13e1

[vega65]

I am working on a 13E1 project.
The datasheet does not give:

µ for tetrode connection
ra for tetrode connection
gm for tetrode connection

As I would like to test 13E1 connected as recommended by O H Shade et al, It would be great if anyone has the "missing data"

[kenpeter]

Addition of the screen deliberately breaks the intrinsic negative
feedback of the simple Triode. Therefore, there is no meaningful
"Mu" for a Tetrode when strapped as such. You could calculate
from Gm and Rp at any given point. But it isn't something that
gives the same result at all points as it does with a Triode.

For a Schaded Tetrode, Mu is computed externally. A weighted
sample of the plate swing is fed back to the grid. The ratio of
resistors and/or transfomers involved set the limit for Mu.

Actual Schaded Mu is always somewhat less than the ratio of
external feedback, as the gain of the tetrode itself is finite.

It is a "connect the dots" game between a Tetrode's imperfect
curves and the voltage fed back that gives the set of curves
which once again resemble a Triode.

The broken Triode is repaired! And we gain a screen to help
boost the electrons along. Best of both worlds.

[vega65]

A norwegian enthusiast I spoke with told me that mu is about 220 and rp ca 10k6 tetrode connected .according to shade it should result in a mu ca 9.5 if 10 % feedback . Still missing gm tetrode