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On April 3rd, I picked up a 2213A. While testing it, I noticed that the trace does not fill the whole display regardless of position settings. I tried messing around with the controls to see if I could fix it without opening the scope, but I had no luck doing that. Also, I found that sometimes a signal was displayed even when the trace was set to ground. The other day, I opened up the scope (the cover won't come off all the way, but it comes off enough for me to access the boards) so I could calibrate it. I bought a copy of the 2213A service manual, and proceeded to adjust the horizontal amplifier gain. However, even with the gain turned to the max, the trace does not fill the display. Both the trace after adjusting and the mysterious waveform are shown here:
The wave disappears if I ground the shroud surrounding the CRT. I will try to get the cover off so I can check connections and voltages.
Can someone help me work through calibrating this scope and getting it to work properly? For your information, this is my first ever oscilloscope.
If you want more information and/or details, please let me know; I would be happy to provide them.
By the way, how do I properly reply to a reply on a topic? I tried posting a reply 3 times the last time I posted, but none of them showed up.
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Hello Lukus, See some answers next to your questions... On Sun, Apr 8, 2018 at 05:57 pm, Lukus wrote: On April 3rd, I picked up a 2213A. While testing it, I noticed that the trace
does not fill the whole display regardless of position settings. I tried
messing around with the controls to see if I could fix it without opening the
scope, but I had no luck doing that.
Also, I found that sometimes a signal was
displayed even when the trace was set to ground. Indeed it's a weird waveform. Did you try to change the sweep speeds (Time/Div), and or the input attenuator (Volts/Div) settings? Does that change the way that "wave" shows on the screen, this may tell you/us something about where this "signal" is sneaking into the circuits. The other day, I opened up
the scope (the cover won't come off all the way, but it comes off enough for
me to access the boards) so I could calibrate it. I bought a copy of the 2213A
service manual, and proceeded to adjust the horizontal amplifier gain. Usually the Tek manuals are very comprehensive and you should get instructions on how to open it properly. However, even with the gain turned to the max, the trace does not fill the
display. Both the trace after adjusting and the mysterious waveform are shown
here: I wouldn't have jumped directly into changing the scope's calibration, without first checking the basics, and I`m afraid that even doing that, you didn't really ruled out anything. There are two things that you will see on this forum, which are general and mandatory advice before diving into anything more involving (like fiddling with the calibration adjustments): 1. Check the "so called" low voltage power supplies...(LVPS is everything that is not the C.R.T. High voltages) not necessarily a "low" voltage. Among the low voltages there are usually voltages in the 50~60 volts ballpark, and in the 100~140V ballpark. 1a.for correct voltages (you will need a VoltMeter, at least, and preferably one that you can trust the measurement). 1b. For ripple, and since this is the first oscilloscope you have, I suppose you can't check the ripple and/or power supplies waveforms, so it must suffice you measure the AC voltage of the DC power supplies. Those ripple voltages are usually in the millivolts arena, at most, in the 100ths of volt, so you will need a relatively sensitive AC voltmeter (again that you can trust). 2. Looking for signs of false-contacts or conditions that are usually associated to false-contacts, like signs of corrosion, excess of dust or dirty innards, signs of humidity... and preemptively, trying to clean the easily accessible switches with I.P.A. or contact cleaner. If the latter, make sure you use a contact cleaner that's safe to plastics... The manual is your friend here. Don't apply any cleaner without first checking in the manual if that switch in particular has special recommendations for cleaning. In doubt... don't. Exercising the switches and potentiometers usually help to clean them, and also reveal if they are showing signs of dirtiness / false contacts. It's common that some lubricants dry out and leave an insulating film that sometimes render the switch or potentiometer totally dead or opened, and often this is not an irreversible condition. One example to this topic is the "Beam Finder" switch, false contact on it is known to cause this kind of problem (of compressed gain, on either X, or Y axis). The wave disappears if I ground the shroud surrounding the CRT. I will try to
get the cover off so I can check connections and voltages. The strange waveform may be nothing, it may just be noise pickup that's happening because the cover is partially opened (so that it's natural connection to ground is broken, as it remains grounded while closed) but at the same time, it's in close range to sensitive electronics that will pickup noise from the nearby big piece of metal... or the cover, while ungrounded, may be picking up strong EMI interference from the Power supply, and transmitting it (by capacitive coupling) to the sensitive parts that it may be nearby. Can someone help me work through calibrating this scope and getting it to work
properly? For your information, this is my first ever oscilloscope. You came to the right place. I don't know the 2213 in particular, but surely other folks will jump in and help. If you want more information and/or details, please let me know; I would be
happy to provide them. Let us know about the Low Voltage power supply voltages... and if the manual helped you with opening the scope (completely). By the way, how do I properly reply to a reply on a topic? I tried posting a
reply 3 times the last time I posted, but none of them showed up. Do you use an e-mail client? or you read / reply directly from Tekscopes 开云体育 web interface? Rgrds, Fabio
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As Fabio said, DO NOT jump into calibration. you only make more work for yourself.
That waveform definitely indicates bad filters on the PS, especially with the trace turning backwards as it seems to do. In fact if there is no input that waveform is coming from the PS, which makes it phased with the aberration in the sweep which would not be visible normally without input;
The very first thing I would do it to check the ESR of the PS filter caps.
If you have another scope I can tell you how to build an ESR indicator which is quite effective if you have no other means. It can be done with a meter and a function generator as well but with a bit less accuracy. In fact I believe I should post about that.
If you have another scope though you can just simply scope the PS outputs. Most supplies have a pi filter, so you must scope both the first and second filter for that source. I suspect both are bad in a source that is common to both axes.
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On Sun, Apr 8, 2018 at 05:57 pm, Lukus wrote:
The other day, I opened up the scope (the cover won't come off all the way,
but it comes off enough for me to access the boards) so I could calibrate it.
I worked on a 2215 and it is similar. that issue is a simple one but I don't remember exactly. I know I felt like an (_|_)hole when I figured it out. I think it was a matter of tilting it the right way. So I read this is your first scope (and therefore only scope) ? If so I can tailor this ESR gizmo to accommodate. Just let me know.
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The other day, I opened up the scope (the cover won't come off all the way,
but it comes off enough for me to access the boards) so I could calibrate it. The case normally fits the 22xx scope's frame very closely so any kind of dent or deformity uses up all of the available space between case and frame. If the deformity isn't too bad, you can "walk" the case off of the frame by pulling the case back as far as you can by wiggling and pulling the case from the frame on one side, and then go to the other side and do the same thing. If you see the case is moving back a little bit each time you do this, keep doing it until the case falls off. This process will help repair the outer case by gently pushing those tight spots out. Once the case is off, look inside to see what is hitting the frame, and then do whatever you can to move those areas of the case out a bit more. tom jobe... PS Forget your calibration plan until you have all of the basics fixed as the scope is completely incapable of operating properly the way it currently is. The 2213A is a fine scope and and combined with the Tektronix service manual you have a nice analog electronics classroom in a simple box. The 2213A is the simplest model of a fine series of oscilloscopes which include the 2215A, 2235, 2236, 2220, 2232 and many others. For most of your repair work any 2215A or 2235 service manual will suffice if a 2213A manual is hard to come by. You can work on most of this scope while it is running (using a large amount of caution of course!), and you can replace common parts that wear out (such as the electrolytic capacitors you need to replace) without taking much apart. tom jobe...
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It appears a free service manual is available here :
Looks like 2 there, one is 15 MB and the other is 83 MB, obviously take the bigger one... :-)
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That is quite a selection of free manuals someone is offering, but both of the manuals they have are for the non-A version of the 2213 which is a much different oscilloscope than the 2213A, especially in the power supply section where many of the age related problems are found.
The best copy of the manual I have for the 2213A came from Artek Media for very little money.
Original printed copies of the 2213A Service Manual are somewhat rare and and usually 'pricey'.
I bought a 're-printed' copy of the 2213A manual years ago on eBay before I had the capability to print schematics on 11 x 17 paper and I found that 2213A 're-print' to be useless.
tom jobe...
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On 4/11/2018 2:32 AM, Jeff Urban wrote: It appears a free service manual is available here :
Looks like 2 there, one is 15 MB and the other is 83 MB, obviously take the bigger one... :-)
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I encourage the OP to go for the Artek Media 2213A pdf manual. I have it and the quality is
superb, color, hi-res, full size fold out schematics, page links.......and you get it immediately.
Ted
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On 11 Apr 2018 at 5:58, tom jobe wrote: That is quite a selection of free manuals someone is offering, but both of the manuals they have are for the non-A version of the 2213 which is a much different oscilloscope than the 2213A, especially in the power supply section where many of the age related problems are found. The best copy of the manual I have for the 2213A came from Artek Media for very little money. Original printed copies of the 2213A Service Manual are somewhat rare and and usually 'pricey'. I bought a 're-printed' copy of the 2213A manual years ago on eBay before I had the capability to print schematics on 11 x 17 paper and I found that 2213A 're-print' to be useless. tom jobe... On 4/11/2018 2:32 AM, Jeff Urban wrote: It appears a free service manual is available here :
Looks like 2 there, one is 15 MB and the other is 83 MB, obviously take the bigger one... :-)
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If this post shows up, then email seems to be working.
I have been trying to use the web interface. I successfully posted using
the web interface, but I every time I reply to my topic, my post doesn't
show up; rather, when I click "Reply to Group", I am directed to a page
which reads {"DraftID":<number>}. The post never shows up after that.
In the meantime, I managed to convince the shroud to loosen its death grip
on my scope. I tested the power supply voltages as per the service manual,
and they are all within the given ranges. My multimeter reads 0.0mV AC when
connected to the test points, so either I am doing something incorrectly or
there is no ripple.
For those who are recommending service manuals, I already have one, as
mentioned in the original post. I got mine from Artek.
-Lukus
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Lukus
OK what are your failure symptoms again now that you have determined that the PS is probably OK??
Your web posting problem may be that you are not logged into groups IO first...
-DC
manuals@...
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On 4/12/2018 4:20 AM, Lukus wrote: If this post shows up, then email seems to be working.
I have been trying to use the web interface. I successfully posted using
the web interface, but I every time I reply to my topic, my post doesn't
show up; rather, when I click "Reply to Group", I am directed to a page
which reads {"DraftID":<number>}. The post never shows up after that.
In the meantime, I managed to convince the shroud to loosen its death grip
on my scope. I tested the power supply voltages as per the service manual,
and they are all within the given ranges. My multimeter reads 0.0mV AC when
connected to the test points, so either I am doing something incorrectly or
there is no ripple.
For those who are recommending service manuals, I already have one, as
mentioned in the original post. I got mine from Artek.
-Lukus
--
Dave
Manuals@...
www.ArtekManuals.com
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On Thu, Apr 12, 2018 at 01:32 am, Artekmedia wrote:
Your web posting problem may be that you are not logged into groups IO
first...
Yes, and what browser and what type of email ? I use old FF18 here, and gmail web based which is always signed in. Up until a couple days ago I didn't even have a password for this site, it just logged me in automatically. And then I was logged out. At least it is not picky about the password, Like "GIVEmeaccessnowyou$%^$%orIamgoingtoblowyourdamnheadoff123". And then : "sorry, that password has been taken". But after creating a password it again logs me in automatically. It may have a set interval when it will force me to sign in again, but now at least I can. So far so good. I have physical control of my PCs, so I don't really worry about it. If I did online banking it might be different.
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I think it stores the password in a cookie (or, at least, the fact that you are already logged in). If you clean out the right cookies, you'll be signed out.
Thanks,
Barry - N4BUQ
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On Thu, Apr 12, 2018 at 01:32 am, Artekmedia wrote:
Your web posting problem may be that you are not logged into groups IO
first...
Yes, and what browser and what type of email ?
I use old FF18 here, and gmail web based which is always signed in. Up until
a couple days ago I didn't even have a password for this site, it just
logged me in automatically. And then I was logged out.
At least it is not picky about the password, Like
"GIVEmeaccessnowyou$%^$%orIamgoingtoblowyourdamnheadoff123". And then :
"sorry, that password has been taken". But after creating a password it
again logs me in automatically. It may have a set interval when it will
force me to sign in again, but now at least I can. So far so good. I have
physical control of my PCs, so I don't really worry about it. If I did
online banking it might be different.
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I am not having issues posting to or reading from the group. Things are
figured out.
Artekmedia
The main problems with the scope are as follows:
1. The trace does not fill the display.
2. Even when the trace is set to ground, a waveform is shown.
Both are demonstrated in this image:
The mystery waveform was not present when I first tested the scope, so it
might be related to not having the cover in place.
I have limited experience, but I think the trace not filling the display is
the more important issue to fix; however, both must be fixed before I can
use this scope for real.
Details on issue 1:
When I adjust the horizontal position knob, the trace moves properly, but
at a point about 3/4 to the right on the display, the trace "hits a wall"
for lack of a better word. The left end of the trace still moves, but the
right end gets cut off. This leads me to believe that there is an issue
with the horizontal deflection plates; it's possible that one is
disconnected. I can post a video of this behavior when I get home.
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I have not worked on this particular scope in over 15 years ( HV problem in the past) I would tend to think the problem is more likely a problem somewhere in the Horizontal amplifier circuit, especially since you get some deflection to the right just not all the way to the right. You dont say in this most recent post but when you move the trace to the LEFT can you drive the trace beginning off the left hand side of the screen?.
If you have full sweep to the left but not the right I am guessing that if you swap the leads to the deflection plates from the amp board that the problem will now appear on the left and not the right assuming you had full sweep on the left before. This will also tell you that the problem is in the Horizontal Amp board and not the CRT
-DC
manuals@...
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On 4/12/2018 6:16 PM, Lukus wrote: I am not having issues posting to or reading from the group. Things are
figured out.
Details on issue 1:
When I adjust the horizontal position knob, the trace moves properly, but
at a point about 3/4 to the right on the display, the trace "hits a wall"
for lack of a better word. The left end of the trace still moves, but the
right end gets cut off. This leads me to believe that there is an issue
with the horizontal deflection plates; it's possible that one is
disconnected. I can post a video of this behavior when I get home.
-=-=-=-=-=-=-=-=-=-=-=-
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Hi Lukus,
On the points you outlined below, all fine but, still...
1. Did you manage to fully remove the cover?
2. Is the waveform that isshowing (with input set to GND) still happens with the big ungrounded metal can away from the sensitive input circuitry?
3. Did you have chance to measure the Low Voltage Power Supply voltages?
4. And last, but not least (and maybe that should be the first, did you try to exercise the Beam Finder button? It may be stuck-in or it may be presenting false-contacts, and this is a very common fault.
Reason I'm insisting on this last point is that, by looking at the waveform, it's more or less centered on the screen (with position controls showing visibly more or less centered on the photo... so they agree), and evenly distributed (the curls have more or less the same size to the left and to the right, up and down) inspiring that amplifiers are working more or less linearly.
The fact that the trace "hits a wall" when moving towards one side, is also consistent with the behavior of the "Beam Finder", as if it's stuck "on"...and it will be even more consistent if you answer that it also hits a wall moving to the other direction... because this is exactly what "beam finder" is supposed to do...
It brings the trace to a centered area on-screen, but always biased to the side or quadrant from where the trace is being "pulled" from, to give you hints where the trace is hidden, in case you have a combination of signal and position controls so wrong that you can't locate the trace, and it does that by limitting the gain of both Vertical and Horizontal amplifier, at the same time that it "clips" their minimum and maximum voltages to assure that trace is always on-screen.
It also sets the trace intensity to a level that is surely visible no matter other conditions, in case the operator is not finding the trace just because it's dimmed.
I look forward on seeing your answers.
Rgrds,
Fabio
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On Thu, Apr 12, 2018 at 03:16 pm, Lukus wrote:
I am not having issues posting to or reading from the group. Things are
figured out.
Artekmedia
The main problems with the scope are as follows:
1. The trace does not fill the display.
2. Even when the trace is set to ground, a waveform is shown.
Both are demonstrated in this image:
The mystery waveform was not present when I first tested the scope, so it
might be related to not having the cover in place.
I have limited experience, but I think the trace not filling the display is
the more important issue to fix; however, both must be fixed before I can
use this scope for real.
Details on issue 1:
When I adjust the horizontal position knob, the trace moves properly, but
at a point about 3/4 to the right on the display, the trace "hits a wall"
for lack of a better word. The left end of the trace still moves, but the
right end gets cut off. This leads me to believe that there is an issue
with the horizontal deflection plates; it's possible that one is
disconnected. I can post a video of this behavior when I get home.
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Fabio
1. Yes, the cover is off, as I mentioned previously.
2. The waveform still happens with the cover far away. I'll try moving the
scope to another location and see what happens then.
3. Yes, I measured the voltages, and they are all within spec as per the
service manual. I mentioned this previously.
4. Exercise the beam find button? Oh boy, I've pressed it about 200 times
in a row to make sure it isn't stuck. It works fine. Maybe I can get in
there and clean it, but I'm fairly sure this isn't beam find being stuck.
It might be partially activated or something (not sure if that can happen
in this sort of device). I'll post a video of the behevior when I get home.
Artekmedia
Yes, I can drive the left end of the trace off the screen.
-Lukus
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Then swap the deflection plate leads. I am betting? that the problem reverses itself. If it does reverse then the problem is in the amp not the tube ...My money is on the amp.
-DC
manuals@...
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Artekmedia
Yes, I can drive the left end of the trace off the screen.
-Lukus
--
Dave
Manuals@...
www.ArtekManuals.com
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Lukus,
If you look carefully at the trace you posted you will see that the spot is not moving uniformly from left to right but is making a loop in synchronism with the Y deflection so that part of the time it is actually moving backwards. This is usually caused by severe ripple on one of the low voltage supplies which is feeding into both X and Y amplifiers. Are you able to measure the ripple level on +100V, +30V, +8.6V and -8.6V? Ideally you would have access to another scope to do this, but you can use an AC voltage reading on a multimeter if it has a DC blocking capacitor.
Regards,
Roger
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Hi,
I have no experience with this scope model, but I have a 465b, which had a similar problem. Horizontal trace was only 7 divisions long. In my case the problem was traced to the 1x gain setting potentiometer in the horizontal output amplifier. This pot was found to be open circuit on the slider terminal, hence behaving like a fixed resistor.
I have had more open potentiometer problems on the same scope, in the calibrator circuit, which was not providing any output. Problem was traced to an open potentiometer used for setting the 300mV amplitude.
May be you too can look for any faulty gain adjusting pots in horizontal section.
Shailendra
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I had a drifted balance resistor in the deflection amplifier once.
Don't recall which one, but it was a 1/4w one, causing the feedback to be too high, hence the smaller deflection.
Notation home right now, when back, I will look for more info.
Leo
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Fabio Trevisan
Jeff Urban
satbeginner