No.119 - Racal-Dana 9900 Universal Counter Timer Repair
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- Опубліковано 8 лис 2023
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This 9900 Universal Counter Timer has a broken IC, not faulty......just broken!
NOTE: Beryllium Oxide is often used in ceramic IC packages and in dust form can be harmful, so please beware. Don't breath it in and handle safely.
See: materion.com/-/media/files/co...
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Re-uploaded to add in notice about the ceramic possibly being made out of Beryllium Oxide and the possible health issues. Better safe than sorry.
See the link in the video description.
Unlikely. Beryllium oxide is used as an insulating substrate with excellent heat conductivity. You'll find it in RF power transistors.
Agreed, possibly Aluminum Oxide or Magnesium Oxide?.....but at end of day who knows! I am borrowing a diamond tester (electronic device) which is apparently quite reliable at testing for Beryllium Oxide.
Thanks for the warning about Beryllium Oxide. That stuff is quite scary. I think people often encounter it when tearing down microwave ovens where it's used as an insulator in the magnetron. Better safe than sorry is absolutely the right call when doing any sort of grinding or filing of unknown ceramics!
@@chongli297 Beryllium oxide is perfectly safe in bulk. The danger comes if you grind it into dust and inhale it. Don't worry about lumps of it.
@@donepearce Yeah though from what I've seen, people unknowingly take a dremel to it and create a ton of fine dust
Wow. That dodged a bullet. That LSI spun around 180 degrees and it still worked after correcting the orientation and (awesomely) grinding down the package to tack solder on the lead? That's how I'd like to remember myself and my electronics technician past. LOL. You are a master.
Ah, the memories of units like this back in the day when I worked for Welwyn Electronics in the north of England as a calibration Engineer.
Keep up the excelent work Ian
Cheers Peter.
I love the repair
Thanks Ian. I wondered what happened first time.
Me too.
Yeah, I don’t like to do it as I lost some good comments. Oh well!
Well done! Glad that chip survived being inserted backward.
If you're ever in a similar position, you can poke around with a multimeter with the diode check function. Inputs are going to look about the same, outputs are going to look the same but different from inputs, power and ground stand out.
Nice repair, I've wanted to buy one of Racal's 500x DMMs for a while but people that sell them don't want to ship them overseas. They used to make good gear.
Nice repair, Ian. Beautiful job on that ceramic IC; it should have been a total loss. The way that unit's internal oscillator is configured on a separate board at the back of the enclosure just cries out for a high-accuracy, high-stability upgrade. Future video?
It’s a 5MHz crystal oscillator on that wee Pcb I believe, if it had been 10MHz then it would have been easier by just adding an OCXO.
@@IanScottJohnstonGreat repair. I just got one of those £13 ebay 10MHz OCXO for my HP5334B. Just aging it at the moment... pretty stable already. For your unit, just add one flipflop to divide by 2 ?
@@TheHWcave very true, I have a few 10MHz OCXO lying about……might just do the flip flop upgrade.
Fantastic fix Ian =D
Cheers !
@ 15:32 It should work on the 10^4 range, but you didn't give it enough time. It takes a count every 10 seconds on that range. I have the 9901 & 9904. Also a few 1991 & 1998's. Bit of a Racal Dana nut :) Nice repair. 👍
Yep, saw that when I was editing the video. Cheers.
I have to say thats a lovely layout inside there. Oh yeah I found the HP 3245 bits I didnt use from one of the last videos you did if you still want them.
Send me an email.
I think I have the same counter on my bench at work that I accidentally borrowed from ferranti about 30 years ago. They work ok but not stunning and really lacking in decimal places for modern radio work, from memory they are quite low frequency range about 30mhz , still nice to have an LED display for easy of reading. Oh the push switches need cleaning periodically. Those electrolytics of that style will be bad.
Not having an MCU can be a good thing .
God I'm reallly staring to hate the sponsor promotions that are popping up on UA-cam.. I pay good money to get of ads on UA-cam and the ads/sponser clips are starting to be everywhere. The whole point of paying for no ads it to see no ads but here they are. So annoying.
Gotta make your money somehow 🤷♂️
I can’t speak for UA-cam Ad banners as I have YT Premium, but for my own sponsor Ad I wouldn’t be able to make videos without them. I feel your pain though, some sponsor Ads on channels I follow last for 5 mins.
pft, don't like em ? don't watch them, skip to the parts you want to watch.
You pay for youtube? Just run and ad blocker
@@timturner7609
And which one does not bring up a timed "No ad blockers allowed" message from UA-cam ? It runs as long as the average ad.