Tuesday, August 3, 2010

further ado about nothing

Hmph. This evening I reassembled my high vacuum system and not terribly surprisingly, I still have a gross leak... according to the gauges built into the system... the system I bought at an auction for $20... the system which I and a good friend have systematically rebuilt from the ground up... with the exception of the gauge electronics.

Well, I've got the roughing pump running at least. VERY rough. If I could believe the panel gauges (and I cannot) the pressure is bottoming out at just over 100 millibar.

The reason I've revisited the vacuum system so soon is that I have constructed a device (ye gods how I love that phrase) which I wish to encapsulate in epoxy. (it's another special effect for the Mad Science Light Switch)

To do encapsulation properly (ie; without voids) one needs a reasonable vacuum pump. I now have a reasonable vacuum pump again, although I do wish its vacuum were a bit MORE than reasonable. I'll need a few more bits of plumbing to connect the plasma cleaning chamber I'm going to use for this to the vacuum cart, but I ought to be able to get it done during the next week or two.

The hilarious part - to me - is that the electronics in the "trusted" gauge controller are so old, I will have to apply power to them gently -- slowly increasing the voltage from zero, using a variable transformer -- over the period of, say, an hour. This old-timer's trick may preserve the old high voltage filter capacitors inside which need to be "re-formed" after having sat idle for many years. It would be -- unpleasant -- should one of them fail within the chassis. Ick.

I do love old tube equipment though. Using it in the winter saves on heat. And fire bottles have such a cheerful glow.

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