Re: Placing Shelf on Casters for HP Equipment-cooling
On 11/9/21 6:29 AM, alwyn.seeds1 wrote: Out from behind the rack rather than from the woodwork.
The 8642A Signal Generator has holes in the top and bottom covers- I have allowed 1U above and below for air intake- is this unnecessary? As with everything else, use judgment. If there are vents, either they were there for good reason or they were specified in error, like someone being too paranoid. I don't have any 8642As, but if I did, I would err on the side of caution and leave that gap as you have. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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You need to bear in mind that power resistors of the ceramic wirewound, or metal film, variety are heaters. They are designed to get very hot at their *rated* power. 200C is typical. Most wirewound resistors can be made to glow red hot without anything more than a little discoloration. The wire used is typically nichrome heating element wire. For safety issues, engineers usually don't want anything that hot inside of their chassis, but in cases where they need bulk power dissipation, sometimes they do. Assuming that these resistors are DC load, resistors, measure the voltage across the resistor using a dc meter, and plug that value into Power = V*V/R, and if Power is less than the resistor's rated value, you are probably ok. Engineers typically spec their resistors to run at about 1/2 the manufacturer's rated power. There is no point in paying for a large power resistor if you don't need a large power resistor. -Chuck Harris On Tue, 09 Nov 2021 04:04:39 -0800 "Richard Merifield" <coitboy2000@...> wrote: Thanks Morris, yes I will transfer it over to 240V.
...Before I did so I noticed R30 was
scolding hot like my other unit. I wonder whether they ever
considered high wattage resistors for R30 ?
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Thanks Morris, yes I will transfer it over to 240V.
My second 200CD serial Prefix 333 arrived today, that is already 240V so I can double check my wiring.
I tried it on the dimb bulb and it seemed ok so I ramped it up with the variac to 240V and out popped a clean sign wave..... incredible, this unit looks untouched like the last although getting the tubes out for a clean was far more difficult suggesting they have never been pulled. I noticed a bit of a smell and established C13 was getting very hot so shut it down. Before I did so I noticed R30 was scolding hot like my other unit. I wonder whether they ever considered high wattage resistors for R30 ?
I now have a double restoration underway, nice to save some HP history. This unit has a charcoal case and the other is a textured copper/brown colour.
Yes I am in Newcastle NSW, Australia. Love to know if anyone has a tube tester nearby and willing to check a few tubes. It seems like an indispensable item if you do a lot of tube work I guess ?
Regards
Richard
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Re: Placing Shelf on Casters for HP Equipment-cooling
Dear Dave,
Out from behind the rack rather than from the woodwork.
The 8642A Signal Generator has holes in the top and bottom covers- I have allowed 1U above and below for air intake- is this unnecessary?
Regards,
Alwyn
_____________________________________________________
Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.
SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom. _____________________________________________________
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Re: HP ET8866 True RMS meter - any info on this?
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Re: HP ET8866 True RMS meter - any info on this?
OK, I've got some pictures for you: The front panel:  The probe:  Right side:  Left side:  The circuit board: 
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Re: Placing Shelf on Casters for HP Equipment
I use a straight line layout, with two rows of benches. so I can just turn around to work on the other set of benches. I currently have seven workbenches, in several different outbuildings. My other shop is 18' by 28' wher I do metalworking, or scrap old equipment. About 300 banana boxes. two rows deep along the outside walls and tree deep down the center gives a? lot of cheap storage. Junk equipment is stored there, along with salvaged parts and used circuit boards. Things that I don't need to get to, very often.
On Mon, Nov 8, 2021 at 5:16 PM Paul Bicknell < admin@...> wrote:
Hi Michael?
Regarding your line Why would you put a rack behind a four foot deep workbench? and i would agree as 24 inch would be about wright
I think there might be a typo in the original
as i would take ( arranged in a "L" with a 45" splice ) as arranged in a "L" with a 45 degree splice
Regards Paul?
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Re: Placing Shelf on Casters for HP Equipment
That large detached garage was why I bought this house. I installed a 100A breaker box in it, and installed switches by each door to divide the 10' by 20' bays in half, so you can light any 10' by 10' square that you want. Double, duplex outlets every ten feet along the walls, and the rear 10; by 40' is for office and storage., if I don't get around to building a 40 foot long bench against the rear wall. I also installed dual duplex outlets under each pair of light switches on the door posts. Everything in EMT, except for cords where the overhead lights plug in.
I'm envious, Michael!? I'm lucky if I have 50 square feet.? More if I move the car out of the garage, though.? Few hundred sq ft max.? ?Jim
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message -------- Date: 11/8/21 12:34 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment
Some of the racks are free standing, and others are beside the bench. My workshop is 1200 square feet, in a stand alone garage.
On Mon, Nov 8, 2021 at 3:17 PM Bruce < bruce@...> wrote: Interesting idea - but if the rack is behind a bench, the drawers are?
a bit difficult to get to.? Much depends on how yu position the?
equipment "racking" relative to the work space.
Cheers!
Bruce
Quoting "Michael A. Terrell" <terrell.michael.a@...>:
> I collected turntable drawers from old school intercom systems. With a
> little work, I turned them into drawers to go in the lower part of racks to
> store cables and small equipment.
>
> On Mon, Nov 8, 2021 at 3:05 PM Bruce <bruce@...> wrote:
>
>> One disadvantage to racks is that it is difficult to utilize the space
>> below bench level.? If you look at HP packaged configurations (HP
>> 8510C for example) does not have front panel control or is controlled
>> ia GPIB.
>>
>> True, things like power supplies can be used on the lower level, but
>> generally bench top access is required for test equipment - GPIB
>> control is an option but commercial software is expensive and
>> configuration management can be complicated.
>>
>> Cheers
>>
>> Bruce
>>
>>
>>
>> Quoting Dave McGuire <mcguire@...>:
>>
>> > On 11/7/21 9:53 PM, Jim Ford wrote:
>> >> 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.
>> >
>> >? ?The HP System I (example: 8640B) chassis system has handles built
>> > into the side frame castings, and ears that work with them.? The
>> > System II (example: 8566, 8350) chassis systems have ears that work
>> > standalone, and ears that work with handles.
>> >
>> >? ? ? ? ? ? ?-Dave
>> >
>> > --
>> > Dave McGuire, AK4HZ
>> > New Kensington, PA
>> >
>> >
>> >
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
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Re: Placing Shelf on Casters for HP Equipment
I was just trying to point out that racks aren't always obvious at first glance. Back in the late '80s I worked a few doors from a Diebold office. They frequently tossed entire, obsolete racks of equipment in their dumpster. Short, enclosed but usually only a bit dusty. Another place where I worked scrapped tractor trailer loads of electronics. At times I had to send 20+ nice racks to the scrapyard, because no one wanted them, even for free. Some high speed drum printers were built on four foot tall racks, and like the full sized ones, no one wanted them. I did take a nice pair of Aluminum racks with clear doors that had housed some DEC VAX systems. They are so deep that a lot of equipment can be mounted using both ends. Racks are out there, if you keep your eyes open.
Thanks, Michael.? ?Always interesting to hear how people have obtained equipment, on-topic or not.? ? ? ? Jim
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message -------- Date: 11/8/21 9:36 AM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment
Yes, it was 'Point Of Sale' hardware. I bought both minicomputers, ten in counter LASER scanners along with 14 cash registers and 14 printers. Two complete systems, from two stores..They threw in two chargers and an electric pallet jack, all for $100. I scraped the scanners for the LASER tubes and power supplies. I sold them for $400, and I got about $75 for the machined aluminum housings. The profits went to more equipment for the shop, at the Orlando Hamfest.
I take it POS stands for Point Of Sale, not Piece Of S***.? When I was in engineering school in the 1980s, we used the DEC Pro 350 computers, and they actually had an operating system called pOS!? Not a well thought out name!? ? ? ?Jim Ford?
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message -------- Date: 11/8/21 12:33 AM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment
There are also 23" wide racks that came from the Telco industry.
I have two, dual sized enclosed racks They are 19", but you can remove the doors and side panels, then turn it 90 degrees to use it as a 23" rack.
They are from some long gone National Semiconductor Datachecker POS systems that were scrapped 25 years ago. On Sun, Nov 7, 2021 at 10:31 PM Dave McGuire < mcguire@...> wrote: 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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HP83595A/B (HP 8350) ROM firmware required
Hello!
Any one has an 83595 plugin (HP 8350) with firmware rev.7 ? I need the U1 U2 ROM contents to make it work with 8510B. At this moment I only found the rev. 4 on KO4BB, and seems only the rev.7 work with 8510B.?
If you got an 83595 with firmware rev.7 please upload the ROM content to KO4BB, and/or let me know.?
Thanks lot !
p.s? to check the plugin firmware revision:? switch 8510B on [ shift ] [ 99 ]. Look the number shows on the plugin display.
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Re: HP 83592B hangs 8350B sweeper
Guss you have an A6 from 83595. I would replace U1 U2 ROMs with 'correct' firmware to convert it in to a 26.5G 83595 instead replace those precision resistors.
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Re: Placing Shelf on Casters for HP Equipment
Hi Mat
We seem to have gone backwords did you receive my privet Email with the picture of the side rails
Theas being a lot cheaper than slides even if you have the correct both halves of a slide installing them can take
5 times the time compared to a side rail, mainly if the rack is built and you are modifying it
PS Dave is correct on all pointes Regards Paul
toggle quoted message
Show quoted text
-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Dave McGuire Sent: 09 November 2021 01:55 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment On 11/8/21 8:24 PM, Matt Huszagh wrote: I'm still trying to understand how heavy pieces of equipment are
supposed to be supported within a 19" rack. Here's what I understand
so far. There seem to be basically three options, the first two being
more "official" than the third.
The first option is that support rails are fastened to the rack in
holes oriented 90 degrees relative to the normal front and back
mounting holes. I've attached a photo that shows this, stolen from
ment-ie-hp8644ab/. I'm not endorsing the non-metal screws here, but
this is the best picture I could find that illustrates the concept.
These are called "rails". The module is placed on these rails. Then,
flanges attached to the front of the instrument are fastened to the
holes on the front of the rack. The rails support most of the weight
instead of the front flanges. From the front it only looks like the
instrument is attached to the rack from the flanges; the rails are not
visible. These rails additionally do not take up any "rack unit"
space, so that one instrument can be placed immediately below or above another.
The second option is that the instrument is somehow fastened to "slides"
that are capable of supporting the instrument weight. These seem nice
but are more expensive. I won't discuss this further since I don't
know much about it yet.
The third option is to use a shelf that attaches to all 4 posts of the
rack on the front and back facing fastening holes. Then, the equipment
simply sits on this shelf (these shelves sometimes support being
pulled out). When using sufficiently heavy-duty shelves (e.g., the
black box
RM399 that Dave mentioned), multiple instruments can be stacked on top
of each other, all supported by the same shelf. This seems like the
somewhat less "official" solution but nonetheless works. One
difficulty with it is that you can only remove the top-most instrument of a shelf.
Is this a correct assessment? More or less. First, there's nothing more or less "official" here; these are all perfectly valid and common approaches. And there's also cantilevered mount, which is when the rack mount ears of the mounted device support the entire weight of the device. I like option 1 (well option 2 as well, but that seems a bit more
complicated and probably quite a bit more expensive). My difficulty
with this is that I'm having trouble finding suitable rails (to use
the above terminology). NavePoint sells these server rack rails:
rails-full-depth/
But, the problem with them seems to be that they mount to the front
and back of the rack. The instrument flange (or "ears") would then
need to mount over these. So, when you unfasten the flanges to remove
the instrument you lose the rail support. One way around this would be
to simply rest the instrument on the rails and not fasten the flanges.
That's probably ok. This is a very common approach for stationary applications, not fastening the ears if the unit is otherwise supported. Rack slides are less common for test equipment than for computer equipment. Rack slides typically cost hundreds of dollars, and must be specifically supported by (i.e., designed for use with) a given piece of equipment. Rack slides usually come in two pieces: the part that is screwed to the unit, an the part that's screwed into the rack. Sometimes there's a third "floating" piece in the middle, but that's not as common as it used to be. There are many variations, some of which work well, and some, not so much. Modern server-class computer equipment manufacturers, in particular, seem to take great delight in making their rack slides incompatible with those of their competitors, and even with their own, from model to model and from generation to generation. It is a racket. (heh, get it? ;)) The terminology is very flexible, mainly because these things are so damn common, and have been for so many years, across so many different industries. People come up with their own unofficial terms ("ears") and they stick, and some eventually become a part of the vernacular. Slides, rails, shelves, and ears are the terms that you will likely hear the most often in this context. Sometimes people use "rails" and "slides" interchangeably. There are also variations, like shelves that mount on slides. There are also other neat accessories, like drawers (actual drawers, like for tools, cables, or...well, underwear) that are rack-mounted. In the context of test equipment, I suggest that you not get your heart set on slides. They're less common in that world than in some others, they're difficult to find, and they're very expensive. One reason they're difficult to find is that warehouse grunts pull instruments (or computers) out of racks and leave the rack-side parts of the slides in the racks, and auction off the unit with half of the slides still screwed to the unit. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Placing Shelf on Casters for HP Equipment
On 11/8/21 8:24 PM, Matt Huszagh wrote: I'm still trying to understand how heavy pieces of equipment are
supposed to be supported within a 19" rack. Here's what I understand so
far. There seem to be basically three options, the first two being more
"official" than the third.
The first option is that support rails are fastened to the rack in holes
oriented 90 degrees relative to the normal front and back mounting
holes. I've attached a photo that shows this, stolen from
. I'm
not endorsing the non-metal screws here, but this is the best picture I
could find that illustrates the concept.
These are called "rails". The module is placed on these rails. Then,
flanges attached to the front of the instrument are fastened to the
holes on the front of the rack. The rails support most of the weight
instead of the front flanges. From the front it only looks like the
instrument is attached to the rack from the flanges; the rails are not
visible. These rails additionally do not take up any "rack unit" space,
so that one instrument can be placed immediately below or above another.
The second option is that the instrument is somehow fastened to "slides"
that are capable of supporting the instrument weight. These seem nice
but are more expensive. I won't discuss this further since I don't know
much about it yet.
The third option is to use a shelf that attaches to all 4 posts of the
rack on the front and back facing fastening holes. Then, the equipment
simply sits on this shelf (these shelves sometimes support being pulled
out). When using sufficiently heavy-duty shelves (e.g., the black box
RM399 that Dave mentioned), multiple instruments can be stacked on top
of each other, all supported by the same shelf. This seems like the
somewhat less "official" solution but nonetheless works. One difficulty
with it is that you can only remove the top-most instrument of a shelf.
Is this a correct assessment? More or less. First, there's nothing more or less "official" here; these are all perfectly valid and common approaches. And there's also cantilevered mount, which is when the rack mount ears of the mounted device support the entire weight of the device. I like option 1 (well option 2 as well, but that seems a bit more
complicated and probably quite a bit more expensive). My difficulty with
this is that I'm having trouble finding suitable rails (to use the above
terminology). NavePoint sells these server rack rails:
But, the problem with them seems to be that they mount to the front and
back of the rack. The instrument flange (or "ears") would then need to
mount over these. So, when you unfasten the flanges to remove the
instrument you lose the rail support. One way around this would be to
simply rest the instrument on the rails and not fasten the
flanges. That's probably ok. This is a very common approach for stationary applications, not fastening the ears if the unit is otherwise supported. Rack slides are less common for test equipment than for computer equipment. Rack slides typically cost hundreds of dollars, and must be specifically supported by (i.e., designed for use with) a given piece of equipment. Rack slides usually come in two pieces: the part that is screwed to the unit, an the part that's screwed into the rack. Sometimes there's a third "floating" piece in the middle, but that's not as common as it used to be. There are many variations, some of which work well, and some, not so much. Modern server-class computer equipment manufacturers, in particular, seem to take great delight in making their rack slides incompatible with those of their competitors, and even with their own, from model to model and from generation to generation. It is a racket. (heh, get it? ;)) The terminology is very flexible, mainly because these things are so damn common, and have been for so many years, across so many different industries. People come up with their own unofficial terms ("ears") and they stick, and some eventually become a part of the vernacular. Slides, rails, shelves, and ears are the terms that you will likely hear the most often in this context. Sometimes people use "rails" and "slides" interchangeably. There are also variations, like shelves that mount on slides. There are also other neat accessories, like drawers (actual drawers, like for tools, cables, or...well, underwear) that are rack-mounted. In the context of test equipment, I suggest that you not get your heart set on slides. They're less common in that world than in some others, they're difficult to find, and they're very expensive. One reason they're difficult to find is that warehouse grunts pull instruments (or computers) out of racks and leave the rack-side parts of the slides in the racks, and auction off the unit with half of the slides still screwed to the unit. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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My brother is helping a friend sell off his tektronics, hp, heathkit test and measurement collection
My brother is helping and old friend sell off his test equipment collection. He has Tek, HP and Heathkit stuff and more.? My brother's email is codaman33@..., contact him for pictures in info. He lives in Houston down by NASA.
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Re: Placing Shelf on Casters for HP Equipment
I'm still trying to understand how heavy pieces of equipment are
supposed to be supported within a 19" rack. Here's what I understand so
far. There seem to be basically three options, the first two being more
"official" than the third.
The first option is that support rails are fastened to the rack in holes
oriented 90 degrees relative to the normal front and back mounting
holes. I've attached a photo that shows this, stolen from
. I'm
not endorsing the non-metal screws here, but this is the best picture I
could find that illustrates the concept.
These are called "rails". The module is placed on these rails. Then,
flanges attached to the front of the instrument are fastened to the
holes on the front of the rack. The rails support most of the weight
instead of the front flanges. From the front it only looks like the
instrument is attached to the rack from the flanges; the rails are not
visible. These rails additionally do not take up any "rack unit" space,
so that one instrument can be placed immediately below or above another.
The second option is that the instrument is somehow fastened to "slides"
that are capable of supporting the instrument weight. These seem nice
but are more expensive. I won't discuss this further since I don't know
much about it yet.
The third option is to use a shelf that attaches to all 4 posts of the
rack on the front and back facing fastening holes. Then, the equipment
simply sits on this shelf (these shelves sometimes support being pulled
out). When using sufficiently heavy-duty shelves (e.g., the black box
RM399 that Dave mentioned), multiple instruments can be stacked on top
of each other, all supported by the same shelf. This seems like the
somewhat less "official" solution but nonetheless works. One difficulty
with it is that you can only remove the top-most instrument of a shelf.
Is this a correct assessment?
I like option 1 (well option 2 as well, but that seems a bit more
complicated and probably quite a bit more expensive). My difficulty with
this is that I'm having trouble finding suitable rails (to use the above
terminology). NavePoint sells these server rack rails:
But, the problem with them seems to be that they mount to the front and
back of the rack. The instrument flange (or "ears") would then need to
mount over these. So, when you unfasten the flanges to remove the
instrument you lose the rail support. One way around this would be to
simply rest the instrument on the rails and not fasten the
flanges. That's probably ok.
Any advice (and especially pictures!) illustrating proper use etc. would
be greatly appreciated. As always, thanks so much.
Matt
|
Re: Placing Shelf on Casters for HP Equipment
One other thing that I should mention here is side panels. One big difference between most test equipment and most server-class computer equipment is where the actual air intakes are. On most (most!) server-class computer equipment, the air intakes are on the front. On most (again, most!) test equipment, the air intakes are along the sides. Both typically exhaust to the rear.
Some racks from the computer world have fairly tight-fitting side panels. You can almost always leave them on, but it pays to take a look in there to ensure that there's enough "breathing room" for the vented sides of (usually HP) test equipment to ingest air.
-Dave
toggle quoted message
Show quoted text
On 11/8/21 5:54 PM, Paul Bicknell wrote: OK Dave
Regarding the air vents on top I stand corrected and was thinking of Audio
equipment and power supplies
Regarding 100% rack capacity OK for a rack with 1 KW consumption but a rack
with 2 Kw consumption we require a bit of space
And above 2 KW we require a bit of management such as Fans
I think the key line hear is as you say
Be consistent about front-to-back vs. back-to-front cooling, so that one
instrument doesn't ingest another instrument's exhaust, and it's perfectly
fine. (and very common)
Best Regards Paul
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Dave McGuire
Sent: 08 November 2021 22:24
To: [email protected]
Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP
Equipment
On 11/8/21 4:57 PM, Paul Bicknell wrote:
Plus you cannot pack a 19 inch rack 100 % ?and that is a different
subject if a unit has vent holes on the top you require 1 U space
above or sometimes a fan tray Vertical cooling goes against every accepted standard for rack-mount
system design. In practice, almost nothing actually does it.
Now watch people will come out of the woodwork quoting one make/model of
thing that does, but my point stands.
For decades I have packed racks 100% full with 24/7-running equipment.
Be consistent about front-to-back vs. back-to-front cooling, so that one
instrument doesn't ingest another instrument's exhaust, and it's perfectly
fine. (and very common)
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
--
Dave McGuire, AK4HZ
New Kensington, PA
|
Re: Placing Shelf on Casters for HP Equipment
I'm envious, Michael!? I'm lucky if I have 50 square feet.? More if I move the car out of the garage, though.? Few hundred sq ft max.? ?Jim
Sent from my Verizon, Samsung Galaxy smartphone
toggle quoted message
Show quoted text
-------- Original message -------- From: "Michael A. Terrell" <terrell.michael.a@...> Date: 11/8/21 12:34 PM (GMT-08:00) Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment
Some of the racks are free standing, and others are beside the bench. My workshop is 1200 square feet, in a stand alone garage.
On Mon, Nov 8, 2021 at 3:17 PM Bruce < bruce@...> wrote: Interesting idea - but if the rack is behind a bench, the drawers are?
a bit difficult to get to.? Much depends on how yu position the?
equipment "racking" relative to the work space.
Cheers!
Bruce
Quoting "Michael A. Terrell" <terrell.michael.a@...>:
> I collected turntable drawers from old school intercom systems. With a
> little work, I turned them into drawers to go in the lower part of racks to
> store cables and small equipment.
>
> On Mon, Nov 8, 2021 at 3:05 PM Bruce <bruce@...> wrote:
>
>> One disadvantage to racks is that it is difficult to utilize the space
>> below bench level.? If you look at HP packaged configurations (HP
>> 8510C for example) does not have front panel control or is controlled
>> ia GPIB.
>>
>> True, things like power supplies can be used on the lower level, but
>> generally bench top access is required for test equipment - GPIB
>> control is an option but commercial software is expensive and
>> configuration management can be complicated.
>>
>> Cheers
>>
>> Bruce
>>
>>
>>
>> Quoting Dave McGuire <mcguire@...>:
>>
>> > On 11/7/21 9:53 PM, Jim Ford wrote:
>> >> 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.
>> >
>> >? ?The HP System I (example: 8640B) chassis system has handles built
>> > into the side frame castings, and ears that work with them.? The
>> > System II (example: 8566, 8350) chassis systems have ears that work
>> > standalone, and ears that work with handles.
>> >
>> >? ? ? ? ? ? ?-Dave
>> >
>> > --
>> > Dave McGuire, AK4HZ
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Re: Placing Shelf on Casters for HP Equipment
"Dave McGuire" <mcguire@...> writes: "Stuff fits." I can send you pictures if you want. ;) These
problems were solved decades before either of us was born. (and I've got
twenty years on you) No problem with that! And pictures would be amazing. Did you make your own supports from angle irons, Dave? It sounds like
getting 1.5 in sq angle irons 1/8" thick and then drilling custom holes
for mounting to the rack could work well here. I expect the trick is
drilling the holes at just the vertical height so that the modules sit
on the angle iron but the flanges still mount to the front panel. No, I'm too much of a perfectionist (read: snob) (and have too little
free time) to do that. I get proper rack rails, usually Navepoint these
days.
If it's not too much trouble, would you mind sending me a link to the Navepoint rack rails you get? I think I'm not finding quite the right thing.
At the museum, though, we occasionally receive equipment with angle
iron stock, and sometimes even [puke] WOOD, used as rack shelves.
Use the right tool for the job.
Thanks Matt
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Re: Placing Shelf on Casters for HP Equipment
OK Dave
Regarding the air vents on top I stand corrected and was thinking of Audio
equipment and power supplies
Regarding 100% rack capacity OK for a rack with 1 KW consumption but a rack
with 2 Kw consumption we require a bit of space
And above 2 KW we require a bit of management such as Fans
I think the key line hear is as you say
Be consistent about front-to-back vs. back-to-front cooling, so that one
instrument doesn't ingest another instrument's exhaust, and it's perfectly
fine. (and very common)
Best Regards Paul
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-----Original Message----- From: [email protected][mailto: [email protected]] On Behalf Of Dave McGuire Sent: 08 November 2021 22:24 To: [email protected]Subject: Re: [HP-Agilent-Keysight-equipment] Placing Shelf on Casters for HP Equipment On 11/8/21 4:57 PM, Paul Bicknell wrote: Plus you cannot pack a 19 inch rack 100 % ?and that is a different
subject if a unit has vent holes on the top you require 1 U space
above or sometimes a fan tray Vertical cooling goes against every accepted standard for rack-mount system design. In practice, almost nothing actually does it. Now watch people will come out of the woodwork quoting one make/model of thing that does, but my point stands. For decades I have packed racks 100% full with 24/7-running equipment. Be consistent about front-to-back vs. back-to-front cooling, so that one instrument doesn't ingest another instrument's exhaust, and it's perfectly fine. (and very common) -Dave -- Dave McGuire, AK4HZ New Kensington, PA
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Re: Placing Shelf on Casters for HP Equipment
On Sun, Nov 7, 2021 at 03:27 PM, Matt Huszagh wrote:
Some things to note. I'd estimate the total weight of my equipment
between 500 and 1000 lb. The diameter of the wheels is only 2". this is on
flat, hardwood floor.?
The castor raceway circumference and the ball bearing size, on the swivel) determine the carrying capacity of the swivel section, given the wheel can support that capacity.
If one is using traditional type castors... roughly a wheel, and axle, inside a U shaped frame... The leg thickness (the part through which the wheel axle passes)... and the leg width... will determine if the castor will fail due to a thrust loading. Forged steel (expensive) is stronger than stamped steel (cheaper); but the yield strength steel... is well large (strong if you like) The thicker a material is, compared to its width, the more it resists bending/folding... forged steel parts can be thicker than stamped ones.
Similar to the castor legs, wider... and larger diameter, castor wheels, support more weight. Given the load, larger diameter wheels are easier to roll. Larger diameter wheels have more of the wheel in contact with the floor.
Nylon wheels are harder, resist cracks, resist wheel flattening (due to infrequent moving)... but nylon wheels are hard. (larger diameter, wider, nylon wheels will reduce the pressure on the floor material.)
?
The required load capacity, per castor might be calculated by,
?
L = ( D+Z x S )/n
?
L = Required load capacity of the wheel
or castor
D = Dead weight of the shelving unit
Z = Maximum additional load (weight of the stuff on the shelves.)
n = Number of? castors used
S = Safety factor
?
n.b. the wheel is where the 'rubber' (weight) hits (contacts) the road (floor).
n.b. collapsed shelving is a drag.
?
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Dave McGuire
Jim Allyn - N7JA
Michael A. Terrell
Paul Bicknell
