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833A model

Posted: Thu Mar 31, 2011 1:43 pm
by jarek
Ok, that's serious---does anybody have a spice model for 833A,
correctly reproducing both A1 and A2 curves?
Thanks!
jk

Posted: Thu Apr 07, 2011 6:02 pm
by sbench
I'll add one into the triode_nh.txt "drop down" files. It models anode and grid currents reasonably well. I'll attach a .PDF to this reply that gives the differences between the tube data and what I was able to achieve.

Stephie <3

Posted: Sat Apr 09, 2011 3:56 am
by jarek
Stephie, thank you very much! I think I want to kill myself in a spectacular way with 833 :S

Posted: Sat Apr 09, 2011 5:02 pm
by sbench
833A is a spectacular device with which to perform that operation. :D

Only certain of the devices in the "library" support A2 (811, 801 come to mind) in a realiatic way, although I've added some level of grid current support to most models (but not all). Most of those, except for ones that I've explicitly "worked on" (e.g., the 833A), support grid current only as a constant "on" resistance in A2 region. That allows you to see "clipping" but it is not accurate in terms of required drive. The 833 came out relatively well.

The "RF" tubes, 801A, 811A, 813, 833, 6146 and a few others are accurate in A2 (and in Class B, and Class C RF).

Somewhere in my queue of projects is a "retro" ham transmitter for 160, 80, and 40 for CW and AM. 3 6146 in the final RF, and 2x6146 modulators. At my current availability of time, I should get to that in the next couple centuries.

Stephie <3