B+K Precision Model 470 CRT CATHODE RAY TUBE TESTER/REJUVENATOR - Overview

This video is an overview of the Dynascan Corporation (later: Maxtec International Corporation), (later again: B&K Precision Corporation) B+K (B&K) (BK) Precision Model 470 Cathode Ray Tube Tester/Rejuvenator (CRT Tester/Rejuvenator).
It seems over I guess 60 years of buy outs, mergers, model succession, there has been an extensive amount of brand alterations. And whilst B&K Precision Corporation discontinued the line on 1st May 2007 with the Model 490B it seems these testers are heralded as some of the most reliable of their respective category.
In this video I cover a Model 470 purchased from eBay 17th Feb 2022 for £122.01. It seems to be in relatively complete condition, including most if not all original paperwork and 7 CRT socket adapters. Adapters included: CR-3, CR-5, CR-15, CR-21, CR-23, CR-24, CR-25.
Shown in the video is a high-level overview of what I have bought, a basic cleaning process and general maintenance (replacing the plug and using Deoxit on some of the pots), reassembly and general demonstration of the unit as per the manual’s guidance.
As promised in the video I have uploaded all documentation to archive.org (except the setup chart as there are better newer resources for this). (Links further down)
Chapters:
0:00 Introduction & overview of what I’ve bought
12:39 Starting to look at the servicing and maintenance
14:27 Disassembly of the device
18:22 Cleaning the pots
20:27 Rewiring the plug
24:33 The cleaned-up tester in all its glory
26:44 Testing the tester
30:23 TV test attempt #1
36:49 TV test attempt #2
41:34 TV test attempt #3
42:24 TV test attempt #4 (this one is the main demonstration)
55:00 Summary
Constructive feedback is welcomed in the comments. Thank you for taking the time to view.
Like what you see? Say thanks by buying me a drink! www.buymeacoffee.com/retrobri...
 
Further reading and resources:
Adapter datasheets: elektrotanya.com/showresult?w...
Info on how to build your own adapters:
forums.arcade-museum.com/thre...
Mouser Parts:
www.mouser.co.uk/ProductDetai...
www.mouser.co.uk/ProductDetai...
Setup chart information database:
tubular.atomized.org/
CRT repair bible:
web.archive.org/web/2004060512...
B&K Precision Corporation:
www.bkprecision.com/products/...
B&K Precision Corporation - CRT Setup - 467/470/480/490/490B:
bkpmedia.s3.amazonaws.com/dow...
CRT Wiki informational page (very useful):
wiki.arcadeotaku.com/w/CRT_de...
Archive.org upload of documentation from my channel:
archive.org/details/@the_retr...

[@BlondieSL]

Just in case there's someone out there who tries to rejuvenate a CRT and they are not aware of this, I want to WARN people,
DO NOT TEST OR REJUVENATE the CRT when it's face down!!! ESPECIALLY ON A COLOR CRT!!!
What people often are not aware of, is that as you try to rejuv a CRT, there are usually (often) shorts.
When the short is "cleared" there's a tiny piece of metal that goes flying off.
If you have the CRT on its face, like at 35:45, the flying metal will fly down to the FACE of the tube and destroy the phosphor. (B&W CRT)
In a color CRT, the metal bits will fly onto the shadow mask (screen behind the phosphor with all the super tiny holes for the beams to pass through). Most of the time, the metal filings will get stuck into the holes! This, of course, stops the beam from getting through the hole(s) at that point and will show on the front as a black spot. On modern LCD panels, we'd call that dead pixels. But CRTs don't have pixels, so we just call them dead spots.
SOMETIMES (not often) if that happens, one MIGHT be able to put the CRT back to normal position and lean it slightly back, being super careful to not break the neck, then start bumping the front of the CRT where the dead spots are located.
*OF COURSE, NEVER HIT HARD NOR WITH ANYTHING THAT IS SOLID. Only the hand and GENTLY!*
I learned that lesson early on as I was learning how to repair TVs all those millions of years ago. LOL well, it seems that long ago. LOL
😁⏰

[@TheRetroBristolian]

Thanks for the comment and feedback to the video. All great points, I wasn't planning to rejuvenate with it face down however I can see why you would say what you've said for clarity and to help others.
Thanks for stopping by - take care.

[@lableu758]

Important information, i saw it (face down) in other video so thx to have precised it

[@BlondieSL]

@@lableu758 I should have mentioned too, not ONLY face down for rejuvenating.
And older CRT (usually) tiny bits of metal can blow off the elements in the neck, even on a good tube. So when placing face down, it is possible for bits to block holes in the shadow mask.
The reason I know about this... .sigh... is because when I first started repairing TVS (2.5 million years ago, it seems) is because I had this happen a few times until I realized what was going on.

[@scratchback2001]

That noise is normal. It's a wiper running over coils of wire. It's called a Rheostat.

[@Coderjo.]

Looking at the parts list you uploaded (thank you for that, BTW), the heater voltage knob is a wire-wound pot, rather than a carbon pot, which is why it has that scratchy feeling.

[@TheRetroBristolian]

Thanks for the comment, you are right on the pot, someone else commented this as well! I don't have formal electronics knowledge I just potter (excuse the pun) and learn, so it's great to get corrected on these things. Glad you have found use from the uploads - that took quite a while! take care.

[@jims2222]

This is a terrific review for this tester and it was very generous of you to spend the time it takes to scan all of those relevant documents. The addition of the information links is over the top, great job. The noisy potentiometer is a wire wound device and that noise is normal. These are generally low ohm, high wattage potentiometers or rheostats used for voltage adjustments. Standard carbon trace potentiometers generally wouldn't work well for that purpose. Very good video.

[@TheRetroBristolian]

Thanks for taking the time to comment and give feedback. It was a lot of time and effort to scan and upload the docs but it felt good to get it done and potentially help others/let others get use/enjoyment out of it. Really interesting to hear about the differences with wire wound pots - thanks for sharing the knowledge. take care.

[@BlondieSL]

Phew! I'm so glad that you informed him about the wire-wound pot. Yes, it sounds perfect.
THAT is exactly how it sounds and in fact, it sounds like it's in new condition too.
Those wire-wound pots, when they start to fail, usually by the wire having been over heated, they'll take on a grinding sound and even "skipping" sound (smooth, then rough).
To be honest, I was rather surprised that he didn't know this before opening up a device like this.

[@TheRetroBristolian]

@@BlondieSL Thanks for the comment! Whilst I've been playing with electronics for many years I have no formal training and some information can slip through the net. That's one reason I make these videos is to share what I know, and find out what I don't know, so I really appreciate people dropping by with constructive feedback. Many thanks.

[@sumobast]

A fantastic, comprehensive overview of this rejuvenator! This is just what I've been looking for since I purchased one about 6 months ago. Havent used it yet but I feel a lot more confident after seeing this and i'll be checking out all the links you provided. Thank you.

[@TheRetroBristolian]

Thanks for the kind words, I'm glad you found it useful. In hindsight I didn't actually show the rejuvenation part but I guess I can do a quick follow up when I find a TV I can connect to and actually show the results.

[@sumobast]

@@TheRetroBristolian That would be awesome. Look forward to it when you find a suitable candidate.

[@popculturecreations9852]

How do you know what model number CRTs it works on? My CRT 25VGDP22 CRT tube model number

[@TheRetroBristolian]

I kind of feel like you've missed the point of the video a bit, I put a lot of effort into uploading all the documentation and providing the links to everything you would need in the video description. you simply take the tube model you have, go to the tubular site and search for it, I even demonstrate that in the video. I've done it for you here - tubular.atomized.org/tube/25VGDP22 It seems that tube uses the CR-24 neck adapter. This is a somewhat common adapter, you follow the steps I take to setup the rejuvenator with the values found on the tubular site. I hope that helps 🙂