I wrote:
"When switched-off, voltage drop across the tube is Eb"

Owen Duffy wrote:
"That is wrong."

Yes as a general statement, that is wrong. The instantaneous drop across
the tube is the sum of Eb and EL, the signal voltage across the load.

Terman shows this in Fig. 13-1(b) on page 449 of his 1955 opus.

Fig. 13-1(e) shows the plate current pulse which is less than 180
degrees in duration as the tube is biased beyond cut-off.

My switch analogy is imperfect but good enough to exemplify
dissipationless resistance as a part of the output impedance of a Class
C amplifier.

Best regards, Richard Harrison, KB5WZI