Search found 380 matches

by ian_krase
Wed Jan 17, 2018 8:29 am
Forum: Images du Jour
Topic: My Attempt at a DIY Ionization Gauge
Replies: 1
Views: 122

Re: My Attempt at a DIY Ionization Gauge

It works! Collector at ground, grid at about +28V, filament biased to between +2V and +5V to prevent electrons from hitting the collector. The exact filament bias voltage needs to be adjusted to zero the gauge. Filament emission current is about 70 microamperes. Collector current is read out on the ...
by ian_krase
Wed Jan 17, 2018 7:52 am
Forum: The Trading Post
Topic: Does anybody want 40kv wire?
Replies: 2
Views: 91

Re: Does anybody want 40kv wire?

Not certain, would need to check. Approximately 18 AWG with insulation that brings the OD to about 9mm. Pretty flexible.
by ian_krase
Sat Jan 13, 2018 3:11 am
Forum: The Trading Post
Topic: Vacuum Throttle Valve
Replies: 9
Views: 250

Re: Vacuum Throttle Valve

Conflat is normally measured by the OD of the flange in inches.
by ian_krase
Thu Jan 11, 2018 3:11 am
Forum: The Trading Post
Topic: Does anybody want 40kv wire?
Replies: 2
Views: 91

Does anybody want 40kv wire?

I have a source of 40kv insulated wire. Can sell 10 foot sections for $15 plus postage.
by ian_krase
Wed Jan 10, 2018 8:56 pm
Forum: Vacuum Technology (& FAQs)
Topic: cheap solenoid valve
Replies: 3
Views: 127

Re: cheap solenoid valve

Almost certainly requires high pressure in one direction to make the valve open. Not really useful for vacuum.
by ian_krase
Tue Jan 09, 2018 7:12 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: A Bunch of Failures
Replies: 46
Views: 1129

Re: A Bunch of Failures

There is one difference: Pfeiffer pumps use moderately higher viscosity oil. I doubt it matters.
by ian_krase
Mon Jan 08, 2018 9:05 am
Forum: New User Chat Area
Topic: A Quick Question
Replies: 2
Views: 110

Re: A Quick Question

Definitely.

Alternatively you can use Torr Seal (aka Hysol 1C) which is good to at least 10E-5.
by ian_krase
Sun Jan 07, 2018 11:35 am
Forum: Vacuum Technology (& FAQs)
Topic: Severe Outgassing Problems
Replies: 7
Views: 207

Re: Severe Outgassing Problems

Note that methanol is rather toxic, so some people avoid using it altogether. When baking out, one problem is that evaporated vapor can then condense or adsorb onto a chamber wall that is at a lower temperature... where it can then outgas from.This is part of the reason for popularity of heating tap...
by ian_krase
Sat Jan 06, 2018 9:11 am
Forum: Interesting Links
Topic: Identifying coax connections etc
Replies: 3
Views: 137

Re: Identifying coax connections etc

Don't forget the Spellman PL259 with long banana-tipped coax extension.
by ian_krase
Thu Jan 04, 2018 8:15 pm
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Electrometers and Picoammeters
Replies: 14
Views: 395

Re: Electrometers and Picoammeters

There definitely are plenty of Electrometer grade opamps. I was asking how you get that invulnerabile vacuum tube goodness.