807 Beam TetrodeGeneral InformationThe 807 valve is an indirectly heated beam tetrode designed for various uses including RF Amplifiers and Public address systems. The heater is made for operation in parallel with other valves in AC operated equipment. The valve is a beam tetrode unit capable of an output of around 15 watts. It is a standard ST16 valve with anode connection to Top Cap ion a 5 pin base. Characteristics
*The voltage should not vary more than 5% from the rated value if the valve is used under Class AB2 conditions or where the operating conditions are close to the maximum rating. Nor should it be more than 7% if used under Class A or AB1 conditions. Dimensions
Maximum overall length 146mm Mounting Position - VerticalIn extreme circumstances the valve may be run horizontally, then the plane of the major axis of the control grid & screen must be on a vertical plane. The plane will be correct if pin 3 is on the vertical diameter of the valve base. Adequate ventilation should be considered when using this valve in equipment as it will become very hot in use. BASE - American 5 pin (UX5)Top Cap - American Miniature - CTICONNECTIONS
Pin 1 Heater Ratings
† In order to avoid parasitic oscillation the anode and pin 2 should be connected together through a 100 ohm resistance or an RF choke of approximately 20 microhenries. * These ratings are absolute and must be reduced under certain specified conditions referred to later I this report. Frequency RatingsThe ratings given in the above paragraphs apply to frequencies up to 60 Mc/s. Above this frequescy the maximum anode voltage and anode dissipation must be reduced in the correct proportion. So at 80 Mc/s they are reduced by 80% and at 120 Mc/s to 50% of the values specified. The valve is not normally satisfactory for operation at frequencies higher than this. Inter-electrode Capacitances (approx)
Typical Operation at Audio Frequencies
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Triode Connection (Pin 2 and top cap strapped) | ||||
Heater voltage | 6.3 | 6.3 | V | |
Anode Voltage | 250 | 250 | V | |
Grid Voltage | -20 | - | V | |
Autobias resistor | - | 500 | Ω | |
Anode current (no signal) | 40 | 40 | mA | |
Anode Impedance | 1700 | - | Ω | |
Amplification factor | 8 | - | ||
Mutual Conductance | 4.7 | - | mA/V | |
Anode load Impedance | 5000 | 6000 | Ω | |
Peak AF Grid Voltage | 20 | 20 | V | |
Total Harmonic Distortion | 4.5 | 4.0 | % | |
Power Output | 1.3 | 1.1 | W |
The curves shown below display power output, harmonic distortion and input signal voltage for fixed bias and autobias.
Class 'A' Amplifier (Push-Pull)
Triode Connection (Pin 2 and top cap strapped) | |||||
Values are for 2 valves. |
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Anode Voltage | 250 | 250 | 325 | 325 | V |
Grid Voltage | -20 | - | -30 | - | V |
Autobias resistor | - | 250 | - | 375 | Ω |
Anode Current (no signal) | 80 | 80 | 80 | 80 | mA |
Output load Impedance |
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(anode to anode) 5000 | 5000 | 8000 | 8000 | Ω | |
Peak AF Grid Voltage | 40 | 40 | 60 | 60 | V |
Total Harmonic distortion | 0.35 | 0.4 | 0.7 | 0.6 | % |
Power Output | 3.5 | 3.1 | 5.75 | 6.0 | W |
The curves shown below display power output, harmonic distortion and input signal voltage for fixed bias and autobias of 250V HT and 325V HT.
Class 'A' Amplifier (Single Ended)
Tetrode Connection | ||||||
Anode Voltage | 250 | 250 | 350 | 500 | 500 | V |
Screen Voltage | 250 | 250 | 250 | 200 | 200 | V* |
Grid Voltage | -14 | - | -18 | -14.5 | - | V |
Autobias Resistor | - | 170 | - | - | 280 | Ω |
Anode Current | 72 | 75 | 54 | 50 | 50 | mA |
Screen Current | 5.0 | 5.4 | 2.5 | 1.6 | 1.6 | mA |
Anode Impedance | 22,500 | - | 33,000 | 38,500 | - | Ω |
Mutual Conductance | 6.0 | - | 5.2 | 5.7 | - | mA/V |
Anode load Impedance | 2500 | 2500 | 4200 | 6000 | 6000 | Ω |
Peak AF Grid Voltage | 14 | 16 | 18 | 14.5 | 15.5 | V |
Total Harmonic distortion | 10 | 10 | 15 | 11.6 | 13.6 | % |
Power Output | 6.5 | 6.5 | 10.8 | 11.5 | 11.0 | W |
* When the anode volts are greater than the screen volts, a potentiometer should be used between the HT and chassis bypassing to AF signals rather than a series resistor.
The curves shown below display power output, harmonic distortion and input signal voltage for 250V fixed bias and autobias.
Class 'A' Amplifier (Single Ended)
Values are for 2 valves
Tetrode Connection | ||||||||
Anode Voltage | 250 | 270 | 270 | 500 | 500 | 600 | 600 | V |
Screen Voltage | 250 | 270 | 270 | 300 | 300 | 300 | 300 | V |
Grid Voltage | -16 | -17.5 | - | -27 | - | -29.5 | - | V |
Autobias Resistor | - | - | 125 | - | 270 | - | 360 | Ω |
Peak AF Grid-Grid Voltage | 32 | 35 | 40 | 54 | 72 | 59 | 81 | V |
Anode current (no signal) | 120 | 134 | 134 | 100 | 100 | 80 | 80 | mA |
Anode current (max. signal) | 140 | 155 | 145 | 154 | 119 | 150 | 97 | mA |
Screen Current (no Signal) | 10 | 11 | 11 | 2.5 | 2.5 | 1.5 | 1.5 | mA |
Screen Current (max. Signal) | 16 | 17 | 17 | 20 | 16.5 | 17.5 | 17.5 | mA |
Output load Impedance |
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Anode to anode | 5000 | 5000 | 5000 | 8000 | 9000 | 10,000 | 10,000 | Ω |
Total Harmonic distortion | 2 | 2 | 4 | 2.6 | 2.7 | 2.2 | 4.1 | % |
Power Output | 14.5 | 17.5 | 18.5 | 38 | 32.5 | 47.5 | 36.5 | W |
The curves shown below display power output, harmonic distortion and input signal voltage for fixed bias and autobias.
Class 'ABI' Amplifier (Push-Pull)
Values are for 2 valves.
Triode Connection (Pin 2 and top cap strapped) | ||
Anode Voltage | 400 | V* |
Grid Voltage | -45 | V |
Anode Current (no signal) | 60 | mA |
Anode Current (max. signal) | 140 | mA |
Output load Impedance (anode to anode) | 3000 | Ω |
Peak AF Grid to Grid Voltage | 90 | V |
Total Harmonic distortion | 3 | % |
Power Output | 15 | W |
*If any variations are made it must be noted that the maximum ratings must not be exceeded.
The curves shown below display power output, distortion and input signal.
Class 'ABI' Amplifier (Push-Pull)
Values are for 2 valves.
Tetrode Connection | |||
Anode Voltage | 360 | 360 | V |
Screen Voltage | 270 | 270 | V |
Grid Voltage | -22.5 | - | V |
Autobias resistor | - | 250 | Ω |
Anode current (no signal) | 88 | 88 | mA |
Anode current (max. signal) | 138 | 100 | mA |
Screen Current (no Signal) | 5 | 5 | mA |
Screen Current (max. Signal) | 16 | 19 | mA |
Output load Impedance |
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Anode to anode | 6600 | 9000 | Ω |
Peak AF Grid to Grid Voltage | 45 | 57 | V |
Total Harmonic distortion | 1.8 | 4.0 | % |
Power Output | 26.5 | 24 | W |
The curves shown below display power output, distortion and input signal voltage.
Class 'AB2' Amplifier (Push-Pull)
Values are for 2 valves.
Tetrode Connections | ||||||
Maximum Ratings |
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Anode Voltage | 600 | V | ||||
Screen Voltage | 300 | V | ||||
Signal DC Anode Current | 120 | mA | ||||
Signal Anode Input Power | 60 | W | ||||
Signal Screen Input Power | 3.5 | W | ||||
Anode Dissipation | 25 | W | ||||
Typical Operating Conditions |
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Anode Voltage | 360 | 360 | 400 | 500 | 600 | V |
Screen Voltage | 225 | 270 | 300 | 300 | 300 | V |
Grid Voltage | -18 | -22.5 | -25 | -29 | -30 | V |
Anode current (no signal) | 78 | 88 | 90 | 72 | 60 | mA |
Anode current (max. signal) | 162 | 220 | 240 | 240 | 200 | mA |
Screen Current (no Signal) | 3.5 | 5 | 5 | 5 | 5 | mA |
Screen Current (max. Signal) | 21 | 35 | 23 | 22 | 21 | mA |
Output load Impedance |
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Anode to anode | 6000 | 3800 | 3200 | 4240 | 6400 | Ω |
Peak Grid to Grid Input Power | 190 | 400 | 200 | 200 | 100 | mW |
Total Harmonic distortion | 8 | 10 | 4 | 4.5 | 3.5 | % |
Power Output | 31 | 47 | 55 | 75 | 80 | W |
The Anode and screen voltages must be within 5% and constant and the grid bias at 3% between no signal and max. signal. The driver stage should be capable of supplying the grids of the 2 valves with the specified peak voltages with low distortion. The transformer or driver valve grid circuit should not have a greater resistance than 500Ω and the impedance or leakage inductance should not be greater than 700Ω.
The curves shown below display power output, distortion and input signal voltage.