Search found 719 matches

by Jerry Biehler
Tue Oct 15, 2019 5:14 am
Forum: Vacuum Technology (& FAQs)
Topic: First ever Turbo experience
Replies: 16
Views: 540

Re: First ever Turbo experience

I think I fried bearings on a varian pump by running it without cooling and it was connected to a SEM, so no gas load. So watch it, I would at least put a muffin fan on it like in the manual.
by Jerry Biehler
Mon Oct 14, 2019 6:58 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Possible Sputter Conductivity Issues
Replies: 7
Views: 239

Re: Possible Sputter Conductivity Issues

On deposition system all the power feedthroughs are covered with a cap that kind of looks like a copper pipe end cap with a hole in the center. The conductor passes though and the concave side covers a portion of the insulator. This creates a "shadow" and prevents material from coating the insulator...
by Jerry Biehler
Thu Oct 10, 2019 12:37 am
Forum: Vacuum Technology (& FAQs)
Topic: First ever Turbo experience
Replies: 16
Views: 540

Re: First ever Turbo experience

Manual is here, its kind of awful, I use a similar vintage pump in my SEM. https://fusor.net/board/viewtopic.php?t=8021 Pumping unit turns on a relay that can control the fore pump and the turbo I believe. Heater is for baking out, rarely used. First thing I would do is change the oil, it uses the s...
by Jerry Biehler
Wed Sep 25, 2019 12:11 am
Forum: Vacuum Technology (& FAQs)
Topic: TurboVac 50 troubleshooting
Replies: 8
Views: 428

Re: TurboVac 50 troubleshooting

Im betting you dont have as low foreline pressure as you thing you do. The nt-50 will light fail if the drive does not see fast enough acceleration and that is usually from too high of pressure.
by Jerry Biehler
Sun Sep 08, 2019 12:43 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Photography of Plasma and Glow Discharge
Replies: 5
Views: 381

Re: Photography of Plasma and Glow Discharge

Get a chunk of leaded glass if you are having x-ray problems. For you and the camera.
by Jerry Biehler
Sun Sep 08, 2019 12:41 am
Forum: Vacuum Technology (& FAQs)
Topic: Turbopump Bearing Kits - anybody have experience?
Replies: 3
Views: 466

Re: Turbopump Bearing Kits - anybody have experience?

I replaced one in a large 1000l/s pfeiffer, pretty easy. I found a company that made Steel/SiC bearings and selected one the right size. The only difference was the plastic keeper for the balls was different but I was able to transfer from the old to the new. Alpine Bearing makes a lit of bearing ki...
by Jerry Biehler
Thu Sep 05, 2019 6:34 am
Forum: Vacuum Technology (& FAQs)
Topic: Turbomolecular pump troubleshooting (EXT255H with EXDC80)
Replies: 44
Views: 2881

Re: Turbomolecular pump troubleshooting (EXT255H with EXDC80)

How much is it heating up? Its going to heat up some what just dropping the 80v to the logic levels a lot of the circuitry runs at. But generally speaking, something is wrong. I would put a scope across your power supply and see if you see a power sag when the turbo tries to start up. I have had an ...
by Jerry Biehler
Wed Sep 04, 2019 4:06 am
Forum: Vacuum Technology (& FAQs)
Topic: Turbomolecular pump troubleshooting (EXT255H with EXDC80)
Replies: 44
Views: 2881

Re: Turbomolecular pump troubleshooting (EXT255H with EXDC80)

Sounds dead to me. But make sure your switch is connected to ground and not 24v. It pulls the start switch low to start.
by Jerry Biehler
Fri Aug 09, 2019 7:21 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Reforming capacitors in consumer electronics?
Replies: 5
Views: 1323

Re: Reforming capacitors in consumer electronics?

About the only thing I have worried about reforming is my big yag laser welder. It sat for about 15 years before I powered it up. To reform the caps on that I used a 300v power supply and charged the bank up over a period. Seemed to work fine, nothing blew up when I connected it to mains. Im not sur...
by Jerry Biehler
Fri Aug 09, 2019 7:10 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Interest in RGAs (possibly a candidate for an FAQ?)
Replies: 18
Views: 3463

Re: Interest in RGAs (possibly a candidate for an FAQ?)

The preamp and amp circuits for the faraday cup designs are out there. I have the schematics for the quadrex RGAs, should be easy enough to copy. But I still would never want to build a RGA. I have other things I would rather be not doing. lol Yeah, we were looking at possibly just recoating the cha...