Search found 336 matches

by Rex Allers
Tue May 05, 2020 8:19 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Help with HV adjustable power supplies for radiation detectors.
Replies: 38
Views: 9151

Re: Help with HV adjustable power supplies for radiation detectors.

John,

Any chance you could find and share a link (Mouser or etc.) to the kind of supply you are talking about?

Or details of the manufacturer/model.
by Rex Allers
Tue May 05, 2020 7:53 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Ludlum model 3 issues
Replies: 12
Views: 2747

Re: Ludlum model 3 issues

Richard, not sure your easy answer is correct. I've never had a Ludlum Model 3 so have zero direct knowledge but here's a version of that pic that I modified. Lud3 pic.jpg So I added two outlines of possible connections on the board, one is orange, one is green. You propose an inline set of connecti...
by Rex Allers
Thu Apr 23, 2020 7:59 am
Forum: Items wanted
Topic: Edwards TAG controller
Replies: 6
Views: 2462

Re: Edwards TAG controller

I'm not an expert but I did a little looking at documents and your original post doesn't make sense to me. The EXDC doesn't seem to be a turbo pump but rather a control module that attaches directly to one of several ETX... turbo pumps. If you have an EXDC mounted on the side of an ETX turbo, it loo...
by Rex Allers
Sun Apr 19, 2020 7:41 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Solderless Grid Design with Shaft Coupler
Replies: 8
Views: 2473

Re: Solderless Grid Design with Shaft Coupler

Your work on this grid is really good, I congratulate you. I'm thinking, though, that you seem to have a small cylindrical chamber. Maybe a cylindrical grid like one of Doug Coulter's designs might be appropriate to also try. Here's one I made. grid example.jpg Needs a lathe to make, though. End pie...
by Rex Allers
Sun Mar 22, 2020 8:31 am
Forum: Philo T Farnsworth Archive
Topic: Finding The Trailhead
Replies: 4
Views: 2300

Re: Finding The Trailhead

Thanks Richard. Excellent and informed details, as usual.
by Rex Allers
Sun Mar 22, 2020 4:44 am
Forum: Philo T Farnsworth Archive
Topic: Finding The Trailhead
Replies: 4
Views: 2300

Re: Finding The Trailhead

Richard,
Your post starts with PTFA and continues to use that (acronym?). In this thread I have not found a definition.

From context it seems to be some organization or group. For the record here, what exactly is PTFA?
by Rex Allers
Wed Mar 18, 2020 12:26 am
Forum: Images du Jour
Topic: Reverse engineering a big old smoke detector
Replies: 9
Views: 3108

Re: Reverse engineering a big old smoke detector

Ah, I'm with you now. It hadn't registered with me that you had an F5B and it was a different design.

The pics you shared are great, especially with the blue glow of where the alpha is.

Thanks for sharing that.
by Rex Allers
Tue Mar 17, 2020 8:55 pm
Forum: Images du Jour
Topic: Reverse engineering a big old smoke detector
Replies: 9
Views: 3108

Re: Reverse engineering a big old smoke detector

A bit of follow-up. I connected with Geo and he hasn't actually had any direct experience with these old smoke detectors. So I guess what I got from him was second hand. On Prutchi's page that I shared a link to, he did have some reference in a link near the end of his page but that site is now gone...
by Rex Allers
Tue Mar 17, 2020 10:10 am
Forum: Vacuum Technology (& FAQs)
Topic: Beware of shipping costs!!
Replies: 8
Views: 2287

Re: Beware of shipping costs!!

Yes, LDS has lots of vacuum parts and their prices are good...
but their shipping has always been pretty high.

Not sure if shipping is part of their profit structure. If not, they should look into better options.
by Rex Allers
Mon Mar 16, 2020 5:33 am
Forum: Images du Jour
Topic: Reverse engineering a big old smoke detector
Replies: 9
Views: 3108

Re: Reverse engineering a big old smoke detector

David Prutchi, who has created and shared on the internet and in a book, many physics experiments with custom built apparatus, was the source where I learned about these old smoke detectors. I thought the page he made might have been taken down but seems not. Here it is: http://www.diyphysics.com/20...