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Parameters at operaing point
Ua =  [V] Ia =  [mA] Ug =  [V] Ri =  Ra =  [KΩ]
S =  [mA/V] µ [V/V] Pa = 
Harmonic distortion for Uinp =  
h2 =  [%] h3 =  [%] h4 =  [%] htot =  [%]
Single Stage Grounded Cathode Amplifier Parameters
SE Output Stage Parameters
SE Output Transformer Parameters
No. of tubes
(parallel connection)
Iamax Uamax Ugmin Ugmax
[mA] [V] [V] [V]
Lower frequency
limit FL
distortion ML
Upper frequency
limit FH
distortion MH
[Hz] [dB] [Hz] [dB]
impedance RL
Screen voltage
Us (pentodes)
[Ω] [V]
Symbol Description
Ua Anode voltage at operating point.
Ia Anode current at operating point.
Ug Bias voltage (grid voltage) at operating point.
Ri Plate (internal) resistance at operating point.
Ra Plate load resistance.
S Transconductance calculated at operating point.
µ Amplification factor of a tube at operating point.
Pa Anode power dissipation at operating point.
Is Screen grid current (tetrodes and pentodes).
Ps Screen grid power dissiparion at operating point.
Rk Cathode resistor.
Prk Power dissipation of cathode resistor.
G(rk) Gain of a single stage amplifier with cathode resistor.
G(rk=0) Gain of a single stage amplifier without or bypassed cathode resistor.
ML Lower frequency distortion at frequency FL
MH Higher frequency distortion at frequency FH
Pout(t) Power dissipated in the anode circuit of SE amplifier
Pout Output power (SE) - Pout(t) corrected by transformer efficiency
η Output transformer efficiency (usually in the range from 0.8 to 0.9)
L1min Minimum inductance of the primary winding of output transformer
L1smax Maximum leakage inductance of the primary winding of output transformer
N Output transformer windings ratio (ω21)
Additional Information
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