Selfrunning cold electricity circuit from Dr.Stiffler

[DrStiffler]

@ALL

MPSA06, the most valued transistor in the world, soon to go the way of Barium Magnets.

In SEC Exciter circuits one should watch the hfe of the transistor(s). For example SEC PCBs are shipped with a transistor with an hfe <255 (currently). The transistors if used with the parasitic plate WILL degrade. The hfe will decrease. Typical 255 will drop to 100-120 after 10 hours of use at 36vdc (parasitic plate units).

So, install a socket and check the hfe often, it will change.

[Loki67671]

@ALL

MPSA06, the most valued transistor in the world, soon to go the way of Barium Magnets.

In SEC Exciter circuits one should watch the hfe of the transistor(s). For example SEC PCBs are shipped with a transistor with an hfe <255 (currently). The transistors if used with the parasitic plate WILL degrade. The hfe will decrease. Typical 255 will drop to 100-120 after 10 hours of use at 36vdc (parasitic plate units).

So, install a socket and check the hfe often, it will change.

@Dr. Stiffler,
Yes indeed, I saw it already with this exercise and one of my SEC3's now that you mention it. I'll bet the VLT's are beat too! Today I ran a board all day inside of a cardboard ring with the SS vessel and 500ml of distilled water sitting on top of it. Even without insulating wrap in the basement here there is a clearly a significant visible increase in water temperature. I also found some other interesting items like the effectiveness of star topology grounding. I'm gaining much confidence in these upcoming calibration and heat runs. It appears that there is plenty to spare after today.  I'm kind of surprised but pleased at the same time. No insulation at all in this basement?  My input voltage is rock solid and clearly there is a downward trend in the input power. Tuning changes, degrading transistor, degrading neon and etc. That transistor downstairs right now has about 16 to 18 hours of run with the parasitic plate. It won't start a neon without tuning way down into heavy ion flow so it will retire ASAP. 

Capacitors in series divide as the reciprocal of sum of reciprocals so the more we add the lower the capacitance goes. Removing the leads from 4148's and board mounting will reduce and basically fix the inductance value to a very low value also. Self resonant frequency is higher due to decreasing capacitive reactance. Ooooo?  Can I explore the pipe organ in this way? We will run into construction limitations as we go higher and higher in frequency but what about clusters of devices sharing the same parasitic with loads tuned in this manner? Constructed in such a way as to minimize or better yet utilize interelectrode reactances? Hmmmm. 

Interesting and Fun Sunday indeed!

Best regards,

Jim 

[forest]

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DrStiffler

[storre]

@stiffler, Loki67671: Thanks for the recommended equipment list! I'm waiting for my boards to arrive and can't wait to dig in!

[DrStiffler]

@All
Well we have less than (10) sec boards left and they can be configured either 3's or 20's and I need some vacuum tubes so am offering to trade a board for tubes (in working condition, high trans conduction).

The list of tubes I need is;
2) OD3
1) OB2
1) 5517
1) 5U4
1) 6AU5
2) 6V6
2) 12BH7
1) 12AU7
3) 12AX7

If you have any or all these and would like a sec3 or 20 send me an emal and we will work out the details. Send to stifflerscientific@embarqmail.com

Thanks