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Advance Electron Tube Data Sheet
Western Electric 437A Electron Tube
Description |
The 437A electron tube is a high figure of merit triode with an indirectly heated cathode. It was designed primarily for the output amplifier of the L-3 tandem two stage amplifier. |
Characteristics |
|
Heater Voltage |
6.3 volts |
Cathode Current (Eb = 160 volts; Eccl = +7.5 volts; Rk = 262 ohms) |
36.5 milliamperes |
Transconductance |
46000 micromhos |
General Characteristics
Electrical Data |
|
Heater Voltage |
6.3 volts |
Heater Current |
450 milliamperes |
Direct Interelectrode Capacitances |
Without External Shield |
With External Shield RETMA #309 |
Grid to Plate (maximum) |
3.8 |
3.8 uuf |
Input: g to(h+k+i.s.) |
11.1 |
11.3 uuf |
Output: p to(h+k+i.s.) |
1.0 |
2.1 uuf |
Mechanical Data |
|
Cathode |
Coated Unipotential |
Bulb |
T9 |
Base |
See outline diagram below |
Mounting Position |
Any |
Dimensions and pir. |
See outline diagram below |
Maximum Ratings, Design Centre Values |
|
Plate Voltage |
250 volts |
Plate Dissipation |
7.0 watts |
Control Grid Dissipation |
See footnote 1 |
Cathode Current |
45 milliamperes |
Heater-Carthode Voltage |
50 volts |
Bulb Temperature |
130° centigrade |
Maximum Circuit Values |
|
Grid Circuit Resistance: |
|
For Fixed Bias |
0.05 megohm |
For Cathode Bias |
0.10 megohm |
Typical Operating Conditions And Characteristics |
Plate Voltage |
140 |
180 |
160 |
volts |
Control Grid Voltage |
-2.0 |
-3.0 |
--- |
volts |
Control Grid Supply Voltage 2 |
--- |
--- |
+7.5 |
volts |
Cathode Bias Resistor 2 |
--- |
--- |
262 |
ohms |
Plate Current |
29.0 |
25.0 |
36.5 |
milliamperes |
Amplification Factor |
41.0 |
41.0 |
41.0 |
|
Plate Resistance |
950 |
980 |
900 |
ohms |
Transconductance |
43000 |
42000 |
46000 |
micromhos |
Control Grid Voltage (approximate) for Plate Current of 10 microamperes |
-5.0 |
-6.3 |
--- |
volts |
Modulation |
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|
Second Order (2F) 3 |
--- |
--- |
-37 |
db |
Third Order (3F) 4 |
--- |
--- |
-56 |
db |
Load Resistance |
--- |
--- |
270 |
ohms |
Note 1: |
Operation with the control grid positive with respect to cathode is not recommended. |
Note 2: |
Reference point for control grid voltage is the negative end of the cathode bias regulator. |
Note 3: |
Ratio of product to fundamental at output for 0.1 volt rms signal from grid to cathode. |
Note 4: |
Ratio of product to fundamental at output for 0.2 volt rms signal from grid to cathode. |
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