Tektronix 2467B Oscilloscope Restoration

[@alexsinclair2012]

Thank you for this invaluable video. I bought a 2465B for chump change and got a ton of caps for recapping the PSU. Major props for reminding us of the backup battery and how to retain the calibration data.

[@johnshires5007]

Good job, Ewan. There's no charge for the sawdust. Great to see it restored to its former glory.

[@fredmitchel1236]

Good job...you are very meticulous and have patience.... Good deep dive I have a Tek 2465 CT....and you teaching inspire me

[@iontesu2911]

Cool video. Quick suggestion regarding the battery replacement. Instead of hooking two batteries with different voltages in parallel (I’m sure the batteries were slightly unhappy about the event…) you could have connected a diode in series with the 3.0V backup battery (as in the schematic CR2770). Even with the diode drop, after removing the original battery you’d have 3.0-0.6=2.4V which is above the 2.0V limit.

[@Ozymandiuus]

Very prudent suggestion to be heeded here. If by chance the old lithium battery got grumpy enough to drop to 0v, it could result in some very sad consequences, perhaps the least of which is the loss of the VRAM data. The addition of a diode or at least a current limiting resistor in series with the AA cells is most certainly advisable.

[@raymonddompfrank1789]

Apart from screen burnout, which doesn't happen at sensible brightness, MCP CRT's suffer from exhaustion of the special layer that covers the inside of each MCP channel and which produces the secondary electrons. With time, the electron multiplication is diminished, resulting in ever lower amplification. Most used MCP CRT's, even if used at low intensity, show darker areas where the trace sits most of the time, like at the center horizontal and in the readout area. To spread wear in the readout area, the 2467 periodically automatically moves the location of the readout display a bit.

[@NearFarMedia]

Yeah, you really have to baby these CRT's to make them last. I'll have to get myself a 2465B for day to day use to save this MCP CRT for when I really need it.

[@raymonddompfrank1789]

@@NearFarMedia Good idea! The larger screen and the better graticule illumination are added advantages.

[@raymonddompfrank1789]

The remark about the ElCap (C1101/C1102) starting at 10:12 is incorrect, unless I'm very much mistaken. It's also in Yachad's otherwise excellent write-up about recapping these 'scopes. First of all, this sort of caps has a standard tolerance of at least +/- 20%. Second, the circuit delivers about -13.1V, called "-8V Unregulated" in the schematics. It is the input voltage to the -8V regulator. The transformer that drives these caps (T1060) provides only "Unregulated" voltages, see dwg in the schematics. I am not aware of any precision requirements for any of the ElCaps in these PSU's.

[@NearFarMedia]

Ah, I read the same in that guide, and was working from memory... In any case, replacing like for like is usually a good idea anyway, unless you really know what you are doing (or it's something basic like a linear power supply, where usually you can up the capacitance a bit pretty safely)

[@raymonddompfrank1789]

@@NearFarMedia That's what we all do. If you look at the schematics, you'll see it's just a voltage pump to get about -13V to feed the -8V regulator.

[@danishnative9555]

Very cool. Bearing replacement on now un-obtainium fan motor. Thumbs up.

[@mtkoslowski]

I own one of these. Thank you very much for making this video. This is a lifesaver for me.

[@mariomionskowski6223]

Well done and your friends did a nice job too.

[@thatampguy]

Brilliant use of that flux pen!did any of the silicon grease go over the wiper or track?

[@NearFarMedia]

I used a plastic safe white lithium grease and yep, put it thinly on the wiper and track, like the manufacturer did originally. That way the track will be lubricated to reduce wear. As a side note, I don't think it matters for trimpots, but avoid using silicone grease in switches, apparently any arcing in the switch can slowly turn the silicon in the silicone grease into silicon carbide which is an insulator and very(!) hard and abrasive....

[@mikaelstrom1114]

Great video, thanks! Im just about to recapp a 2465B, same PSU. Are you aware of any updated BOM for recapp? Also, you mention som resistors in the PSU that should be replaced, but never point out which. Thanks in advance!

[@fredknox2781]

At 23:38 is the 9714 printed on the Panasonic battery a date code? If so, that battery is pretty old. What is the shelf life of that battery?

[@yenaurapourtoulmonde]

Excellent!

[@anthonywilliams7052]

At 23:38 that battery is dated 9714, so 1997 and 14th week, it's already 23 years old when you made the video! Time for ANOTHER new battery.

[@NearFarMedia]

That number is just a production batch number, it's not actually a date code. I have purchased a number of verified brand new batteries and the codes were no where near the actual date, some used letters as well as numbers and others would have been in the future..

[@anthonywilliams7052]

@@NearFarMedia That's good, thought you'd have to do it over again. I miss when things didn't have to have backup batteries or need a microscope to solder something.

[@raymonddompfrank1789]

Very nice video, Jared. Anyone interested can do the job (and some extra things) with it.

[@NearFarMedia]

Yeah, the power supply work is pretty easy and the Rifa cap replacement is basically mandatory. The cap replacement on the main board is a bit trickier simply due to the fiddly nature of removing the delicate board, but those caps are mostly ok to leave alone on most units I expect.

[@joseriggio4366]

unfortunately can only left one thumb up, you deserve thousends👍👍👍👍👍

[@adrianschneider4441]

Definitely interested in a video on that other 2467.

[@NearFarMedia]

One I get a few more bits of test gear sorted out, I'll be able to fix it and make a video. I won't make any promises on how long it'll take..... :P

[@raymonddompfrank1789]

Many people can't resist the temptation to replace any dipped tantalum caps they see. There are two blue ones on the older processor board, C2350 and C2470, visible at 21:57. They sit above half way below the processor and just above the battery.

[@NearFarMedia]

True, the older tants in Tek gear are good for one thing. Helping us to pick up a good deal on second hand equipment. :D Often just replacing a few burnt tantalums in a bit of faulty gear brings it right back to life! Which reminds me, I have to do exactly that in a Tek 577 curve tracer I have sitting here....

[@xXCowGoesWoofX7]

Hey I have an early serial # 2465b which I suspect has the same keeper battery as yours. I have access to a bench power supply, would you still suggest soldering a battery pack to the board over using the supply? Somehow the battery is still going, probably because there are like 5 original hours on the unit but I need to consider replacing it in the near future.

[@NearFarMedia]

If you use a bench power supply make sure to use an isolated battery powered or butane powered soldering iron so you don't short out the battery via a ground loop and lose the memory. Using a battery pack eliminates this possibility.

[@xXCowGoesWoofX7]

@@NearFarMedia I figured it would be something like that, I'll likely just follow the battery pack method when the time comes. I also saw some people online replacing the ram chip with fram on an adapter board, any idea if it works here? A hurdle with the non dallas chip is how to dump my current good firmware to back it up and use later without losing power.

[@W3KW]

Wow. The flat flex resto! Come on! Amazing. Do you make these available?

[@NearFarMedia]

I'll have to check if I still have any left over. But they are easy to order on PCBWay.

[@daveedgar2688]

@@NearFarMedia Just wondering if you have an update as mine needs replacing and no experience with designing something like this.

[@daveedgar2688]

Sorry just figured out how to search PCB way....

[@cyberlightbeing]

Which vacuum desolder gun have you used? Thanks for the great video 🙂

[@KeithWilbraham]

Hi, I too am waiting for the video on your Tek 2467. Have you had any progress yet? Do you happen to know if the ram swap is similar please? Many thanks for your great videos. K

[@t1d100]

Another great video! Thank you. Capacitors are made with different types of technologies. What type of capacitor do I need to replace "refers?" If more than one type would do the job, what are my choices, so that I can weigh benefits against cost?

[@NearFarMedia]

If you see any of the dirty nasty Rifa caps in your gear, just replace them wholesale with any quality film caps of the same safety rating (X or Y class) and the same capacitance and equal or greater voltage rating. I don't even bother testing them, they are always cracked and will eventually fail. Don't skimp on the safety ratings! You don't want them to cause problems if they go faulty. :)

[@fullwaverecked]

Great video mate! Question - If I have 3 Kikusui COS5060 "3" channel scopes running at once, do I have a 9 channel 60 KHz party goin on? Cheers from SLC Utah!

[@geoffespeland1028]

I have a 2445A scope and I did a cap job on the power supply, including the Rifa caps. I didn't do the main board coz I couldn't figure out how to remove it. Did you replace the caps on the main board with it in place or did you remove it? I still have a drift problem also. The trace drifts up slowly (very slowly). If you have any ideas about fixing that, I'm all ears. All the voltages read within specs but I just realized as I'm writing this I didn't check them for any drift. I loved the video. It was very informative. Any help is greatly appreciated. Thanks

[@NearFarMedia]

Removing the main board is a pretty involved process, I wouldn't recommend it unless you really need to. I removed mine because I like living dangerously, but usually it's just the capacitors in the power supply that need replacing. Don't forget to (carefully!) replace the memory backup battery too so you don't lose the calibration memory due to a flat battery. Also the SMD tantalums on the CPU board (The one on the right hand side) if present as they ALWAYS leak. I'm not sure about the drift problem, but I'd check voltages as you suggest. Also the service manual is pretty good for troubleshooting and performance testing these scopes.

[@robertsteentjes3870]

Hallo NFM what equipment do you use to dril out the solder connection out?

[@NearFarMedia]

I use a Hakko solder sucker attached to my solder station to suck the solder away.

[@robertsteentjes3870]

Hallo NFM do you have a cover voor the tektronics 2465B art nr 200-3199-01

[@jeanious2009]

29:00 I swore you was going to say the electrons fly right out on any 90 degree corner on a pcb! 😂

[@damonkatos4271]

I have a stack of these in my garage :)

[@ElectricEvan]

The 7104 had the same CRT as the 2467B. While the 2467B was up to 400MHz the 7104 was 1GHz! For the time there was nothing that could beat it.

[@NearFarMedia]

I'll have to keep an eye out for a 7104, would be interesting to have a poke at.

[@raymonddompfrank1789]

The 7104 had an MCP CRT, like the 2467. It's not the same CRT however.

[@ElectricEvan]

@@raymonddompfrank1789 Are you sure about that? I could find the model info for the CRT used in the 7104 but not the 2467. I had always assumed it was the same one because the geometry of the 2467 is all weird compared to the rest of the 24xx because the CRT is long and the screen is narrow.

[@raymonddompfrank1789]

@@ElectricEvan I’m quite sure. The CRT in the 7104 is much bigger and since the 7104 not only has a vertical BW of 1 GHz but also a *horizontal* BW of 350 MHz (!) it has vertical *and* horizontal distributed plates. Also, it has many more geometry adjustment pins.

[@raymonddompfrank1789]

@@ElectricEvan The CRT in the 2467 is a 154-0896-01 or "T2467"

[@andrewverran3498]

Greetings from Radelaide, did you move to Japan as there is a nice 2nd hand oscilloscope market? Cheers

[@NearFarMedia]

Hello fellow Adelaide electronics enthusiast! 😃 The electronics here in Japan was a welcome surprise, and at least a little bit of a contributing factor to my decision to stay. 😂

[@andrewverran3498]

@@NearFarMedia 😆

[@patrickdixon4945]

So how do you unclip the plastic over over the main smoothing caps?

[@patrickdixon4945]

OK, manged to do it. You have to push a screwdriver or similar down between the 2 caps and push the tab over at the bottom (whilst pulling the cover off of course)

[@raymonddompfrank1789]

Even fast analog 'scopes suffer from lack of image brightness, not because the trace moves too fast but because it doesn't hit each spot on the screen often enough. So, not a speed but a duty cycle issue. As an example, not even a Tek 7904 500 MHz BW analog 'scope is able to clearly show a one-shot edge with say 4 ns rise time at 10 ns/div. At 1 kHz it's a no-show, at 100 kHz or 1 MHz repetition rate, it isn't a problem. The single-shot is no problem for a 7104 or 2467(B).

[@ManofCulture]

33:31 FANtastic repair 👍👍👍

[@Coolman6564]

Which of the Hakko desoldering stations do you have? I've always wanted one but they get beefy very quickly.

[@NearFarMedia]

I use an FM-206 station, so yeah, pretty beefy. :D

[@felipechan9654]

Gd day sir, I have a tek 2445b 150mhz model, the trace on channel 1 and 2 sometimes goes up until it disappear (off screen) and some time the trace goes down the screen until its off the screen, what must be the trouble sir? What section of the scope could have cause this problem? Any help would be appreciated thank you sir.

[@NearFarMedia]

Sounds like you need to check the vertical position control circuit, or the vertical amplifier section. You can find the manuals on tekwiki, and if you make a post on the tekscopes groups.io page or the eevblog forums, someone will be able to get you sorted. :)

[@nrcha]

Well done! I would have just run some wires instead of ordering a new flat flex. But it’s great to know that it is possible to order some if needed. By the way - do you know if it is possible to restore the bluish case color (coating?). I have some scratches that I would like to touch up. Is there a color code for the “Tektronix blue”, perhaps? :)

[@NearFarMedia]

The blue coating appears to b some kind of plastic coating of some sort. It comes up pretty clean with some dishwashing soap and a soft scrubbing brush. As for repairing scratches, there is a few threads over on the tektronix Groups.io group on paint codes and the like for various paint colours.

[@nrcha]

@@NearFarMedia I will check it out, thanks

[@NearFarMedia]

Hi, I just found this link you might find useful: groups.io/g/TekScopes/files/Tek%20Paints.pdf

[@nrcha]

@@NearFarMedia Thanks for the link. Mailing groups, what a bizzare way of communicating, reminds me of Fidonet days :D Yet, it is a goldmine when it comes to Tek info, thanks again.

[@thelastofthemartians]

Mate I hope that 9714 marking on your new battery is not the date code :-/

[@NearFarMedia]

It was brand new off the shelf... it certainly didn't have 13 years of dust on it. I hope it's newer. :D

[@johnbonham7515]

NFM Hi, remember you have to substract the diode forward voltage (usually 0.7 volts) to the battery voltage, and that's the voltage the ram chip will receive, around 2.3 volts, very close to the lower limit.

[@raymonddompfrank1789]

@@johnbonham7515 Correct. OTOH, the battery voltage remains constant for most of its life and above 3V. Also, at the extremely low current for the backup, the forward voltage will probably be lower than 0.7V, more like 0.65V or even lower for most GP Si diodes.

[@JohnUsp]

Do you recommend replacing the Dallas DS1225AD by the RAMTRON FRAM FM1808-70-P 256kb?

[@NearFarMedia]

I haven't tried this mod myself, as my scopes don't use the Dallas battery backed RAM. Unfortunately I can't comment on the mod as I have no personal experience with it

[@Gordonseries385]

👍

[@andrewverran3498]

Hi from Adelaide, i have a TelInstruments 25mhz scope which my ex pushed off the bench and took a big fall and now have a ch1 vertical position problem.. Any ideas where you think i should start troubleshooting as i pretty intermediate. .? kzbin.info/www/bejne/m6eXZ4SmmLBrgZY Much appreciated

[@NearFarMedia]

Here is a Tektronix document on troubleshooting scopes. www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf Basically all analogue scopes work the using the same principles, so this should help you figure out what's wrong. Also, check around for a user or even better a service manual, schematics make things much easier to troubleshoot. I would first be checking the CRT, it is delicate and if it was damaged in the fall, you might be better off scrapping the scope and getting another...

[@roedyhellyeah]

I hate the flex pcbs