6AG5 pentode

Here is a nice sharp cut-off RF pentode with low capacitance, high gm and nice curves: 6AG5.

Also the triode curves are interesting with a mu of about 50:

I spent a bit of time this morning developing a pentode model:

There is a bit of saturation above 16mA hence the gap between curves. However, this isn’t important as the valve won’t be used near this area.

Spice models

Pentode:

Triode:

This valve was recommended to me by my friend Nick W. He has used it with great results as a driver to a local feedback output DHT stage. Perfect candidate which I will put in use at some point.

Hope these curves and the models are useful to you.