Need help running LTSpice model of an Avalanche Pulse Generator

[Tectonic]

I'm trying to run an LTSpice model of the Avalanche Pulse Generator detailed on page 93 of Linear Technology's AN47.

This is the circuit found in the application note:

This is my LTSpice design:

The voltage ramps up to 90V just like it's supposed to but the output does not act as described in the application notes. First it oscillates at about 19kHz from 0V to 210nV for about 20ms. After this it drops to 0V for 115ms, and then rapidly pulses for 1 ms between -100nV and 640nV.

Any ideas on how to fix this circuit so that it pulses to 10V instead of 640nV?

 

[dick_freebird]

You need a BJT model that acts realistic under breakdown
conditions, which is roughly none of the older ones. Or add
a C-B zener and parameterize it roughly right.

Notes say "Q1 may require selection to get avalanche
behavior..." and notes a 82% yield of suitable devices in
a blind sample, back in the day, and that manufacturers
do not tend to guarantee or rate for this.

 

[Tectonic]

I suppose the 2N2369 model included in LTSpice doesn't work then. Are there spice models of Avalanche transistors which are known to work properly? My google-fu isn't turning up anything terribly useful.