1994-2021 by William A. Beech, NJ7P

Wed, 29 Mar 2023 00:47:10 -0700