Re: Saving 576 plots (again)
Since you have all of the "bits" needed with an LCD Display, it would be nice to be able to have an on-board USB Interface and application software with storage and overlays to display it on a desktop or laptop.
Imagine the ease at which devices could be compared, documented, etc...
I only wish Simmconn Labs had added that to my HP-8566 Spectrum Analyzer LCD kit.
Ross
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Zentronics42@... Sent: Monday, May 02, 2022 8:56 AM To: [email protected]Subject: Re: [TekScopes] Saving 576 plots (again) John, In putting in this effort in to a 576, retrofitting it for an LCD display rather than a CRT. A requirement for this project in my mind will be to delete the need for the HV transformer. This would open up the field significantly if a display could be fabricated as well as not need the -4kv and 200 Vdc supplies. It would extend the life time of the units significantly. Zen -----Original Message----- From: [email protected] < [email protected]> On Behalf Of John Griessen Sent: Monday, May 2, 2022 10:48 AM To: [email protected]Subject: Re: [TekScopes] Saving 576 plots (again) On 5/2/22 08:30, Eric wrote: I think in the rigol world last time I tried it the best resolution I
got on the input is 10's of mV steps. So you would be able to get
close but there might not be enough adjustment on the digital scope.
At higher price points this is less of an issue of course.
In a hypothetical. If I aligned a 576 with the built in tube. Then
took a scope and tapped the vert and Horz signals for X-Y. I would
want to do a full realignment of the circuits to the new graticule. Your earlier idea of using an LCD screen instead of borrowing a scope screen leaves off the electrostatic CRT display and limitations of 60 Hz AC sweeping. Two ADCs are needed, one for V one for I. and some code to overlay the up and down sweeps of collector voltage, then stop acquiring til next sweep, display the curve with "graticule" scale marks and V/div, I/div labels, and make this available to output as text data, or as an image file over the USB port. The text data is easier, (less code to write), and just pipe the data to gnuplot at the computer connected to the curve tracer. The culture shock schematics can give you an example system that is similar to look at for ideas. The HV board layout is helpful to see how the HV is divided down to record it:
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Re: OT+DC was Re: [TekScopes] 2465 Calibration
Yup.
My first Oscilloscope was a Tektronix 551 back in 1979. It had 98 Tubes.
It had 2 parts. The Oscilloscope and a separate Power Supply. I located the Power Supply under my bench on a step stool.
They didn't put two handles on the Oscilloscope for no reason...
Ross
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Roy Thistle Sent: Sunday, May 01, 2022 11:13 AM To: [email protected]Subject: Re: OT+DC was Re: [TekScopes] 2465 Calibration On Sat, Apr 30, 2022 at 12:33 PM, si_emi_01 wrote:
There are always Electromagnetic fields - even gravity
To be clearer, if not somewhat pedantic, there are fields everywhere: electromagnetic, gravitational, strong weak. Although general relativity shows light conforms to the curvature of space-time, gravity is usually only relevant to Tek when it comes to Series 500 scopes. This is a theory of gravity your back with appreciate, if you don't verify it. -- Roy Thistle
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Re: Saving 576 plots (again)
On 5/2/22 08:55, Zentronics42@... wrote: In putting in this effort in to a 576, retrofitting it for an LCD display rather than a CRT. A requirement for this project in my mind will be to delete the need for the HV transformer. I think letting the 575 576 577 drift off into oblivion with repairs only, not mods is more like it. What I'm describing is a standalone transistor and tube tester that takes 15 X 10 cm of benchtop and weighs 3 lbs and outputs tidy graphs with timestamps for simplifying sharing your test results...
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Re: Saving 576 plots (again)
John,
In putting in this effort in to a 576, retrofitting it for an LCD display rather than a CRT. A requirement for this project in my mind will be to delete the need for the HV transformer. This would open up the field significantly if a display could be fabricated as well as not need the -4kv and 200 Vdc supplies. It would extend the life time of the units significantly.
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of John Griessen Sent: Monday, May 2, 2022 10:48 AM To: [email protected]Subject: Re: [TekScopes] Saving 576 plots (again) On 5/2/22 08:30, Eric wrote: I think in the rigol world last time I tried it the best resolution I
got on the input is 10's of mV steps. So you would be able to get
close but there might not be enough adjustment on the digital scope.
At higher price points this is less of an issue of course.
In a hypothetical. If I aligned a 576 with the built in tube. Then
took a scope and tapped the vert and Horz signals for X-Y. I would
want to do a full realignment of the circuits to the new graticule. Your earlier idea of using an LCD screen instead of borrowing a scope screen leaves off the electrostatic CRT display and limitations of 60 Hz AC sweeping. Two ADCs are needed, one for V one for I. and some code to overlay the up and down sweeps of collector voltage, then stop acquiring til next sweep, display the curve with "graticule" scale marks and V/div, I/div labels, and make this available to output as text data, or as an image file over the USB port. The text data is easier, (less code to write), and just pipe the data to gnuplot at the computer connected to the curve tracer. The culture shock schematics can give you an example system that is similar to look at for ideas. The HV board layout is helpful to see how the HV is divided down to record it:
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Re: Saving 576 plots (again)
On 5/2/22 08:30, Eric wrote: I think in the rigol world last time I tried it the best
resolution I got on the input is 10's of mV steps. So you would be able to
get close but there might not be enough adjustment on the digital scope. At
higher price points this is less of an issue of course.
In a hypothetical. If I aligned a 576 with the built in tube. Then
took a scope and tapped the vert and Horz signals for X-Y. I would want to
do a full realignment of the circuits to the new graticule. Your earlier idea of using an LCD screen instead of borrowing a scope screen leaves off the electrostatic CRT display and limitations of 60 Hz AC sweeping. Two ADCs are needed, one for V one for I. and some code to overlay the up and down sweeps of collector voltage, then stop acquiring til next sweep, display the curve with "graticule" scale marks and V/div, I/div labels, and make this available to output as text data, or as an image file over the USB port. The text data is easier, (less code to write), and just pipe the data to gnuplot at the computer connected to the curve tracer. The culture shock schematics can give you an example system that is similar to look at for ideas. The HV board layout is helpful to see how the HV is divided down to record it:
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Re: Saving 576 plots (again)
I second this I still need to get one of these spun up as well. But Dennis's document is fantastic.
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Jim Ford Sent: Monday, May 2, 2022 9:19 AM To: [email protected]Subject: Re: [TekScopes] Saving 576 plots (again) Since you are planning to test vacuum tubes, David, look up Dennis Tillman's excellent write-up on how to mate a curve tracer with a tube tester. If you haven't already.Jim Ford Sent from my T-Mobile 4G LTE Device -------- Original message --------From: David Aurora <electronics@...> Date: 5/2/22 1:35 AM (GMT-08:00) To: [email protected] Subject: [TekScopes] Saving 576 plots (again) After years of wanting one, I've finally bought a 576 which I believe is currently sitting in customs 20 minutes from my place. Like quite a few people out there I'm mainly planning to use this for measuring/matching tubes, so while I'm waiting I've been trying to think of the best way to store the plots for future reference.I've searched through this group a lot (it really seems like the best resource out there!) and I see tonnes of suggestions of how people could/might store plot data, but haven't really come across anyone definitively saying "I did it this way and it works great". Anyone out there actually had functional success with the various methods discussed (digitising outputs via USB/cheap AD converter modules, taking photos and using image to CSV converter programs/etc)?It seems like a lot of those chats wind up going off on tangents of trying to control the unit from a computer, or trying to capture the readout settings and so forth but I really can't see that stuff being worth the extra effort for my or many peoples needs. Realistically, if you can get the image on a DSO it's simple to save that plot as a CSV file and adjust scaling to match the curve tracer settings from there, the relative plot points should be plenty to work with.So yeah, I'm curious if many people have tried the various ideas suggested with any success? If not, how are people saving plots? Cameras? Tracing paper over the screen? Manually entering plot data into spreadsheets? Other?Thanks!
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Re: Saving 576 plots (again)
Martin,
Depends highly on the digital scope. And the vertical step
resolution. I think in the rigol world last time I tried it the best
resolution I got on the input is 10's of mV steps. So you would be able to
get close but there might not be enough adjustment on the digital scope. At
higher price points this is less of an issue of course.
In a hypothetical. If I aligned a 576 with the built in tube. Then
took a scope and tapped the vert and Horz signals for X-Y. I would want to
do a full realignment of the circuits to the new graticule. Not only to
compensate for the 10 X 8 graticule but also to compensate for the scope
front end and probe loading. This would make the qualitative measurements as
accurate as possible. Under less than Ideal conditions. Unless I am missing
something?
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Martin via groups.io Sent: Monday, May 2, 2022 10:03 AM To: [email protected]Subject: Re: [TekScopes] Saving 576 plots (again) On 2. May 2022, at 14:51, Zentronics42@... wrote:
...You will not be able to make quantitative measurement however due to the scope graticule not being an exact match for the tube graticule. Why? The 576 has a "ZERO" and "CAL" button, placing the dot in the lower-left or upper-right corner of the graticule. You just have to align the amplification and offset of the scope to match. Of course, most scopes do not have the 10x10 but an 8x10 graticule, so you have to do some additional math. If you intend to save it on a file and put in on your computer you can overly any grid you like. It does not even have to match at the beginning... cheers Martin
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Re: Saving 576 plots (again)
Bonjour cher Monsieur
We have 576 and 577 for decades. ours were from local auction and Ham radio Fleas.
Typically shipping them is risky as the CRT and panel controls are easily damaged, sine they are heavy and bulky.
Few sellers are qualified to test fully or package safety for common carrier freight.
---------
All that aside, we found the lissijous type display needs a HV diff amp at the CRT V,H deflection plates.
Then a pair of ADC.
Still most digital devices and computer data acquisition cannot use the XY easily. Finally the scale factor fiber optic readouts cannot be easily acessed.
We avoided the problem by fashioning a CRT hood from an old scope camera adapter hood, then added a mask and support bracket for an iPhone. We setup the shot, place the iPhone on the mask, and set-up for a nin flash macro, perhaps 2x scale.
Result is all ambiance light is excluded, and a perfectly focused and centered image, with the iPhone coplanar to the CRT face.
Both scale factor and graticule lights are dimmed to setup the best compromise between them and the CRT traces.
We use the same technique on our 7104, 7904 as well as with 7K Spectrum Analyzer plug-ins on 7603.
Happy to send photos if of any interest.
Bon courage
Jon
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Re: Saving 576 plots (again)
On 5/2/22 06:51, Zentronics42@... wrote: At present there is not anything that can reliably capture the wave form for storage out of a 576. However a scope in X-Y mode tapping the vert and horizontal will do the trick. You will not be able to make quantitative measurement however due to the scope graticule not being an exact match for the tube graticule.
I have some information out there on rebuild and restoration of these units.
I would like the solve the tube issue permanently however this is currently above my skill level, but I am rapidly gain ground on it. I am thinking about tapping the preamp signal running that through an ADC Then possibly driving an LCD replacement screen as well as a digitized output for a 576 and 577. This reminds me of my open hardware project electroporator. It's a pulse generator, (for low power pulses), with an ADC capturing each "shot". There's no need for a knob twister pulse generator like the 576, 575, 577 when you have a micropython based MCU driven pulse generator and data acquisition system already, the only outside parts needed would be adding more power and voltage capability. The short pulses that are good for testing power semiconductors are already included in such a system. My electroporator system could be modified a little to make more powerful pulses, and the selection of series resistors could be a classic knob twist, or relays and code. Culture Shock is the name of the electroporator project. covers how to get schematics and edit them with lepton-schematic, a FOSS schematic editor available as a package on debian based linux systems. Ask me more questions if interested. -- John Griessen -- building lab gear for biologists Albuquerque NM blog.kitmatic.com
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Re: AWG2021 Sample Waveform Library
On Thu, Apr 28, 2022 at 04:59 PM, Lawrance A. Schneider wrote:
As a member of the unwashed, I ask: What is a waveform library?
Arbitrary Waveform Generators run a repeating digital to analogue conversion on a series of numbers, so a waveform library is sets of data corresponding to various patterns such as sine waves, saw tooths, pulses etc. Regards, John
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Re: Saving 576 plots (again)
On 2. May 2022, at 14:51, Zentronics42@... wrote:
...You will not be able to make quantitative measurement however due to the scope graticule not being an exact match for the tube graticule. Why? The 576 has a "ZERO" and "CAL" button, placing the dot in the lower-left or upper-right corner of the graticule. You just have to align the amplification and offset of the scope to match. Of course, most scopes do not have the 10x10 but an 8x10 graticule, so you have to do some additional math. If you intend to save it on a file and put in on your computer you can overly any grid you like. It does not even have to match at the beginning... cheers Martin
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Re: 7000 plugin socket side covers?
Very interesting. I was unaware of that page. It gives me some hope.
Thanks,
Barry - N4BUQ
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----- Original Message ----- From: "Joel B Walker" <joelandjoyce@...>
To: "tekscopes" <[email protected]>
Sent: Monday, May 2, 2022 7:24:46 AM
Subject: Re: [TekScopes] 7000 plugin socket side covers? I'm interested in hearing what can be done for this problem. I have five 7000
instruments. My most recent aquisition has the outside cover for the horizontal
bay refusing to stay snapped in place. The piece looks perfect, but just won't
stay snapped on. There is an article on the Tekwiki about these things, but it
is geared towards the inside covers. Basically they are wedging a strip of
plastic between the circuit board and the cover to hold it in place. This won't
work for the outside ones.
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Re: Saving 576 plots (again)
Since you are planning to test vacuum tubes, David, look up Dennis Tillman's excellent write-up on how to mate a curve tracer with a tube tester.? If you haven't already.Jim Ford?Sent from my T-Mobile 4G LTE Device
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-------- Original message --------From: David Aurora <electronics@...> Date: 5/2/22 1:35 AM (GMT-08:00) To: [email protected] Subject: [TekScopes] Saving 576 plots (again) After years of wanting one, I've finally bought a 576 which I believe is currently sitting in customs 20 minutes from my place. Like quite a few people out there I'm mainly planning to use this for measuring/matching tubes, so while I'm waiting I've been trying to think of the best way to store the plots for future reference.I've searched through this group a lot (it really seems like the best resource out there!) and I see tonnes of suggestions of how people could/might store plot data, but haven't really come across anyone definitively saying "I did it this way and it works great". Anyone out there actually had functional success with the various methods discussed (digitising outputs via USB/cheap AD converter modules, taking photos and using image to CSV converter programs/etc)?It seems like a lot of those chats wind up going off on tangents of trying to control the unit from a computer, or trying to capture the readout settings and so forth but I really can't see that stuff being worth the extra effort for my or many peoples needs. Realistically, if you can get the image on a DSO it's simple to save that plot as a CSV file and adjust scaling to match the curve tracer settings from there, the relative plot points should be plenty to work with.So yeah, I'm curious if many people have tried the various ideas suggested with any success? If not, how are people saving plots? Cameras? Tracing paper over the screen? Manually entering plot data into spreadsheets? Other?Thanks!
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Re: DM501A Input Leakage Source
I figured, Roman.? But it's good to get the information out there for those who haven't been designing boards for decades.JimSent from my T-Mobile 4G LTE Device
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-------- Original message --------From: romeo987 <romeo987@...> Date: 5/2/22 3:47 AM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] DM501A Input Leakage Source Jim,Yes, brain f**t, of course solder mask.Roman
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Re: Saving 576 plots (again)
In the days of old storage on a 576 could be done with a grease pencil on the plastic or cameria system. There is someone who supposedly has a trace saver out on E-bay but they want $3500. And there are some things in the listing that give me pause especially spending that kind of capital on a unit. Like "Fully calibrated unit" further in the listing " We don¡¯t Calibrate the 576 because it takes to long for bench time". At present there is not anything that can reliably capture the wave form for storage out of a 576. However a scope in X-Y mode tapping the vert and horizontal will do the trick. You will not be able to make quantitative measurement however due to the scope graticule not being an exact match for the tube graticule.
I have some information out there on rebuild and restoration of these units.
I would like the solve the tube issue permanently however this is currently above my skill level, but I am rapidly gain ground on it. I am thinking about tapping the preamp signal running that through an ADC Then possibly driving an LCD replacement screen as well as a digitized output for a 576 and 577. But this is as far as I have gotten at the moment. I would like to extend the usefulness of the 576 out a few more decades if I can.
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of David Aurora Sent: Saturday, April 30, 2022 9:07 PM To: [email protected]Subject: [TekScopes] Saving 576 plots (again) After years of wanting one, I've finally bought a 576 which I believe is currently sitting in customs 20 minutes from my place. Like quite a few people out there I'm mainly planning to use this for measuring/matching tubes, so while I'm waiting I've been trying to think of the best way to store the plots for future reference. I've searched through this group a lot (it really seems like the best resource out there!) and I see tonnes of suggestions of how people could/might store plot data, but haven't really come across anyone definitively saying "I did it this way and it works great". Anyone out there actually had functional success with the various methods discussed (digitising outputs via USB/cheap AD converter modules, taking photos and using image to CSV converter programs/etc)? It seems like a lot of those chats wind up going off on tangents of trying to control the unit from a computer, or trying to capture the readout settings and so forth but I really can't see that stuff being worth the extra effort for my or many peoples needs. Realistically, if you can get the image on a DSO it's simple to save that plot as a CSV file and adjust scaling to match the curve tracer settings from there, the relative plot points should be plenty to work with. So yeah, I'm curious if many people have tried the various ideas suggested with any success? If not, how are people saving plots? Cameras? Tracing paper over the screen? Manually entering plot data into spreadsheets? Other? Thanks!
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Re: 7000 plugin socket side covers?
I'm interested in hearing what can be done for this problem. I have five 7000 instruments. My most recent aquisition has the outside cover for the horizontal bay refusing to stay snapped in place. The piece looks perfect, but just won't stay snapped on. There is an article on the Tekwiki about these things, but it is geared towards the inside covers. Basically they are wedging a strip of plastic between the circuit board and the cover to hold it in place. This won't work for the outside ones.
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Re: 7000 plugin socket side covers?
A few days ago, I moved a side cover from a donor instrument to my extender (which had one cover missing). I found it a delicate process. The plastic seemed to be dangerously brittle; but, I got it moved without damage. As I recollect, one edge WAS slightly different and I took this into account when prying off and installing. So far, it seems OK ; but I haven't tried the extender yet.
My backup plan was to fabricate a part from 0.040" and/or 0.062" FR4, using epoxy for fabrication and a milling machine, with a fine carbide cutter, for coutouring. I haven't needed to do this; but it should work.
Stephen Menasian
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Re: DM501A Input Leakage Source
Jim,
Yes, brain f**t, of course solder mask.
Roman
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Alternate trace sweep length disparity 547
Has anyone encountered a sweep discrepancy with the alternate mode on a 547? I have calibrated the caps and resistors in both time-bases to match each other. When using the A sweep by itself the trace is perfect. When using the B trace by itself it is again, perfect. When you use alternate mode the A sweep contracts as per the photo. The top waveform is the A. It is a 10kHz square wave. The effect is most noticeable at 50uS and higher which lead me to suspect stray capacitance in the horizontal switch or something, however if I electrically isolate the alternate traces by pulling the multi-vibrator transistors out, A sweep is again spot on even though the horizontal switch is set to Alternate mode. Very frustrating fault and annoying to use like this. This is the very last issue with my 547 as I have replaced nearly everything and it works brilliantly apart from this small niggling issue. Has anyone had this problem? Thanks! Deon /g/TekScopes/photo/274749/3423741?p=Created%2C%2C%2C20%2C2%2C0%2C0
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After years of wanting one, I've finally bought a 576 which I believe is currently sitting in customs 20 minutes from my place. Like quite a few people out there I'm mainly planning to use this for measuring/matching tubes, so while I'm waiting I've been trying to think of the best way to store the plots for future reference.
I've searched through this group a lot (it really seems like the best resource out there!) and I see tonnes of suggestions of how people could/might store plot data, but haven't really come across anyone definitively saying "I did it this way and it works great". Anyone out there actually had functional success with the various methods discussed (digitising outputs via USB/cheap AD converter modules, taking photos and using image to CSV converter programs/etc)?
It seems like a lot of those chats wind up going off on tangents of trying to control the unit from a computer, or trying to capture the readout settings and so forth but I really can't see that stuff being worth the extra effort for my or many peoples needs. Realistically, if you can get the image on a DSO it's simple to save that plot as a CSV file and adjust scaling to match the curve tracer settings from there, the relative plot points should be plenty to work with.
So yeah, I'm curious if many people have tried the various ideas suggested with any success? If not, how are people saving plots? Cameras? Tracing paper over the screen? Manually entering plot data into spreadsheets? Other?
Thanks!
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Jean-Paul
Martin
TV7