Author Topic: Tektronix 2465B oscilloscope teardown  (Read 440319 times)

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Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1200 on: October 27, 2018, 07:35:29 pm »
Ok dried the board for a while and popped in temporary elco subs for the removed leaky caps so I could take some measurements around the DAC. Please see attached image with schematic of the DAC input resistor network. All voltages in red taken with a HP974A DMM. I have not checked yet any of the resistor values, which I assume cannot be checked in-circuit anyhow.

Not sure if anyone has records of what the correct voltages should be around these nodes so as to compare and try to figure out which ones are probably bad without having to pull one by one to test them. For me once a SMD part out it will probably stay out and a new replacement will go in instead. So i rather will try to keep as many as possible of the undisturbed originals and try to deduce which might be bad with these voltage measurements.

The +1.36V out at the + side of C2420 only measures a mere +0.25V or so (all measurements where a bit jumpy and dance around 0.1-0.2V). Likewise the -1.25V output has only 0.23V (at pin 13 of IC2420).

Anyone out there that has done these same measurements on a good scope?
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1201 on: October 27, 2018, 07:42:46 pm »
Try to find 070-6863-01 which is newer, preferably the searchable version.

Turns out I actually had the -01 version, but had chosen the other one because it has a very handy page navigation side bar that makes it so much easier to land on the right page, for example 6-10 instead of the page number that the Acrobat reader shows. But the -01 is definitively much more up to date and will use it from now on. Thanks.
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1202 on: October 28, 2018, 07:59:09 am »
So I build a simulation of the resistor divider of the DAC input with 5% resistors on a protoboard so I could make some voltage reading comparisons. I am assuming that the two DAC reference inputs are high impedance and do not account for much if any change on the actual resulting voltages (please correct me if I am wrong on this). I also adjusted the 10V input voltage to match the 9.988V actually seen on the scope, and adjusted the wiper of the 20K trimmer to match 5.51V as seen on the scope as well. The results are on the attached picture.

The total series resistance of this network measured roughly about 38~39K (I left out the 15uF C2010 capacitor on purpose to be able to measure this resistance). I measured about 268uA current flowing through the divider, which I calculated taking the voltage across  the 1K R2016 resistor, the upper leg of the divider, which is 9.988v - 9.72v = 268mV / 1K = 268uA. Again, these are 5% resistors, so readings will be slightly off here and there, but should definitively be good enough for a general comparison.

Now going back to my original readings on the scope (I re-posted the picture showing those readings as well), the voltage difference on the 1K R2016 resistor is only 9.988-9.926 = 62mV, which if I assume the 1K resistor is still within its value, there are only 62uA of current flowing into the resistor network. Way too low. This I would think would mean that one or more resistors have gone high (or open). My first suspect would be R2012 10K, as the voltage on pin 15 of the DAC (-Ref) is more than twice as high as expected, and this resistor is the lower leg of the voltage divider. Then again, maybe R2013 has gone high (or open), as the +Ref voltage is about 2.25v low compared to my simulation.

I could try to further tweak my breadboard simulation to see if I can find a combination that would arrive at the actual voltages read on the scope. That would of course only be practical if one assumes that only one or maybe two resistors have sustained damage, but given that more than two might be bad, it might be a futile exercise.

Time now for a break, get some Zzzzs.... its almost 4am.
 

Offline grbk

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1203 on: October 29, 2018, 12:50:14 am »
Ok dried the board for a while and popped in temporary elco subs for the removed leaky caps so I could take some measurements around the DAC. Please see attached image with schematic of the DAC input resistor network. All voltages in red taken with a HP974A DMM. I have not checked yet any of the resistor values, which I assume cannot be checked in-circuit anyhow.

Not sure if anyone has records of what the correct voltages should be around these nodes so as to compare and try to figure out which ones are probably bad without having to pull one by one to test them. For me once a SMD part out it will probably stay out and a new replacement will go in instead. So i rather will try to keep as many as possible of the undisturbed originals and try to deduce which might be bad with these voltage measurements.

The +1.36V out at the + side of C2420 only measures a mere +0.25V or so (all measurements where a bit jumpy and dance around 0.1-0.2V). Likewise the -1.25V output has only 0.23V (at pin 13 of IC2420).

Anyone out there that has done these same measurements on a good scope?

Before I replaced the resistors, my reference voltages measured +0.27V and -0.25V which lines up well with your measurements. I didn't measure any of the other node voltages, sorry.

So I build a simulation of the resistor divider of the DAC input with 5% resistors on a protoboard so I could make some voltage reading comparisons. I am assuming that the two DAC reference inputs are high impedance and do not account for much if any change on the actual resulting voltages (please correct me if I am wrong on this). I also adjusted the 10V input voltage to match the 9.988V actually seen on the scope, and adjusted the wiper of the 20K trimmer to match 5.51V as seen on the scope as well. The results are on the attached picture.

The total series resistance of this network measured roughly about 38~39K (I left out the 15uF C2010 capacitor on purpose to be able to measure this resistance). I measured about 268uA current flowing through the divider, which I calculated taking the voltage across  the 1K R2016 resistor, the upper leg of the divider, which is 9.988v - 9.72v = 268mV / 1K = 268uA. Again, these are 5% resistors, so readings will be slightly off here and there, but should definitively be good enough for a general comparison.

Now going back to my original readings on the scope (I re-posted the picture showing those readings as well), the voltage difference on the 1K R2016 resistor is only 9.988-9.926 = 62mV, which if I assume the 1K resistor is still within its value, there are only 62uA of current flowing into the resistor network. Way too low. This I would think would mean that one or more resistors have gone high (or open). My first suspect would be R2012 10K, as the voltage on pin 15 of the DAC (-Ref) is more than twice as high as expected, and this resistor is the lower leg of the voltage divider. Then again, maybe R2013 has gone high (or open), as the +Ref voltage is about 2.25v low compared to my simulation.

I could try to further tweak my breadboard simulation to see if I can find a combination that would arrive at the actual voltages read on the scope. That would of course only be practical if one assumes that only one or maybe two resistors have sustained damage, but given that more than two might be bad, it might be a futile exercise.

Time now for a break, get some Zzzzs.... its almost 4am.

This is an interesting exercise and if you're inclined to continue I would be interested to hear the results. Even if you find that all resistors except one or two measure okay, I would still recommend you replace all of the ones with visible corrosion to prevent any future problems, so long as you think you can remove them easily without damaging the board. I believe the precision 10K ones do tend to go high or open.

Edit: I can't spell.
« Last Edit: October 29, 2018, 09:06:05 pm by grbk »
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1204 on: October 29, 2018, 08:55:42 pm »
Progress!

So I went to try and test the DAC reference resistors in-circuit to try and determine which ones would be more suspect. To start I measured across the two 10.0K resistors, and one was measuring around 160K and the other was even higher around 300K I think it was, so they had to be bad. A good start would be to pull those out, one at a time. I pretty much routinely solder 1206 SMD parts by hand with a fine tip for one of my commercial projects that uses a few of these on the board, done with a T7 fine tip and a Weller 25W pencil iron "dimmed down" with a light dimmer to reduce somewhat the tip temperature. First I scraped a bit the dull solder on both ends of the resistors, and then added a bit of fresh solder, and after doing this on both ends the resistors would stand up on one end almost like it wanted to come off with the tip and without almost any effort at all. Luckily these parts don't seem to be held onto the the board other than with the two solder junctions, no other additional bonding stuff as it sometimes happens. So minimal stress to the board pads.

Went first to pull R2012 10.0K, but by mistake ended up pulling R2016. Ooops. Even tough it initially had some serious crud on the ends, turns out it appeared to be still ok, a quick check measured  1.001K, so not far off if anything but now that it is out will definitively replace it. Next I went to get R2012, one of the 10.0K resistors, which this time was the correct one, and came out very easily as well. But this one measured completely open. Same was the case of R2013, the other 10.0K resistor. Two for two, so far so good. So I figured now that I have these 3 resistors out of the network I could probably make some in-circuit tests of the remaining ones. R2011 a 4.75K resistor measured very close at 4.749K, so leave that one alone for now. R2015 the 82.5K one measured 60.6K, and R2014 221K measured 64.2K across it. Since both these resistors are connected together as well as to R2010 the 20K trimmer, it would be expected those readings to be way off their actual value. But where they still correct? So I took my previously "protoboarded" 5% resistor network simulator and pulled out the two 10K and the 1K resistor, and measured across the 220K, and it measured 60K, and the 82K resistor measured at 63K. That is very close to what I am getting on the A5 board so for now will not disturb them. BTW R2520 and R2521 which are 681-ohm 0.1% resistors used to convert the output current of the DAC to a voltage, in circuit measured 687 and 691 ohms respectively, so for now I will consider them good enough as well, and at least no opens.

So getting back to my project that uses 1206 resistors, by chance it happens to use some 10K and 1K units as well, and I had plenty of them in the parts drawers. Only thing these are 5% tolerance, but I though, what the heck, just for temporary testing purposes they are certainly better than an open resistor. So in went two 10K and one 1K 5% (I hope nobody pukes, probably the nice purist guys at Tekgroup probably would at least cringe at this, so maybe for now will keep it my little secret). Also reinstalled the temporary leaded elco filter caps (pulled from an old board, but checked for ESR and value) and back in went the A5 board. See attached picture of the reworked board with the temporary resistors and caps.

Before power up I held the tip of the DMM on the the +1.36V test point (I found a convenient location to be at the positive end of C2420). At initial power up it was still showing the same +0.26V as before, -oh crap no progress at all. But then 1-2 seconds later the screen readout came to life! I measured again and I now was getting +1.3848V, not exactly "on-spec" but close enough for now. And the -1.25V ref voltage (measured at pin13 of U2420) was at -1.2688. Wahooo!

On startup the scope cycles through all the test steps lighting up the front panel indicators in sequence, and at the end no errors are shown.

So, looks like I made some progress after all! Calibration will for now obviously be way off, but I am not going to mess with the +1.36V setting until I put in the proper tolerance resistors. No sense disturbing that setting at this point. On the last picture (ITS ALIVE!!! - remember the movie Young Frankenstein 1974?), for purely academic reasons I set the timing Alpha time cursors centered onto 2 divisions, and with the time base set at 500nS its obvious the resulting 973nS reading (which should have been exactly 1000nS) tells it all. But for now, today was a good day and I am happy with this progress. Will be placing the A5 parts order at Mouser tonight!
« Last Edit: October 29, 2018, 08:59:08 pm by AMR Labs »
 

Offline tautech

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1205 on: October 29, 2018, 09:30:13 pm »
@AMR Labs
Wouldn't you just measure a few of your 5% resistors on hand to find some that fall within a 1% tolerance and use those ?
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Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1206 on: October 29, 2018, 10:44:15 pm »
@AMR Labs
Wouldn't you just measure a few of your 5% resistors on hand to find some that fall within a 1% tolerance and use those ?

Well, the 10.0K resistors have to be 0.1% tolerance, the rest 1%. But I figured this was just a test exercise to see if the screen would come  to life once the DAC ref voltages were back in the ballpark, or if there might be other problems. Now I know for sure. I'm planning to order the proper resistors anyhow, so I just did not see the need to do any close matching if the strictly test results where probably going to be pretty much the same. I would have used leaded 5% 1/4Wresistors if I didn't have these 1206 SMDs handy. The resistors I end up using where checked, tough. One was 10.01K and the other 9.98K, even being from the same batch next to each other on the tape. Don't remember now the 1K, but it was also quite close. Then there is also the temperature coefficient and long term stability to take into account, which are qualities of metal film, and mine are just "film" resistors so not really suitable candidates even if a very close match would have been found.
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1207 on: October 30, 2018, 01:08:37 am »
EXER O5 DATA

HRS ON: 365
PWR ON/OFF: 125

Does this sound real for an early 90's scope? Or perhaps these counters might have been reset at some point?

Also copied EXER 02 RAM calibration data, took a video while scrolling through from address 00 to FF, and wrote them down by hand as well, just in case.
 

Offline BravoV

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1208 on: October 30, 2018, 01:23:52 am »
My 2465B bought in 2011 had 292 on hours & and on/off counter at 349, I guess that depends on previous owner usage, but yours look pretty low count, assuming its not tampered.


Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1209 on: October 30, 2018, 02:56:48 am »
My 2465B bought in 2011 had 292 on hours & and on/off counter at 349, I guess that depends on previous owner usage, but yours look pretty low count, assuming its not tampered.

I guess that must be the scope that started this thread? I saw you also got lucky that the front cover and a storage pouch where included, mine came with those as well, but no probes. Very hard to get those accessories included nowadays on a low or even mid priced 2465x on ebay, specially the front cover. I have seen these sold separately for $100, just for the cover. And you also have a TEK made U800. In what serial number group is yours? Mine is 55xxx and most chips inside have a 1990 date code, including the NVRAM. From the inscriptions and labels on the front cover and on one side, this might have been a field unit that was not really taken out that much, and who knows maybe even less once the problems created by the leaky caps started to show up. The inside is almost pristine, very little dust only in a few places, if any at all. No signs of anyone tampering inside either.
« Last Edit: October 30, 2018, 05:05:17 am by AMR Labs »
 

Offline BravoV

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1210 on: October 30, 2018, 09:59:54 am »
My 2465B bought in 2011 had 292 on hours & and on/off counter at 349, I guess that depends on previous owner usage, but yours look pretty low count, assuming its not tampered.

I guess that must be the scope that started this thread? I saw you also got lucky that the front cover and a storage pouch where included, mine came with those as well, but no probes. Very hard to get those accessories included nowadays on a low or even mid priced 2465x on ebay, specially the front cover. I have seen these sold separately for $100, just for the cover. And you also have a TEK made U800. In what serial number group is yours? Mine is 55xxx and most chips inside have a 1990 date code, including the NVRAM. From the inscriptions and labels on the front cover and on one side, this might have been a field unit that was not really taken out that much, and who knows maybe even less once the problems created by the leaky caps started to show up. The inside is almost pristine, very little dust only in a few places, if any at all. No signs of anyone tampering inside either.

Yes, thats the only one I have, wish I have more especially the 2467B one.  :P

Really like the blue front cover, as its made from a really-really strong & thick plastic, even the whole scope can stand on it's front panel safely with that thing attached, like photos at the 1st post, and its really convenient for minor repair or inspection job at the scope.  :-+

My 2465B was built at Guernsey UK, with unique "G" prefix at the serial G150XXX.

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1211 on: October 30, 2018, 04:51:38 pm »
Yes the 2467B is nice, but since they are in great demand prices are through the roof, compared to the 2465B. Lots of people looking to get one, but waiting for the right/fair price.

I agree the front cover is very important to have, more so to get it with the scope in the first place, and yes definitively makes it easier to rest the scope on its face upside down to safely remove the back panel. I was even feeling a bit apprehensive of buying a scope like this without the front cover, as it is a very effective layer of protection against bent/broken controls due to shoddy packaging or in-transit mishandling. More than a few horror stories out there of mangled front panels.

Was going back to page one and looking at your pictures of the scope, very nice indeed. Which reminds me, at some point I will probably have to check on the power supply caps, and wrestle with those two boards to get them out.

BTW looking at you options sticker in the back, mine is a bit different, and the only option marked on this one is numbered 46, which I still have not been able to figure out what it is. Do you (or anyone ) know what option 46 is for? Asked before but no answers, so give it another try.

So from the origin of your scope I assume you are located on the other side of the "pond". Bet you never thought about this thread lasting so many years.
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1212 on: October 30, 2018, 05:03:03 pm »
Updated A5 DAC area parts layout, and Ref voltage test points. Wish I had this info when I first started. Hope it helps the next 2465B owner(s) down the line.

Mouser parts order to rebuild the A5 DAC resistors and caps almost ready to be sent out. I am also ordering one DS1225AD-150 to have it handy, even tough I eventually want to go the FM16W08 way. Still have to buy a programmer as well. From what I read so far, the GQ-4X programmer is the one to get, as I understand it is compatible with both the DS1225 and FM16W08.

Not sure what 28-DIP socket to order tough, Mouser is only showing me one from 3M (PN 517-4828-3004-CP) with dual leaf type compression contacts, which I assume will be fine for the DS1225, but I wonder if down the line it will also handle the pins on the SOIC28-DIP28 converter PCB needed for the FRAM.
« Last Edit: October 30, 2018, 05:07:23 pm by AMR Labs »
 

Offline cheeseit

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1213 on: October 30, 2018, 06:45:05 pm »
Actually that kind of socket fits the DS1225 poorly, at least the ones I have, but the pins on the converter (standard pin headers) fits very well. They may damage the socket because of sharp edges but I don't plan on removing it again so no problem. The same is true for machined sockets I believe.

GQ-4X is a nice programmer and will work.
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1214 on: October 30, 2018, 07:05:47 pm »
Actually that kind of socket fits the DS1225 poorly, at least the ones I have, but the pins on the converter (standard pin headers) fits very well. They may damage the socket because of sharp edges but I don't plan on removing it again so no problem. The same is true for machined sockets I believe.

Can you by any chance recommend a better socket, and possibly a source?

Thanks for the input.
 

Offline med6753

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1215 on: October 30, 2018, 07:31:18 pm »
Yes the 2467B is nice, but since they are in great demand prices are through the roof, compared to the 2465B. Lots of people looking to get one, but waiting for the right/fair price.

I agree the front cover is very important to have, more so to get it with the scope in the first place, and yes definitively makes it easier to rest the scope on its face upside down to safely remove the back panel. I was even feeling a bit apprehensive of buying a scope like this without the front cover, as it is a very effective layer of protection against bent/broken controls due to shoddy packaging or in-transit mishandling. More than a few horror stories out there of mangled front panels.

Was going back to page one and looking at your pictures of the scope, very nice indeed. Which reminds me, at some point I will probably have to check on the power supply caps, and wrestle with those two boards to get them out.

BTW looking at you options sticker in the back, mine is a bit different, and the only option marked on this one is numbered 46, which I still have not been able to figure out what it is. Do you (or anyone ) know what option 46 is for? Asked before but no answers, so give it another try.

So from the origin of your scope I assume you are located on the other side of the "pond". Bet you never thought about this thread lasting so many years.

Good deal on getting your DAC issues straightened out.  :-+ And yes, recapping the Regulator and Inverter boards should be next on the agenda. You can follow my post back in July on getting those boards out with minimal hassle.

Edit, starts at reply 1091.
« Last Edit: October 30, 2018, 07:33:23 pm by med6753 »
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Offline macboy

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1216 on: October 30, 2018, 11:39:43 pm »
I normally wouldn't clutter a technical thread with such stuff, but since this is the definitive 2465 thread, I'll mention I've posted a probe pouch and a front cover over in the buy/sell forum:
https://www.eevblog.com/forum/buysellwanted/fs-(canada)-tek-2465-2467-front-cover-and-probe-pouch/
 

Offline med6753

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1217 on: October 30, 2018, 11:58:58 pm »
I normally wouldn't clutter a technical thread with such stuff, but since this is the definitive 2465 thread, I'll mention I've posted a probe pouch and a front cover over in the buy/sell forum:
https://www.eevblog.com/forum/buysellwanted/fs-(canada)-tek-2465-2467-front-cover-and-probe-pouch/

Already have 2 probe pouches and while I'd really like to have a front cover for my 2465 I think $76 USD plus shipping is a little (no, a lot) too much.   :-- (And yes, I understand they are rare and sell at a premium which is why mine will remain naked)
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Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1218 on: October 31, 2018, 12:13:29 am »
Good deal on getting your DAC issues straightened out.  :-+ And yes, recapping the Regulator and Inverter boards should be next on the agenda. You can follow my post back in July on getting those boards out with minimal hassle.
Edit, starts at reply 1091.

Thanks for the heads up Med, will certainly take a look at it! The traces seem a bit fuzzy under certain conditions, specially while using the 10x horizontal magnification, and most probably recapping the PS might help cleaning up the traces. On the other hand, it really helps using the 20MHz BW limit, it makes the traces much sharper. That tells me there must be HF noise probably creeping in through the power supply.

Here is a pic of the scope still triggering on a 800.000MHz signal, even tough at this point the trace looks quite fuzzy due to the vertical input amp gain running way out of bandwidth (the input signal was 400mV). The automatic counter would only read up to 650MHz. But in general the counter doesn't seem to be very accurate, always seems to be off by 10% or so. Even with an accurate 10MHz signal the 2465B was showing a counter best reading at something like 10.173 MHz. I guess that is what that 2465B C/T option is all about to tighten up the counter accuracy. My 2247A was effortless counting the same signal as 10.000071MHz (yes the scope counter calibration is actually off by about 71Hz), and counter is good and stable to about 300-350MHz.

BTW the traces look much brighter on this picture than they actually where, was trying to avoid using a flash, so the camera opened way up. Nowhere near what looks like CRT melting levels.
« Last Edit: October 31, 2018, 12:50:22 am by AMR Labs »
 

Offline AMR Labs

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1219 on: October 31, 2018, 12:43:35 am »
Already have 2 probe pouches and while I'd really like to have a front cover for my 2465 I think $76 USD plus shipping is a little (no, a lot) too much.   :-- (And yes, I understand they are rare and sell at a premium which is why mine will remain naked)

Not too long ago a 2465B cover (new style with the indentation) sold on ebay for a cool 100 bucks plus shipping from the Philippines. But it took quite some time to sell. Supply and demand market, unfortunately. I was looking for these for some time anticipating my future scope would not have it, and not even one other ever came up. I'm glad I actually got lucky, makes me think the scope alone actually sold for a mere $110, plus the cover (and a pouch).
 

Offline med6753

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1220 on: October 31, 2018, 02:27:18 am »
Good deal on getting your DAC issues straightened out.  :-+ And yes, recapping the Regulator and Inverter boards should be next on the agenda. You can follow my post back in July on getting those boards out with minimal hassle.
Edit, starts at reply 1091.

Thanks for the heads up Med, will certainly take a look at it! The traces seem a bit fuzzy under certain conditions, specially while using the 10x horizontal magnification, and most probably recapping the PS might help cleaning up the traces. On the other hand, it really helps using the 20MHz BW limit, it makes the traces much sharper. That tells me there must be HF noise probably creeping in through the power supply.

Here is a pic of the scope still triggering on a 800.000MHz signal, even tough at this point the trace looks quite fuzzy due to the vertical input amp gain running way out of bandwidth (the input signal was 400mV). The automatic counter would only read up to 650MHz. But in general the counter doesn't seem to be very accurate, always seems to be off by 10% or so. Even with an accurate 10MHz signal the 2465B was showing a counter best reading at something like 10.173 MHz. I guess that is what that 2465B C/T option is all about to tighten up the counter accuracy. My 2247A was effortless counting the same signal as 10.000071MHz (yes the scope counter calibration is actually off by about 71Hz), and counter is good and stable to about 300-350MHz.

BTW the traces look much brighter on this picture than they actually where, was trying to avoid using a flash, so the camera opened way up. Nowhere near what looks like CRT melting levels.

Does your 2465B have the Counter/Trigger option? If yes and you don't have the equipment as per the manual to calibrate it I have an alternate procedure that came from an old gray bread on the Yahoo Tek group that is simple and will get it dead nuts.
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Offline med6753

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1221 on: October 31, 2018, 02:30:56 am »
Already have 2 probe pouches and while I'd really like to have a front cover for my 2465 I think $76 USD plus shipping is a little (no, a lot) too much.   :-- (And yes, I understand they are rare and sell at a premium which is why mine will remain naked)

Not too long ago a 2465B cover (new style with the indentation) sold on ebay for a cool 100 bucks plus shipping from the Philippines. But it took quite some time to sell. Supply and demand market, unfortunately. I was looking for these for some time anticipating my future scope would not have it, and not even one other ever came up. I'm glad I actually got lucky, makes me think the scope alone actually sold for a mere $110, plus the cover (and a pouch).

Considering that I paid a grand total of $60 for my 2465 paying more for a piece of plastic makes absolutely no sense to me.  :palm:
An old gray beard with an attitude.
 

Offline BravoV

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1222 on: October 31, 2018, 07:50:08 am »
Was going back to page one and looking at your pictures of the scope, very nice indeed. Which reminds me, at some point I will probably have to check on the power supply caps, and wrestle with those two boards to get them out.

Yep, especially the film caps as others experienced in this thread.


BTW looking at you options sticker in the back, mine is a bit different, and the only option marked on this one is numbered 46, which I still have not been able to figure out what it is. Do you (or anyone ) know what option 46 is for? Asked before but no answers, so give it another try.

Sorry, I have no idea at all.


So from the origin of your scope I assume you are located on the other side of the "pond". Bet you never thought about this thread lasting so many years.

Yeah, I started this just to share the teardown photos as I didn't find any at this forum, it is now growing into a big thread with so many valuable information by many contributors, you included.  :clap:

Offline grbk

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1223 on: October 31, 2018, 04:58:41 pm »
Does your 2465B have the Counter/Trigger option? If yes and you don't have the equipment as per the manual to calibrate it I have an alternate procedure that came from an old gray bread on the Yahoo Tek group that is simple and will get it dead nuts.

I would be interested to see it if you don't mind sharing.
 

Offline med6753

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Re: Tektronix 2465B oscilloscope teardown
« Reply #1224 on: October 31, 2018, 05:51:54 pm »
Does your 2465B have the Counter/Trigger option? If yes and you don't have the equipment as per the manual to calibrate it I have an alternate procedure that came from an old gray bread on the Yahoo Tek group that is simple and will get it dead nuts.

I would be interested to see it if you don't mind sharing.

No problem. In few days after I return home. Don't have it with me at the moment.
An old gray beard with an attitude.
 
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