Tektronix 224 Oscilloscope Repair and Modification 

I just watched this again for review. I need to make a battery pack for a HP portable scope I purchased. I wish it only had a few batteries like yours but it is going to take 80 batteries to make the 24 volt battery pack. I think I have decided to make 2 packs like yours but 4 batteries across and 10 pairs long. That will give me a pack with enough current but at 12 volts. I will make 2 packs then joint them in series to get the 24 volts. There are so many different ways to do the job. I could have made 4 24 volt packs and join them together for more current. There is good logic in the way you divided the pairs of batteries and I like that. Thanks again for all your videos, I know how much work it takes to make them!

A 1971 ancient Tektronix 211 oscilloscope I have uses 10 AA nicads in series for its internal source of power. The unit is about the same size as the one in this video but is an ancestor. It is a 500Khz single channel scope. The 10 NiCad AA batteries are in two packs of 5 cells. The length of each is a tad shorter than a AA battery, it is a tabbed AA variant with no positive button top and one has to be careful that a rebuilt pack will fit. One mine I had Digikey custom make each pack 2 decades ago with the AA variant that is tad less long. The actual service manual I got in teh early 1990's was from Dean Kidd the retired Tektronix employee that knew everything aboyt Tektronix. He passed away at 88 back in 2015. His knowledge of Tek stuff was outstanding.

Watching your channel there are many great "tips and tricks" you pass along - but the one I have really tried to adopt in my own work is the care and consideration you give to every part of the work you do. You approach every task with equal care and consideration and the end result is immaculate.

Watching this in 2020 was interesting given battery technology, but my mind began to slowly blow as you wrapped up the battery build. The sheer cleanliness of the wrap, the foam blocks, the WEATHER STRIPPING . Nice. Not sure why this channel doesn't have more subs!!

Ahhhh i discovered your channel two days ago and i really like it. Its much better than many other electronics channels. Very knowledgeable and humble, a great ambience, no ridiculous extreme closeups of hand drawn diagrams (Great Scott), a great voice (sometimes i get ear fatigue when i watch EEVblog) and a peek into some enjoyable RF equipment troubleshooting, something i always found daunting and tedious. Kudos for the great content and knowledge you share! Best regards.

I find myself watching your videos even if they aren't pertinent to things I'm working on. I find that I ALWAYS learn something and have watched just about everything you've posted haha

Thanks mr Carlson for your very engeneus way of making an akkupack 9 v. DC for a portable oscilloscope 224 tektronix

Like you, I found a friend who had one of these. He had lost the power supply, and it didn't turn on, so he gave it to me. Well, you video showed me how to remove the LAB. It was dead so no wonder it wouldn't turn on. I plugged it into my bench supply and....it works perfectly. This little scope is so amazing! It will never leave my hands. Yes, a little slow, but, it's just so cute. As an aside, he used it twice for a purpose he had. Used it twice and it went to the back of an equipment locker, never to be seen or used since, and I'm guessing, 1994.

Just found your channel. I'm impressed. I love the quality. I've been watching the EVBlog and Signal path for years. Not sure why I never found your channel before.

What a neat little scope. Great video as always Mr C. Some great tips on soldering a battery pack together. Thanks.

Another masterpiece Mr Carlson. I did a battery pack like this a few years ago. Didn't have heat shrink big enough to fit but a section from an old inner tube stretched over the assembled pack perfectly.

Dandy find Paul. Your perfection in repair is very admirable.Jim

I've got the 222. I like to work on arcade and pinball machines and sometimes I want to see a digital signal. This little thing is great for bringing the test equipment to the device under test instead of the other way around!

had one of those on the ship back in my navy days, used for doing maintenance and alignments. was nice and lite compared the others we had.

15:00 -Soldering to battery tutorial. -Thanks for the tips Paul, it came in handy for me!

Talking about 60mhz scopes I am in the process of repairing a Trio CS-1060 oscilloscope with an intensity problem. Thought I had fixed it tested last night calibrated it . Put the covers on this morning and the same fault has returned with a smell of ozone. I have removed covers and will let you know what the fault was I am still investigating the cause of the fault. Intermittent faults are a pain. Excellent video on swapping battery packs and a very nice looking scope at that and a very good buy should serve you for years to come.

Hi Paul, Wow, that scope is great condition. I bet you smiled all the way home. A small and useful piece of equipment to have around. Good video. 73

What a great modification to the battery pack. Your videos are very addictive. Thanks for making them..

Nice fix for the battery. It looks like it came with the scope! As I try to learn electronics, I like the detailed stuff.

Cool little device Paul - really enjoyed the video. I always look forward to another of your episodes. 73, Bill.

TEK never shipped a turkey. I used the 224 in the field for a number of years and loved it. Just for simple stuff, but I was on Broadcast towers, way up in the wind and rain. What fun! Anyway, the scope always did what it was supposed to do.

Nice score and modification! Thanks Paul.

Two thumbs up! This would be great for on-site guitar amp/sound reinforcement/entertainment work (except for wireless mics & IEMs, of course). Since this video was made, I believe the local battery store has a number of NiMH packs of comparable voltage, capacity, and physical dimensions - I'm sure the price differential is notable - that would fit the bill. But, it was a good application of your "Soldering batteries" tutorial. Keep up the great work. 73 de KA2EMI

Recently acquired the high-voltage version of this, the Tektronix 220PS Power Scope. Of course the battery was dead, so I built one with solder as in this video, and one with spot-welded nickel strips, both with a 3A fuse mid-pack. Both work great, and the welded one with Ikea 2450 batteries ran over 9 hours before the low battery indicator came on. Thanks, Mr. Carlson!

Interesting project. I like it when people find ways to fix things instead of just throwing them out! If you want something fun to tackle, I have an Icom IC-706Mk2G that I've been troubleshooting (no power up) and haven't found the issue as of yet. Though I am slowly working through the schematic following the "HV" line.

I rebuild battery packs professionally and must say you did a fine job. Typically on NiMh cells a resistance welder is used with nickel tabs so as not to damage the valve that opens should the battery fail and need to vent. A glue jig is used to hold everything level and together.

I love the way you make everything so neat. I can appreciate the thought that goes into each project.

What a cool little scope, thanks for sharing!

Way to save old obsolete test gear you can’t get parts for! BRAVO!! I done the same thing on my Tektronix TDR, my Sitemaster antenna analyzer, the Tektronix 222 Oscilloscope, and several HT’s that use those “flat” batteries for the memory..... It works great! And I save an otherwise useful piece of electronics from the scrap heap!

I enjoy the facts in these videos. Facts are important. I would have tried to recondition the lead acid battery using an analogue of a Ring Smartcharge or colourably similar..though the argument of Mr Carlson vis leakage is valid. Excellent engineering by Mr C as always.

When this little guy was first released in the early 70’s, I wanted it so badly but couldn’t afford it!

Hi Paul - Thanks for the battery trick. I am an HVAC guy (Formerly a 2nd Class Radio Telephone licensee) and my electronic leak detector battery pack went belly up. Those batteries are 60 clams or so. Anyhow, it turns out there are a quad of "4/5A" batteries in there that I found online for about 6 bux. I was concerned about soldering them even though I have done that in the past. I hear all these warnings, but thought "hey, as long as I do it quick with a hot iron..." Lol, and wouldn't you know it - I am watching your video because I also like that "cute 224" for no good reason really, and here you are giving that great battery tip! The only thing I am a little skeptical about is that super glue idea. I never seem to have a lot of luck with super glue, but maybe, since the battery insulator material is plastic... hmmm. Thanks again for another great video!

Can you address how these would be recharged once they have been soldered together permanently in their series-parallel network? Does the scope's own recharging circuit, intended for the lead acid batteries, still work adequately? If not, then do you have to remove the whole pack to charge externally from the scope? And if externally, what method do you use for the recharge? It seems to me that these are not intended to be recharged in this configuration...... When you started this, I assumed that you were going to somehow rig up a few AA cell holders, of the type that each hold two cells, with the holders connected series-parallel but arranged so you could still extract the cells for individual recharging in "normal" NiMH charger(s). Would have been a pain, but as you suggested initially you did not buy this for serious use, rather just for occasional demos, so recharging would be infrequent. Or maybe you just figured that the initial charge, pre-networking, would last indefinitely for your occasional demos? As a side note, I used to use one of the similar (and earlier) tiny Tek dual channel ANALOG scopes (which had some kind of analog delay line (as I recall) and a phosphor-type "memory") rather extensively decades ago....maybe 35 years or so ago). I think those had regular BNC connectors for the probes. On that scope, the whole right side had traditional buttons and knobs for control of the two channels, and the battery pack was on the back end. The scope fit into a bag that you could hang from your neck, with the CRT screen pointing up so I could look down to read it, leaving my hands free. I recall the bandwidth was quite low, no more than 20MHz I think. I would not mind having one of those again now, just for show and tell!

Great little scope and great technique for creating a specialized battery pack. I would like to know more about how you intend to charge this battery. Charging different types of batteries would be a great topic for a future video.

Very nice score Paul. And that retro battery pack is awesome! Thanks for another cool video.

Great attention to detail was always.

Next time try desoldering wick (the one without flux) to join the cells. Flexible and much bigger surface area. Used this for high current discharge packs and it works like a charm

That's a neat little scope. Nice work on that battery pack!

Your repairs are just flawless.

Excellent video. Good find, too. Interesting to compare that in size and capabilities to your Tek 555, the one with over 100 tubes. This one is easier on the electric bill. Thanks for so much good useful info.

Good to see the insulation on the links between each paralleled pair of cells, but you forgot to put some on the link between the positive ends on the paralleled pairs! The risk of shorting between the positive cap and the negative case is the same... Enjoyable video all the same, thanks :)

Mr. Carlson, you are first well documented case of osciloscopemania, Congratulations ! And btw. If talk to matchmaker try to find a lady who is either HAM radio or tube amp maniac.. Good luck !

lovely little scope and great condition. .And a very nice battery build. ..

That's a nice scope Paul and a clear sharp display too. Great for some field work as it's so portable. Being battery driven too makes it safe for every circumstance. Nice build with the batteries by the way. I bet that performs better than the PC run Velleman I bought 2 years ago. I now have a Siglent SDS1102CML, WOW what a step up huh? Love your vids, they always have a great quality of delivery to them, Precise information, clearly thought out dialogue and with safety in mind. Please keep them coming.

that's a great little scope, love it! another brilliant video, thanks!

As always, a great tutorial Paul.

I have often soldered batteries into packs using a 100 watt soldering iron with a big thick tip. Contact time with the cell was similar to what I'm seeing in your video if not shorter. I didn't experience any loss of capacity worth noting.

Jan 2020: I just found a Tenma 32-335 scope at my local electronics recycle center for pennies on the dollar. Of course as-is. Screen about the same size. Hope to get it back in shape with your invaluable tips.

the battery fix is going to be useful for a very early tube tone generator in my vintage collection.thanks for the vid. very handy.was wondering just how to pull it off without having to hook it up to the power supply.instant solution.

Mister : Great job !!! Well done ... I love your lab !!! I smell the passion and cleaver .... Eric from France

Great tips on putting the battery pack together....I'll remember this.

What a lovely little scope! Now with a new lease of life.

Great video and beautiful little scope! Really glad I found your channel, Paul. I'm into vintage computers and some of them have integrated CRT monitors, so any future videos on CRT discharging and safe repair would be much appreciated. Thanks.

Another good one. Must be nice to have all the toys.

Paul, After seeing this Great video, I purchased a Tek 222A off E-bay which is a 10 Mhz version of the 224. I m going to make the battery pack. I also found plans for adapters allowing the use of P6100 1M probes. I only have one P400 probe. The Series 222, 222A, 222PS and 224 use probes with a 333K impedance rather that 1M. The plans build a 666K adapter to make the compensation to 1Meg. it also has an adapter using push-on BNC probe tip connectors and connector pin parts to mate to the probe connections used on the scope. Found on the design on the TEK Wiki. Google will find it.

Another great video Paul. That's a cool little oscope.

finally! Been dying for your next video! Well done! Thank you

"IT'S ALIVE" great video man Thanks for sharing.

Mr Carlson that is the cutest Oscilloscope I have ever seen and you did such a neat job of battery building.

That was awesome! Love that little tek scope

I love that scope and it's funny cute is what I said as soon as I saw the thumbnail. Coming from my background I'd have had my soldering cert card pulled if I quenched a joint (or even had a small fan blowing over my work station for that matter) but it's a great tip for doing batteries on personal/non life critical equipment.

So tiny and well kept... awesome find and battery solution :)

Another great, interesting and educational video. Thank you.

Cute indeed! It could snuggle up to its great uncle Tek 555 to keep warm in those long winter nights.

Great video. And that's a cute oscilloscope!

It is nice as well to have the opportunity to work with it because it is isolated and does not have any reference to ground. Beautiful thing!

Good call with the insulating barriers. The tradeoff with the superior capacity and energy density of new battery technology is that the battery materials are highly reactive and unstable under non-standard operating conditions.

Sometime back I had to stop using Duracell's because (even using all the tricks shown) I had several of them go high-impedance (even though they still had their original capacity!). When I opened them up found metalized-plastic for the +-connection that was low temp plastic. I don't know how the green ones like you used are but I had nearly 50% failure. I've been making packs for over 40 years and was just astonished at the result. I suspicion that it was some form of a fusing scheme. I now stick to Energizers because they are much more tolerant (i.e. I've soldered and un-soldered them multiple times). I actually prefer LiOn (cylindrical) cells since they hold their charge so well, have great capacity for a unit like this that will probably see infrequent use but needs to be ready to go when needed...

Hello Paul. Another fantastic video. I used a scope very similar to that in the field. Thank you very much, the battery build was very useful. All my best. Bobby

Excellent video Paul. I love the Tektronic scopes. It would be good to see a picture of the 224 sitting on the 555 for comparison. lol Brad

I like to use some plumbers paste (for copper pipe) with "no clean" when soldering cells the solder flows very well, better then some fluxes even.

hello Paul, I've found your channel and I'm impressed.thank you for sharing, i subscribe and like all of your videos.

Nice find and job on the battery. The scope looks mint ! Interesting to know the use of inductor as fuse. The other day there was a Commodore 64 with a completely burnt out inductor which fed power to the video modulator. Not sure if that was its intended purpose. In the Tandberg Sølvsuper 11 (1973) radio it has a incandescent bulb in series with the zener-based voltage regulator feeding everything except the power amp. It lights up when the stereo indicator bulb lights up. People say it is used as a fuse, but maybe its intention is to burn off some heat and voltage before the regulating transistor.

You sir are a wonderful youtuber. I'm sorry you don't have more followers. I like your delivery style more than Dave @eevblog. Please keep up the wonderful work.

Excellent video, very well explained. Thanks for all your work making these videos.

What a lovely build - thank you. BTW in New Zealand the white pipe which you used to insulate the wiring is known as spaghetti.

Man, you got a great deal on the Oscope!

Neat little scope and another nice video.

Hi Paul! Great little project! Reminds me I have to tackle a few rebuilds on some old HT battery packs I have laying around. Hint hint, would still love to see a video on discharging capacitors ( unless I missed it). 73 Scott

Now I want ONE!!!!!!!!!!!!!!!! don't have a digital scop only an Hameg 604 so next on my list is a Digital one :) Great vid as always

A cute little scope...it does look mint for sure....

Thanks again for another great vid... what a nice find!

Just Brilliant, could watch you all night

Usually it sounds like you have meticulously thought out what to say next in a video. This one sounds a bit more off the cuff, especially when you explain how you got the scope. I like that very much. And nice job on the scope.

Awesome job on that battery pack!

"cute " was the exact word I thought 20 years ago when I was handed one of these for my job, and still think that adjective is right on, and you said it, "cute".

Very nice looking scope!

I really enjoy your videos, Mr Carlson!

Good suggestion for to solder batteries without damaged them!Thanks

Great video, I have the 222 model with fixed leads. I have a almost dead battery myself, so I'll be making a new pack soon.

Nice neat Battery !!! Cute Baby Oscilloscope !!!!

Just a point that the charging arrangements for lead acid and NiMh differ even when the voltage is nominally the same. Here, the charge limit voltage for 4xLead-acid will probably be too low to give full charge on 7xNiMh. Although it would extend the life to not charge fully anyway. Very neat pack, nice job.

Cute little scope. Has that less is more look to it. Great little scope for doing on sight repairs. And like you said, its a CRT. Double thumbs up on this find. :) What, no tab spot welder? I made one several years ago and love it. Generates almost no heat because it happens in a fraction of a second. You can literally touch the spot weld as soon as you do it. No need to cool the battery and oh so fast.

Neat job. I´ve enjoyed, thanks for being so didactic.

Paul! could you demonstrate the capability of the Tektronix 224 scope with a follow up video? I would be curious to see what this little instrument can do. Your idea of a alternative power pack is superb approach to solving the battery issue making the unit truly portable. "Well Done"

Just love that baby scope 🙂

I'm Jealous, I would love to have a scope like that. My birthday is coming up...!!! LOL Great Video Paul

Beautifully done.

Good job Paul.

Wow, this is the largest cup that I have ever seen..... oh wait, it's the scope that is so tiny. Cute! Great video btw. Big thumbs up!!!