RadioBanter - View Single Post - any spice models for 1S5 or other battery tubes?

June 9th 04, 12:30 AM

In article ,
(The Eternal Squire) writes:

The subject says it all. Anyone simulating RF rather than audio tubes
for 45-65 Volt B+?

thanks in advance

I've simulated a few tubes just by making a dependent constant-
current source for the plate plus a fixed resistor for the plate
resistance in parallel to it. The dependent constant-current
source would be referred to the voltage across a resistance
or other component (see the particular SPICE program). That
assumes linear amplification in the tube.

If there's a real need of simulating full plate characteristics, you
would have to get a SPICE package that lets you describe the
plate characteristics as an equation and then plug that equation
into the net list. Not at all easy and you would need old tube
datasheets.

Those same old tube datasheets would yield gm and rp for a
particular supply voltage and that can be used for small-signal
amplification in pencil-and-paper plus calculator "analysis."
Figure the rp as a fixed resistance with the RF plate load and
the gm as the constant current across that entire RF load.
Voltage amplification is then the product of gm times RF load.