Re: Placing Shelf on Casters for HP Equipment
Very cleverly done Dan. I like it. ¨C Mike ? Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 ?
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From: [email protected] < [email protected]> On Behalf Of Daniel Nelson via groups.io Sent: Sunday, November 7, 2021 11:15 PM To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment ? After some years of fooling around with stacking stuff, I gave that up and moved everything on edge. The bench is made of pine 2x4 with 1-1/8" Black Iron pipe for shelf support and library board for the decking.? There are outlet strips on the wall behind and a power conditioner on the bottom in the corner. See the photos. I often work on things with the displays turned, so no problem putting things in on edge. At least I can take one item out at a time. Some connections have been extended to the front using the top rack flange as a holder for BNC bulkhead connectors.? So, this has worked for me and provides a really good packing density. Photos attached.
Dan in Chandler, AZ
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Re: Placing Shelf on Casters for HP Equipment
? I like the casters you chose.? The leveling feet will allow you to unload the casters which will stabilize the cart and prevent flat-spotting the wheels over time.? It might save it from making dents in the hardwood as well.? It looks like a good design as long as the c-channels are well attached. When loading it I would recommend trying to keep the COG low if practical just as an added precaution.? When you roll it keep the speed low and you should be okay even if the seemingly inevitable cable flop under a wheel happens as it always seems to.? I also like the shelves, but the ribs may be hard on the feet if you slide an instrument sideway.? Many Metro racks have wire shelves which aren't compatible with the feet on instruments.? Even with the plastic or wood shelf covers the feet tend to catch and can break.? Obviously you won't want to put any equipment on slides on a rack like this.
? Metro racks are great but I have seen several plastic corner clips fail over the years.? That can cause items to slide off a shelf but usually they don't drop far enough to do that.? I think the failures were due to the interlocking ring shearing off in the post due to shock loads from rolling over joints in concrete and such.? I have some aluminum corner clips that I use if I am loading a rack up heavy.? I have never had seen of those fail, but I don't know where to get them.? All my Metro racks came second hand after heavy abuse and the spare clips were salvaged off damaged ones.? Now I have so much stuff on and around them I can't roll them.
Good luck with your shelf,
Clay Scott
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Re: Placing Shelf on Casters for HP Equipment
While we¡¯re on the subject I¡¯ll share a few other things I think I know about instrumentation racks.
I agree the best name for them is a ¡°19 inch rack¡±. That¡¯s the actual width of the front panel of an instrument that will fit it. Note: many instruments are made to fit in this size rack but may not have flange kits or what I¡¯ve heard called ¡°ears¡± that have to be the same height as the instrument (U size mentioned by another contributor here) and mounted on the sides of the instrument with screws then mounted in the rack.
Most modern racks do not have threaded holes for the flanges to be mounted to. Instead a special nut with an integrated clip is needed for each flange hole. They are clipped onto the rack at each point on both sides where there is a flange hole. This is one way in which the variety of instrument heights is accommodated.
To support the weight of equipment, the rack usually has L shaped rails that mount to the sides at front and back to support the weight of each instrument. In really fancy setups especially where in rack serviceability is needed, slides are used instead of simple rails.
These racks often have solid sheet metal sides and some even have doors to cover front and or the back often with locks to prevent tampering with the equipment or interconnections. With covers they are often called instrument cabinets. Now that they have solid sides, they often need and come with fans near the bottom and perforated top or sides to manage heat created by the instruments. They usually have power distribution built in too.
Another type of rack, usually called a ¡°telco rack¡± are completely open and the vertical sides are often made of ~3¡± wide aluminum U channel. These usually have threaded holes every 1/2¡± on each side the entire length. These racks are often 7 or 8 feet tall. These aren¡¯t very useful for instruments and usually hold shallow network gear or patch panels.
Mark
Ex HP/Agilent Employee
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On Nov 7, 2021, at 5:38 PM, Matt Huszagh <huszaghmatt@...> wrote:
?"Dave McGuire" <mcguire@...> writes:
You're not familiar with 19" racks, which have been ubiquitous in
many industries for about a century?
- test equipment
- computing
- telephony
- sound reinforcement
- pro music gear (synthesizers, audio processing)
- industrial automation
- [probably more that I can't think of offhand]
I'm not trying to talk down to you, man, but I can't see how anyone
who has lived on Earth for awhile couldn't know about these. Heck, my
grandmother suggested to me that I should get one when I was about 14,
in the 80s. I googled "HP test equipment rack" and the 19" rack popped up. I have
seen these before, though I didn't know the term (or know that it was a
standard). I also did not know that these are what HP, Agilent and
Keysight use for their test equipment racks.
I'm not sure if this is a good excuse but I'm relatively young (< 30)
and only been doing electronics for the last couple years, when I
started teaching myself. I also don't come from an engineering
background, so I've probably missed some things that are evident to
others in the field. I did study physics undergrad though, and research
is one of the places I've come across these. But, none of us were too
concerned that these were called 19" racks.
Matt
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Re: Placing Shelf on Casters for HP Equipment
Dan -
Really dense - how is your neck :-)
Cheers!
Bruce
Quoting "Daniel Nelson via groups.io" <djn@...>:
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After some years of fooling around with stacking stuff, I gave that up and moved everything on edge. The bench is made of pine 2x4 with 1-1/8" Black Iron pipe for shelf support and library board for the decking.? There are outlet strips on the wall behind and a power conditioner on the bottom in the corner. See the photos. I often work on things with the displays turned, so no problem putting things in on edge. At least I can take one item out at a time. Some connections have been extended to the front using the top rack flange as a holder for BNC bulkhead connectors.? So, this has worked for me and provides a really good packing density. Photos attached.
Dan in Chandler, AZ
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Re: Placing Shelf on Casters for HP Equipment
Yes, of course! (Face palm!) I own a 437B power meter, a 11720A pulse modulator, a 5316A frequency counter, and two 11713A attenuator/switch driver boxes (one in use, and one is the parts mule), all 2 RU high. I haven't stuck them in the microwave rack in my garage yet because 1) I haven't decided if I want to take up rack space yet, and 2) I don't have the rack ears and hardware to put those half-rack width boxes together yet.
I was moving stuff around on the bench and accidentally yanked on the cable running between my only 11713A at the time and an 8494 or 8495 step attenuator, probably 9 months ago. Broke a pin off the Viking connector and rather than trying to find a new connector, I just bought another 11713A on ebay for about $40. Those things are cheap and available these days. So the one with the busted pin is now a parts mule.
Ah, another thing to know about 19 inch racks is the support angle brackets along the sides, although somebody partially covered the subject already. I didn't know anything about those until recently. Yes, heavy test equipment needs angle irons along the sides, bolted onto the side panels. Lightweight audio gear with limited depth, not so much. Rack ears are special angle irons that bolt onto the sides of the piece of equipment at the front, and then bolt onto the rack at both sides. For heavy TE, they only serve to keep the box from moving, but in the case of shallow, lightweight audio boxes, they could support the entire box. Rack ears may or may not be compatible with the handles that one would want to attach if just stacking TE on a bench or cart. HP gear does have handles and rack ears that work together, at least the 8566 spec an and 8530 sweep oscillator. Handy to keep the handles on there, should rearrangement be necessary.
HTH.
Jim Ford
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------ Original Message ------ From: "Dave McGuire" <mcguire@...> To: [email protected]Sent: 11/7/2021 9:36:21 PM Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment On 11/7/21 6:59 PM, Jim Ford wrote:
I can't think of any even numbered RU height boxes, though. There are lots. From HP, there are many half-rack-width instruments that are 2U tall, and bolt together side-by-side to mount in a rack: 34401A, 3468A, 3478A, 33120A, 3314A/3315A, 437B, 438A, etc etc etc.
For full-width 2U instruments, there are the "big" DMMs like the 3450A/3455A/3456A/3457A/3458A, the wonderful and underappreciated 3488A, and since you mentioned the 8566 spectrum analyzer, there's its sidekick, the 85650A quasi-peak adapter, all 2U.
There are many, many others.
-Dave
-- Dave McGuire, AK4HZ
New Kensington, PA
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Re: Placing Shelf on Casters for HP Equipment
After some years of fooling around with stacking stuff, I gave that up and moved everything on edge. The bench is made of pine 2x4 with 1-1/8" Black Iron pipe for shelf support and library board for the decking.? There are outlet strips on the wall behind and a power conditioner on the bottom in the corner. See the photos. I often work on things with the displays turned, so no problem putting things in on edge. At least I can take one item out at a time. Some connections have been extended to the front using the top rack flange as a holder for BNC bulkhead connectors.? So, this has worked for me and provides a really good packing density. Photos attached.
Dan in Chandler, AZ
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Re: Placing Shelf on Casters for HP Equipment
On 11/7/21 6:59 PM, Jim Ford wrote: I can't think of any even numbered RU height boxes, though. There are lots. From HP, there are many half-rack-width instruments that are 2U tall, and bolt together side-by-side to mount in a rack: 34401A, 3468A, 3478A, 33120A, 3314A/3315A, 437B, 438A, etc etc etc. For full-width 2U instruments, there are the "big" DMMs like the 3450A/3455A/3456A/3457A/3458A, the wonderful and underappreciated 3488A, and since you mentioned the 8566 spectrum analyzer, there's its sidekick, the 85650A quasi-peak adapter, all 2U. There are many, many others. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Placing Shelf on Casters for HP Equipment
On 11/7/21 8:38 PM, Matt Huszagh wrote: I googled "HP test equipment rack" and the 19" rack popped up. I have
seen these before, though I didn't know the term (or know that it was a
standard). I also did not know that these are what HP, Agilent and
Keysight use for their test equipment racks. Well, they followed the 19" rack standard. Just like all of the computer manufacturers (HP included) followed it too. The vernacular: One "rack U" (rack unit) is 1.75". A "1U" rack-mounted device is 1.75" tall, a "2U" chassis is 3.5", etc. About 95% of the hardware you'll run across, test equipment and server-class computers alike, is sized in these increments. Soon you'll be able to recognize them on sight and plan out your rack space allocations: "Oh, I see that HP 3325A is a 3U box". "Ah, I can put a 1U file server right here". Look for a picture of the front one of these racks, empty, and look at the holes facing you on the left and right. Notice the spacing pattern of the holes. It looks irregular, but if you stare at it for a moment you'll see that they're spaced out for 1.75" increments. All of this works amazingly well, and you will love it. This isn't just test equipment stuff. If you haven't ever seen a datacenter in person, surely you've seen pictures of them. Those are the same racks. Keyboardless synthesizers, signal processors, and amplifiers in recording studios and on on concert stages...same racks. AT&T came up with this standard for telephony equipment in 1922...Yes, 99 years ago. I'm not sure if this is a good excuse but I'm relatively young (< 30)
and only been doing electronics for the last couple years, when I
started teaching myself. I also don't come from an engineering
background, so I've probably missed some things that are evident to
others in the field. I did study physics undergrad though, and research
is one of the places I've come across these. But, none of us were too
concerned that these were called 19" racks. It's not a good excuse. ;) But it's never too late to catch up, and you can fill in all of the knowledge blanks here. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Placing Shelf on Casters for HP Equipment
On 11/7/21 10:02 PM, Andrew Hakman wrote: Racks work great when they come together as a system, like you buy a stack of dell servers, and you buy them with a dell rack at the same time, then it all works great. Or you have a bunch of HP equipment -that's setup for rack mounting- and you have an HP test equipment rack. Don't even think about putting HP test equipment into an HP "server" rack - things will inevitably not work somehow. When you try to put a bunch of random stuff together into a random rack, you end up with all sorts of incompatibilities really quickly. The second thing you need after you get a rack is access to a metal brake and a drill press (at the very least) so you can make up custom brackets and other random things you need to get stuff to actually fit into the rack you have. Or at the very least, some way to cut up plywood to make shelves (yes, you can buy shelves, but "rack shelves" tend to be stupidly expensive, but then again so is plywood now... sometimes you can't win for trying!) While there are definitely some annoying issues, it's not that bleak. It's just a matter of getting the right hardware, primarily the cage nuts/Tinnerman clips/etc that fit, and the screws to fit those. From my desk in my lab, I can see three Sun racks, one Compaq rack, two DEC racks, one HP rack, and one Spirent rack, all but the latter two having been designed for computers, and all are full of test equipment. No issues. The big problems start when you start trying to use, for example, Dell rack slides on a piece of HP test equipment. Don't even bother. Get generic rack rails or shelves, like Navepoint, Black Box, etc, and install them in the rack using cage nuts or Tinnerman clips that fit that rack. All of those nuts and clips and such are available on eBay (people taking them home from work by the pocketful) or aftermarket on Amazon etc. All are cheap. My all-time favorite rack shelves for heavy things are Black Box model RM399. They are dramatically overpriced (Black Box..) but they can sometimes be found on the surplus market via eBay. They will hold vast amounts of gear, four or five heavy HP RF instruments per shelf, very securely, and their mounts are adjustable for racks of different depths. Navepoint makes nice stuff but the steel they use is softer than it should be. Don't overload them. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Question: XY (XYZ or Vector) instrument CRT, replacement with an LCD ?
Hello Folks,
in case anyone of you is looking for a decent C tutorial - the
folks from ByteGarage in Italy currently has their large C
programming video course, totally for free:
It is still free for two days, so maybe collect it.
Tam
With best regards
Tam HANNA
Enjoy electronics? Join 19k7 other followers by visiting the Crazy Electronics Lab at
On 2021. 11. 07. 21:05, peter bunge
wrote:
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Thanks John; I have ruled out Python for now but
may?learn it some?day.?
20 years using C does not make me a programmer but I have
built many successful projects with the tools I have.
Many seem to be missing the point that I am looking for the
shortest learning curve. The two missing items are a C
compiler with a nice IDE to run on Windows and learning
graphics with it.
I understand the following (TurboC)
/*
Simple example to draw circle */
#¾±²Ô³¦±ô³Ü»å±ð¡±²µ°ù²¹±è³ó¾±³¦²õ.³ó¡±
#¾±²Ô³¦±ô³Ü»å±ð¡±³¦´Ç²Ô¾±´Ç.³ó¡±
void
main()
{
int
gd=DETECT,gm;
initgraph(&gd,
&gm, ¡°c:/tc/bgi ¡°);
circle(330,180,100);
getch();
closegraph();
}
I
just need to get started with software running on a Windows
computer to?write programs like that.? I have done similar
on a low res LCD with a PIC.
The
best advice so far was the free MS Visual C which I will try
to load. There is a very nice Tutorial that I partly
completed on?the version that was not free.?
I
hope the free version is as good.
Is
anyone interested in helping with a PC controlling an HP
Impedance analyzer?
Peter
On Sun, Nov 7, 2021 at 1:38 PM
John Griessen < john@...> wrote:
On 11/7/21 09:39, peter bunge wrote:
> I am not a programmer and like to keep things simple.
> The reason I like the PIC over Arduino and RaspberryPi is
that I can make custom PCBs and program the pins on the PIC to
be
> convenient.
micropython on a STM32F4 or others might interest you.? It's
still a learning curve.? STM32's have lots of GPIOs ports and
such
that can be remapped? in various alternate ways, but not pin
by pin.? The power and grounds and XTAL in/out don't remap,
but some
redundant ones can be left off.
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Re: Placing Shelf on Casters for HP Equipment
The biggest thing to consider with a rack is support at the back. Lots of racks have no back rails to support long / heavy equipment. And the next thing is what brackets you need to actually have support in the back. Long L profiles down the sides? Does your rack have mounting holes in the right orientation to mount such brackets? Back rails? Does your equipment have adjustable back mounting points (as your back rails will inevitably be a different depth than any other rack in existence)
Another thing to consider is depth - a rack might be fine for some applications, but completely useless for others. Even fairly deep racks might not be deep enough if you want to put a server in it later. I had a rack that worked well for a lot of stuff, until I got a SuperMicro server case (one of the ones with 20 SATA hotswap bays on the front) - it was much deeper than my rack, and there was absolutely no way to even mount it's rails into the rack, as the minimum depth of the adjustable rails was deeper than the deepest setting of the rails in the rack. I got another rack which I thought was deep enough (from an ancient SGI "supercomputer")... nope, still not deep enough. I gave up and put the server on top of the rack!
Racks work great when they come together as a system, like you buy a stack of dell servers, and you buy them with a dell rack at the same time, then it all works great. Or you have a bunch of HP equipment -that's setup for rack mounting- and you have an HP test equipment rack. Don't even think about putting HP test equipment into an HP "server" rack - things will inevitably not work somehow. When you try to put a bunch of random stuff together into a random rack, you end up with all sorts of incompatibilities really quickly. The second thing you need after you get a rack is access to a metal brake and a drill press (at the very least) so you can make up custom brackets and other random things you need to get stuff to actually fit into the rack you have. Or at the very least, some way to cut up plywood to make shelves (yes, you can buy shelves, but "rack shelves" tend to be stupidly expensive, but then again so is plywood now... sometimes you can't win for trying!)
Also, I'd be leery of "Metro" shelves that someone else mentioned. I have some in my garage, and they're disappointingly not rigid or sturdy. I have some with tools on them (which are pretty heavy), and the wheels have cracked, both the hard plastic wheel itself, as well as where the castor mounts to the corner posts, and that shelf is never even moved. Also the shelves don't take that much weight before they start flexing. Good for restaurants that maybe put a couple of boxes of food on each level, which is not _that_ heavy, but not really great for tools or test equipment that's actually heavy. Also wire shelves tend to be a pain - equipment feet get stuck in them, you can't put small things there without it falling through - solid smooth shelves are the way to go.
The "Rivitier" tear-drop style stuff is better, depending on what gauge you get, but still not perfect. You stack a few rack mount boxes on top of each other on one shelf, and you'll still end up with flex in the shelves.
On Sun, Nov 7, 2021 at 6:15 PM Bruce < bruce@...> wrote: Matt -
I tend to agree with your reasoning on a number of point -?
particularly access.? 19" racks are an excellent choice for equipment?
that is committed to a particular configuration - e.g. An 8510 network?
analyzer along with the IF, test set, committed source.? Note that I?
am assuming a single rack, not multiple racks bolted together.
Some benefits:
1) Strength and design
2) Order - many have cable routing channels
3) Good rear access
4) Ventilation
5) Built in power distribution
BUT there are some disadvantages:
1) Horizontal access (unless you bolt multiple racks together)
2) Accommodating non 17" wide equipment (Yes - Hp has solutions for?
this but part are expensive and hard to find)
3) Changing configurations (the relationship between various pieces)?
and access to features accessed from the rear of the equipment e.g?
Z-axis on Tek scopes, sweep out of signal generators and spectrum?
analyzers, etc
My advice would be to use what you currently have - note things that?
are "problems" and decide whether a rack is necessarily the est?
solution.
As I mentioned above, sometimes it is and sometimes not.? My current?
arrangement is similar to yours; it works well for me because I?
frequently reconfigure stuff.? It is much messier (at least the part?
that can be seen) that something built in a bunch of bolted together?
racks, but that is part of the ambiance of a home lab :-)
BTW - I have moved 3 times and think before moving again, I may?
consider dying :-)
Cheers!
Bruce
Quoting Matt Huszagh <huszaghmatt@...>:
> I keep basically all of my large and heavy (mostly HP) equipment on a
> heavy-duty shelf I ordered from McMaster-Carr
> (). I recently moved and wound up with
> less space than I previously had. Before, I left about 2.5' behind the
> instrument rack to be able to access the backs of the equipment. But, I
> could really use that space in the new spot. So, I thought it might be
> nice to put my normally stationary shelf on casters. This way I can roll
> the shelf out when I need access to the rear of the instruments and keep
> it against the wall for normal use. However, I'd very much like to
> ensure my equipment doesn't go toppling over when I move it. I posted
> about this on eevblog
> ()
> and received some really great advice, which has gotten me to the
> current iteration of the design (more on this momentarily). However, I
> wanted to field advice from people on this thread who are probably more
> used to large and heavy equipment than most.
>
> I've modeled the shelf + casters in CAD and added pictures to this
> post. The leveling+swiveling casters are also from McMaster-Carr
> (). Basically, I'll put the shelf on
> two C channels. The channel will be bolted to the shelf just below each
> vertical column. I've designed the length of the channel to be longer
> than the depth of the shelf so that the distance between the center of
> the wheels when both wheels are rolled inward is still wider than the
> depth of the shelf (24").
>
> Some things to note. I'd estimate the total weight of my equipment
> between 500 and 1000 lbs, though I'm guessing. The diameter of the
> wheels is only 2". However, I'll be careful to ensure there is nothing
> in the path of the wheels when I roll it out or in. Also, this is on
> flat, hardwood floor. Most of the weight of the shelf is placed on the
> middle two shelves since that's where it's accessible. Obviously from a
> stability perspective it would be better if it were on the
> bottom. Unfortunately, that's not an option. Though I wouldn't
> necessarily be opposed to putting weights on the bottom shelf if people
> feel that's a major improvement.
>
> Lastly, a previous thread here
> (/g/HP-Agilent-Keysight-equipment/topic/racks_for_older_equipment/72918532?p=Created%2C%2C%2C20%2C1%2C0%2C0&prev=1)
> contained some good information about this topic. The takeaway seemed to
> be that proper NSF metro racks are a good way to achieve what I'm
> looking for. And, from Don's comment, it sounds like this is what HP
> used for their mobile cal lab, which is obviously a big
> endorsement. However, I've already sunk a good chunk of money into this
> shelf and would like to use it rather than buying something new. Also,
> my uninformed impression is that my shelf looks a bit sturdier than the
> metro racks. I could very well be wrong though and would be greatful to
> hear why!
>
> Thanks!
> Matt
>
>
>
>
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Re: Placing Shelf on Casters for HP Equipment
Hi,
do not take it too hard. We all live under the rock sometimes...and finding the right term can be most of the problem...especially if you are not a native speaker.
Tam
With best regards
Tam HANNA
Enjoy electronics? Join 19k7 other followers by visiting the Crazy Electronics Lab at
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On 2021. 11. 08. 2:38, Matt Huszagh wrote:
I'm not sure if this is a good excuse but I'm relatively young (< 30)
and only been doing electronics for the last couple years, when I
started teaching myself. I also don't come from an engineering
background, so I've probably missed some things that are evident to
others in the field. I did study physics undergrad though, and research
is one of the places I've come across these. But, none of us were too
concerned that these were called 19" racks.
Matt
|
Re: Question: XY (XYZ or Vector) instrument CRT, replacement with an LCD ?
The absolutely simplest platform to do this on would be Parallax Propeller 1 or Propeller 2.
For signals slow enough for a plotter, or maybe into audio frequencies, a propeller 1 can directly sample an external ADC and generate live VGA display output using external RAM, or internal RAM if low resolution would be enough (say 640x480 or 800x600). It¡¯d be scaled up too.
Propeller 2 has enough RAM to generate 1080p HDMI directly off its pins, fully software defined. Those are both. exceedingly powerful platforms for how simple they are, and Prop 2 makes many Arm SoCs look like slow monsters in comparison.
With Propeller 1 think of early Tek digital scopes in terms of resolution and capability. It is available in a DIP 40 package after all, there¡¯s only so fast you can go before pin parasitics make it not worth your while. Still, two chips and some discrete parts is all you need, and it will fit on a breadboard. 8 cores, hard 24 MIPS each, all timings fully deterministic.?
For Propeller 2, the chip has an 8-bit video ADC on every pin, as well as a very stiff 8-16bit DAC that updates in nanoseconds. It got 32 pins, all equivalent, all having those analog peripherals. Internal RAM bandwidth is measured in gigabytes/s, and everything is hard real time ¨C no caches, no fluff, and an instruction set purposefully designed for humans to write in. You can do a XY display using nothing but the evaluation kit, quite literally.
I¡¯d advise anyone who hasn¡¯t looked into it to consider those platforms. They are a joy to work with. A rudimentary 4MHz analog bandwidth X+Y display can be had in an afternoon, with direct HDMI output from Prop 2, or an extended audio bandwidth from Prop 1, onto a VGA analog connector. Prop 1 can sigma-delta sample audio frequencies without external hardware. With an external ADC it gets more capability but at that point Prop 2 is a good alternative.?
Cheers, Kuba
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6 nov. 2021 kl. 4:33 em skrev peter bunge <bunge.pjp@...>:
? I looked at the 1700 page data sheet for the Arm Cortex 32 bit CPU and the much smaller development board data sheet (30 pages?). It looks complicated! I have a RaspberryPi 3 inserted in a SmartiPi Touch Case with wireless ISB keyboard. I think it would be easier to use and it has a higher resolution screen. $350 Cdn if I remember correctly. It may be easier to replace in 5 years time when the ST becomes obsolete.
I am impressed with the video and would love to add an LCD to my HP4192A Impedance Analyzer that has no CRT and expects an XYY analog pen plotter. Anyone interested please contact me privately and maybe we can do something. I also have a Tek 576 Curve Tracer but the CRT is good and I have a spare. I can see the advantages of updating it. Keep me in the loop,?I may be able?to contribute. I updated my HP8753B with the Newscope LCD and am delighted with it. My HP8757C has a colour LCD and is excellent but a bit dim in bright lighting, as is my HP54542C DSO. Getting a digital screen capture would be great as well. My 3 HP mentioned have ways to get a screen capture (John Miles 7470A emulator, Prologix USB/GPIB, and a USB floppy reader). What language is the software written in? I am struggling with a decision to learn Python but have pretty well decided to stick to C which I use for programming PICs. Python would be a huge distraction and time burner for me. Peter
hi,
In the event of instrument CRT death, one might want to do a replacement having an LCD display:
The question is:
-- are there any existing modules ( or schematics, or projects )? that might be used for an HP older instrument having an XY (XYZ or Vector) type CRT that would allow replacement of the CTR with an LCD ( & also provide a laptop connection for data manipulation & saving ) ?
This question is for a Vector type XY or XYZ CRT?? found in some older scopes, ... & ? for example the Tek 576 Curve Tracer ( CT ) :
??? {??? Raster type CRT to VGA type modules can be had inexpensively on eBay for ~ $29,etc.? .... and is not the topic in this thread }
There has been some recent discussion about this for the Tek 576 CT on that Groups .io .... without a resolution as of yet,
but the same solution *might* be of use to older HP instruments as well ?
/g/TekScopes/topic/86718765
and
/g/TekScopes/topic/69490299#164207
Anyway, looking for a solution to this XY ( XYZ, Vector )? type CRT to LCD problem.
{ Not wanting to replace the CRT with another CRT ! }
There is an example of someone doing a retrofit add-on LCD module for an HP 141T 18GHz SA:
The individual did not make any further YouTube video upgrades to that project; but it is a start !
The discussed ST LCD module is not too expensive ( $55 to $130 ).
The video Arcade Game folks do have an expensive module that can do this for their Vector type CRT's,
... discussed in the Tek Curve Tracer CRT discussion : /g/TekScopes/topic/86718765
However, this Tempest module ( ~$525 !! ) & the NewScope modules are way too expensive !
-- So, would not be buying those at all !
So, looking for a less expensive module or schematics of such to attempt a DIY for the XY (XYZ or Vector) CRT to LCD replacement.
>> Anyone having specific detailed technical knowledge for an XY (XYZ, Vector) to LCD module, or schematics? to the above issue ?
? would be appreciated.
thank you,
rick
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Re: Placing Shelf on Casters for HP Equipment
Matt -
I tend to agree with your reasoning on a number of point - particularly access. 19" racks are an excellent choice for equipment that is committed to a particular configuration - e.g. An 8510 network analyzer along with the IF, test set, committed source. Note that I am assuming a single rack, not multiple racks bolted together.
Some benefits:
1) Strength and design
2) Order - many have cable routing channels
3) Good rear access
4) Ventilation
5) Built in power distribution
BUT there are some disadvantages:
1) Horizontal access (unless you bolt multiple racks together)
2) Accommodating non 17" wide equipment (Yes - Hp has solutions for this but part are expensive and hard to find)
3) Changing configurations (the relationship between various pieces) and access to features accessed from the rear of the equipment e.g Z-axis on Tek scopes, sweep out of signal generators and spectrum analyzers, etc
My advice would be to use what you currently have - note things that are "problems" and decide whether a rack is necessarily the est solution.
As I mentioned above, sometimes it is and sometimes not. My current arrangement is similar to yours; it works well for me because I frequently reconfigure stuff. It is much messier (at least the part that can be seen) that something built in a bunch of bolted together racks, but that is part of the ambiance of a home lab :-)
BTW - I have moved 3 times and think before moving again, I may consider dying :-)
Cheers!
Bruce
Quoting Matt Huszagh <huszaghmatt@...>:
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I keep basically all of my large and heavy (mostly HP) equipment on a
heavy-duty shelf I ordered from McMaster-Carr
(). I recently moved and wound up with
less space than I previously had. Before, I left about 2.5' behind the
instrument rack to be able to access the backs of the equipment. But, I
could really use that space in the new spot. So, I thought it might be
nice to put my normally stationary shelf on casters. This way I can roll
the shelf out when I need access to the rear of the instruments and keep
it against the wall for normal use. However, I'd very much like to
ensure my equipment doesn't go toppling over when I move it. I posted
about this on eevblog
()
and received some really great advice, which has gotten me to the
current iteration of the design (more on this momentarily). However, I
wanted to field advice from people on this thread who are probably more
used to large and heavy equipment than most.
I've modeled the shelf + casters in CAD and added pictures to this
post. The leveling+swiveling casters are also from McMaster-Carr
(). Basically, I'll put the shelf on
two C channels. The channel will be bolted to the shelf just below each
vertical column. I've designed the length of the channel to be longer
than the depth of the shelf so that the distance between the center of
the wheels when both wheels are rolled inward is still wider than the
depth of the shelf (24").
Some things to note. I'd estimate the total weight of my equipment
between 500 and 1000 lbs, though I'm guessing. The diameter of the
wheels is only 2". However, I'll be careful to ensure there is nothing
in the path of the wheels when I roll it out or in. Also, this is on
flat, hardwood floor. Most of the weight of the shelf is placed on the
middle two shelves since that's where it's accessible. Obviously from a
stability perspective it would be better if it were on the
bottom. Unfortunately, that's not an option. Though I wouldn't
necessarily be opposed to putting weights on the bottom shelf if people
feel that's a major improvement.
Lastly, a previous thread here
(/g/HP-Agilent-Keysight-equipment/topic/racks_for_older_equipment/72918532?p=Created%2C%2C%2C20%2C1%2C0%2C0&prev=1)
contained some good information about this topic. The takeaway seemed to
be that proper NSF metro racks are a good way to achieve what I'm
looking for. And, from Don's comment, it sounds like this is what HP
used for their mobile cal lab, which is obviously a big
endorsement. However, I've already sunk a good chunk of money into this
shelf and would like to use it rather than buying something new. Also,
my uninformed impression is that my shelf looks a bit sturdier than the
metro racks. I could very well be wrong though and would be greatful to
hear why!
Thanks!
Matt
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Re: Placing Shelf on Casters for HP Equipment
Yeah, hard to know sometimes that what seems second nature to some of us may not be familiar to others. I deal with both DC to microwave electronics and audio, so it's a double whammy for me! The audio racks tend to be less expensive and not as beefy. Audio boxes with single boards inside them and just a few chips don't need nearly as much heft in supporting them as say, a 112 pound HP 8566 spectrum analyzer, as you can imagine.
Another good thing to know is that 1 rack unit (1 RU) = 1.75 inches. That is the smallest (AFAIK) height of a box to be mounted in a 19 inch rack. The two units of the aforementioned 8566 are each 3 RU, or 5.25 inches high. 5 RU is common in microwave instrumentation, as well (8.75 inches tall). I can't think of any even numbered RU height boxes, though.
Good luck in setting up your lab!
Jim Ford
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------ Original Message ------ From: "Matt Huszagh" <huszaghmatt@...> To: "Dave McGuire" <mcguire@...>; [email protected]Sent: 11/7/2021 7:38:07 PM Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment "Dave McGuire" <mcguire@...> writes:
You're not familiar with 19" racks, which have been ubiquitous in
many industries for about a century?
- test equipment
- computing
- telephony
- sound reinforcement
- pro music gear (synthesizers, audio processing)
- industrial automation
- [probably more that I can't think of offhand]
I'm not trying to talk down to you, man, but I can't see how anyone
who has lived on Earth for awhile couldn't know about these. Heck, my
grandmother suggested to me that I should get one when I was about 14,
in the 80s. I googled "HP test equipment rack" and the 19" rack popped up. I have
seen these before, though I didn't know the term (or know that it was a
standard). I also did not know that these are what HP, Agilent and
Keysight use for their test equipment racks.
I'm not sure if this is a good excuse but I'm relatively young (< 30)
and only been doing electronics for the last couple years, when I
started teaching myself. I also don't come from an engineering
background, so I've probably missed some things that are evident to
others in the field. I did study physics undergrad though, and research
is one of the places I've come across these. But, none of us were too
concerned that these were called 19" racks.
Matt
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Re: Placing Shelf on Casters for HP Equipment
"Dave McGuire" <mcguire@...> writes: You're not familiar with 19" racks, which have been ubiquitous in
many industries for about a century?
- test equipment
- computing
- telephony
- sound reinforcement
- pro music gear (synthesizers, audio processing)
- industrial automation
- [probably more that I can't think of offhand]
I'm not trying to talk down to you, man, but I can't see how anyone
who has lived on Earth for awhile couldn't know about these. Heck, my
grandmother suggested to me that I should get one when I was about 14,
in the 80s. I googled "HP test equipment rack" and the 19" rack popped up. I have seen these before, though I didn't know the term (or know that it was a standard). I also did not know that these are what HP, Agilent and Keysight use for their test equipment racks. I'm not sure if this is a good excuse but I'm relatively young (< 30) and only been doing electronics for the last couple years, when I started teaching myself. I also don't come from an engineering background, so I've probably missed some things that are evident to others in the field. I did study physics undergrad though, and research is one of the places I've come across these. But, none of us were too concerned that these were called 19" racks. Matt
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Re: Placing Shelf on Casters for HP Equipment
On 11/7/21 7:56 PM, Matt Huszagh wrote: I understand many people like to re-engineer things their way but, HP, Agilent and Keysight must have already put a lot of thought and effort into the instrument racks they and other T&M companies sell. I find these racks very cheap at ham swap meets or the local junk yard.
Is there a problem with them for your application? Probably not. I'm just not familiar with these; I don't even know what
they look like. If you have a picture or something else that would be
great to see.
You're not familiar with 19" racks, which have been ubiquitous in many industries for about a century? - test equipment - computing - telephony - sound reinforcement - pro music gear (synthesizers, audio processing) - industrial automation - [probably more that I can't think of offhand] I'm not trying to talk down to you, man, but I can't see how anyone who has lived on Earth for awhile couldn't know about these. Heck, my grandmother suggested to me that I should get one when I was about 14, in the 80s. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Richard,
The voltage at the R40/31/30 junction should be in the order of -180VDC with respect to the chassis. Note that this is the negative bias voltage generated across R40.
If your voltage is +132V at R40/31/30 you have big troubles ¨C maybe check again to see if it is in fact negative.
Next check the voltages at the cathodes of V2 and V4 these should be in the vicinity of -3.6VDC ¨C mine are -3.2 and -2.8 and the generator works OK. This is pin 3 on V2 and 4.
Also check the grids of V2 and 4. Pin 2, ?and these should be around -19.5 or some such. Again mine are different at -16.5 and -16.7.
Another check is to monitor the voltage at the junction of
R40/31/30 whilst changing the Range switch from x100 to x 10K. there should be very little if any change. This checks to see if there are any issues with the two output transformers.
One more thing ¨C on almost every 200CD that I have see C12 100uF NON POLARISED has gone bad. As we are only looking at the DV characteristics at present disconnect C12 9accross C30/31) and see if
there are any changes to the DC bias voltages.
?
Good luck
Mark
?
?
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From: [email protected] <[email protected]>
On Behalf Of Richard Merifield via groups.io
Sent: Sunday, 7 November 2021 8:44 PM
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] HP200CD oscillator
?
I repaired L2 as best I could and it measured ok so thought I would give it a try. I suspect on 6AU6 may be part of my problem. I swapped them around and I now have a perfectly functional unit as far as I can tell, except R30 gets scolding
hot still. I have 4 more 6AU6 coming.
I measured the voltage at the R40/R31/R30 junction at 132V DC and -5.8V and -5.3V on the other side of R30 and R31 respectively with respect to chassis ground. Why would R30 get twice as hot as R31 given those measurements? Don't they effectively have almost
the same current flowing across them ? I desoldered R30 and it measure 3.1kOhm but perhaps something else is wrong with it ?
I think I am getting closer
Regards
Richard
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Re: Placing Shelf on Casters for HP Equipment
"mark hawk" <mvhawk@...> writes: I understand many people like to re-engineer things their way but, HP, Agilent and Keysight must have already put a lot of thought and effort into the instrument racks they and other T&M companies sell. I find these racks very cheap at ham swap meets or the local junk yard.
Is there a problem with them for your application? Probably not. I'm just not familiar with these; I don't even know what they look like. If you have a picture or something else that would be great to see. Matt
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Re: Placing Shelf on Casters for HP Equipment
I understand many people like to re-engineer things their way but, HP, Agilent and Keysight must have already put a lot of thought and effort into the instrument racks they and other T&M companies sell. I find these racks very cheap at ham swap meets or the local junk yard.
Is there a problem with them for your application?
Mark Hawk
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Dave McGuire