Search found 320 matches

by Rex Allers
Fri May 08, 2020 12:05 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Ludlum model 3 issues
Replies: 12
Views: 1998

Re: Ludlum model 3 issues

Did you find something that made it start working? Does it go beyond 750 V?
by Rex Allers
Thu May 07, 2020 2:10 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Ludlum model 3 issues
Replies: 12
Views: 1998

Re: Ludlum model 3 issues

Sarmad, I spent a bit of time today trying to understand the Model 3 circuits. It seems that the Mod 3 manual on the Ludlum page I linked earlier has schematics and board layouts that don't match yours. I assume the doc is for a newer version. One significant difference is the shape of the board tha...
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: 6992

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: 1998

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: 1585

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: 1967

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: 1459

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: 1459

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: 2385

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: 2385

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...