Speaking of which, I could use a shorter four-post instrument rack with adjustable rails, but they never seem to come up on eBay--just the flimsy audio and gigundo server racks.
Any sourcing suggestions? I bought my present HP one from long-lost SED regular ecnerwal in about 2009.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Hunt up an old Tek rolling cart. They have two vertical pillars which are std 19" wide opening. Good heavy duty cart with 600Lb smooth rool casters. Most come with shelves and drawers too (which can be re-sold if not desired).
I'm from back then too, so I remember them fondly. (Well, the 7000 series, not the 5XX tube monsters.)
You couldn't fit a stack of 19" rack equipment on a 7000-series cart, because it's too narrow. I haven't used the ginormo tube-scope carts, but in general tippable carts are way too short and unstable. It's hard to see how you could get more than one or (at most) two large instruments on those before the tipping motion became dicey.
I've got instruments on Ikea kitchen carts, which are fine, but I need a second real rack.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Phil Hobbs wrote in news:arudnYqcBfI1jQ snipped-for-privacy@supernews.com:
These were not "tipping carts". These monsters could mount a friggin shuttle cockpit console. ;-)
The K420 series. I have a couple that have five foot tall pillars on them. The casters are to die for in mobility terms.
Floor space is a bit of an issue, because we've got a lot of good stuff:
So I really need a shorter version of the big HP rack in the photos.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
I designed a CSEM receiver 20 or so years ago with sub 100pV noise (0.01-15Hz BW and 120dB overall gain) with a similar architecture. These worked with Ag-AgCl field sensors with a source resistance of about 5 ohms.
I'd expect modern CSEM receivers to have improved on that - a google or patent search might give you some ideas?
Just as a reminder, Paul and I made a simple 65 pV/rt-Hz preamp, all the how-to details reported in AoE III, pages 505 to 508.
--
Thanks,
- Win
Are you planning on using the rack as a mobile device?
Because they are almost always fitted with small diameter hard casters.
Those Tek carts, BTW can have heavy items fitted right down next to the floor. It ain't no scope cart. New ones sell for $1500. That is all we use in our labs. The last one had four in it, right before the boss moved.
If you look at the big rack, you'll find that it's sitting on a chunk of butcher block with large cast-iron cylindrical casters with heavy solid tires from McMaster-Carr. It rolls great. The smaller rack won't need such beefy wheels.
Carts I can get for cheap, but I really want a rack. Failing all else, I can get a couple of two-post relay racks and have some cross braces welded on, but there must be some of the old-timey ones rattling round out there. Maybe I'll do a road trip to the Dayton Hamfest this year.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
In grad school my prof found racks expensive, but the wood shop was cheap, we had wooden racks, 2x4 boxes, with metal cross braces, slots in the
2x4 held plywood shelves.George H.
Plywood takes a permanent sag under weight.
I use metal shelves from Global:
With 20 ga steel, they can support 200 lb per shelf. That's enough for a HP
8566 plus a stack of signal generators, dmms, vna, etc. or inventory per shelf. I get the 97" corner struts so I can cut them to whatever height I need. I put angle iron on the bottom of the legs and drill holes for casters or rollers to move them around. They are not expensive.One thing that threw me off at the beginning is they do not itemize orders when you buy multiple shelves. They simply send whatever shelves and support struts are necessary to fulfil the order. You have to sort them out yourself to match the type and number of shelving you ordered. But this is easy once you figure it out.
Global is a Canadian company. You should be able to find equivalent companies across the US.
The beast is currently sitting on my front porch, having been delivered earlier today. The box weighs over 100 pounds, so I'll have to get DFH to help move it. Probably nobody is going to steal it in the night.
Film at 11. ;)
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Sheeesh! I have three different dolly types to cope with such, plus a block-and-tackle... quite convenient when you're 78 ;-) ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
It's what you learn, after you know it all, that counts.
I did this, at around age 60...
all by my lonesome... the lift-table is quite the nicest tool. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
It's what you learn, after you know it all, that counts.
I usually get stuff delivered to the house, because there's nearly always somebody here. I'm generally at the lab during business hours, but not always. So this beast will be going in DFH's truck tomorrow.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
The Harvard Over-40 Rowing Club once had some tee shirts made that said, "The older we get, the better we were." ;)
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
only
eally
f ned
h
Hydraulics... one use and you are spoiled for the rest of your life. :^) GH
Too soon, old... too late, smart. At my age "smart" outfoxes sore or torn rotator cuffs. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
It's what you learn, after you know it all, that counts.
Yep, Hydraulics are your friend... ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
It's what you learn, after you know it all, that counts.
Yeah, it's just a straight-through D-9 as it turns out.
I see what you mean by "1/f challenged"--it's about 7 nV/sqrt(Hz) in the flatband, but 100 nV/sqrt(Hz) at 1 kHz, which is about where it flattens out. The corner seems to be about 26 kHz, which isn't great.
However, with a decent preamp it'll be a great advance over analogue RF spectrum analyzers and scope FFTs.
I'm looking forward to trying out that code that you kindly sent me.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.