Search found 316 matches

by Bob Reite
Tue Jan 19, 2021 12:08 am
Forum: Images du Jour
Topic: Six Inch Cross Fusor
Replies: 16
Views: 1015

Re: Six Inch Cross Fusor

What voltage are you hoping for? That's a pretty long insulator. If you go much over 35 KV, the sharp edges of the nuts on top are going to cause corona issues.
by Bob Reite
Mon Jan 11, 2021 12:11 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: 125kV Fusor
Replies: 13
Views: 1180

Re: 125kV Fusor

I calculate that he is doing 7.35E+07 N/S isotropic! WOW! That breaks Jon Rosenstiel's record of 1.2E+07 n/s. But not too surprising if he is running 100 KV. I'd advise going to remote control operation. Inverse square law is your friend. Not only because of the dangers from X-rays and neutrons, but...
by Bob Reite
Sat Jan 09, 2021 5:22 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: 125kV Fusor
Replies: 13
Views: 1180

Re: 125kV Fusor

Don't know the calibration factor of his detector but those numbers sound like he is in the 5xe07 range. May be close to a record for our group.
by Bob Reite
Thu Jan 07, 2021 7:00 pm
Forum: Announcements and Site Administration Topics
Topic: Not a covid post! Get ready for the vacuum
Replies: 13
Views: 982

Re: Not a covid post! Get ready for the vacuum

Laughing at the reference to linear or log taper pots. While the classic big hamfests such as the Hamcation, Hamvention and Ham-Com will not take place this year, smaller local fests may start up this Summer. I'm hoping so, I got a lot of electronic stuff in the garage, that I'd rather sell to a ho...
by Bob Reite
Thu Jan 07, 2021 6:52 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: High Voltage Probe
Replies: 3
Views: 405

Re: High Voltage Probe

Is that a series parallel arrangement? Or all in series with a zig zag? To replace my 600 meg resistor that went bad, I opted to buy 6 Vishay/Dale 100 megohm resistors model ROX-2 that are intended for high voltage use. Hopefully you don't have trouble with corona at the top end of your series string.
by Bob Reite
Sat Jan 02, 2021 3:28 am
Forum: Announcements and Site Administration Topics
Topic: Not a covid post! Get ready for the vacuum
Replies: 13
Views: 982

Re: Not a covid post! Get ready for the vacuum

I got one side of the garage full of stuff for the ewaste hauler, once they are open for business again!
by Bob Reite
Sat Jan 02, 2021 1:51 am
Forum: Announcements and Site Administration Topics
Topic: Not a covid post! Get ready for the vacuum
Replies: 13
Views: 982

Re: Not a covid post! Get ready for the vacuum

Well for me it has been "Work as usual". Since by and large, transmitter sites are unattended these days I did not have to worry about exposure to COVID-19. I don't think that the big hamfests will resume in 2020. Orlando Hamcation has already been canceled, and I don't think that the Ohio Hamventio...
by Bob Reite
Sat Jan 02, 2021 1:39 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Beam on Target Project (BOT 2021)
Replies: 45
Views: 3829

Re: Beam on Target Project (BOT 2021)

Might be late to the discussion, it looks like you got it working, but I'd put in a circulator. That way, the magnetron would always see a good load, any mismatch would go to a reject load.
by Bob Reite
Tue Dec 29, 2020 3:01 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Beam on Target Project (BOT 2021)
Replies: 45
Views: 3829

Re: Beam on Target Project (BOT 2021)

Yes, I work with the stuff and consider the world above 900 MHz to be black magic.
by Bob Reite
Tue Dec 22, 2020 7:49 am
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: A 50kV supply with 33mA drive ability
Replies: 10
Views: 1312

Re: A 50kV supply with 33mA drive ability

I have a filtered supply, so I can give a DC resistance for the plasma. Now it's going to vary depending on pressure!

I generally operate at 12-14 microns. At that pressure, the system draws 7 mA with 40 KV applied. So that's a DC resistance of 5.7 megohms in round numbers.