|
While I've got it out, is anyone interested in the 647 tentative spec?
?
-Dave
|
Yes, i am interested in the scan ;-)
Matt
toggle quoted message
Show quoted text
--- In TekScopes@..., d.seiter@... wrote:
While I've got it out, is anyone interested in the 647 tentative spec?
-Dave
|
|
|
Here's the scan of the Tentative 647 spec.? Sorry it's a bit of a mess!? I can't figure out how to force?our copier to scan one 8x11 at a time instead of what it sees on the scan bed.? There must be a way, but it's not obvious.? If anyone has pdf editing software and wants to fix it, have at it!
?
-Dave
From: "mattko87" To: TekScopes@... Sent: Thursday, January 24, 2013 1:10:51 PM Subject: [TekScopes] Re: Tentative 647 scan?
?
Yes, i am interested in the scan ;-)
Matt
--- In TekScopes@..., d.seiter@... wrote:
>
>
>
> While I've got it out, is anyone interested in the 647 tentative spec?
>
>
>
> -Dave
>
|
Thanks for scanning it! I cleaned it up a bit:
-Kurt
toggle quoted message
Show quoted text
--- In TekScopes@..., d.seiter@... wrote:
Here's the scan of the Tentative 647 spec.?? Sorry it's a bit of a mess!?? I can't figure out how to force??our copier to scan one 8x11 at a time instead of what it sees on the scan bed .?? There must be a way, but it's not obvious.?? If anyone has pdf editing software and wants to fix it, have at it!
-Dave
----- Original Message -----
From: "mattko87"
To: TekScopes@...
Sent: Thursday, January 24, 2013 1:10:51 PM
Subject: [TekScopes] Re: Tentative 647 scan?
??
Yes, i am interested in the scan ;-)
Matt
--- In TekScopes@... , d.seiter@ wrote:
While I've got it out, is anyone interested in the 647 tentative spec?
-Dave
|
Beautiful - thank both of you!
Bernd
?
In a message dated 1/24/2013 8:20:03 P.M. Pacific Standard Time,
sipespresso@... writes:
toggle quoted message
Show quoted text
?
Thanks for scanning it! I cleaned it up a bit:
-Kurt
---
In TekScopes@...,
d.seiter@... wrote:
>
>
>
> Here's the scan of the
Tentative 647 spec.?? Sorry it's a bit of a mess!?? I can't figure
out how to force??our copier to scan one 8x11 at a time instead of what
it sees on the scan bed .?? There must be a way, but it's not
obvious.?? If anyone has pdf editing software and wants to fix it, have
at it!
>
>
>
> -Dave
>
>
>
> ----- Original Message -----
>
>
> From:
"mattko87"
> To: TekScopes@...
> Sent: Thursday, January 24, 2013 1:10:51 PM
> Subject:
[TekScopes] Re: Tentative 647 scan?
>
> ??
>
>
>
>
> Yes, i am interested in the scan ;-)
>
> Matt
>
> --- In TekScopes@... ,
d.seiter@ wrote:
> >
> >
> >
> > While
I've got it out, is anyone interested in the 647 tentative spec?
> >
> >
> >
> > -Dave
>
>
>
|
That looks MUCH better- thanks!
-Dave
From: "sipespresso" To: TekScopes@... Sent: Thursday, January 24, 2013 8:19:54 PM Subject: [TekScopes] Re: Tentative 647 scan?
?
Thanks for scanning it! I cleaned it up a bit:
-Kurt
--- In TekScopes@..., d.seiter@... wrote:
>
>
>
> Here's the scan of the Tentative 647 spec.?? Sorry it's a bit of a mess!?? I can't figure out how to force??our copier to scan one 8x11 at a time instead of what it sees on the scan bed .?? There must be a way, but it's not obvious.?? If anyone has pdf editing software and wants to fix it, have at it!
>
>
>
> -Dave
>
>
>
> ----- Original Message -----
>
>
> From: "mattko87"
> To: TekScopes@...
> Sent: Thursday, January 24, 2013 1:10:51 PM
> Subject: [TekScopes] Re: Tentative 647 scan?
>
> ??
>
>
>
>
> Yes, i am interested in the scan ;-)
>
> Matt
>
> --- In TekScopes@... , d.seiter@ wrote:
> >
> >
> >
> > While I've got it out, is anyone interested in the 647 tentative spec?
> >
> >
> >
> > -Dave
> >
>
|
Really nice. Once again the depth and team spirit of this forum shines. ? Curious…. The specification indicates that the scope can take 20G’s acceleration in any plain for a total of 12 hits. I assume that the 11ms duration is to give an idea of the impulse imparted for said acceleration. Anyway, these numbers seem to indicate that this scope could have been used to drive pilling and/or break concrete and be “oK” afterwards. I realize the analogy is a bit boastful, nonetheless for a piece of electronics to take that kind of abuse and keep functioning is impressive. More impressive to publish it as such. ? So to the question, some place along the line those kind of specifications appear to have been dropped and/or were no longer important. (well at least I don’t see them in the catalogues for the 7000 series scopes I concentrate on). ? By way of learning for me. Why were these kind of specifications important for the earlier scopes? What made them less important in later scopes? Do specifications like that exist for later scopes? I looked in a few 7000 series manuals and did not see anything resembling acceleration specs so again I assume not… However, my sample is extremely small so making any conclusions would be foolhardy. Hopefully some of you that have been in the industry for years will have better insight. ???? ? In any event, thanks as always for the bandwidth and the free education. Rob ????? ?
toggle quoted message
Show quoted text
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of d.seiter@...
Sent: Thursday, January 24, 2013 10:48 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Tentative 647 scan?? ? That looks MUCH better- thanks! -Dave
From: "sipespresso" <sipespresso@...>
To: TekScopes@...
Sent: Thursday, January 24, 2013 8:19:54 PM
Subject: [TekScopes] Re: Tentative 647 scan?
? Thanks for scanning it! I cleaned it up a bit:
-Kurt
--- In TekScopes@..., d.seiter@... wrote:
>
>
>
> Here's the scan of the Tentative 647 spec.?? Sorry it's a bit of a mess!?? I can't figure out how to force??our copier to scan one 8x11 at a time instead of what it sees on the scan bed .?? There must be a way, but it's not obvious.?? If anyone has pdf editing software and wants to fix it, have at it!
>
>
>
> -Dave
>
>
>
> ----- Original Message -----
>
>
> From: "mattko87"
> To: TekScopes@...
> Sent: Thursday, January 24, 2013 1:10:51 PM
> Subject: [TekScopes] Re: Tentative 647 scan?
>
> ??
>
>
>
>
> Yes, i am interested in the scan ;-)
>
> Matt
>
> --- In TekScopes@... , d.seiter@ wrote:
> >
> >
> >
> > While I've got it out, is anyone interested in the 647 tentative spec?
> >
> >
> >
> > -Dave
> >
>
|
Well, ?the catalogs from the mid to late 60's show Tek scopes around fighters, subs (if I recall correctly), etc. ?Maybe they were trying to impress military types that were used to seeing G ratings? ?A real flimsy guess... ? That's a lot of acceleration for a big piece of test gear!
-Dave
From: "Rob" To: TekScopes@... Sent: Thursday, January 24, 2013 10:16:57 PM Subject: RE: [TekScopes] Re: Tentative 647 scan?
?
Really nice. Once again the depth and team spirit of this forum shines. ? Curious…. The specification indicates that the scope can take 20G’s acceleration in any plain for a total of 12 hits. I assume that the 11ms duration is to give an idea of the impulse imparted for said acceleration. Anyway, these numbers seem to indicate that this scope could have been used to drive pilling and/or break concrete and be “oK” afterwards. I realize the analogy is a bit boastful, nonetheless for a piece of electronics to take that kind of abuse and keep functioning is impressive. More impressive to publish it as such. ? So to the question, some place along the line those kind of specifications appear to have been dropped and/or were no longer important. (well at least I don’t see them in the catalogues for the 7000 series scopes I concentrate on). ? By way of learning for me. Why were these kind of specifications important for the earlier scopes? What made them less important in later scopes? Do specifications like that exist for later scopes? I looked in a few 7000 series manuals and did not see anything resembling acceleration specs so again I assume not… However, my sample is extremely small so making any conclusions would be foolhardy. Hopefully some of you that have been in the industry for years will have better insight. ???? ? In any event, thanks as always for the bandwidth and the free education. Rob ????? ? From: TekScopes@... [mailto:TekScopes@...] On Behalf Of d.seiter@...
Sent: Thursday, January 24, 2013 10:48 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Tentative 647 scan? ? ? That looks MUCH better- thanks! -Dave
From: "sipespresso" <sipespresso@...>
To: TekScopes@...
Sent: Thursday, January 24, 2013 8:19:54 PM
Subject: [TekScopes] Re: Tentative 647 scan?
? Thanks for scanning it! I cleaned it up a bit:
-Kurt
--- In TekScopes@..., d.seiter@... wrote:
>
>
>
> Here's the scan of the Tentative 647 spec.?? Sorry it's a bit of a mess!?? I can't figure out how to force??our copier to scan one 8x11 at a time instead of what it sees on the scan bed .?? There must be a way, but it's not obvious.?? If anyone has pdf editing software and wants to fix it, have at it!
>
>
>
> -Dave
>
>
>
> ----- Original Message -----
>
>
> From: "mattko87"
> To: TekScopes@...
> Sent: Thursday, January 24, 2013 1:10:51 PM
> Subject: [TekScopes] Re: Tentative 647 scan?
>
> ??
>
>
>
>
> Yes, i am interested in the scan ;-)
>
> Matt
>
> --- In TekScopes@... , d.seiter@ wrote:
> >
> >
> >
> > While I've got it out, is anyone interested in the 647 tentative spec?
> >
> >
> >
> > -Dave
> >
>
|
20G isn't much - if you drop it two feet onto concrete it will get a much harder G shock than that.
Regards,
David Partridge
|
20G isn't much - if you drop it two feet onto concrete it will get a much harder G shock than that. Some time ago I collected a 5-series scope, and as a result of handle rot the whole massive scope crashed to the concrete path. Made a hell of a bang. And missed my toes thank heavens Turned it on and it worked perfectly! Hat's off to Tek's designers. Craig
|
On 01/25/2013 01:16 AM, Rob wrote:
Really nice. Once again the depth and team spirit of this forum shines.
Curious…. The specification indicates that the scope can take 20G’s acceleration in any plain for a total of 12 hits. I assume that the 11ms duration is to give an idea of the impulse imparted for said acceleration. Anyway, these numbers seem to indicate that this scope could have been used to drive pilling and/or break concrete and be “oK” afterwards. I realize the analogy is a bit boastful, nonetheless for a piece of electronics to take that kind of abuse and keep functioning is impressive. More impressive to publish it as such.
So to the question, some place along the line those kind of specifications appear to have been dropped and/or were no longer important. (well at least I don’t see them in the catalogues for the 7000 series scopes I concentrate on).
By way of learning for me. Why were these kind of specifications important for the earlier scopes? What made them less important in later scopes? Do specifications like that exist for later scopes? I looked in a few 7000 series manuals and did not see anything resembling acceleration specs so again I assume not… However, my sample is extremely small so making any conclusions would be foolhardy. Hopefully some of you that have been in the industry for years will have better insight.
In any event, thanks as always for the bandwidth and the free education.
Rob
Rob, Dunno about lab scopes, but back when I was an avionics comm/nav tech in the USAF, the F-4 had a 23 channel UHF aux reciever, tube technology. One of the last steps in the tech order after repair and/or alignment, was the "drop test." You had to slide the aux receiver out of the bench rails, lift it about 4" and drop it onto the bench. Then, pick it up, slide it back into the bench rails, power it up and see if it still worked. Thing weighed about 60 lbs or so too. My guess as to why we did that, after getting out of the fixing biz and into the flying biz (flew different F-4's for a little over 10 years) was to ensure the receiver had nothing loose inside, and could handle the forces put on it during the flight regime - 6 - 7 G's typical during a fighter mission - though those are sustained G's not instantaneous G's like the drop test gave the receiver. Never did see an o'scope mounted in a fighter though... ;-) Mark
|
--- In TekScopes@..., "Rob" wrote:
Really nice. Once again the depth and team spirit of this forum shines.
Curious?�?. The specification indicates that the scope can take 20G?�?s acceleration in any plain for a total of 12 hits. I assume that the 11ms duration is to give an idea of the impulse imparted for said acceleration. Anyway, these numbers seem to indicate that this scope could have been used to drive pilling and/or break concrete and be ?�?oK?�? afterwards. I realize the analogy is a bit boastful, nonetheless for a piece of electronics to take that kind of abuse and keep functioning is impressive. More impressive to publish it as such.
Proximity fuzes would like a word with you... How does 100000G and 20000RPM sound to you? With tubes.
|
In 1970 my brother in law was in a head on collision at 70 mph, he had
a 453 in the back of the station wagon, there was a heavy stamped steel
protective barrier behind the front seat.? The 453 almost broke through
the barrier behind my brother in laws head.? The insurance company
looked at the 453 and wrote it off as scrap.? The company sent it to Tektronix
in Dallas, they put a new case on it and sent it back, all OK.
Leon Robinson ?? K5JLR
Political Correctness is a Political Disease.
|
--- On Fri, 1/25/13, Craig Sawyers wrote:
From: Craig Sawyers
Subject: RE: [TekScopes] Re: Tentative 647
scan?
To: TekScopes@...
Date: Friday, January 25, 2013, 3:52 AM
?
> 20G isn't much - if you drop it two feet onto concrete it will get a much
harder
> G shock than that.
Some time ago I collected a 5-series scope, and as a result of handle rot
the whole massive scope crashed to the concrete path. Made a hell of a
bang. And missed my toes thank heavens
Turned it on and it worked perfectly! Hat's off to Tek's designers.
Craig
|
--- In TekScopes@..., "Rob" wrote:
Really nice. Once again the depth and team spirit of this forum shines.
Curious?�?. The specification indicates that the scope can take 20G?�?s acceleration in any plain for a total of 12 hits. I assume that the 11ms duration is to give an idea of the impulse imparted for said acceleration. Anyway, these numbers seem to indicate that this scope could have been used to drive pilling and/or break concrete and be ?�?oK?�? afterwards. I realize the analogy is a bit boastful, nonetheless for a piece of electronics to take that kind of abuse and keep functioning is impressive. More impressive to publish it as such.
So to the question, some place along the line those kind of specifications appear to have been dropped and/or were no longer important. (well at least I don?�?t see them in the catalogues for the 7000 series scopes I concentrate on).
By way of learning for me. Why were these kind of specifications important for the earlier scopes? What made them less important in later scopes? Do specifications like that exist for later scopes? I looked in a few 7000 series manuals and did not see anything resembling acceleration specs so again I assume not?�? However, my sample is extremely small so making any conclusions would be foolhardy. Hopefully some of you that have been in the industry for years will have better insight.
Almost all Tek instruments were tested for dynamics, both earlier and later versions. This included acceleration and vibration. Acceleration is tested as deceleration. The instrument is firmly attached to a large steel plate in a test stand. The plate is dropped from a standard distance. An elastomeric moderator (block of rubber) is placed at the bottom of the test stand, where the plate will hit to control the G force. The moderator integrates the peak deceleration force over time. Different types and sized of rubber are used. Soft rubber lowers the peak G force, spreading it over a longer time. As it gets stiffer, the peak gets higher, but the duration of the deceleration is lower (energy = Mass * velocity^2). If you took the rubber out (never done in practical testing), the G force would be huge (tens of thousands of Gs) with ultra-short duration. Basically, the tiny flexing of the massive steel elements would limit the peak force from becoming an impulse function (infinite peak with 0 time). Changing the drop height allows fine tuning of the test forces. An acceleratomer is attached to the plate to monitor the force and time. Testing is either started at a low value and worked up, or a dummy weight with the same mass as the item to be tested is first bolted to the test stand to calibrate the force. The dynamics specs were not listed in the later catalogs as they were contained within the military specification that most instruments were designed to, which was listed. Typically it was MIL-T-28800C – class 5 for lab instruments, or class 3 for portable instruments. (MIL-T-28800B preceded `C', and MIL-T-28800A precede B) - Steve
|
Thanks Steve, all that makes sense to me. I also understand how the rubber deformation method brings some meaning to the 20G over 1ms into perspective (or the impulse). I also understand the disconnect between my original post and the tens of thousands of G’s others mentioned. I did not try to translate the 20G over 1ms into an actual impulse. So I do not know how it compares to others. ? Anyway, do you have a feel for if or how the specifications changed over the years? Said another way, where the same military specs understood when the 647 specification was written (I know Tektronix was enough on the leading edge that some specifications were written to what there equipment was capable of vs. any real world need/criteria.). Would a 647 and a 7000 series scope meet the same requirements? How about modern solid state scopes?. Conversely as people became more acquainted with both Oscilloscopes and solid state electronics. Where they allowed to be manufactured less bullet proof (for lack of better wording), ? The biggest reason I am asking all of this is because of the trouble I have had shipping my refurbished scopes after I have sold them. I package them what I consider to be very well. However the post office is capable of defeating even the best packaging it seems. Then again, perhaps the 7000 series scopes (non-militarized especially) are more fragile then they appear to be on the bench and my packaging is indeed not adequate. Would one expect a 647 or other scope with the specification they claimed to survive better than a 7000 series or 475 or??? Given the post offices apparent ability to reach well above a 20G threshold. ? As always Thank you for your time and the bandwidth. ?????Rob ?
toggle quoted message
Show quoted text
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Steve
Sent: Friday, January 25, 2013 5:16 PM
To: TekScopes@...
Subject: [TekScopes] Re: Tentative 647 scan?? ?
Almost all Tek instruments were tested for dynamics, both earlier and later versions. This included acceleration and vibration.
Acceleration is tested as deceleration. The instrument is firmly attached to a large steel plate in a test stand. The plate is dropped from a standard distance. An elastomeric moderator (block of rubber) is placed at the bottom of the test stand, where the plate will hit to control the G force. The moderator integrates the peak deceleration force over time. Different types and sized of rubber are used. Soft rubber lowers the peak G force, spreading it over a longer time. As it gets stiffer, the peak gets higher, but the duration of the deceleration is lower (energy = Mass * velocity^2). If you took the rubber out (never done in practical testing), the G force would be huge (tens of thousands of Gs) with ultra-short duration. Basically, the tiny flexing of the massive steel elements would limit the peak force from becoming an impulse function (infinite peak with 0 time). Changing the drop height allows fine tuning of the test forces. An acceleratomer is attached to the plate to monitor the force and time. Testing is either started at a low value and worked up, or a dummy weight with the same mass as the item to be tested is first bolted to the test stand to calibrate the force.
The dynamics specs were not listed in the later catalogs as they were contained within the military specification that most instruments were designed to, which was listed. Typically it was MIL-T-28800C – class 5 for lab instruments, or class 3 for portable instruments. (MIL-T-28800B preceded `C', and MIL-T-28800A precede B)
- Steve
|
I remember a similar thread some time ago where one of the members
who had worked at Tektronix recalled the testing of new exotic
equipment. He mentioned the weeping and wailing (probably teeth
being gnashed too) when some mega bucks piece failed and an $8,000
CTR was reduced to shards of glass laying in the bottom. I guess
it's much more common now, particularly in the auto industry where
every model has to be crash tested. Formula 1 cars also now have to
be crash tested and the benefits are very plain to see. Crashes into
barriers at 150 MPH that once would have been fatal usually now
result in the drivers walking away. Indeed, it's no longer permitted
but divers would often sprint back to the pits and get into the
spare car to continue the race.
Don Black.
?
On 26-Jan-13 1:02 PM, Rob wrote:
toggle quoted message
Show quoted text
?
Thanks Steve, all
that makes sense to me. I also understand how the
rubber deformation method brings some meaning to the
20G over 1ms into perspective (or the impulse). I also
understand the disconnect between my original post and
the tens of thousands of G’s others mentioned. I did
not try to translate the 20G over 1ms into an actual
impulse. So I do not know how it compares to others.
?
Anyway, do you
have a feel for if or how the specifications changed
over the years? Said another way, where the same
military specs understood when the 647 specification
was written (I know Tektronix was enough on the
leading edge that some specifications were written to
what there equipment was capable of vs. any real world
need/criteria.). Would a 647 and a 7000 series scope
meet the same requirements? How about modern solid
state scopes?. Conversely as people became more
acquainted with both Oscilloscopes and solid state
electronics. Where they allowed to be manufactured
less bullet proof (for lack of better wording),
?
The biggest
reason I am asking all of this is because of the
trouble I have had shipping my refurbished scopes
after I have sold them. I package them what I consider
to be very well. However the post office is capable of
defeating even the best packaging it seems. Then
again, perhaps the 7000 series scopes (non-militarized
especially) are more fragile then they appear to be on
the bench and my packaging is indeed not adequate.
Would one expect a 647 or other scope with the
specification they claimed to survive better than a
7000 series or 475 or??? Given the post offices
apparent ability to reach well above a 20G threshold.
?
As always Thank
you for your time and the bandwidth.
?????Rob
?
?
?
Almost all Tek instruments were tested for dynamics,
both earlier and later versions. This included
acceleration and vibration.
Acceleration is tested as deceleration. The instrument
is firmly attached to a large steel plate in a test
stand. The plate is dropped from a standard distance. An
elastomeric moderator (block of rubber) is placed at the
bottom of the test stand, where the plate will hit to
control the G force. The moderator integrates the peak
deceleration force over time. Different types and sized
of rubber are used. Soft rubber lowers the peak G force,
spreading it over a longer time. As it gets stiffer, the
peak gets higher, but the duration of the deceleration
is lower (energy = Mass * velocity^2). If you took the
rubber out (never done in practical testing), the G
force would be huge (tens of thousands of Gs) with
ultra-short duration. Basically, the tiny flexing of the
massive steel elements would limit the peak force from
becoming an impulse function (infinite peak with 0
time). Changing the drop height allows fine tuning of
the test forces. An acceleratomer is attached to the
plate to monitor the force and time. Testing is either
started at a low value and worked up, or a dummy weight
with the same mass as the item to be tested is first
bolted to the test stand to calibrate the force.
The dynamics specs were not listed in the later catalogs
as they were contained within the military specification
that most instruments were designed to, which was
listed. Typically it was MIL-T-28800C – class 5 for lab
instruments, or class 3 for portable instruments.
(MIL-T-28800B preceded `C', and MIL-T-28800A precede B)
- Steve
|
I mentioned this before on the list. An in-law worked at Tektronix and apparently at the time, they did "shake and bake" tests in a big environment box to see what would fail and when. The oscilloscopes that survived or were repaired could be bought by the employees at a discount. That policy was stopped when someone got greedy and too many units started showing up on the gray market. Tektronix scrapped the destructive test units after that. That is how I ended up with a 2246 and 2247A. On Sat, 26 Jan 2013 14:12:08 +1100, Don Black <donald_black@...> wrote: I remember a similar thread some time ago where one of the members who
had worked at Tektronix recalled the testing of new exotic equipment. He
mentioned the weeping and wailing (probably teeth being gnashed too)
when some mega bucks piece failed and an $8,000 CTR was reduced to
shards of glass laying in the bottom. I guess it's much more common now,
particularly in the auto industry where every model has to be crash
tested. Formula 1 cars also now have to be crash tested and the benefits
are very plain to see. Crashes into barriers at 150 MPH that once would
have been fatal usually now result in the drivers walking away. Indeed,
it's no longer permitted but divers would often sprint back to the pits
and get into the spare car to continue the race.
Don Black.
|
--- In TekScopes@..., Don Black wrote:
I remember a similar thread some time ago where one of the members who
had worked at Tektronix recalled the testing of new exotic equipment. He
mentioned the weeping and wailing (probably teeth being gnashed too)
when some mega bucks piece failed and an $8,000 CTR was reduced to
shards of glass laying in the bottom. I guess it's much more common now,
particularly in the auto industry where every model has to be crash
tested. Formula 1 cars also now have to be crash tested and the benefits
are very plain to see. Crashes into barriers at 150 MPH that once would
have been fatal usually now result in the drivers walking away. Indeed,
it's no longer permitted but divers would often sprint back to the pits
and get into the spare car to continue the race.
Don Black.
On 26-Jan-13 1:02 PM, Rob wrote:
Thanks Steve, all that makes sense to me. I also understand how the
rubber deformation method brings some meaning to the 20G over 1ms into
perspective (or the impulse). I also understand the disconnect between
my original post and the tens of thousands of G's others mentioned. I
did not try to translate the 20G over 1ms into an actual impulse. So I
do not know how it compares to others.
Anyway, do you have a feel for if or how the specifications changed
over the years? Said another way, where the same military specs
understood when the 647 specification was written (I know Tektronix
was enough on the leading edge that some specifications were written
to what there equipment was capable of vs. any real world
need/criteria.). Would a 647 and a 7000 series scope meet the same
requirements? How about modern solid state scopes?. Conversely as
people became more acquainted with both Oscilloscopes and solid state
electronics. Where they allowed to be manufactured less bullet proof
(for lack of better wording),
The biggest reason I am asking all of this is because of the trouble I
have had shipping my refurbished scopes after I have sold them. I
package them what I consider to be very well. However the post office
is capable of defeating even the best packaging it seems. Then again,
perhaps the 7000 series scopes (non-militarized especially) are more
fragile then they appear to be on the bench and my packaging is indeed
not adequate. Would one expect a 647 or other scope with the
specification they claimed to survive better than a 7000 series or 475
or??? Given the post offices apparent ability to reach well above a
20G threshold.
As always Thank you for your time and the bandwidth.
Rob
*From:*TekScopes@... [mailto:TekScopes@...]
*On Behalf Of *Steve
*Sent:* Friday, January 25, 2013 5:16 PM
*To:* TekScopes@...
*Subject:* [TekScopes] Re: Tentative 647 scan?
Almost all Tek instruments were tested for dynamics, both earlier and
later versions. This included acceleration and vibration.
Acceleration is tested as deceleration. The instrument is firmly
attached to a large steel plate in a test stand. The plate is dropped
from a standard distance. An elastomeric moderator (block of rubber)
is placed at the bottom of the test stand, where the plate will hit to
control the G force. The moderator integrates the peak deceleration
force over time. Different types and sized of rubber are used. Soft
rubber lowers the peak G force, spreading it over a longer time. As it
gets stiffer, the peak gets higher, but the duration of the
deceleration is lower (energy = Mass * velocity^2). If you took the
rubber out (never done in practical testing), the G force would be
huge (tens of thousands of Gs) with ultra-short duration. Basically,
the tiny flexing of the massive steel elements would limit the peak
force from becoming an impulse function (infinite peak with 0 time).
Changing the drop height allows fine tuning of the test forces. An
acceleratomer is attached to the plate to monitor the force and time.
Testing is either started at a low value and worked up, or a dummy
weight with the same mass as the item to be tested is first bolted to
the test stand to calibrate the force.
The dynamics specs were not listed in the later catalogs as they were
contained within the military specification that most instruments were
designed to, which was listed. Typically it was MIL-T-28800C -- class
5 for lab instruments, or class 3 for portable instruments.
(MIL-T-28800B preceded `C', and MIL-T-28800A precede B)
- Steve
The environmental and dynamic specs have not really degraded much over the years. When scopes started to include floppy disk drives, then embedded PC, then had to relax the operating temperature range, as these components are only rated for operation up to +40 degrees C, rather than the +50 that standard class 5 requires. Most of the vendors shifted to the +40 spec, because the drives were not available with the higher operating temp. Unfortunately, the +40 spec has become the defacto standard, and is applied to other instruments which don't even have these components. People say this is not a serious reduction in performance, as 40 degrees is not often encounter in a lab. While this is true, the +40 does limit operation in some rack mount setups, as the cooling air is often mixed with the exhaust air from other instruments. Active probes can be installed between cards in a rack, and situations where instruments with a +40 degree rating will overheat. - Steve
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Thanx for scanning the 647 tentative specs. I have three 647a?s and several 547?s, beautiful pieces of technical design of a gone era.
搁别苍é
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--- In TekScopes@..., tubesnthings@... wrote:
Beautiful - thank both of you!
Bernd
In a message dated 1/24/2013 8:20:03 P.M. Pacific Standard Time,
sipespresso@... writes:
Thanks for scanning it! I cleaned it up a bit:
_
()
-Kurt
--- In _TekScopes@... (mailto:TekScopes@...) ,
d.seiter@ wrote:
Here's the scan of the Tentative 647 spec.?? Sorry it's a bit of a
mess!?? I can't figure out how to force?? our copier to scan one 8x11 at a time
instead of what it sees on the scan bed .?? There must be a way, but it's
not obvious.?? If anyone has pdf editing software and wants to fix it, have
at it!
-Dave
----- Original Message -----
From: "mattko87"
To: _TekScopes@... (mailto:TekScopes@...)
Sent: Thursday, January 24, 2013 1:10:51 PM
Subject: [TekScopes] Re: Tentative 647 scan?
??
Yes, i am interested in the scan ;-)
Matt
--- In _TekScopes@... (mailto:TekScopes@...) ,
d.seiter@ wrote:
While I've got it out, is anyone interested in the 647 tentative spec?
-Dave
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David C. Partridge
David Hess