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I started to use my recently received Leo Bodner Fast Rise Pulse Generator (BNC) on my Tek 547/1A1 before wondering if I should seek advice here. I will stipulate that I had looked through the archive for hints as to how to set it up to adjust the H.F. response of the vertical amplifier and will also stipulate that I had remembered to install a 50-ohm terminator between it and the 1A1 input. While reading many interesting tangents and helpful hints, I didn't see anything about using the Bodner on lower bandwidth scopes such as mine. Perhaps, this is an important hint, come to think of it. . .
Would my trying to flatten the top of the square wave with the input Volts/Div. set at 0.2, sweep at .1 microsecond, which is the fastest on this dear old beast, and magnifying the sweep by 5 yield valid results? The test result sheet included with the Bodner shows the amplitude at 0.891 volts, Risetime at 36.02 pS, Falltime at 31.14 pS, overshoot at 3.2%, and undershoot at 5.6%. (Risetime of the 547/1A1 is supposed to be 7 nS.) Viewing the waveform with these settings showed some problems with the top of the square wave that did not appear when I put the Volts/Div. at .5 or 1 (don't quite remember which, now). Not magnifying the sweep made the wave form look like that of the Tek 106 output on a 310A scope.
I would also note that the only 547 manuals that I have or have seen on TekWiki show this step only using the 067-0521-00/TU-7/1M1, rather than the 106 and a 1A1. While I have a 067-0521-00 and think that it has allowed me to peak the HF response fairly well, it could be well out of calibration. It also does not check the whole signal chain as would using the Bodner or the 106 with the 1A1 would - not to state the obvious. Also, I have no way of confirming the accuracy of the 067-0521-00 output because the 453 and 547 are my fastest scopes. Only other ones that I have are the 310As, which I would like to calibrate, too. (Like others here, I work in the AF range, admire the quality of these scopes, and haven't really needed anything modern, although the maintenance of these antiques has tried my patience a few times in the last few months.)
My rationale for using the Bodner is to confirm function of this and my 453 vertical amplifiers before undertaking any (additional) attempts to adjust the output of my 106 and 107 Square Wave Generators. (I had chimed in on attempts to repair another party's 106 earlier this year.) I cannot tell if both of those generators are the source of various waveform distortions or if both of my scopes are the culprit.
Initial adjustments on the 547 did allow me to almost flatten the top of the square wave, but I would like to try to improve the results - if I am on the right track.
PMF
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I bought one last week to play with. I also bought one of the eBay versions too.
I want characterize the difference between my two R7103/7A29/7A29/7B10, 7854/7A19/7A19/7B87/7B80, 5104 Digital, 7934/7A19/7A19/7B85/7B80, 7S11/T11 Plug-ins, 7S12 Plug-in Input and 2465B. I should have a CSA, but I don't. Haven't needed one yet.
I am particularly interested to see what the R7103s and the 5104 comparison shows.
Ross
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of PMF Sent: Thursday, April 28, 2022 2:59 PM To: [email protected]Subject: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? I started to use my recently received Leo Bodner Fast Rise Pulse Generator (BNC) on my Tek 547/1A1 before wondering if I should seek advice here. I will stipulate that I had looked through the archive for hints as to how to set it up to adjust the H.F. response of the vertical amplifier and will also stipulate that I had remembered to install a 50-ohm terminator between it and the 1A1 input. While reading many interesting tangents and helpful hints, I didn't see anything about using the Bodner on lower bandwidth scopes such as mine. Perhaps, this is an important hint, come to think of it. . . Would my trying to flatten the top of the square wave with the input Volts/Div. set at 0.2, sweep at .1 microsecond, which is the fastest on this dear old beast, and magnifying the sweep by 5 yield valid results? The test result sheet included with the Bodner shows the amplitude at 0.891 volts, Risetime at 36.02 pS, Falltime at 31.14 pS, overshoot at 3.2%, and undershoot at 5.6%. (Risetime of the 547/1A1 is supposed to be 7 nS.) Viewing the waveform with these settings showed some problems with the top of the square wave that did not appear when I put the Volts/Div. at .5 or 1 (don't quite remember which, now). Not magnifying the sweep made the wave form look like that of the Tek 106 output on a 310A scope. I would also note that the only 547 manuals that I have or have seen on TekWiki show this step only using the 067-0521-00/TU-7/1M1, rather than the 106 and a 1A1. While I have a 067-0521-00 and think that it has allowed me to peak the HF response fairly well, it could be well out of calibration. It also does not check the whole signal chain as would using the Bodner or the 106 with the 1A1 would - not to state the obvious. Also, I have no way of confirming the accuracy of the 067-0521-00 output because the 453 and 547 are my fastest scopes. Only other ones that I have are the 310As, which I would like to calibrate, too. (Like others here, I work in the AF range, admire the quality of these scopes, and haven't really needed anything modern, although the maintenance of these antiques has tried my patience a few times in the last few months.) My rationale for using the Bodner is to confirm function of this and my 453 vertical amplifiers before undertaking any (additional) attempts to adjust the output of my 106 and 107 Square Wave Generators. (I had chimed in on attempts to repair another party's 106 earlier this year.) I cannot tell if both of those generators are the source of various waveform distortions or if both of my scopes are the culprit. Initial adjustments on the 547 did allow me to almost flatten the top of the square wave, but I would like to try to improve the results - if I am on the right track. PMF
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PMF
I have a bunch of calibration videos out on you tube about doing these adjustments. Not on a 547 but 465's and 485's I have also been told that 475's are on the way. The adjustment display is the same for the 500 series as for the 4xx series. It is critical that the rise time not be over damped if this is the case the scope will lose bandwidth. If you make the square wave look nice and clean the vertical will come out slow. In a 4xx you can loose 25-30Mhz in the high frequency compensation. The channel is linked below. The HF comp procedure is pretty much the same just with faster or slower edges.
Of specific interest
7a26 -
7A15A -
465B Vertical section -
485B Vertical Section -
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of PMF Sent: Thursday, April 28, 2022 4:59 PM To: [email protected]Subject: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? I started to use my recently received Leo Bodner Fast Rise Pulse Generator (BNC) on my Tek 547/1A1 before wondering if I should seek advice here. I will stipulate that I had looked through the archive for hints as to how to set it up to adjust the H.F. response of the vertical amplifier and will also stipulate that I had remembered to install a 50-ohm terminator between it and the 1A1 input. While reading many interesting tangents and helpful hints, I didn't see anything about using the Bodner on lower bandwidth scopes such as mine. Perhaps, this is an important hint, come to think of it. . . Would my trying to flatten the top of the square wave with the input Volts/Div. set at 0.2, sweep at .1 microsecond, which is the fastest on this dear old beast, and magnifying the sweep by 5 yield valid results? The test result sheet included with the Bodner shows the amplitude at 0.891 volts, Risetime at 36.02 pS, Falltime at 31.14 pS, overshoot at 3.2%, and undershoot at 5.6%. (Risetime of the 547/1A1 is supposed to be 7 nS.) Viewing the waveform with these settings showed some problems with the top of the square wave that did not appear when I put the Volts/Div. at .5 or 1 (don't quite remember which, now). Not magnifying the sweep made the wave form look like that of the Tek 106 output on a 310A scope. I would also note that the only 547 manuals that I have or have seen on TekWiki show this step only using the 067-0521-00/TU-7/1M1, rather than the 106 and a 1A1. While I have a 067-0521-00 and think that it has allowed me to peak the HF response fairly well, it could be well out of calibration. It also does not check the whole signal chain as would using the Bodner or the 106 with the 1A1 would - not to state the obvious. Also, I have no way of confirming the accuracy of the 067-0521-00 output because the 453 and 547 are my fastest scopes. Only other ones that I have are the 310As, which I would like to calibrate, too. (Like others here, I work in the AF range, admire the quality of these scopes, and haven't really needed anything modern, although the maintenance of these antiques has tried my patience a few times in the last few months.) My rationale for using the Bodner is to confirm function of this and my 453 vertical amplifiers before undertaking any (additional) attempts to adjust the output of my 106 and 107 Square Wave Generators. (I had chimed in on attempts to repair another party's 106 earlier this year.) I cannot tell if both of those generators are the source of various waveform distortions or if both of my scopes are the culprit. Initial adjustments on the 547 did allow me to almost flatten the top of the square wave, but I would like to try to improve the results - if I am on the right track. PMF
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PMF one other thing to note after looking up the 1a1 you will need a 50 Ohm terminator to get the rise time out of the Leo pulser. These can be had for $20.00 an example is here
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of PMF Sent: Thursday, April 28, 2022 4:59 PM To: [email protected]Subject: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? I started to use my recently received Leo Bodner Fast Rise Pulse Generator (BNC) on my Tek 547/1A1 before wondering if I should seek advice here. I will stipulate that I had looked through the archive for hints as to how to set it up to adjust the H.F. response of the vertical amplifier and will also stipulate that I had remembered to install a 50-ohm terminator between it and the 1A1 input. While reading many interesting tangents and helpful hints, I didn't see anything about using the Bodner on lower bandwidth scopes such as mine. Perhaps, this is an important hint, come to think of it. . . Would my trying to flatten the top of the square wave with the input Volts/Div. set at 0.2, sweep at .1 microsecond, which is the fastest on this dear old beast, and magnifying the sweep by 5 yield valid results? The test result sheet included with the Bodner shows the amplitude at 0.891 volts, Risetime at 36.02 pS, Falltime at 31.14 pS, overshoot at 3.2%, and undershoot at 5.6%. (Risetime of the 547/1A1 is supposed to be 7 nS.) Viewing the waveform with these settings showed some problems with the top of the square wave that did not appear when I put the Volts/Div. at .5 or 1 (don't quite remember which, now). Not magnifying the sweep made the wave form look like that of the Tek 106 output on a 310A scope. I would also note that the only 547 manuals that I have or have seen on TekWiki show this step only using the 067-0521-00/TU-7/1M1, rather than the 106 and a 1A1. While I have a 067-0521-00 and think that it has allowed me to peak the HF response fairly well, it could be well out of calibration. It also does not check the whole signal chain as would using the Bodner or the 106 with the 1A1 would - not to state the obvious. Also, I have no way of confirming the accuracy of the 067-0521-00 output because the 453 and 547 are my fastest scopes. Only other ones that I have are the 310As, which I would like to calibrate, too. (Like others here, I work in the AF range, admire the quality of these scopes, and haven't really needed anything modern, although the maintenance of these antiques has tried my patience a few times in the last few months.) My rationale for using the Bodner is to confirm function of this and my 453 vertical amplifiers before undertaking any (additional) attempts to adjust the output of my 106 and 107 Square Wave Generators. (I had chimed in on attempts to repair another party's 106 earlier this year.) I cannot tell if both of those generators are the source of various waveform distortions or if both of my scopes are the culprit. Initial adjustments on the 547 did allow me to almost flatten the top of the square wave, but I would like to try to improve the results - if I am on the right track. PMF
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PMF,
Please disregard the second message as I missed the part about the 50 Ohm terminator. What I get for typing out emails and getting interrupted. I will base what I am about to say out of the 7K world as that is my strong spot.
Typically when adjusting a 7K Frame and associated plugins the order is frame -> then plugins. The use of the calibration plugin is to make sure the HF response of the port is correct before adjusting the HF of the plugin. If the port response is off this offset will then also be tuned in to the plugin. If the plugin is moved to another frame it is out now due to the HF of the frame The calibration plugin has a known step response to adjust the frame. There are notes in the 7k frame manual that say you can do the adjustments with out the calibration plugin. But if this is done then there is no guarantee that the plugin will meet spec if it is moved to another frame.
After digging in to the adjustment document of the 1a1 like in the 4xx and 7xxx gear there is a frequency compensation in all voltage ranges 0.05 all the way through 20V it is adjustment capacitors C104-112 both C and B one of the reasons for good waves forms on some ranges and bad on other could be some miss adjustments or faults in the attenuator for the ranges. Referencing table 7-2 on page 7-24 of the late serial number manuals.
This creates a chicken and egg problem. Is the attenuator out or is the frame out? Given that the waveforms look good on some ranges but bad on the other leads me to believe that it is the attenuator that is out rather than the 547 but I can not say for sure. Another thing to note in doing these types of adjustments is the leo pulser may only be flat for a specified time. TD pulsers that tech made have this problem. Only flat for 10ns. A type 106 is used for the low and mid frequency compensations and a TD pulser is used for just the HF comp. the waveform of the TD pulser slowly fall off after 10ns and is no longer flat.
If needed I can check flatness of a leo pulser I have 2 available in the lab.
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Zentronics42 via groups.io Sent: Thursday, April 28, 2022 9:27 PM To: [email protected]Subject: Re: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? PMF one other thing to note after looking up the 1a1 you will need a 50 Ohm terminator to get the rise time out of the Leo pulser. These can be had for $20.00 an example is here Zen -----Original Message----- From: [email protected] < [email protected]> On Behalf Of PMF Sent: Thursday, April 28, 2022 4:59 PM To: [email protected]Subject: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? I started to use my recently received Leo Bodner Fast Rise Pulse Generator (BNC) on my Tek 547/1A1 before wondering if I should seek advice here. I will stipulate that I had looked through the archive for hints as to how to set it up to adjust the H.F. response of the vertical amplifier and will also stipulate that I had remembered to install a 50-ohm terminator between it and the 1A1 input. While reading many interesting tangents and helpful hints, I didn't see anything about using the Bodner on lower bandwidth scopes such as mine. Perhaps, this is an important hint, come to think of it. . . Would my trying to flatten the top of the square wave with the input Volts/Div. set at 0.2, sweep at .1 microsecond, which is the fastest on this dear old beast, and magnifying the sweep by 5 yield valid results? The test result sheet included with the Bodner shows the amplitude at 0.891 volts, Risetime at 36.02 pS, Falltime at 31.14 pS, overshoot at 3.2%, and undershoot at 5.6%. (Risetime of the 547/1A1 is supposed to be 7 nS.) Viewing the waveform with these settings showed some problems with the top of the square wave that did not appear when I put the Volts/Div. at .5 or 1 (don't quite remember which, now). Not magnifying the sweep made the wave form look like that of the Tek 106 output on a 310A scope. I would also note that the only 547 manuals that I have or have seen on TekWiki show this step only using the 067-0521-00/TU-7/1M1, rather than the 106 and a 1A1. While I have a 067-0521-00 and think that it has allowed me to peak the HF response fairly well, it could be well out of calibration. It also does not check the whole signal chain as would using the Bodner or the 106 with the 1A1 would - not to state the obvious. Also, I have no way of confirming the accuracy of the 067-0521-00 output because the 453 and 547 are my fastest scopes. Only other ones that I have are the 310As, which I would like to calibrate, too. (Like others here, I work in the AF range, admire the quality of these scopes, and haven't really needed anything modern, although the maintenance of these antiques has tried my patience a few times in the last few months.) My rationale for using the Bodner is to confirm function of this and my 453 vertical amplifiers before undertaking any (additional) attempts to adjust the output of my 106 and 107 Square Wave Generators. (I had chimed in on attempts to repair another party's 106 earlier this year.) I cannot tell if both of those generators are the source of various waveform distortions or if both of my scopes are the culprit. Initial adjustments on the 547 did allow me to almost flatten the top of the square wave, but I would like to try to improve the results - if I am on the right track. PMF
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Zen,
In that case, I might return to the 067-0521-00 to see what the waveform looks like after I blundered into adjusting the whole system with the Bodner. You make a very good point anent standardizing, so to speak, the mainframe so that all plugs-in behave, and I will return to this MO, even though I have but one 500 series scope.
Fortunately, I had two or three bumps well beyond 10 nS in the waveform, at least as I left it, so I probably did not attenuate the bandwidth too much. I am also glad you replied, for this is the only 'scope whose vertical amplifier I 'adjusted.'
Unfortunately, this probably indicates that my 106 & 107 square wave generators are faulty, but at least it is good to know where to start. Somehow.
PMF
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In looking at the type 107 it looks like there is not much that will fail in it other than the normal power supply caps. The 106 has a lot more going on in it. If I can capture some waveforms from a working 106 let me know. I have one in the lab. I also have 2 leo pulsers in the lab so I can take some pictures on a 7k frame of what it looks like. But I think my slowest plugins are 75Mhz. but that would get close to the 1a1.
Also when doing the HF alignment the only thing of interest in the wave form is the rise and transition to the flat top of the wave form. Nothing in wave shape matters after that. The way the alignments go is to start out slow and long flattening out the waveform working forward to the rising edge sharpening up the corner as the steps progress. The deeper in to the process the more zoomed in on the corner. The more zoomed in on the corner the less the rest of the wave form matters.
That being said I have had some plugins that were very badly miss aligned (from the Ebay) that took 4-5 passes of the compensation procedure to get them to rights.
If I can help out in any way let me know
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of PMF Sent: Thursday, April 28, 2022 11:09 PM To: [email protected]Subject: Re: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? Zen, In that case, I might return to the 067-0521-00 to see what the waveform looks like after I blundered into adjusting the whole system with the Bodner. You make a very good point anent standardizing, so to speak, the mainframe so that all plugs-in behave, and I will return to this MO, even though I have but one 500 series scope. Fortunately, I had two or three bumps well beyond 10 nS in the waveform, at least as I left it, so I probably did not attenuate the bandwidth too much. I am also glad you replied, for this is the only 'scope whose vertical amplifier I 'adjusted.' Unfortunately, this probably indicates that my 106 & 107 square wave generators are faulty, but at least it is good to know where to start. Somehow. PMF
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IIUC, the Bodnar pulser does not output a flat waveform ¨C all design effort went into getting the fastest possible rise. 067-0521 and 106 put out a flat waveform. Dave Wise From: [email protected] < [email protected]> On Behalf Of PMF via groups.io Sent: Thursday, April 28, 2022 1:59 PM To: [email protected]Subject: [TekScopes] Leo Bodner Fast Rise Pulse Generator for 453 & 547? I started to use my recently received Leo Bodner Fast Rise Pulse Generator (BNC) on my Tek 547/1A1 before wondering if I should seek advice here. I will stipulate that I had looked through the archive for hints as to how to set it up to adjust the H.F. response of the vertical amplifier and will also stipulate that I had remembered to install a 50-ohm terminator between it and the 1A1 input. While reading many interesting tangents and helpful hints, I didn't see anything about using the Bodner on lower bandwidth scopes such as mine. Perhaps, this is an important hint, come to think of it. . . Would my trying to flatten the top of the square wave with the input Volts/Div. set at 0.2, sweep at .1 microsecond, which is the fastest on this dear old beast, and magnifying the sweep by 5 yield valid results? The test result sheet included with the Bodner shows the amplitude at 0.891 volts, Risetime at 36.02 pS, Falltime at 31.14 pS, overshoot at 3.2%, and undershoot at 5.6%. (Risetime of the 547/1A1 is supposed to be 7 nS.) Viewing the waveform with these settings showed some problems with the top of the square wave that did not appear when I put the Volts/Div. at .5 or 1 (don't quite remember which, now). Not magnifying the sweep made the wave form look like that of the Tek 106 output on a 310A scope. I would also note that the only 547 manuals that I have or have seen on TekWiki show this step only using the 067-0521-00/TU-7/1M1, rather than the 106 and a 1A1. While I have a 067-0521-00 and think that it has allowed me to peak the HF response fairly well, it could be well out of calibration. It also does not check the whole signal chain as would using the Bodner or the 106 with the 1A1 would - not to state the obvious. Also, I have no way of confirming the accuracy of the 067-0521-00 output because the 453 and 547 are my fastest scopes. Only other ones that I have are the 310As, which I would like to calibrate, too. (Like others here, I work in the AF range, admire the quality of these scopes, and haven't really needed anything modern, although the maintenance of these antiques has tried my patience a few times in the last few months.) My rationale for using the Bodner is to confirm function of this and my 453 vertical amplifiers before undertaking any (additional) attempts to adjust the output of my 106 and 107 Square Wave Generators. (I had chimed in on attempts to repair another party's 106 earlier this year.) I cannot tell if both of those generators are the source of various waveform distortions or if both of my scopes are the culprit. Initial adjustments on the 547 did allow me to almost flatten the top of the square wave, but I would like to try to improve the results - if I am on the right track. PMF
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I tried mine on a 2815 (like a 2225) 50MHz without and with a 50 ohm feedthru at .05uS
each pulse is about 1 div spaced by 1 div not a perfect square wave but pretty close at
that speed, fastest on the scope. Rarely do I use that end of the sweep.
Other than the signal level (dropped about half) I really did not notice any other changes
by adding a terminator.
Maybe magnafication would show something?
--
Jeffeelcr
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Jeff,
The pulse rise time at the scope input gets (with such a fast generator) determined by the effective RC at the scope input. Without terminator that will be 1 ns, with terminator 0.5 ns. That corresponds to rise time 2.2 ns and 1.1 ns. Even if the scope were perfect you couldn't notice this at 0.05 us/div. It (and the difference) would be seen at 10X magnified sweep. But the rise time of the 50 MHz scope is about 6.5 ns and will be increased to about 6.86 ns and 6.59. I doubt you can see the difference at all even at 10X magnified sweep.
Albert
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Albert, I tried it later and no I did not notice any difference at any magnified setting.
It did however prove to me that thing is flying fast.
Jeff
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Jeffeelcr
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Zen,
I did make some progress with the 067-0521-00 Calibration Fixture on my 547 and need only remove a small dip or 'anti-bump,' if I may, in the first 10 nS of the top of the square wave. Otherwise, I seem to have the requisite 7 nS rise time per the instruction manual and proper squareness of the waveform. Once this is all settled, I will try to tame the square waves coming out of the Tek 106 & 107.
What about the Bodner for the 453? It seems like that scope would be a reasonable candidate while conceding what D. Wise had noted about the waveform so generated by the Bodner. Of course, I suspect that it would be better for me to mend the 106 properly so that I could get the proper square wave for the 453, but as I have never touched the HF response of that scope, I am tempted to leave it alone for the moment.
PMF
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PMF