Yes. In addition, having the signals ground there will help against nearby lightning strikes.
Was reading about some of the Hi-Lumi upgrades to CERN over lunch. Retained was
-new big hole in ground
-lots of shiny hogged from solid
-Will take 8 years.
-Great job titles like 'inner triplet magnets engineer'
But I have no idea yet why crabs are needed...
Sigh, where to start.
It is a high luminosity upgrade, uses niobium tin quadrupole magnets. NbSn is a real pita as it requires high temp heat treatment after the coils are formed. It is too brittle to bend after reaction, so is wound prior using glasscloth insulation and vacuum impregnation afterwards. They will run at 1.88 Kelvin in superfluid helium. I suspect they have three consecutive quads with very little spacing between just prior to collision, so that is where "triplet" comes in as it requires one cryostat to put all three quads in.
Crab is crab cavity. They are used to slightly skew the bunches just prior to collision. Think of it in terms of drifting a car, but in this case they "drift" the particle bunches so that when they cross at a small angle, they are parallel. Supposed to increase the number of collisions, so they say..
Ya hafta laugh at the job descriptions. "Wanted, individual with experience in superfluid inner triplet superconducting magnets". Send resume....
It's like they don't already know every person on the planet who actually understands what the job description is, nevermind experience.
jn
Hi Dan,
No, can't send the schematic to ANYONE. Demian asked me also. This is Richard N. Marsh's intellectual property, it is his his design and it is proprietary, as such I made a promise that I wouldn't give/share/send the schematic to anyone. I have not and will not, and I like it that way.
Unless and until Richard N. Marsh directs me otherwise, in writing it shall remain safe and unshared.
It is a pretty darn robust unit.
I did pick up another unit the HTTP 7000, the earlier version of this unit. I need to crack it open and see how it is internally. I think it was sitting on the floor in someones garage or basement and suffered flood damage, appears only on the back panel...the gold is corroding.
Cheers,
PS - My advice is to find one used that isn't working and buy it. Yeah shipping is a pain over sea's buy maybe you can talk to an expat who's coming to this side of the pond and returning to your side of the pond.
Yah, those niobium rf cavities handle lots of volts.
What could possibly go wrong?
Famous last words.. Like "hey Earl, hold my beer and watch this"...
jn
Quite some years ago I had a customer with the ground traces on his
preamp vaporized. He had plugged into the RCA outlet for sound on his
(major brand name) television. RCA ground was very live, and I called
him right away...
I remain confused on this issue there are several mentions of a PC at every device supposedly to prevent output spew. So what is it? This would cost serious dollars (frankly sounds like sales talk or even the B word).
I wish people would stop putting words in my mouth, I question audibility and ask for some accountability. This becomes nothing matters and everything sounds the same.
I took a 1970's Triniton in to service in our lab and when I pushed it back to get a better look the chassis frame touched the metal shelf on our benches with spectacular results.
I've read that some of those TVs were using tubes specified with constant current filaments (0.3A) rather than constant voltage filaments (like 6.3V). As such, all filaments were in series and connected through a ballast power resistor (to drop the extra voltage) straight to the AC mains. And they had no power transformers, the anode voltages were derived by ballast resistors directly from the rectified and filtered mains. Was this a widespread technology?
The Zenith yes, including a now unobtainium ballast tube the Trinitron was all solid state except of course the CRT I forgot the reason the chassis could be hot.
Yes, but they used polarized AC plugs. However, many homes were built before polarized sockets were used. People were advised to have an electrician come in and replace all the wall sockets in the house, but few could afford that, which was the same reason they were buying cheap radios and TVs with polarized plugs. People often didn't know why one plug blade was wider than the other but they knew if filed down to fit it seemed to work okay. And, heck, even if the chassis was hot, there was a plastic case and plastic knobs to insulate it.
Things started to seriously change after they outlawed 2-wire un-polarized extension cords. Eventually, people got the idea.
Of course there are still devices that used 2-wire polarized power, but now they are 'double-insulated,' and pretty much all wall sockets in existence are polarized, even if some old houses may still not have 3-prong grounded outlets.
Last edited:
Really where was that? Some of my neighbors still have knob and tube. Don't you mean without polarized plugs?
The typical process is to change the codes and all new work has to comply, plenty of old apartments here with extension cords stapled to the baseboards.
That would probably be Zenith/Motorola out of Schaumberg Il my first interview. The guy told me that designing out a 5 cent component merited a "big" bonus, I passed.
Yup we bought a house in Sarasota Fl. with a few.
Thus the reason at the service centers I worked at we had B&K Isopacks feeding Variacs...
As a side note, the first TV my parents had was an old Hotpoint (then GE) with a metal case wrap. The chassis was insulated by plastic standoffs and knobs but there was leakage. On cold Saturday mornings we used to sit on the cast iron radiators while we watched cartoons. If you forgot to stand up and reached over to adjust the volume and touched the case you would get lit up like a Christmas Tree! When I think of how dangerous that was...but we used to laugh at the kid who was dumb enough to forget...ahhh the innocence, I mean ignorance of youth...
Howie
Last edited:
Knob and tube is quite safe in walls, arguably safer than Romex due to the 14"+ spacing between hot and neutral...but sorry about the ground or lack thereof. I have helped friends run green #12 THHN around in the walls and crawl spaces of their houses to add grounds...what a pain.
Howie
Philips / Magnavox Greenville TN.
Philips sold the plant in 1997 to Five Rivers Equipment co. The plant closed Sept 2006.
I would say some time between 1997 and 2006. Possibly as late as 2006 because TV manufacturing equipment is listed in the sales info.
Five Rivers' Equipment Sold At Auction | Business | greenevillesun.com
Last edited:
I would add to this that a two-wire AC distribution system like knob and tube without a third ground wire can be made safe without a grounding conductor when integrated with a GFCI breaker in the main panel.
Howie
Didn't matter what was in the walls, it was just that the receptacles were unpolarized. It would be a matter of an electrician unscrewing one receptacle, figuring out which was the hot and which was the neutral, and replacing the old receptacle with a polarized one.
The situation was that all the discount store radios and tvs where polarized. They had a tag on the AC cable to only plug into a polarized outlet, and to get an electrician if your outlet was unpolarized. Well, people skipped the electrician and DIY'ed it by using a ground-lift plug that was polarized socket to unpolarized plug, or by filing down the strange wide blade that didn't fit in the existing socket for some reason or other (and they either didn't read the tags or ignored them, as you may surmise). Because radios and tvs were getting cheap they could be put in more than one room, but that would mean a lot of receptacles to replace. Usually didn't happen.
Last edited:
- Status
- Not open for further replies.