I have found my racks at the MIT flea in the past. The great thing about 2 posters is they easily come apart and can fit in the car. Plus the pieces by themselves are reasonable in weight. Regards Paul
On Tue, Jun 11, 2019 at 2:05 PM Tom Knox <[email protected]> wrote: > Hi All; > I have found when rack hunting it is best to look at local test equipment > auctions. Even really nice racks often do not receive any bids and more > importantly no shipping. In my labs I use exclusively Agilent/Keysight > because they are exceptional quality and parts a commonly available. The > one minor problem is they are a touch narrow, and some items like Wavelek > calibrators are a really tight fit, but workable. I find in local auctions > when they show up they are (like other racks) usually very inexpensive. The > trick is if you have any plan to go to racks in the future start looking > early and buy when you see them even if not yet prepared to use them and > store them until needed. > Hope that helps > > Tom Knox > > 303-554-0307 > > [email protected] > > "Peace is not the absence of violence, but the presence of Justice" Both > MLK and Albert Einstein > > ________________________________ > From: time-nuts <[email protected]> on behalf of Bob > Albert via time-nuts <[email protected]> > Sent: Tuesday, June 11, 2019 9:59 AM > To: Perry Sandeen via time-nuts > Cc: Bob Albert > Subject: Re: [time-nuts] Excellent equipment rack > > Very interesting! Recently I had a somewhat similar experience. My > neighbor was throwing out some shelving that looked like what I need. It > was gray steel, all the vertical parts needed but no shelves. I made > shelves from plywood and ended up with a nice addition to my lab. To make > it mobile I sat it on a dolly that fit almost perfectly so now I can move > it. > I put my VNA and some tools on it and it's a perfect fit in the corner of > the room. > Just because I am an electronics engineer doesn't mean I can't do > mechanical stuff. > Bob > On Tuesday, June 11, 2019, 08:00:43 AM PDT, Glenn Little WB4UIV < > [email protected]> wrote: > > Here is what a U is: > > Main article: Rack unit <https://en.wikipedia.org/wiki/Rack_unit> > > Racks are divided into regions, 44.50 millimeters (1.752??in) in height, > within which there are three complete hole pairs in a vertically > symmetric pattern, the holes being centered 6.35 millimeters (0.25??in), > 22.25 millimeters (0.88??in), and 38.15 millimeters (1.50??in) from the > top or bottom of the region. Such a region is commonly known as a *U*, > for /unit/, or, in German, *HE*, for /H??heneinheit > <https://de.wikipedia.org/wiki/H%C3%B6heneinheit>/, and heights within > racks are measured by this unit. Rack-mountable equipment is usually > designed to occupy some integer number of U. For example, an > oscilloscope <https://en.wikipedia.org/wiki/Oscilloscope> might be 4U > high, and rack-mountable computers are mostly between 1U and 4U high. A > blade server <https://en.wikipedia.org/wiki/Blade_server> enclosure > might require 10U. > > Occasionally, one may see fractional U devices such as a 1.5U server, > but these are much less common. > > The height of a rack can vary from a few inches, such as in a broadcast > console, to a floor mounted rack whose interior is 45 rack units (200.2 > centimeters or 78.82 inches) high, with 42U being a common > configuration. Many wall-mounted industrial equipment enclosures have > 19-inch rack rails to support mounting of equipment. > > > A R-390 is 10.5 inches tall so it is 6U. > > Your rack could be drilled for using mounting screws of: 10-32, 12-24, > M6 or require a nut plate for equipment mounting. > > 73 > Glenn > > On 6/11/2019 2:02 AM, Perry Sandeen via time-nuts wrote: > > Yo Bubba Dudes!, > > Needing to go vertical with my test equipment I went bottom feeding for > an equipment cabinet on ebay. > > To make a long search story short: they were way too expensive, too > heavy to ship and too far away for pickup. > > So I kept searching and finally came across what was listed as *42U Four > Post Open Frame Server Data Rack 19 inches.?? Adjustable depth 23 to 32 > inches.ebay number 152319524877.Sold by Raising Electronics for US $188 and > free shipping. > > I was unsure what a *U* height meant put it seemed tall enough so I > bought one. > > I was a little apprehensive about this being a Chinese metal product.?? > I was very pleasantly proven very wrong. > > Although it only comes with a picture of an assembled unit it has been > engine ed so there is no way you can assemble improperly. The four posts > are all equal and can be installed with any end up or down and the top and > bottom brackets will fit.?? It comes with the exact 50 M6-20 head bolts and > nuts needed for assembly.?? The nearest SAE equivalent bolt size is 1/4 20 > x 1/2L which I purchased to hold L shelf brackets to the frame. > > I set the depth of mine to 26 inches so my 5370's fit well and I had > space for both power and BNC cables to be inside the frame. > > > > This rack is designed to be bolted to the floor.?? Wanting to be able to > move it, I cut a piece of 3/4 inch plywood a little longer and wider then > the base footprint and installed 4 inch tall Harbor Freight swivel casters > on the four corners for ease of movement in any direction, even on floor > carpeting.?? After assembly it was 6 ft 9 inches tall. > > > > Now this being a bolted together *skeleton frame* it is prone to > twisting and or becoming a parallelogram sideways.?? To prevent twisting, I > fitted a plywood board on the top bolted to the top front and rear angle > pieces.?? To prevent a side-to-side movement required an 8 inch wide piece > of scrap aluminum plate bolted to the rear vertical posts.?? This is easy > to do as there are a plethora of precision spaced holes available. > > There was some very serious thought given to the vertical post design.?? > It has six 90 degree folds done in such a way that the inner edge on each > outer side gives a 19 inch opening. > > ??However behind it is as inner fold where one can install recessed L > shaped brackets. Now the inner fold is about and inch narrower than the > outside edge.This allows making a wider shelf that can *float* on top the > brackets but can't slide out either end. > > This was very useful when configuring the instrument arrangement. > > I also found that with the bottom shelf being just 6 inches above the > floor I was able to install more equipment in the same vertical space than > in my previous normal sized equipment cabinet. > > Another bonus with this type of configuration is that it's easier to > keep the equipment cool and it's much lighter. > > Regards, > > Perrier > > > > > > > > > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > -- > ----------------------------------------------------------------------- > Glenn Little ARRL Technical Specialist QCWA LM 28417 > Amateur Callsign: WB4UIV [email protected] AMSAT LM 2178 > QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR > "It is not the class of license that the Amateur holds but the class > of the Amateur that holds the license" > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
