Tektronix 475A Power Supply and Scope Repair (With Soldering)

Рет қаралды 3,471

Күн бұрын

A huge thank you again for all that continue to Join us in the lab for repairs and alignments. The channel would not exist with out all of you so thank you again for dropping by.
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Patreon - / zenwizard_studios
Paypal - Zenwizard@Zenwizardstudios.com
In this video we take a look at power supply repair on a 475A that was here in the lab with a fault on the -15Vdc supply. People have been asking for videos detailing soldering and repair so that is included in this video. With that down the rabbit hole we GO!
** Repair exposes the Tech to mains electric and should only be done by trained personnel. Errors can be fatal. **

Пікірлер: 11

@r.f.lab-renefilho1453 9 ай бұрын

Nice job ! I am working a National VP-5230S without schematic. Problems solved in horizontal because a diode leakedg and searching about substitute to the 2SC1326 because the vertical circuit sometimes stop and the trace gonne ! Congrats and best regards

@thanhhuynh272 9 ай бұрын

Give that shorted tant a “send-off” to polarized capacitor Valhalla by dabbibg it across the lowest source impedance you can muster, (Car Battery or similar). I have a 465 (without the DMM on top), it has an intermittant transistor in the feedback loop of the EHT supply, sometimes it works, sometimes it stops and the tube looses its EHT. this transistor has its base connected to the lower end of that beryllium oxide thick film high value dropper resistor. Most transistors and other semis in these old Tek CRO,s are in dockets but this little bugger has its base lead soldered to the ceramic tag strip and I either need to solder very quick without melting it all or find some of that sabvit solder with copper and silver dissolved in it to saturation…sippose I could cut the base off and solder the replacement transistor to the old lead…but for now I just put up with it! Somewhere I have an old Tek video waveform monitor with some valvrs in it and a LOT of those ceramic tag strios. There is a reel of sabvit solder in there fastened to the chassis….how nice and thoughtful those Tek guys were!!

@ZenwizardStudios 9 ай бұрын

I have a solder video coming out that will address this but the short answer is Kester 24-7068-1402 Alloy is Tin 96.5% / Silver 3.0% / Copper 0.5%. I use this a lot on ceramic strip work Type 184, 106, 191 all of them are mainly ceramic strip construction. I was looking for 5% silver but I have not found any alloy yet that fits this bill. The ceramic strips need a good thermal mass iron though the ceramic will soak a surprising amount of heat before the joint melts.

@zyeborm 9 ай бұрын

Low impedance short circuit detection has found me many a blown tantalum when I couldn't find it other ways ;-)

@hughgilbert390 9 ай бұрын

The trimmer capacitors have a very limited rotational life. They open after several calibration cycles. I had to replace all of them on my unit. The fault tag listed the problem as fails calibration, beyond economical repair.

@gregjones3660 9 ай бұрын

12:10 I didnt know that Owen Wilson repaired radios...

@domingoderivas8410 9 ай бұрын

Hello, congratulations on your work, I have a question for you, I have an oscilloscope similar to yours, in my case it is a Tektronic 465, would you have a diagram of this oscilloscope? It would be of great help to me, thank you very much in advance, greetings

@ZenwizardStudios 9 ай бұрын

Thanks, There is an amazing amount of information out there on the 465. I have several videos in the back catalog on repairing and calibrating 465 scopes. I also have another one in que for repair as it is showing some trouble now. So more is on the way. The full service manual can be found at the tekwiki located here: w140.com/tekwiki/wiki/465 The tekwiki is a great resource for all things Tektronix. Zen