Automatic Brightness Control : was it ever implemented ??

#147835

Hi group,

Sometimes I wonder about this... maybe the experts on here have some view on this ??

I mean, the brightness of the trace varies considérably depending on sweep speed, ranging from blinding at slow speed, to barely visible when at full speed + x10 mag turned on, so one has to constantly adjust the brightness control whilst working. 

So, seeing as Tek was the leader in the scope world for decades, always finding ways to improve performance or usability, going to great effort to make nice user interfaces..... did they ever implement some kind of automatic brightness control, so that a use can just adjust the brightness level, and the scope would maintain that setting regardless of the sweep speed ??

I mean OK, would be a bit of a stretch for tube/valve scopes in the 50's/60's, but in the '80s where there were micro-controllers running the state of the art 2400 analog scopes back in the day, it might have been technically possible ?
I don't know... for example, Tek could determine experimentally, how much to vary the voltage on the CRT's grid that's responsible for brightness adjustement, to get a constant brightness, for every time base setting/sweep speed, for a given desired brightness level. then they could put that data in a little look up table. Then, when the user rotates the brightness control on the front panel, instead of the knob driving directly a pot on the CRT grid, it could instethe scope could look that up in the table, and do some basic linear interpolation between two points, when need be, then vary the PDA accordingly.

#147836

[Sorry for the previous message, got sent inadvertently while I was in the middle of writing it  ! :-/ Discard it]

Hi group,

Sometimes I wonder about this... maybe the experts on here have some view on this ??

I mean, the brightness of the trace varies considérably depending on sweep speed, ranging from blinding at slow speed, to barely visible when at full speed + x10 mag turned on, so one has to constantly adjust the brightness control whilst working.

So, seeing as Tek was the leader in the scope world for decades, always finding ways to improve performance or usability, going to great effort to make nice user interfaces..... did they ever implement some kind of automatic brightness control, so that a use can just adjust the brightness level, and the scope would maintain that setting regardless of the sweep speed ??

I mean OK, would be a bit of a stretch for tube/valve scopes in the 50's/60's, but in the '80s where there were micro-controllers running the state of the art 2400 analog scopes back in the day, it might have been technically possible ?
I don't know... for example, Tek could determine experimentally, how much to vary the voltage on the CRT's grid that's responsible for brightness adjustement, to get a constant brightness, for every time base setting/sweep speed, for a given desired brightness level. then they could put that data in a little look up table. 

Then, when the user rotates the brightness control on the front panel, instead of the knob driving directly a pot connected the CRT grid, it could instead 
go to an ADC, the scope could look that up in the table, and do some basic linear interpolation between two points, when need be, then vary the grid voltage as needed.

I only have a 2232 scope, so I don't know about the 24 series. I understand the 24 series was the state of the art of Tek's analog scope, I think they could have easily implemented something like this, from a technical point of view ?

Anyway, I was just curious to know if Tek did it at some point, maybe as one-shot on some particular scope model then abandoned it, or maybe some other scope manufacturer did it ??

Regards,

Vincent Trouilliez

#147839

On Sun, May 13, 2018 at 01:56 pm, Vincent Trouilliez wrote:
So, seeing as Tek was the leader in the scope world for decades, always
finding ways to improve performance or usability, going to great effort to
make nice user interfaces..... did they ever implement some kind of automatic
brightness control, so that a use can just adjust the brightness level, and
the scope would maintain that setting regardless of the sweep speed ??I don't know the full answer, but the nearest I can think of quickly is that some (or all?) of the 7000-series timebase plugins limit the beam current at slow sweep speeds to prevent CRT burn. That's kind of a sweep-speed-dependent intensity control, but definitely not a comprehensive one. 

Chris

#147841

The 2213 that I had for a short while included automatic brightness. On my machine it
seemed to not work very well, perhaps it was defective (forty year old machine) so I wasn't
disappointed that the 2213A which replaced it had dropped auto-brightness in favor of
manually adjusted brightness.

Ted

Show quoted text

On 13 May 2018 at 13:56, Vincent Trouilliez wrote:

[Sorry for the previous message, got sent inadvertently while I was in the middle of writing it  !
:-/ Discard it]


Hi group,


Sometimes I wonder about this... maybe the experts on here have some view on this ??

I mean, the brightness of the trace varies considérably depending on sweep speed, ranging
from blinding at slow speed, to barely visible when at full speed + x10 mag turned on, so one
has to constantly adjust the brightness control whilst working.

So, seeing as Tek was the leader in the scope world for decades, always finding ways to
improve performance or usability, going to great effort to make nice user interfaces..... did
they ever implement some kind of automatic brightness control, so that a use can just adjust
the brightness level, and the scope would maintain that setting regardless of the sweep
speed ??

I mean OK, would be a bit of a stretch for tube/valve scopes in the 50's/60's, but in the '80s
where there were micro-controllers running the state of the art 2400 analog scopes back in
the day, it might have been technically possible ?
I don't know... for example, Tek could determine experimentally, how much to vary the
voltage on the CRT's grid that's responsible for brightness adjustement, to get a constant
brightness, for every time base setting/sweep speed, for a given desired brightness level.
then they could put that data in a little look up table.

Then, when the user rotates the brightness control on the front panel, instead of the knob
driving directly a pot connected the CRT grid, it could instead
go to an ADC, the scope could look that up in the table, and do some basic linear
interpolation between two points, when need be, then vary the grid voltage as needed.

I only have a 2232 scope, so I don't know about the 24 series. I understand the 24 series was
the state of the art of Tek's analog scope, I think they could have easily implemented
something like this, from a technical point of view ?

Anyway, I was just curious to know if Tek did it at some point, maybe as one-shot on some
particular scope model then abandoned it, or maybe some other scope manufacturer did it ??

Regards,


Vincent Trouilliez

#147846

I believe I have seen writing speed enhancement, but not on Teks as far as I remember.

#147852

I think that auto-brightness functions could have been implemented on analog scopes, but only to a certain degree, and it would be quite complicated. The operating and signal conditions can be very broad, so you would have to take into account a lot of variables like sweep rate, signal repetition (trigger) rate, holdoff, delayed sweep operation, whether it's in X10 mag, the number of channels active, the chop vs alternate modes, single-sweep mode, and so on. And that's just for the X-axis. What about the overall deflection velocity and extent, which also depend on the arbitrary vertical signals? You would want to know the actual peak to peak deflection, the risetime or other frequency content information, and the position on-screen - for every applied input signal channel, and make judgement about which parts are to be at the "right" intensity. That's a lot of stuff to figure out for the convenience, versus the simple way of having the user set it for overall appearance preference for given conditions. From the advent of the oscilloscope, all of this would have been nice to have, but is not very practical.

In a more controlled signal and display environment, it's a bit easier. One Tek product I know of that has some degree of auto-ness to this is the 577 curve tracer, which sort of controls intensity in proportion to the length of the horizontal deflection. In fact, the beam can set up to blank out entirely when the collector voltage approaches zero, so instead of a screen-burning bright dot at the origin, it just winks out, but will come right back as the voltage (deflection) goes back up. In this kind of instrument, the signal frequency and deflection ranges are are quite limited, and only so many operational modes are available, so an auto-intensity function is more practical and effective.

Ed

#147856

It seems to me brightness change as a function of sweep velocity might be practical and take care of a lot of problems. I don't know if anything like that was ever offered in a scope.
   Some TV sets have brightness stabilization to eliminate or reduce blooming. I think this is fairly common.
   I remember a very long time ago when some TV sets had automatic brightness control via the ambient light in the room. I don't know if I ever saw one in action and its off topic anyway.

Show quoted text

On 5/13/2018 8:53 PM, Ed Breya via Groups.Io wrote:
I think that auto-brightness functions could have been implemented on analog scopes, but only to a certain degree, and it would be quite complicated. The operating and signal conditions can be very broad, so you would have to take into account a lot of variables like sweep rate, signal repetition (trigger) rate, holdoff, delayed sweep operation, whether it's in X10 mag, the number of channels active, the chop vs alternate modes, single-sweep mode, and so on. And that's just for the X-axis. What about the overall deflection velocity and extent, which also depend on the arbitrary vertical signals? You would want to know the actual peak to peak deflection, the risetime or other frequency content information, and the position on-screen - for every applied input signal channel, and make judgement about which parts are to be at the "right" intensity. That's a lot of stuff to figure out for the convenience, versus the simple way of having the user set it for overall appearance preference for given conditions. From the advent of the oscilloscope, all of this would have been nice to have, but is not very practical.
In a more controlled signal and display environment, it's a bit easier. One Tek product I know of that has some degree of auto-ness to this is the 577 curve tracer, which sort of controls intensity in proportion to the length of the horizontal deflection. In fact, the beam can set up to blank out entirely when the collector voltage approaches zero, so instead of a screen-burning bright dot at the origin, it just winks out, but will come right back as the voltage (deflection) goes back up. In this kind of instrument, the signal frequency and deflection ranges are are quite limited, and only so many operational modes are available, so an auto-intensity function is more practical and effective.
Ed

-- 
Richard Knoppow
dickburk@...
WB6KBL

Chuck Harris

#147860

Seems to me, that all you would need to know
is beam velocity vs beam current.

Intensity is an integral function of beam
velocity and beam current.

So, it would take a circuit that took the vertical
deflection, horizontal deflection, and intensity
control as its inputs, calculated the absolute
velocity of the beam, integrated (differentiated?)
it in some way with the intensity control's setting,
and produced the z-axis drive.

The problem would be that you can't do the velocity
calculation, and the integration (differentiation?)
that would be necessary instantaneously, so there
would seem to be a need for more delay lines.

And, the generated z-axis control would have to
match up very closely with the beam's velocity at
any point, or you would get brightness hangover
around points where the beam speed changed quickly.

Or, you could simply digitize the fast signal, and
display it as a fixed rate raster scan, like they
do with digital scopes...

One thing:  A major complaint about digital scopes
from long time analog scope users is there is no hint
of the intensity that a part of the beam would have,
leading to all sorts of tricks to make the digital
beam look more analog, with variable persistence stuff.

-Chuck Harris

Ed Breya via Groups.Io wrote:

Show quoted text

I think that auto-brightness functions could have been implemented on analog scopes, but only to a certain degree, and it would be quite complicated. The operating and signal conditions can be very broad, so you would have to take into account a lot of variables like sweep rate, signal repetition (trigger) rate, holdoff, delayed sweep operation, whether it's in X10 mag, the number of channels active, the chop vs alternate modes, single-sweep mode, and so on. And that's just for the X-axis. What about the overall deflection velocity and extent, which also depend on the arbitrary vertical signals? You would want to know the actual peak to peak deflection, the risetime or other frequency content information, and the position on-screen - for every applied input signal channel, and make judgement about which parts are to be at the "right" intensity. That's a lot of stuff to figure out for the convenience, versus the simple way of having the user set it for overall appearance preference for given conditions. From the advent of the oscilloscope, all of this would have been nice to have, but is not very practical.

In a more controlled signal and display environment, it's a bit easier. One Tek product I know of that has some degree of auto-ness to this is the 577 curve tracer, which sort of controls intensity in proportion to the length of the horizontal deflection. In fact, the beam can set up to blank out entirely when the collector voltage approaches zero, so instead of a screen-burning bright dot at the origin, it just winks out, but will come right back as the voltage (deflection) goes back up. In this kind of instrument, the signal frequency and deflection ranges are are quite limited, and only so many operational modes are available, so an auto-intensity function is more practical and effective.

Ed

#147861

Auto intensity on the 2215 is based on gate dutycycle, R/C averaged.
It's helpful.
Ed, k1ggi

Show quoted text

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Chuck
Harris
Sent: Monday, May 14, 2018 7:52 AM
To: [email protected]
Subject: Re: [TekScopes] Automatic Brightness Control : was it ever
implemented ??

Seems to me, that all you would need to know
is beam velocity vs beam current.

Intensity is an integral function of beam
velocity and beam current.

So, it would take a circuit that took the vertical
deflection, horizontal deflection, and intensity
control as its inputs, calculated the absolute
velocity of the beam, integrated (differentiated?)
it in some way with the intensity control's setting,
and produced the z-axis drive.

The problem would be that you can't do the velocity
calculation, and the integration (differentiation?)
that would be necessary instantaneously, so there
would seem to be a need for more delay lines.

And, the generated z-axis control would have to
match up very closely with the beam's velocity at
any point, or you would get brightness hangover
around points where the beam speed changed quickly.

Or, you could simply digitize the fast signal, and
display it as a fixed rate raster scan, like they
do with digital scopes...

One thing:  A major complaint about digital scopes
from long time analog scope users is there is no hint
of the intensity that a part of the beam would have,
leading to all sorts of tricks to make the digital
beam look more analog, with variable persistence stuff.

-Chuck Harris

Ed Breya via Groups.Io wrote:
I think that auto-brightness functions could have been implemented onanalog scopes, but only to a certain degree, and it would be quite
complicated. The operating and signal conditions can be very broad, so you
would have to take into account a lot of variables like sweep rate, signal
repetition (trigger) rate, holdoff, delayed sweep operation, whether it's in
X10 mag, the number of channels active, the chop vs alternate modes,
single-sweep mode, and so on. And that's just for the X-axis. What about the
overall deflection velocity and extent, which also depend on the arbitrary
vertical signals? You would want to know the actual peak to peak deflection,
the risetime or other frequency content information, and the position
on-screen - for every applied input signal channel, and make judgement about
which parts are to be at the "right" intensity. That's a lot of stuff to
figure out for the convenience, versus the simple way of having the user set
it for overall appearance preference for given conditions. From the advent
of the oscilloscope, all of this would have been nice to have, but is not
very practical.

In a more controlled signal and display environment, it's a bit easier.One Tek product I know of that has some degree of auto-ness to this is the
577 curve tracer, which sort of controls intensity in proportion to the
length of the horizontal deflection. In fact, the beam can set up to blank
out entirely when the collector voltage approaches zero, so instead of a
screen-burning bright dot at the origin, it just winks out, but will come
right back as the voltage (deflection) goes back up. In this kind of
instrument, the signal frequency and deflection ranges are are quite
limited, and only so many operational modes are available, so an
auto-intensity function is more practical and effective.

Ed

#148000

Thanks everyone for your great input on the subject, was much interesting !  This forum just never disappoints, there is just so much knowledge and experience in here, I just love it :-)

As destiny would have it... I have secured today a deal for a 2215 ! What were the odds ? So I will see for myself how this brightness control performs, and study the schematics to learn the details of its implementation.  Here in Frog land normally the 22XX scopes (regardless of model/performance) sell, " as is", take it or leave it, anywhere between 100+ to 300 Euros, which is not very reasonable and why I never bought one. But the one I saw a couple days ago was only 15 Euros, and in excellent cosmetic nick , front panel dirty but otherwise in tip top shape, no dents, scratches or missing or damaged knobs. I simply couldn't believe my eyes..
In the end the seller removed his ad because he got sooooooooooooo many phone calls that he thought he would take some time to figure out a more appropriate price...
I told him what I thought about it all, how to price it etc... and in the end he agreed to sell it to me rather than to the slew of other candidates ! :-D
We agreed on a more sensible price of 40 Euros, 60 shipped.  Still waaaaaay cheaper that the usual price over here. So it's win-win. He gets 3 times the 15 Euros he advertised at first, and as for me, I get the scope, still for very cheap, even though I should not have gotten it at all because of the fierce competition at such a low price !

I just can't wait to receive it, and see if it's faulty or not (might just work, who knows), and if faulty, if I can manage to fix it...
Well hold on, don't tell me it's the only 22XX scope which does NOT have a service manual available ?! LOL That would be bad luck ! ^^
I got so excited that I didn't even check to make sure there was a service manual for it... worst case scenario I can resell it for twice what I paid for it... but I am really hoping I can fix it and keep it :-)


Vincent Trouilliez

#148020

Show quoted text

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Vincent
Trouilliez
Sent: Wednesday, May 16, 2018 1:02 PM
To: [email protected]
Subject: Re: [TekScopes] Automatic Brightness Control : was it ever
implemented ??

Thanks everyone for your great input on the subject, was much interesting !
This forum just never disappoints, there is just so much knowledge and
experience in here, I just love it :-)

As destiny would have it... I have secured today a deal for a 2215 ! What
were the odds ? So I will see for myself how this brightness control
performs, and study the schematics to learn the details of its
implementation.  Here in Frog land normally the 22XX scopes (regardless of
model/performance) sell, " as is", take it or leave it, anywhere between
100+ to 300 Euros, which is not very reasonable and why I never bought one.
But the one I saw a couple days ago was only 15 Euros, and in excellent
cosmetic nick , front panel dirty but otherwise in tip top shape, no dents,
scratches or missing or damaged knobs. I simply couldn't believe my eyes..
In the end the seller removed his ad because he got sooooooooooooo many
phone calls that he thought he would take some time to figure out a more
appropriate price...
I told him what I thought about it all, how to price it etc... and in the
end he agreed to sell it to me rather than to the slew of other candidates !
:-D
We agreed on a more sensible price of 40 Euros, 60 shipped.  Still waaaaaay
cheaper that the usual price over here. So it's win-win. He gets 3 times the
15 Euros he advertised at first, and as for me, I get the scope, still for
very cheap, even though I should not have gotten it at all because of the
fierce competition at such a low price !

I just can't wait to receive it, and see if it's faulty or not (might just
work, who knows), and if faulty, if I can manage to fix it...
Well hold on, don't tell me it's the only 22XX scope which does NOT have a
service manual available ?! LOL That would be bad luck ! ^^
I got so excited that I didn't even check to make sure there was a service
manual for it... worst case scenario I can resell it for twice what I paid
for it... but I am really hoping I can fix it and keep it :-)

Vincent Trouilliez

#148034

Phew, it's available ^^

Thanks for the link.  It's nice to see that Tek still keeps copies of its old scopes manuals and make them readily available on their site.

It don't understand though, why they don't do it for 100% of their scopes (or various products)... can't believe they "lost" their own manuals ?!...
I don't see the point of releasing only some manuals but not all. All or nothing, I would understand, but doing it halfway, I must say I don't see their point...

Would be good if they released component level information for their more "modern" stuff like the TDS 300/400/500/600/700 scopes which are so wide spread/popular. Maybe if Tekscope members send a petition, begging them... ^^
It's not like they are making any significant amount of money from this 20/30 year old CRT scopes... 

Vincent Trouilliez

#148035

Vince
They release ones that they a copies for. The cost for a big company like Tek to go back and scan the non digitized manuals is not trivial. Then there is the cost of storing, cataloging, 20 or 30 or 40 or more year old product. Staff ,management and physical plant? , and over head costs alone to maintain a "complete" library like this could easily run into Several $100K a year. Very hard to justify that this library would generate much revenue. The user base in general for a lot of this older product is not in the habit of buying much new stuff.

-DC
manuals@...

Show quoted text

On 5/17/2018 2:40 PM, Vincent Trouilliez wrote:
It don't understand though, why they don't do it for 100% of their scopes (or various products)... can't believe they "lost" their own manuals ?!...
I don't see the point of releasing only some manuals but not all. All or nothing, I would understand, but doing it halfway, I must say I don't see their point...

-- 
Dave
Manuals@...
www.ArtekManuals.com

#148054

Yeah, I am not a librarian so if you say it costs so much to stock all their paper/printed manuals.. well you certainly know what you are talking about, it's your area of expertise after all, dealing with tons of manuals. ;-)

But that goes only for the old manuals that were born as printed documents. For these, I gather that Tektronix had them all stored on microfiche,  which the VintageTek museum got hold of from a generous service center. Just need to scan/unlock that resource ! They need 6K to get a suitable scanner, and the fund raising campaign so far gleaned nearly 5,200 of those 6K, almost there ! :-D
I just made a little donation.. 35 USD, not much, but every little helps, hopefully ! Can't afford to give 100 bucks at the moment, and it's not tax deductible as I don't live in the US.

So, at some point, VintageTek Museum will sort us out for all the old stuff.

But where I don't get it, is why Tektronix can't make available all their newer stuff, the "modern" instruments that were designed in the early '90's, all the CRT TDS series for example, which are so popular. Their manuals were designed from the get go in digital form it appears, and hard disk space is cheap enough these days (compared to the size of a PDF manual, even millions of them would fit a single cheap hard drive...), and they already have this existing IT platform to let people download some of the manuals... what would it cost to just add all their existing, digital manuals to this platform ?!  Does not need large rooms to store paper manuals, does not need time to scan/process them... just move them from one folder to another... 
OK, maybe in the early '90s there was no PDF, can't remember, or not as widespread/accepted as it is now. So maybe they need to convert from their original file format, whatever it was, into PDF that people can read... but you only have to write the converter once...

Last thing, as you said : "They don't care because people who want these old manuals, are not the ones who have money to spend on new instruments"... yes, I understand. Most companies reason like this... but it's still a bit short sighted I think : If they had a policy to release manuals for 100% of their instrument, INCLUDING component level manuals as soon as an instrument is out of warranty, or not supported anymore by the service centers, and "advertised" this policy to their customers... this would make these instruments more valuable on the second hand market..  so when you are to shell out 50K for a NEW instrument, and you have the choice between say Tek or HP/Keysight, same price, same specs...  the resale value, included in the Total Cost of Ownership, would be higher for an instrument that the SECOND hand market will value more, because it knows it can fix it and maintain it ?!

Hell... AT LEAST they could offer a service : "give us some money and we will process/revive the manual you want. We charge 50 bucks + 25 cents per page, take it or leave it ". And the they can add this particular manual to their existing on-line database. I am not even asking to get it for free, it's not the point...the point is to be able to get the manuals... at all....
I would happily pay to get manuals for future Tek products I might purchase in the future, just like I was more than happy to buy from you a CD manual a year back, for my '70s rack mount Tek 5111 scope...

Anyway, OK, just day dreaming, Tek is just yet another company that doesn't give a damn for its own history....

At least we have VintageTek that's motivated... can't wait for them to shout out : "we finally got the scanner, fasten your seat belt it's gonna rock and roll from now on ! " ^^

Vincent Trouilliez

Chuck Harris

#148056

Hi Vincent,

It is all much easier to understand if you are a money grubbing,
scoundrel thief.

In a word, the reason they won't make the information available: lawyers.

If they show you the source code for their computer parts, they will get
sued for patent infringement, and will have handed the proof of the
infringement to the opposition for use in court.

If they show you the circuitry they used for their scopes, again they
will get sued for patent infringement.

This is one case where there is a pretty good level of security through
obscurity.  It takes real work to figure out if an algorithm used in
a scope, that has been compiled and linked is something that belongs to
you, but is being infringed.  Especially if the scope compresses the
code in the flash devices, and uncompresses it before it is put into
memory.


-Chuck Harris

Vincent Trouilliez wrote:

Show quoted text

But where I don't get it, is why Tektronix can't make available all their newer stuff, the "modern" instruments that were designed in the early '90's, all the CRT TDS series for example, which are so popular.

#148057

Hi Chuck,

Thanks for that... didn't occur to me :-(

So in short, the patents that Tek filed originally with the intent of PROTECTING themselves... is 20 years down the line playing AGAINST them ? Their own patent keeps the from releasing component level info on their '90's stuff.. shame.

I thought a patent was own by the company, that they could do whatever they wanted with it (they paid to file it, after all), sell it to another company, give it out to whoever as a gift... I guess I am no lawyer, that's for sure ;-)

There is good news though, in what you say (if I do understand correctly that is ! Frog here, not native...) --> it implies/suggests that maybe, maybe... Tek does have a will to release schematics for their newer stuff, progressively, as the patents progressively expire and their hands get untied...
Or maybe someone at Tek will be brave enough to copy all these manuals on a USB drive and post them on the net ! Just like you can find pirate copies of all the schematics for all Apple laptops, as soon as they hit the market... and despite Apple going to great length to keep third party repair shops from repairing anything. So if their schematics escaped,in real time, from a XXXXX billion dollar company that does have an impressive will for anything not to leak.... then maybe schematics will some day manage to escape Tektronix's servers... Just kidding... 
Maybe when I am old and grey, I will be able to download the full schematics for my little TDS 320, and the 784D or 694C I am hoping to buy one day.

For now I am happy to at least have the manuals for my beloved 317, 2232 and 5111, and partial schematics for my TDS 544A :-)

Vincent Trouilliez

Chuck Harris

#148058

I think you have it backwards.

It is very hard to look at circuitry that one of
your engineers creates, and know for certain that
it is free of patent infringements.  Most engineers
are likely to independently "invent" most inventions
given the right set of needs and circumstances.

So, tektronix (purely as an example) has a cabal
of engineers develop a product, and they create
tons of circuitry and code; the odds are very good
that it infringes someone's patent somewhere.

If you put the circuits and the source code out
there for public viewing, then those that are
trolling for infringements only have to get a manual
and look it over for stuff that looks like it might
be in their portfolio of patents, and you are screwed.

If, however, you keep all of that literature secret,
then the trolls have to decompile all of your code,
and figure out what it does, and how.  And they
have to trace your circuit boards, and brute force
the code in your ASICS.  All before they can see if
you have infringed any of their property.

One act costs you the loan of a manual.  The other
is a long term research project taking thousands of
hours.

-Chuck Harris

Vincent Trouilliez wrote:

Show quoted text

Hi Chuck,

Thanks for that... didn't occur to me :-(

So in short, the patents that Tek filed originally with the intent of PROTECTING themselves... is 20 years down the line playing AGAINST them ? Their own patent keeps the from releasing component level info on their '90's stuff.. shame.

I thought a patent was own by the company, that they could do whatever they wanted with it (they paid to file it, after all), sell it to another company, give it out to whoever as a gift... I guess I am no lawyer, that's for sure ;-)

There is good news though, in what you say (if I do understand correctly that is ! Frog here, not native...) --> it implies/suggests that maybe, maybe... Tek does have a will to release schematics for their newer stuff, progressively, as the patents progressively expire and their hands get untied...
Or maybe someone at Tek will be brave enough to copy all these manuals on a USB drive and post them on the net ! Just like you can find pirate copies of all the schematics for all Apple laptops, as soon as they hit the market... and despite Apple going to great length to keep third party repair shops from repairing anything. So if their schematics escaped,in real time, from a XXXXX billion dollar company that does have an impressive will for anything not to leak.... then maybe schematics will some day manage to escape Tektronix's servers... Just kidding... 
Maybe when I am old and grey, I will be able to download the full schematics for my little TDS 320, and the 784D or 694C I am hoping to buy one day.

For now I am happy to at least have the manuals for my beloved 317, 2232 and 5111, and partial schematics for my TDS 544A :-)

Vincent Trouilliez

#148065

Thanks for your perseverance ;-) I get it now.

That's bad news then.. means they will never ever release any schematics.

I wonder though, why they were not "scared" or releasing their schematics up to the '80s, and decided it was suddenly too "risky" when they entered the "digital" age in the early '90's with the first TDS scopes and such.

Only hope would be  (not a lawyer again) : if law states for example, that any patent on such devices, can only be valid up to 30 years no matter what... then it means Tek could release all the schematics with a 30 year (or whatever) delay, knowing that even if they did unwillingly infringe some patent, no matter what it was... they would be safe. Unless such a scenario exist, then yeah I guess there is nothing to hope for, even in 50 years time... :-(

Vincent Trouilliez

Chuck Harris

#148068

In the '80s, companies like tektronix were just starting
to have to deal with these sorts of lawsuits.

Prior to that time, patents were generally owned by companies
that funded the research that resulted in the patent, and
were planning to actually exploit their patent.  Now, large
blocks of patents are bought up by investment companies,
called patent trolls, that exist purely for filing infringement
lawsuits, and charging royalties.

Patents only exist for a short while, and one should be safe
when one expiration term has passed since the instrument was
produced... But then, there are copyrights.

-Chuck Harris

Vincent Trouilliez wrote:

Show quoted text

Thanks for your perseverance ;-) I get it now.

That's bad news then.. means they will never ever release any schematics.

I wonder though, why they were not "scared" or releasing their schematics up to the '80s, and decided it was suddenly too "risky" when they entered the "digital" age in the early '90's with the first TDS scopes and such.

Only hope would be  (not a lawyer again) : if law states for example, that any patent on such devices, can only be valid up to 30 years no matter what... then it means Tek could release all the schematics with a 30 year (or whatever) delay, knowing that even if they did unwillingly infringe some patent, no matter what it was... they would be safe. Unless such a scenario exist, then yeah I guess there is nothing to hope for, even in 50 years time... :-(

Vincent Trouilliez

#148071

Thanks for the enlightenment.

Looks like we live in a really crappy world indeed... not much reason to feel optimistic about the future then :-/

Vincent Trouilliez

开云体育

Automatic Brightness Control : was it ever implemented ??