VCO (expo) Bake Off test results

[harry bissell]

Hope you have been following this thread:

Here's the latest chart

1: Unheated 3046
2: Heated 3046 / no regulation  (VCO4d option - see TomG site)
3: AN-299 3046 Servo  (harry bissell version...)
4: LM 399 / 2N3250  (TO-18 can)
5: LM 399 / 2N3053 (TO-5 can)

The LM 399 have the thermal shield removed, and they are crazy-glued can
to can to the top of 2Nxxxx transistors. Then wrapped in a hollow
packing peanut styrofoam.  Current is 200mA inrush, 23mA at steady state
@ 23 Celsius

These trannys chosen for metal case mounting... NOT for electrical
merit...
2N3250 has substrate mounted to the can TOP and epoxy backfilled, so
thermal coupling might be better than TO-5
2N3053 has hermetic can, with substrate mounted to header (bottom) so
thermal coupling is less ????

The intent is to see if the LM 399 (using the servo heater on board as
an external heater for the tranny) has merit...

Looks to me like it is promising... maybe as good as the 3046 Servo.

This is also available in a TO-92 pkg. as the LM3999... maybe this could
be glued to the 2SC1583 dual ????  I'll have to try it... when I can
find a 2SC1583 in the USA...

I intend to test this with the MAT-01 and -02 in a couple of weeks...
(going to hell...I mean Chicago next week...)

The surface mount MAT-04 might work too, with the LM 399 mounted upside
down over it...

enjoy !!!  :^) Harry
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