Search found 1221 matches

by John Futter
Wed May 13, 2020 7:11 pm
Forum: Vacuum Technology (& FAQs)
Topic: Foreline valve and trap - what is neccesary?
Replies: 13
Views: 652

Re: Foreline valve and trap - what is neccesary?

Putting a much longer hose on the forline will slow pumping speed dramatically not putting a valve on the roughing pump outlet risks oil suck back into turbo -- it is very difficult to remove all the oil from a turbo that has suffed suckback - this usually requires a factory turbo rebuild especially...
by John Futter
Wed May 13, 2020 7:04 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Vacuum Chamber Construction
Replies: 82
Views: 27148

Re: Vacuum Chamber Construction

Take it to a tool making house that has a spark eroder my local one charged $25 per bolt removal and they did such a good job that putting a tap back down the hole removed no material and the correct bolts worked fine mixup between 5/16 and 8mm bolts you now need to buy a tub of no sieze grease i pr...
by John Futter
Sat May 09, 2020 11:28 pm
Forum: Images du Jour
Topic: Neutron Club Application - Nathan Marshall
Replies: 7
Views: 447

Re: Neutron Club Application - Nathan Marshall

Excellent Report Nathan
I'm sure Richard will annoint you shortly
by John Futter
Sat May 09, 2020 8:07 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Preamplifier and P/Z troubles
Replies: 6
Views: 405

Re: Preamplifier and P/Z troubles

Christoffer This is a common problem you need to look up DC restoration circuits for Video video signals suffered from this without restoration due to the large negative excursions of the line and frame sync pulses. then the peak black was reduced by the time taken for the video signal dc level to r...
by John Futter
Fri May 08, 2020 12:38 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Xray high voltage multiplier
Replies: 17
Views: 906

Re: Xray high voltage multiplier

Sarmad All the clues are there now calculate how much current you will have at the output if you use 50 or 60 Hz 220 volts clue =capacitor value of 1000pf for 50 /60 hz work I would expect 1,000,000pf or more per capacitor you can try putting in your component values in to here http://www.blazelabs....
by John Futter
Thu May 07, 2020 7:17 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Xray high voltage multiplier
Replies: 17
Views: 906

Re: Xray high voltage multiplier

Sarmad
I think you will find that you have high frequency unit there
Designed to be driven at 30 -70 kHz
the three wires are likely to be for half bridge drive
by John Futter
Tue May 05, 2020 7:20 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Help with HV adjustable power supplies for radiation detectors.
Replies: 22
Views: 1836

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

Rex
I'll try
I'm in lockdown still but there are people at work who know what we bought i'll see
by John Futter
Tue May 05, 2020 7:31 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Help with HV adjustable power supplies for radiation detectors.
Replies: 22
Views: 1836

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

yes I was talking about reputable supplies not aliexpress or banggood both of the later sell knockoffs that generally take their specs from the original but the product is nowhere near the original this also appies to components like gate driver ics mosfets, IGBTs, RF transistors, ZVS driver boards,...
by John Futter
Tue May 05, 2020 7:24 am
Forum: Images du Jour
Topic: GE dental x-ray heads?
Replies: 5
Views: 736

Re: GE dental x-ray heads?

Rich
glazing of the copper is common for something not used for years. I've seen the same on brush excited gen sets.
i use the 3M green scouring pad with a little water with 30% detergent. wash afterwards with alchohol and dry with hot air gun

bet it works after this