Search found 487 matches

by ian_krase
Thu Sep 27, 2018 5:32 am
Forum: New User Chat Area
Topic: Would a heated Barium oxide filament survive in a deuterium environment?
Replies: 4
Views: 509

Re: Would a heated Barium oxide filament survive in a deuterium environment?

I would worry more about residual air every time you go to to air. Barium is mostly used in vacuum tubes that are never ever vented. A better idea might be yttrium as used in ion gauges - or just bare tungsten, it works and is vastly simpler. I'm curious at this choice of ion gun - it's my impressio...
by ian_krase
Tue Sep 11, 2018 7:46 pm
Forum: Images du Jour
Topic: My first plasma
Replies: 12
Views: 2229

Re: My first plasma

One thing that might be tried is to have separate beam blocks and structural vacuum chamber. The former can be made of cheap thin glass.
by ian_krase
Sun Sep 09, 2018 8:12 am
Forum: Images du Jour
Topic: Sharing hamfest booty images
Replies: 27
Views: 6622

Re: Sharing hamfest booty images

Nice valve! I paid more like 30 for mine!
by ian_krase
Sun Sep 09, 2018 4:07 am
Forum: Images du Jour
Topic: My first plasma
Replies: 12
Views: 2229

Re: My first plasma

Not sure what you mean by an "arc from the grid to the glass" -- may need better pictures.

Your glass looks too clear for sputtering to be a big problem. Is there a hot spot?
by ian_krase
Thu Sep 06, 2018 2:38 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Capacitor blasts and automatic impedance matching
Replies: 1
Views: 444

Capacitor blasts and automatic impedance matching

I am sort of curious whether there's any practical circuit that automatically does some form of impedance matching on capacitor discharges -- can crushers, spot welders, flashlamp flashers, etc.
by ian_krase
Thu Aug 30, 2018 5:30 am
Forum: Vacuum Technology (& FAQs)
Topic: convectron 275 tube and controller
Replies: 9
Views: 1685

Re: convectron 275 tube and controller

Edge 10L -> Shield -> 1 -> Null Whiteblack Edge 11 -> Lowp -> 3 -> Tub 3 Redblack Edg 12 13 -> HighP -> 4 - > Tub1 Red Edge 14 -> Comp -> 8 -> Tub2 Greenblack Edge 15 -> Sense -> 9 -> Tub5 Green Here is the wiring table from my own attempt. The same for both analog and digital gauge controllers. The...
by ian_krase
Sun Aug 26, 2018 4:48 am
Forum: Vacuum Technology (& FAQs)
Topic: convectron 275 tube and controller
Replies: 9
Views: 1685

Re: convectron 275 tube and controller

Oh, also, if these are the controllers with the big .156 pitch edge connector on the back:


Two of the pins on this edge connector need to be connected for the controller to work.
by ian_krase
Fri Aug 24, 2018 8:04 pm
Forum: Vacuum Technology (& FAQs)
Topic: convectron 275 tube and controller
Replies: 9
Views: 1685

Re: convectron 275 tube and controller

Duniway Stockroom sells the connector but it's not in their catalog, yo need to ask for it.
by ian_krase
Mon Aug 20, 2018 12:31 am
Forum: Vacuum Technology (& FAQs)
Topic: Debugging an Inficon PKR 251 Series Gauge
Replies: 3
Views: 779

Re: Debugging an Inficon PKR 251 Series Gauge

Rotary vane pumps definitely get quiet when the pressure and gas load are small, but it's not terribly sensitive.
by ian_krase
Wed Aug 15, 2018 9:29 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: DIY hermetic feedthroughs: Has anybody done this?
Replies: 5
Views: 1219

DIY hermetic feedthroughs: Has anybody done this?

DIY feedthroughs are fairly common in Fusorland because you can make them with rubber or sometimes vacuum-epoxy seals. In the days of John Strong, wax seals were also used. However, the kinds of feedthroughs you can buy, the really hermetically sealed ones, are always either glass to metal sealed or...