March issue of the bell jar - HV supply article

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
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Richard Hull
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March issue of the bell jar - HV supply article

Post by Richard Hull » Sun Mar 22, 2020 7:48 am

Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Dan Knapp
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Re: March issue of the bell jar - HV supply article

Post by Dan Knapp » Sun Mar 22, 2020 11:58 am

Thanks for the link; this is an interesting article. My post is prompted by the section on microwave experiments. First, I think the author should have emphasized a bit more that operating a magnetron without shielding can be dangerous. I also wanted to point out that microwave plasma experiments can be done without removing the magnetron from the oven thus retaining the oven shielding. There is a commercial product called the “Plasma Preen” (plasmapreen.com) which is a microwave vacuum chamber made from a commercial microwave oven. These sell for over $6000, but you can make one from an under $100 oven. In my former life we made one for use in the lab. It consists of a water cooled aluminum base plate with a Pyrex baking dish and rubber gasket inside the oven. Penetrations for the water and vacuum lines must be kept small to prevent microwave leakage. Any modifications to an oven should be checked with a microwave leakage detector. These are readily available and relatively inexpensive. One application potentially of interest to people here is the removal of potting on electronic devices to see what’s inside. A word of warning here is in order. DO NOT use oxygen to hasten this process unless you have the proper vacuum pump with inert oil! Doing so could turn your pump into a bomb. I think the same warning is in order regarding using a Freon to remove silica filler. Nitrogen or air plasma can be done without a special pump, although one would have to wonder whether extended use with air might have some of the hazards of oxygen plasma. More frequent pump oil changes are in order as this use will cause the oil to polymerize faster. Details of the device can be gleaned from the Plasma Preen patent referenced on their web page. I don’t believe making one would constitute infringement as long as you aren’t selling them or using it for a commercial purpose (although any attorneys in the group might correct me).

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Re: March issue of the bell jar - HV supply article

Post by John Futter » Mon Mar 23, 2020 12:44 am

Its a pity the bell jar is not https as this is what happens

Your Internet access is blockedFirewall or antivirus software may have blocked the connection.
Try:

Checking the connection
Checking firewall and antivirus configurations
Running Windows Network Diagnostics
ERR_NETWORK_ACCESS_DENIED

this is from my isp

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Richard Hull
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Re: March issue of the bell jar - HV supply article

Post by Richard Hull » Mon Mar 23, 2020 5:28 am

Wow! That is too bad and most unfortunate. Have you tried the base address first and wandered over to the monthly issues.
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Dan Knapp
Posts: 321
Joined: Wed Aug 06, 2008 12:34 pm
Real name: Dan Knapp

Re: March issue of the bell jar - HV supply article

Post by Dan Knapp » Tue Mar 24, 2020 2:19 am

It works for me just clicking on the link.

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Rich Feldman
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Re: March issue of the bell jar - HV supply article

Post by Rich Feldman » Tue Mar 24, 2020 5:09 pm

It might've been a year since Google searches started deprecating non-https URL's,
and the custodians of many old websites howled about it.

Sounds like today, it depends on ones ISP, VPN workplace policy, etc.
All models are wrong; some models are useful. -- George Box

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