Anyone out there kind enough to help me repair my new Type 547 Tektronix scoop? - Page 1
Forum section: electronics / repair

author: The Guy
author_rank: Regular Contributor
timestamp: August 28, 2017, 06:38:34 pm
content: Looking for someone who understands this scope willing to help me out with the repair. There is a lot of stuff wrong with the scope i believe.I just bought it for a few bucks and I want to fully restore it.Thanks in advance.Guy

author: Old Don
author_rank: Regular Contributor
timestamp: August 28, 2017, 09:10:17 pm
content: Might help to know what country/state/province/county/zone/district you live in.

author: tautech
author_rank: Super Contributor
timestamp: August 28, 2017, 09:17:33 pm
content: Yep, MartinM from the link I provided to his thread.PM him.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 12:47:27 am
content: Quote from: Old Don on August 28, 2017, 09:10:17 pmHi, I'm not living i the usa... . I want to repair it myself so I can learn a thing or twoI just need some guidance from someone who knows the scope.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 12:49:28 am
content: Quote from: tautech on August 28, 2017, 09:17:33 pmThanks, I already contacted Martin through his website Wellenkino.de the other day, but he told me that he was in a fair show in Hannover and he hasn't contacted me back yet.

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2017, 12:52:30 am
content: Quote from: The Guy on August 29, 2017, 12:49:28 amGreat, then send him a link to this thread and sit back and be patient.While you wait you might like to give it a good clean, there's plenty of pics of Martin's methods in his thread.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 01:59:42 am
content: Quote from: tautech on August 29, 2017, 12:52:30 amThank you... I actually joined the yahoo tekscope group and they've helped me a little... In fact I already found some faulty components, but I'm pretty much stuck... since I have no idea where and what replacement parts I need to get. These things are so old! lolI am waiting for some hot wather to clean the circuits... it is raining right now! I am really stuck here Lol

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 29, 2017, 02:24:22 am
content: But what exactly is not working? It's a complex beast...

author: Armadillo
author_rank: Super Contributor
timestamp: August 29, 2017, 02:59:39 am
content: I must say the service manual is amongst the best described I have seen.The scope is a mixture of semiconductor device and valves technology. Opps! Sorry, I have got to raise my hands up in surrender.Can I say is a paid headache, buy someone else trouble so to speak.I mean there are a lot of cheap better scopes around and I don't think you can go anywhere with this one.Let it go, man, lost a few dollars but don't lose your time on it, we call it cut loses.No offense, just my opinion when I see my grandfather technology in pain.BTW, put the country of yours up and I am sure your country men will be eager to help out.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 03:17:40 am
content: I friggin' fixed it!!!! I am smarter than Einstein!! Lol!!Check this out baby:https://youtu.be/KMRNyncKq6Qain't it beautiful? ....IT.IS.AWESOME! Pure tube goodness.Uhhhhh yeahhhhh....bliss bliss blissNOTE: the guys at the tekscopes group helped me out with the troubleshooting method. That's how i did find the faulty component.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 29, 2017, 03:31:18 am
content: Excellent. Let it run for 30 minutes, one hour. If the trace starts to lose focus and "grow", you've got problems.Let's check how it behaves first.

author: Armadillo
author_rank: Super Contributor
timestamp: August 29, 2017, 03:35:08 am
content: Grandfather technology actually works!, my God!

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 03:40:18 am
content: Quote from: Alex Eisenhut on August 29, 2017, 02:24:22 amHorizontal amplifier's transistors Q554 and Q564 were out of whack. It is a transitory fixin' probably tho. The transistors didn't pair well, they were out of balance... so what I did was to look the schematics until I found another 2N2207 transistor somewhere in the circuit (actually the transistor Q424 in schematics page #7), took it out, took the Q554 and Q564 also out, grabbed my DMM, tested them, and voilà... two perfectly matched transistor back in Q554/Q564 positions and the scoopie doopie worked.I reckon it needs a whole calibration... this thing hasn't seen the light (or current), like in 30 years i believe.But it works!!Now...I must say... this thing has the sharpest trace I have ever seen. Amazing.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 03:43:59 am
content: Quote from: Alex Eisenhut on August 29, 2017, 03:31:18 amIt doesn't lose focus/grow, it dims... so I think this one has the classic high voltage CRT trannie issue. Gotta fix that one now.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 03:47:57 am
content: Quote from: Armadillo on August 29, 2017, 03:35:08 amRight? I wanted to have this scope since I like to build guitar tube amps. I am a tube nut. So I wanted an awesome tube scopeI hate chips, I love tubes.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 29, 2017, 03:58:03 am
content: It dims after a few minutes because the circuits are still reaching temperature. Adjust intensity...The HV transformer issue is really when you lose focus and the whole trace blooms. BOY am I glad I got that fixed!Welcome to the very restricted club of working 547 users!

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2017, 04:02:01 am
content: Cool, hope you can keep the ol' girl going.Martin should give you good advice and have some knowledge on things to watch out for.Forget calibration for now as some parts of the circuit will be high impedance so a good clean will reduce leakage paths and get her closer to spec.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 04:05:44 am
content: Quote from: Alex Eisenhut on August 29, 2017, 03:58:03 amGlad to join the club. I've heard only good things about this model.So, do you have a 547?!? Awesome! How do you like it?This one starts dimming like after 5 minutes until it looses all the intensity with the intensity knob topped clockwise. To get the scope back to shine i need to turn it off for a few minutes.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 04:09:39 am
content: Quote from: tautech on August 29, 2017, 04:02:01 amThanks man... waiting for Martin to appear. Finding Martin is a tougher one than finding Wally lol.Yep, gotta wash this babe out first. Then see how the saga continues.

author: The Guy
author_rank: Regular Contributor
timestamp: August 29, 2017, 12:34:37 pm
content: Quote from: Alex Eisenhut on August 29, 2017, 03:58:03 amBtw. How did you fix the HV transformer issue?Cheers.