Search found 294 matches

by Roberto Ferrari
Sun Apr 15, 2018 3:55 pm
Forum: The Trading Post
Topic: Old-Fashioned Vacuum Tube Factory closing down -- may be interesting?
Replies: 1
Views: 308

Re: Old-Fashioned Vacuum Tube Factory closing down -- may be interesting?

Ian Thanks for posting! I had the privilege to meet Mr Harold Ulmer, who started that facility. He gave me a memorable tour and a present: a microfocus X-ray tube. He was a scientific glassblower in Stanford at war time and later he decided to enter in the electron tube business when it was down. He...
by Roberto Ferrari
Fri Mar 09, 2018 12:05 pm
Forum: New User Chat Area
Topic: Use of Swagelok needle valves
Replies: 23
Views: 1047

Re: Use of Swagelok needle valves

I have a similar one but failed to make it leak-free.

Opened, shows two metal surfaces, no seal...
by Roberto Ferrari
Sat Jan 27, 2018 10:24 pm
Forum: Announcements and Site Administration Topics
Topic: PMs stalled
Replies: 4
Views: 383

Re: PMs stalled

Hi Frank
Understood...
Thanks!
Roberto
by Roberto Ferrari
Fri Jan 26, 2018 9:55 pm
Forum: Announcements and Site Administration Topics
Topic: PMs stalled
Replies: 4
Views: 383

Re: PMs stalled

Hi Bruce,

Thanks!

Roberto
by Roberto Ferrari
Fri Jan 26, 2018 6:35 pm
Forum: Announcements and Site Administration Topics
Topic: PMs stalled
Replies: 4
Views: 383

PMs stalled

Hi
For some reason my PMs doesn't come out of the Outbox.
I would appreciate any help!
Thanks,
Roberto
by Roberto Ferrari
Thu Jan 25, 2018 11:49 am
Forum: Images du Jour
Topic: News from Argentina
Replies: 13
Views: 757

Re: News from Argentina

Finn and Dennis,
Thanks for your advice.
We are getting a loaned capacitance manometer 1 torr FS.
As soon as installed, we will report results.
by Roberto Ferrari
Tue Jan 23, 2018 8:22 pm
Forum: Images du Jour
Topic: News from Argentina
Replies: 13
Views: 757

Re: News from Argentina

Hi Finn Thanks for bringing that issue. You are right. We already had those Baratrons for other purposes. Now on eBay seems to be a restriction for exporting those devices, so we feel unsafe buying one and sending to our country. With regard to high vacuum readings we already have a Bayard-Alpert ga...
by Roberto Ferrari
Tue Jan 23, 2018 12:25 pm
Forum: Images du Jour
Topic: News from Argentina
Replies: 13
Views: 757

Re: News from Argentina

Hi Dennis,
Following Mr. Rosenstiel’s suggestion, our water resistor will be a plastic tube with water and a little of copper sulphate.
Yes, the maximum rated voltage for our HV feedthrough is 30 kV.
by Roberto Ferrari
Tue Jan 23, 2018 12:44 am
Forum: Images du Jour
Topic: News from Argentina
Replies: 13
Views: 757

Re: News from Argentina

Jerry: Thanks, good to know that. Dennis: We have an almost complete X-ray equipment. Xformer is under oil, silicon diodes also. We plan to run on the negative half only, with a variac for 220 V (our mains voltage) 20A. As ballast resistor we plan to use a water one, avoiding to open the xformer con...
by Roberto Ferrari
Mon Jan 22, 2018 10:43 pm
Forum: Images du Jour
Topic: News from Argentina
Replies: 13
Views: 757

Re: News from Argentina

Hi Dennis, Thanks for your comments. We have an old pancake Ludlum Model 2. Also assembling a gamma spectrometer but at slow pace. About HVPS we will try first with a low power one, as Mr. Rapp did. He succeded activating silver. And working in modifying an old X-ray equipment, 100 kV 100 mA. Lead s...