Tektronix 2445: My first vintage oscilloscope repair attempt

Comments · 407

• UN

  @Unfinished80 · 3 years ago

  I've dealt with this in industrial equipment. The copper tangs under the relays lose tension over time. When they are new, the tangs are bent out far enough so that they will bend a little angainst the contact pads to maintain connection. However, if the relays are left in the same position most of the time and that coupled with time, temperature cycling, and vibrations cause the tang to deform and lose tension gradually until they are only floating on the contacts. This is why the paper shim was able to restore a little connection, by pushing them slightly closer together. If you want a solid connection, you'll have to re-bend the tangs on the relays. That is much easier said than done but not impossible. Perhaps you could find a tiny shim to go behind each of the tang legs? Good luck and thanks for another great video!

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• JP

  @jp-ny2pd · 3 years ago

  I worked for an electronics engineer for a while in high school. He mainly used digital scopes but he always had that one bench in the corner with all the analog scopes on it. He would throw a sheet over them to keep dust off. I asked him why he keeps them and he just said "For when things get weird" and walked away.

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• LU

  @lukask5285 · 4 weeks ago

  70s and 80s electrical engineering is simply voodoo and utter madness. Impressive.

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• DA

  @Damaniel3 · 3 years ago

  All of the pre-1990 Tek scopes are masterpieces of chassis design and circuit layout.  The early tube-based CRT scopes are especially nicely laid out.

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• KR

  @krandall5285 · 3 years ago

  The way I was taught to clean those gold contacts is with a small strip of white printer paper and IPA.  I have serviced quite a bit of old Tek equipment.  I love Adrian's show, but I would strongly advise against scratching up the pads with a steel implement...

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• CH

  @ChrisB... · 3 years ago

  I bought a pallet of about 20 of these scopes in the early 90's for $5.00. I didn't know what to do with them so I posted a notice at my university's engineering building and ended up selling most of them for $50-$100 each. Pretty nice return on investment! I miss old-style government auctions, mostly because people didn't know about them and you could get great stuff extremely CHEAP!

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• RI

  @rimmersbryggeri · 3 years ago

  I think bending up the relay contacts will do the trick 100% since they are probably work hardned in the position they are now.

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• JO

  @johnglielmi6428 · 3 years ago

  Tektronix are one of the finest made precision instruments ever made. These things were built to last.

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• RA

  @rayburke4386 · 3 years ago

  Hi Adrian , Ray Burke here , I use to work on the Tektronix Portable scope line.  Most of the gold contacts shouldn't be scraped with tweesers, Tektronix in their manuals usually suggested using Isopropal Alchol and a this peace of paper in the service manual unsure about Deoxit?  The problem with the CH 1 and CH2 Attenuators may be the outer mounting ring screwed to the Attenuators, using a thin open end wrench to carifully thghten them, they might be loose from connecting and disconnecting the scope probes.  This could cause the signal to distort. You may contact the Tektronix support forums or the Beaverton Museum.

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• CH

  @chuckthetekkie · 3 years ago

  I love how the PCBs are literal "Resistor Cities"

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• AN

  @AndrewLittleboy1 · 3 years ago

  The inside is a work of art, absolutely beautiful layout.

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• TE

  @tekvax01 · 3 years ago

  Be very careful when touching, cleaning, and rubbing those open hybrid circuits, you can very easily damage the printed high-precision resistive ink printing, which will completely destroy the hybrid. <br>I use to design, construct, and troubleshoot those types of hybrid circuit boards.

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