Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 14558264 times)

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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124275 on: June 26, 2022, 12:30:41 pm »
I guess I've been lucky. No issues with them at all. But given that I'm not going to touch any of them during final calibration unless I have no choice.

Yes, don't touch any of them, don't even BREATHE too close to them !  When I opened the scope, all those trimmers look fine at first, it's only when I tried to operate them, barely touching them with my finger tip, that the knobs started to all off one after the other ! Sometimes just moving the scope the bench was enough to make them self destruct !  :scared:

Luckily you are in the US so you can have all of them for cheap, and fast, from Mouser like I did 5 years ago.

So it's not as big a deal for you as it was for me at the time.

« Last Edit: June 26, 2022, 04:56:18 pm by Vince »
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124276 on: June 26, 2022, 12:46:00 pm »
Ok first thing. Just got back. The 465B does not work. Classic symptom is the power supply gives out after a few seconds. Smells like tant  :-DD. I’m not looking at it yet.
 
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Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124277 on: June 26, 2022, 12:58:50 pm »
Ok first thing. Just got back. The 465B does not work. Classic symptom is the power supply gives out after a few seconds. Smells like tant  :-DD. I’m not looking at it yet.

Welcome back to 400 series I hate the smell of tants in the morning.  :-DD

An old gray beard with an attitude.
 
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Offline BU508A

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124278 on: June 26, 2022, 01:03:34 pm »
Soldering in the field, literally (next 10 seconds):

https://youtu.be/yl0NNmuaSJE?t=346

 :-/O :-+ :-DD
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Offline TERRA Operative

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124279 on: June 26, 2022, 01:06:17 pm »



Ooooh, I hate those blue trimpots, I find they are almost always faulty in the TM500 gear I've repaired. I replace them on sight now...

Interesting. I've never had issues with them.  :-//

Yeah, not sure why I keep finding the bad ones. Usually the grey ones are ok, but I've had a few bad ones of those here and there too. Last one was broken in the center 'axle' so the turny bit kept falling out.

Same here, I concur !  :scared:

When I bought my 5000 series scope, found many of thes horrible trimmers on the two CRT boards. Half of them had fallen apart in the way you describe, knob falls apart because the thin plastic shaft holding it to the body of the trimmer just eventually breaks off, disintegrate, leaving you with no wiper because it's part of the knob !  :palm:  Cheap horrible design.

So I went to replace them all, but to my surprise the pin layout and pitch was somehow unusual and I had difficulty finding a suitable replacement. Eventually found a brand and model that was identical, but hard to find. Since I needed many different values, I could not find any place in Europe that carried all the values I needed in stock. An Ebay seller would have one particular value, another would have another particular value, and Farnell would have 3 or 4 tops. Only Mouser IIRC in the USA had all the values available, so I resorted to paying a silly amount to import them.

So yeah, I HATE those trimmers too ! :-DD




From memory, they are just a 2.54mm (0.1") inline pin spacing. I usually replace them with Bourns multiturn trimpots model 3296W. Gives me super fine control when adjusting and calibrating so I can really dial things in.
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124280 on: June 26, 2022, 01:20:51 pm »
COMPONENT SORTING


OK so as I said I am starting to sort my IC's now. Yesterday I started with the easiest part : the stock of logic chips old man gave me 20 years ago, that he rescued from his work before he retired.
I have never touched them. Still in their original plastic boxes with student-made labels and DIY hot glued cardboard dividers . Only difference is that they have now collected 20+ years of dust, which is really stubborn. I spent about 5 seconds on each and every chip with an ESD Brush to remove as much as I could, and 20 seconds on each plastic box, but 80% of it is there to stay unfortunately. Only way to clean that would be to throw all these chips and boxes in the kitchen sink with hot water and detergent and brush, brush.... might do that one day but not today, too much work, that.
Might also "restore" all these boxes. Remove the crusty dividers, sand down the hot glue, remove the crusty labels (most of them are coming off anyway, glue didn't age well), clean the residues... bring these boxes to new condition... because these are nice standard Euro size boxes which still cost a fortune these days, I could not believe my eyes. I can't afford to mass buy them, so it's worth restoring these old ones to me. YMMV.

So I went through all these chips one by one, cleaning them, inventorying them on paper, then putting all that data into my spreadsheet, attached below.

So it's all TTL chips which I already new of course. There are only x4 CMOS 4000 series part numbers in that drawer.

So in all, about 600+ chips and 75 part numbers or so, enough to blink LEDs for the rest of my life I guess.
x500 74 LS and only x35 74 HCT.
x21 74 'S' and oh my god, no less than x39 vanilla 74 !!!
What amazed me even more is that although a few are dated 1977, fair enough, some are much more recent, dated as late as 1989 !!  :wtf:
Can't believe these antiques were still made in 1989... maybe to satisfy some big customer long term availability contract/requirement or something...

Then I found some even more funky stuff. I just love component archeology. I hated history at school, but somehow when it pertains to old electronic stuff, I love it.

So look what I found :

- A SN75_452B chip. 75 not 74. Datasheet says it's based on the vanilla TTL. It's just a couple two input logic gates (of choice depending on particular part number in the series of chips), with open collector outputs. It's strange because it's completely redundant to me ? I mean there are already open collector gates in the regular TTL portfolio, so why make these special chips to being with ?!  :-//
Or.. maybe, since these chips are really old (vanilla TTL not S nor LS !), at the time the open collector gates did not yet exist in the TTL list, so they made that special chip to fill the gap. Who knows. Maybe someone here does....

- AM25LS2521. 25LS series not 74LS. Made by AMD. Datasheet says it's an  "equal to" operator. It compares two bytes and tells you if they are identical or not.

- A 74 'H' chip. Didn't know that one, will need to look it up.

- An 84LS chip. Yes 84 not 74. Sure knew about the 54 military prefix, but 84 no, never heard of that one. Some more Googling required again...

- I kept the best one for dessert : you know the 74LS, you know the 74HCT .... they are different things inside... but what about mixing the two and making a "HCT_LS" chip ?! Makes zero technical sense ? But I found one ! A 7410, so marked " 74 HCTLS 10 "  How groovy is that !  :-DD
I know, you don't believe me, makes no sense. But you will have to believe me because I never drink nor smoke, not my stuff, so I am always alert and sharp when not sleeping...still don't believe me ? I knew you wouldn't, who would believe such ridiculous claims as a HCTLS chip...I understand you, I do. That's why I anticipated your disbelief and took a picture of that chip, below. Enjoy.
No, it's not Photoshopped, it's real... if you want I can make a video of it, because videos are much more difficult to touch up than a still picture... and would require fancy video editing S/W that certainly would not run on my 15 year old Core2Duo computer that struggles just to keep afloat with 70 Firefox tabs open.

Then I found some more chips hiding in the digital logic " training brief case ", as could be expected. No weird chips in there though.

OK so now that the easy stuff is done, I can start digging into the second drawer of IC's.... this time random tubes of IC's and also some new components bought in the recent years, but I of course long forgot what all that is. That will be much more fun as I have no idea what's in there, it's gonna be a surprise.


 

 

« Last Edit: June 26, 2022, 01:26:11 pm by Vince »
 
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124281 on: June 26, 2022, 01:27:34 pm »

- An 84LS chip. Yes 84 not 74. Sure knew about the 54 military prefix, but 84 no, never heard of that one. Some more Googling required again...


Interesting. I know of the 64xx series that were a Texas Instruments Industrial Grade (−40 °C to +85 °C) that sat in between the standard 74xx and the milspec 54xx. It was only around for a short while.

Sometimes you'll find earlier versions of TTL logic that would have different numbers depending on the manufacturer before it was all standardised to 74 and 54 prefixes.


[EDIT] It seems that 84xx was also used for Industrial Grade parts in Europe. (−25 °C to +85 °C)
« Last Edit: June 26, 2022, 01:32:02 pm by TERRA Operative »
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 
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Offline mansaxel

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124282 on: June 26, 2022, 01:39:40 pm »
I guess I've been lucky. No issues with them at all. But given that I'm not going to touch any of them during final calibration unless I have no choice.

Yes, don't touch any of them, don't even BREATH too close to them !  When I opened the scope, all those trimmers look fine at first, it's only when I tried to operate them, barely touching them with my finger tip, that the knobs started to all off one after the other ! Sometimes just moving the scope the bench was enough to make them self destruct !  :scared:

Luckily you are in the US so you can have all of them for cheap, and fast, from Mouser like I did 5 years ago.

So it's not as big a deal for you as it was for me at the time.

As we've written time and time again, Mouser is probably the best deal there is, as long as you can stockpile needs to exceed the free shipping threshold of 50€ ex VAT. None of the others with similar stock levels even comes close to that deal.

Having said that, TME and Distrelec still get my business from time to time, and in Sweden there's a small dealer, Electrokit, that I try to use now and then, to keep them in business. If they stock the part, they're the fastest option available, and sometimes that's important.

An observation: If TME cut down on the paperwork (it's tons of forms, pro formas, invoices, et c, all printed on the best Warsaw Pact toilet paper), they'd be really dangerous competition to anyone. They'd also be able to make lots more money...

Offline med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124283 on: June 26, 2022, 01:52:02 pm »
Since 30 Oct 2015 I have ordered from Mouser 102 times. I don't even want to add up the total cost.  :o :o :scared: ;D
An old gray beard with an attitude.
 

Offline capt bullshot

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124284 on: June 26, 2022, 02:27:22 pm »

 


Someone had a similar experience before: https://www.eevblog.com/forum/projects/74hctls-logic/msg768989/#msg768989

Apparently they were brothers and sisters to the AHC / AHCT series:

http://www.bitsavers.org/components/samsung/1990_Samsung_AHCT_HCTLS_Data_Book.pdf

There's quite a lot of these logic series (typically) two or three letter designators, and some of them are long forgotten. Some modern ones are quite versatile in terms of level conversion capabilities and voltage domain decoupling (as in VHC, LVX, ...)
« Last Edit: June 26, 2022, 02:39:39 pm by capt bullshot »
Safety devices hinder evolution
 
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124285 on: June 26, 2022, 02:41:29 pm »
...So yeah, I HATE those trimmers too ! :-DD   

Looks like a job for 3DP to me. Setting aside the plastic rot you describe (yuckyputz!  :P), I quite like the beefy ceramic substrate I'm seeing there. I'd try to find a way to fix them.

mnem
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124286 on: June 26, 2022, 02:48:38 pm »
Soldering in the field, literally (next 10 seconds):

https://youtu.be/yl0NNmuaSJE?t=346

 :-/O :-+ :-DD

Fukkin' crazy Germans... wasting all that time on toy train dioramas.  ;) They should be spending it on something important, like hoarding and resurrecting moldy old TE!!!  >:D

mnem
Would probably be cheaper... and take up less space. :-DD
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Offline mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124287 on: June 26, 2022, 02:52:31 pm »
Since 30 Oct 2015 I have ordered from Mouser 102 times. I don't even want to add up the total cost.  :o :o :scared: ;D

Lets not even talk about my Thrifting habit...  :scared:

mnem
...or the mortgage Bezos' Online Crack Shop has on my soul. :'(
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124288 on: June 26, 2022, 03:12:51 pm »

 


Someone had a similar experience before: https://www.eevblog.com/forum/projects/74hctls-logic/msg768989/#msg768989

Apparently they were brothers and sisters to the AHC / AHCT series:

http://www.bitsavers.org/components/samsung/1990_Samsung_AHCT_HCTLS_Data_Book.pdf

There's quite a lot of these logic series (typically) two or three letter designators, and some of them are long forgotten. Some modern ones are quite versatile in terms of level conversion capabilities and voltage domain decoupling (as in VHC, LVX, ...)

THanks a lot !!  :-+

OK so it was a Samsung special then. I downloaded their 1990 Databook you linked to. Boy 817 pages just about their AHCT / HCTLS chips, I now everything I could dream of !  :-DD

Had a quick read at the first pages. So it was called HCTLS not because it was combination of MOS inputs with Bipolar outputs (like some of the guys said on that EEVBlog thread), it was 100% MOS inside, but they used a special process that allowed them to combine both the low consumption of HCT, and the drive capability and speed of TTL LS, and then some on top of that. So the HCTLS naming was most appropriate then ! :-+

OK, that chip is cool and exotic, I will keep it for sure, a nice little piece of electronics history !  :D

Now on to Googling about 84LS and 74H ....

 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124289 on: June 26, 2022, 03:14:23 pm »
Ok Newbury megapost. It has been 3 years since the last one. Bloody COVID.

So what did I bag?



Well first we have the HP 400E AC voltmeter. Paid £20 for it. And it works absolutely fine. Just needs a clean. Has feet and an IEC socket!



Mmmm sexy boards





Next we have the HP 3311A function generator. Again it works absolutely fine. Paid £20 for it too. One of the feet fell to bits in the car but this is sort of expected.



Very nice



Will work out a new foot solution to this...





On with the shit show we have the Farnell B 30/5 power supply which cost me £10. This I have not tested yet as it requires some cleaning and the capacitors checked before I even consider putting power near it.







And now to the 465B which is broken. There are two identified issues with it. Firstly the HT inverter fuse is blown. This is such a common issue I know exactly where to look because I've fixed it at least 10 times now  :-DD



And the culprit came up with the expected zero ohms resistance across it as expected. Lurking in the corner under the HV shield.



Now it won't even start up still. All the rails are fine apart from the +5V which only hits 0.9V and has 2.5 ohms resistance across it. The cause of this is as yet not identified. No tantalum capacitors on the rail appear to be the culprit which suggests the boards need pulling until the faulty one is found and then isolated further. I did isolate it one of two boards though through pulling connectors. One for another day because quite frankly I don't have the time or energy to do it at the moment.

Quick debugging shot however



Worth mentioning here as well. This is probably the final shot that will be taken of this cruddy ass wallpaper. Wish it good riddance!



Also got another copy of Solid State Design For the Radio Amateur for 50p. And the Mullard Transistor Circuits Manual for 50p. Both are for ebay  :-DD



And now for something completely different. A small 50 ohm load. 10KW. And yes, that's the coax connector on the front  :-DD

 
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124290 on: June 26, 2022, 03:20:50 pm »
...So yeah, I HATE those trimmers too ! :-DD   

Looks like a job for 3DP to me. Setting aside the plastic rot you describe (yuckyputz!  :P), I quite like the beefy ceramic substrate I'm seeing there. I'd try to find a way to fix them.

mnem


I think it might be easier (and more durable/reliable) to just cut the missing/broken shaft in a skinny metal rod, drill a tiny hole in the center of the knob and press fit the rob into the knob.  ;D

But the problem remains that the original design is flawed, in that there is nothing that keeps the shaft/knob from lifting out of the bore in the trimmer/ceramic base. Shaft does not "clip" into the trimmer. It's just a smooth skinny cylindrical shape. It holds into the bore merely thanks to interference. There is nothing to ensure "clamping" force onto the knob to make sure the wiper is making a good reliable contact with the track on the ceramic base. So if one could implement such a mechanism, that would be a nice improvement.

Obviously in practice it's not worth the trouble, so long as modern replacements are available, and at a reasonable cost.

But I guess as an exercise, just for the fun of it, yes you could try to make something with your 3D printer(ssss)...

 

Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124291 on: June 26, 2022, 03:26:49 pm »
We're all fucked at some point. It's just about controlling how soon as best as possible.

Just found out how much Russia fucked my pension today. 3 years of contributions down the shitter. I've just shit canned all contributions to it in the short term and will spend it on beer, floozies, scopes and power supplies  8)

So the standard reply to:

Interviewer: Mr. Bloke how are you going to spend your lottery winings?
Mr. Bloke: Well, I'll spend most of it on booze and women, and the rest I'll just fritter away.

Isn't that a paraphrase of something George Best said?    https://twitter.com/football__tweet/status/1362009651080884228?lang=en-GB

The correct attribution of that as a quote is to a Mr. Apocraphous Anonymal of 17 Acacia Avenue, Neasden. Some authorities differ, and attribute it to either a Mr. I.P. Freely or a Mr. Michael Hunt, both said to be residing at 16 Acacia Avenue, Penge.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline Cerebus

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124292 on: June 26, 2022, 03:35:39 pm »
What a nice hack for cleaning soldering pads on a pcb:

https://youtu.be/KDVu06WySjg?t=397

Agreed, neat trick.

(Too long; can't be bothered to watch): Cut a wedge out of high temperature resisting silicone rubber, put it into a [improvised] holder, and use the edge of the wedge to squeegee/wipe solder off pads after heating them to above melting point.

Anybody got a syringe I can use to squeeze the magic smoke back into this?
 
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Offline Vince

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124293 on: June 26, 2022, 03:47:41 pm »


And the culprit came up with the expected zero ohms resistance across it as expected. Lurking in the corner under the HV shield.

That's a rather colourful Tant you have here ! So far I had only seen them yellow orange red or blue, now I see they even exist in flashy green.
Soon we can make a rainbow out of them.

Any other colours I am not aware of ?!  ;D
 

Offline Neomys Sapiens

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124294 on: June 26, 2022, 03:48:40 pm »
Soldering in the field, literally (next 10 seconds):

https://youtu.be/yl0NNmuaSJE?t=346

 :-/O :-+ :-DD
That is the Weller accu station which I mentioned on Discord a week ago.
 
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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124295 on: June 26, 2022, 04:02:03 pm »


And the culprit came up with the expected zero ohms resistance across it as expected. Lurking in the corner under the HV shield.

That's a rather colourful Tant you have here ! So far I had only seen them yellow orange red or blue, now I see they even exist in flashy green.
Soon we can make a rainbow out of them.

Any other colours I am not aware of ?!  ;D

Black, disguised as silver mica brown and the lesser spotted “firey inferno”
 
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124296 on: June 26, 2022, 04:04:51 pm »
And now for something completely different. A small 50 ohm load. 10KW. And yes, that's the coax connector on the front  :-DD



Should have asked the seller if they had a BNC adapter for that thing...  :-DD


Also, that 3311A foot is a prime candidate for the 3D printer. I'd bet there's even a design online already.
Where does all this test equipment keep coming from?!?

https://www.youtube.com/NearFarMedia/
 
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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124297 on: June 26, 2022, 04:06:16 pm »
And now for something completely different. A small 50 ohm load. 10KW. And yes, that's the coax connector on the front  :-DD



Should have asked the seller if they had a BNC adapter for that thing...  :-DD


Also, that 3311A foot is a prime candidate for the 3D printer. I'd bet there's even a design online already.

Yeah highly likely. I may just resort to low tech rubber stick on feet though  :-DD
 

Offline BU508A

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124298 on: June 26, 2022, 04:08:36 pm »
Any other colours I am not aware of ?!  ;D



There you go, now you can build your tant-cap-rainbow.

 ;D

Edit:

Haven't found an octarine one. Sorry.  ;)
« Last Edit: June 26, 2022, 04:14:03 pm by BU508A »
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 
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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #124299 on: June 26, 2022, 04:15:25 pm »



Ooooh, I hate those blue trimpots, I find they are almost always faulty in the TM500 gear I've repaired. I replace them on sight now...

Interesting. I've never had issues with them.  :-//

Yeah, not sure why I keep finding the bad ones. Usually the grey ones are ok, but I've had a few bad ones of those here and there too. Last one was broken in the center 'axle' so the turny bit kept falling out.

Same here, I concur !  :scared:

When I bought my 5000 series scope, found many of thes horrible trimmers on the two CRT boards. Half of them had fallen apart in the way you describe, knob falls apart because the thin plastic shaft holding it to the body of the trimmer just eventually breaks off, disintegrate, leaving you with no wiper because it's part of the knob !  :palm:  Cheap horrible design.

So I went to replace them all, but to my surprise the pin layout and pitch was somehow unusual and I had difficulty finding a suitable replacement. Eventually found a brand and model that was identical, but hard to find. Since I needed many different values, I could not find any place in Europe that carried all the values I needed in stock. An Ebay seller would have one particular value, another would have another particular value, and Farnell would have 3 or 4 tops. Only Mouser IIRC in the USA had all the values available, so I resorted to paying a silly amount to import them.

So yeah, I HATE those trimmers too ! :-DD



Sounds like someone has been guilty of using the wrong type of contact cleaner on those.
Who let Murphy in?

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