Fusor Forums

I believe you should split the electromagnetic, half around the top and half around the bottom. This should change the magnetic circuit potential in the support arms to zero opposite the air gap, the reduced coil diameter requires less wire so you will get more amp turns from your spool. My fading m...

Using Andrews connector autopsy as a starting point I printed a Claymount style HV connector in PLA. It’s a work in progress but basically you cast silicone between a PLA shell and the HV cable to eliminate any air voids between the cable and the shell. The HV connector plug has a 0.5degree taper so...

Try disconnecting the HV tube bias supply and cap or short the connection.

Looking for EMI is a witch hunt and your coupling could be M or E field or simply conducted. If it were me I would float the preamp with a 9V battery and only connect the scope to begin the hunt. If I could float the scope on batteries I would and also position it on a plastic shelf. Then start intr...

I would recommend a full pressure range inverted magnetron like an MPG401. This gauge is re branded and sold by several vacuum outfits, I do not know who the original manufacturer is, no markings on the internal circuit boards provide a hint. I got my Inficon MPG401 some time ago for $100 and it was...

Finn I tested the same tube without any moderator (at sea level) some time ago and decided on proportional operation by using a 1000 volt tube bias. One drawback you can see in the scope capture is that the neutron pulse output amplitude is smaller so shielding the electronics becomes more important...

Niels attached are some pics of a tph 055 that might provide some useful insights for your repair. Mine was missing the other bottom parts when I got it. BTW the tph magnetic bearing also has a 6x13mm ball bearing for takeoff and landing. I investigated high speed ball bearings some time ago. The on...

If your gauge works fine at higher pressures and then stops as the pressure drops you might have a magnetic field strength problem. If you adjust the magnet position and center it over the cell it might operate to a lower pressure. It is also possible heat has demagnetized the magnet. The voltage be...

Tom have you tested your penning gauge electrical feedthroughs as they can leak, mine did and on a nearby part I had a cracked weld. Wrap nearby or all fittings with plastic wrap and/or tape. This helps reduce dust off overspray when hunting for multiple leaks and if possible bag your gauge in secti...

I have one VCR face that has a big dimple on my MFC output fitting. I just stacked two washers. Don’t over tighten, do a leak test and tighten some more if necessary. Also if you use non standard thickness washers, measure the connector thread and calculate how many turns the washer thickness is and...