Tektronix 2225 Oscilloscope Teardown and Calibration - EEVblog #208

[fingerboy18]

I love that old school layout. It's before my time, but I appreciate the hell out of the build quality!

That bottom silkscreen system is absolutely beautiful.  I haven't seen that before.

[mace1337]

I think these scopes were made in the time Fluke worked together with Philips. Philips Test and Measurement was situated in my hometown at the time, and I have a few Fluke DEMO units made in Holland.

Great stuff.

[3n2323]

Great video, thank you!

it is rare to see videos showing the disign thoughts and built quality of a scope, and the process of calibrating it!

great! very informative and useful!

thank you!

[Knaeckebrotsaege]

Oh and btw.. I see Adobe reader.. eeevil :|

Lightweight (and free) alternative: Sumatra PDF (google it)

[Knaeckebrotsaege]

Let's see... "Made in Holland" sticker over the "Made in Taiwan" silkscreen and a board copyright dating 1986, with the IC directly below it (+bodge job) having a 1991 datecode.. hmmmm..

[321reh]

I learned So much about My 2225 without taking it apart!! Now with this video I am equipped to maintain My 2225 ( with my Service Manual ) Thanks Dave!! Once again you have proved to me you are a very good at what you know!!!

[321reh]

Thank You Dave!! Nice Explanation!! I learnt a lot from this video!! Please ignore all negative comments!!! I`m a Electronics Engineering Technologist and Electronics Technician by trade and understood this video perfectly.. I think it`s hilarious that some individuals don`t find it important to have your scope properly calibrated!! And YES there are more problems in scopes or tv`s than just High Voltage Problems!!! I should know I repaired both!!! Your Video was the best 32 min I spent !!!

[321reh]

I can't believe some of the negative comments being expressed in this video!! Dave is explaining the 2225 in a Engineering perspective and in my opinion did a damn good job doing it!! I am Extremely impressed with your explanation( I own a 2225) Am I a Technician,,,,,Nope !! I`m a Electronic Engineering Technologist and ran a VCR repair for 14 years,,so I was a technician and a Engineer!!! Most Technicians can calibrate there scopes with the help of a service manual and a little know how!!!

[Lokivoid]

Looks like its a hell of alot easier to repair than my old tektronix 11401. The PSU fried on it and its been a complete nightmare to isolate the problem, or find a replacement parts for it.

[EEVblog]

@ae4se You still have NOT explained why the vertical adjust control SHOULD be on the main board under the CRT, in the last place I, and I think most people (who do not service these things regularly) would look.

Please enlighten us with your brilliant technical explanation...

[aptsys]

@ae4se Why 'SHOULD' the pot be under the tube?

[sdgelectronics]

@ae4se You're a fool. Maybe you should read your comments before you post. Engineers designed this thing, not a technician.

[gilgameshismist]

@eevblog tongue-angle is easy, not drooling onto the boards while calibrating porn-on-a-stick is the hard part.

[Minifig666]

Only that sticker was made in Holland...

[aptsys]

@ae4se He already addressed the reason that the shields were in place for the high voltage area and he only praised the engineering so why comment negatively about the video.

[EEVblog]

@ae4se Are you saying it's obvious that the vertical gain control would be on the main board under the CRT instead of on the vertical amp board?, and that I (not an experienced Tek service tech) am an idiot for looking their last? Please explain. And as you seem to know, please explain to us why the vertical adjust control is on the main board under the CRT instead of on the vertical amp board...

[toxanbi]

Who else felt horripilation at 03:05?

[heroineworshipper]

Touch the anode lead.

[aptsys]

@ae4se WTF? Your comment doesn't seem to make sense or convey any points. Twat.

[lebeyes]

I found some 50 ohm terminator resistors that are not very precise (51 ohms, 49 ohms). I guess this can influence the calibration?

The terminator resistors are probably from old 10base2 networks that used coax network cables. Are terminators for signal generators and scopes better quality and precision?

[TheEPROM9]

Have you ever worked on CRT electronics designing monitors/TV's?

[321reh]

This is a Awesome Video,,,,,,,,,,,As usual I learned a lot,,Thanks Dave!!! Keep Those Videos Coming.

[321reh]

The Layout is absolutely amazing!!! Incredible Job here....unit was made around 1986--1987......Glad I bought one of these!!!

[elliott1787]

Looks empty compared to my 2221A.

[dmjita]

Dave thank you to make this great job for us every time. Many thanks

[williefleete]

that teardown was just pornographic!

[38911bytefree]

Does the service manual mention something like wait till the unit warm-up prior doing any adjust ?.

[AntiProtonBoy]

Auto transcribe said "often these days" for "half a bee's dick".

[ivaneduardo747]

I din't like the new style for the videos' titles, you know, now that the EEVBlog number is written at the end. I used to identify EEVBlog videos right away when quickly looking though a list of YouTube videos.

[EEVblog]

@ivaneduardo747 I learned that the first few words in the Youtube title are indexed much higher in the rankings than later terms, so decided to swap. If people can't find my videos, they can't watch'em :)

[44209david]

lol and your right about holding your tongue right its just standard practice really for repairs / design with hardware or even software!

[TomCEvans]

Thanks for the video Dave, you have inspired me to break out the service manual on my 2225 and perform some needed adjustments. My 2225 also has a large 1.5M (2W?) resistor soldered to the bottom of the board as R266.

[EEVblog]

@TomCEvans Sounds like a factory mod then, thanks for the confirmation.

[44209david]

you said Tektronix 3000 scope as your signal generation not Agilent but great video as usal Great stuff dave!

[EEVblog]

@44209david Oops :->

[dynetrax]

28:33 "It's slightly off! Half a bee's dick!" lol!!

[omgitschrislol]

If all the components that were convertable to surface mount during design were, how much weight do you think would be saved by using less solder? No video I have seen talks about this when talking about SMD stuff. I know this isnt an SMD video but its a question I have had for a while. Please respond =]

[EEVblog]

@omgitschrislol It ain't just the solder, but lead weight and associated smaller board space as well. I wouldn't like to guess at a number...

[mikeselectricstuff]

Try turning on the auto transcribe - hilarious!

[EEVblog]

@mikeselectricstuff I gave up that long ago, wetting myself was getting embarrassing!

[EEVblog]

@ae4se I don't get it. Was it unreasonable for me to expect the vertical gain adjust pot to be on the vertical board?

[ElectronicsAustralia]

Really great explanation Dave! Love the detail you go to :-)

[2M0JAS]

My tongue angle was all wrong, been struggling for years and now you've helped me fix it!

;-)

[P55CxE9]

what a beauty!

[MedicineForFuel]

Awesome video Dave! Thanks for the "pro tip" about the tounge angle. Lol! Keep it up!

[Madmax23419]

I am made in holland to. :D

[EEVblog]

@Madmax23419 Are you the same vintage as the scope? :->

[Orcinus24x5]

LOL, tongue angle! XD

[pvibien]

At 22:17 i think you meant to say Agilent instead of Tektronix

[KE5SUI]

Half a bee's dick?

[EEVblog]

@KE5SUI Yeah, standard unit of engineering measure.

[DjViOd]

I'm from holland :D

[TheAdambee7]

i still use my old 468s. old Tek scopes are good workhorses. great vid man.

[toddrharrison]

Great video! Just the right detail for the masses to safely check and cal their old scopes.

[Guysm1l3y]

That is a big honking board! Very cool.

[tubefella]

The little spring is to ground the aquadag external coating on the CRT.

[TheElectricnoob]

Any idea what that tune is called ? I've heard it in several videos, mostly demo videos from compressor manufs and such.

[EEVblog]

@TheElectricnoob My video editor VideoStudio can autogenerate music based on length and allows me to tweak the settings. It's a third party add-on, so probably used in other video programs too.

[hitachi088]

i saw a TV one time the every component marked on the PCB with name and polarity everything, i was quite surprise cause the board was literally covered with component. it was a sony or commodore CRT color TV (not sure).

[TheChrisMuncy]

Dave,

Love the enthusiasm for the old electronics. I too have an old 2225 that I've had since essentially new. There is just something about well built electronics from the 80's that you don't see today.

Where did you find the service manual?

[Rebelgium]

I love these kind of videos the most Dave!

[Maytemberr]

"Half a bee's d..." Dave, is that a metric or imperial unit if measure? Think of the poor guy at NIST who's responsible for keeping an accurate reference.

[syncmaster710n14]

Oh you just can't beat the oldies, i have a Hameg scope that i believe was made in the early 80s, and i still use it over a digital scope. I just love the simplicity, no firmware, no usb connector, just a basic BNC and lots of buttons and knobs.

[Intosia]

Holland baby! :D

[horfittunge]

To bad I can't find the pot for adjusting my tongue-angle. :-(

[KozmykJ]

One eye plus the right protruding tongue - the Popeye technique ;-p

[Gameboygenius]

"Half a bee's dick" :D

[fingerboy18]

Dave; you're a riot. "USA, USA.." haha!

[Gameboygenius]

0:38 I see a link! Or at least a 0 ohm resistor. It's near the ribbon cable coming off from the panel board, component index ends with 52.

[w2aew]

Looks like your scope is from the early 90's - note the 1991 datecode on many of your ICs...

[44rdwolf]

Does it say "made in Taiwan" under the "made in Holland" sticker?

[dealio82]

I like the new intro thumbs up

[GoneBadKiwi]

Thumbs up for Daves tongue angle & 1 eye technique

[DanFrederiksen]

I'm glad we are not still stuck at that tech level.

[techgood]

Thank you for all of your videos Dave

[Nippe0000]

whatcamera do you use?

[EEVblog]

@Nippe0000 Canon HF G10

[lovroore]

there is a pot for that :-)

[gemis94]

At 14:26 I wonder if it says TAIWAN under the sticker?

[GLaDOSProductions]

10:12 The dangerous shit!

[Crazyguy88]

Brilliant timing. Just watched the review half an hour ago! ;)

[thewii552]

YAAYY! I have been waiting for this for very long. Thank you!

[JohnM3D]

Ohh, I waited this for so long, thanks!

[mantaz111]

New intro. Sweet! ;D

[EEVblog]

@mantaz111 I've got a slightly different cartoon every time, maybe a new auto-generated intro tune every time too? :->

[barcelona08018]

Hi Dave, how do you usually go about getting hold of service manuals? They can sometimes be pretty hard to come by...

[EEVblog]

@barcelona08018 There are plenty of companies online that sell old scanned user and service manuals, some googling usually finds them.

[barcelona08018]

@EEVblog Thanks Dave. Great vid by the way.

[Zwank36]

love ur tear downs

[Cla0016]

>Wow, did you get that intro music from Better Homes and Gardens?

[dealio82]

Good job man . Hope more from you

[odessa999]

Excellent Vid Dave, more like this please ! :)