Test Equipment Anonymous (TEA) group therapy thread

[Zucca]

Just bought a 34401A 
and i already have an SDM3065X-SC   

i hope it arrives as good as on the pictures.

Amazing machine. It will serve you well.
Problems? No problems, schematics and service manual are available.
And this double the value of the device IMHO.

Spot on Tony!

[med6753]

Got the mini 212 pulled apart again. It appears that the issue is the wiring to the socket of the CRT. As you can see it's a tight mess in there. I can tap on the neck of the CRT and make the trace do some dancing. I had already touched up the soldering of the wiring going up to the A2 board prior but apparently that didn't help. So I have to pull the socket off the CRT and check the connections. With the scope pulled apart as shown it doesn't fail. But as soon as you cram everything back together it goes nuts.   

[beanflying]

Cheap playthings near Sydney 

eBay auction: #324848393872





eBay auction: #324848242577

[capt bullshot]

Just bought a 34401A 
and i already have an SDM3065X-SC   

i hope it arrives as good as on the pictures.

So this is your first proper DMM? 

[McBryce]

Spec just call it whatever you want.... I mean people call their modern fancy SUV a "car", even though it's a small truck. So calling a Sedan a Coupé is a minor adjustment in comparison...in my view.

Actually, most modern SUV's are cars, not trucks. A truck has a separated chassis with the cabin mounted on top, a car has the chassis integrated into the body. As most SUV's are cars that look like they are trucks, the industry came up with the word "cross-over" to describe them (and to confuse everyone with yet another new half defined term).

McBryce.

[dl6lr]

Here are a couple of pictures from the two manuals showing A17 Q9, seems to be mostly the same apart from R53, will double check against the parts list tomorrow night in case of an error, too late tonight, could we have a picture of the actual board fitted?


David

My manual says 4.7 for R53 too and this is populated to the board. I think 4700 is an error, with 4700 you will not drive Q9 to lower the voltage on the output pin and it will convert the circuit from a common mitter to a common collector. Even saturating Q9, which would require about -14V at the base would lower the output only by 1/10 of the voltage, giving a 1.5 volt output swing. But the input to C21 is only about 2.5 to 3V swing as the flipflop Q7/Q8 are feeded with -11V and -15V and the emitter resistor R44 with R41 does not allow for the full voltage swing.

Edit: Photo of board with Q9 removed

[beanflying]

Just bought a 34401A 
and i already have an SDM3065X-SC   

i hope it arrives as good as on the pictures.

And now for the Calibration gear to use the 34401A (after calibration) to go over the rest of you fleet  eBay auction: #194148400767 (100-150 euro max the seller is on drugs)

This UK seller is on another planet  eBay auction: #373067329336

[TERRA Operative]

On the repair front, I opened up my recently acquired HP 334A Distortion Analyzer.

Looks like it's due for a full recap... Some of the Vishay Sprague 30D caps are well on their way to turning themselves inside-out... 
I think I might just replace them with radial United Chemicons, the 30D's aren't anything particularly special, just a general purpose cap, and for the amount of caps I need for this unit, I'd be spending over $150 on 30D caps alone... Even low ESR KY(x) series United Chemicons are almost an order of magnitude cheaper and the technology is much newer too...

While I'm at it, I might replace all the nasty drifty and noisy carbon composite resistors with equivalent 50/100ppm 1% metal film types as I can get them cheap in Akihabara.

Besides that, it looks almost as clean inside as the day it was made.
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1306454

Not sure why those caps have failed in your 334A, looks quite a bit newer than my 333A, also appears most of the carbon comps are already carbon film in your 334A (except that one on the switch).
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1307201

David

Yeah, just a handful of carbon comps in my unit, mostly on the power supply board. I'll swap them all out along with the caps so I don't have to open it up again.

[TERRA Operative]

Got the mini 212 pulled apart again. It appears that the issue is the wiring to the socket of the CRT. As you can see it's a tight mess in there. I can tap on the neck of the CRT and make the trace do some dancing. I had already touched up the soldering of the wiring going up to the A2 board prior but apparently that didn't help. So I have to pull the socket off the CRT and check the connections. With the scope pulled apart as shown it doesn't fail. But as soon as you cram everything back together it goes nuts.   

]https://imageshack.com/i/pnqtzfONj]
]https://imageshack.com/i/pmoLxLlOj]
]https://imageshack.com/i/pmu2FwNQj]

If you want the reproduction rectifier service upgrade PCB I made, I got a bunch of blank PCB's so I can send you a couple for the cost of an envelope while you got it all open again.  

https://drive.google.com/drive/folders/1qnn2AJjWFjsUsR99L_xO5qoBmf0I_Z8V?usp=sharing

[Andrew_Debbie]

And now for the Calibration gear to use the 34401A (after calibration) to go over the rest of you fleet  eBay auction: #194148400767 (100-150 euro max the seller is on drugs)

This UK seller is on another planet  eBay auction: #373067329336

Deshalb nur Abholung oder Versand in Eigenregie des Käufers
solche Geräte sind derzeit für ca. 1400€ im Angebot, teilweise sogar defekt
Ich habe den Preis so angesetzt,

Seller claims broken ones sell for about 1400EUR.    We will see if anyone buys either one at the asking price.   Nicht ich. 

[beanflying]

Clearly the European options are 'bargains'  eBay auction: #192512640027 this seller has been snorting something on another planet....

Just because it is Fluke XXXx means  asking price to some. Working Fluke 51xx Calibrators are less than all of these.

[Andrew_Debbie]

But it was calibrated in 2011.   

[tggzzz]

Tek 2465 in Australia https://www.ebay.co.uk/itm/174993554003

If there were traces before the RIFAs finally fired, it might be worth an offer.

[Andrew_Debbie]

Today's Post brings wires from AliExpress and TTL from Silicon Ark.   


I only needed the SN74193N from Silicon Ark but they have a  £10 minimum order.    The up down range logic on the 5100 is intermittent.  Troubleshooting is going slowly.   Looking at the failure modes the '193 is highly suspect.    I hope it isn't the 74188A  PROM.    The PROM  maps the  range count to the relays and other things that change with range.

Dana supply a truth table, so there is some hope if the PROM is the issue.    I can still get unprogrammed ones.  I would need to build or find a programmer.

[Cubdriver]

Just bought a 34401A 
and i already have an SDM3065X-SC   

i hope it arrives as good as on the pictures.

And now for the Calibration gear to use the 34401A (after calibration) to go over the rest of you fleet  eBay auction: #194148400767 (100-150 euro max the seller is on drugs)

This UK seller is on another planet  eBay auction: #373067329336

The second guy must be building shipping into his price - that thing weighs something like 75 lbs/34kg - no way in hell its shipping ANYWHERE for under $50.  It’s definitely a boat anchor.

-Pat

[med6753]

Got the mini 212 pulled apart again. It appears that the issue is the wiring to the socket of the CRT. As you can see it's a tight mess in there. I can tap on the neck of the CRT and make the trace do some dancing. I had already touched up the soldering of the wiring going up to the A2 board prior but apparently that didn't help. So I have to pull the socket off the CRT and check the connections. With the scope pulled apart as shown it doesn't fail. But as soon as you cram everything back together it goes nuts.   

]https://imageshack.com/i/pnqtzfONj]
]https://imageshack.com/i/pmoLxLlOj]
]https://imageshack.com/i/pmu2FwNQj]

If you want the reproduction rectifier service upgrade PCB I made, I got a bunch of blank PCB's so I can send you a couple for the cost of an envelope while you got it all open again.  

https://drive.google.com/drive/folders/1qnn2AJjWFjsUsR99L_xO5qoBmf0I_Z8V?usp=sharing

I'll PM you.

[Specmaster]

I have the artek manual for the 5245L issued 1965. I have the service manual from BAMA or KO4BB for instruments serial prefix 628 as well.  I see no signs of these board revisions. The artek manual however includes six revisions of the A15/A16 boards. And they state the two high speed boards to be used, maybe the boards 5212L-4A are even slower than the 600kc of the 05232-6016?

When I received the counter (serial prefix 408, clearly marked as defective) the higher speed board however was populated at the upper most digit, so getting the lowest frequency But board and nixie are defective, so I think he swapped the boards to get a 7 digit counter but broke the high speed decimal counter. Will try to fix the board (more than one digit is lighting) which should be doable unless the photocoupler assembly is bad.
On wednesday I get another 5245L with serial prefix 504, let's see what's inside

Manual prefix 408 has: five of 5212L-4A (low frequency) fitted for A10 to A14, two of 5232L-4B (5MC) fitted for A15 & A16, 5245A-65C for A17 and 5245L-4B for A18. These numbers should be printed on the chassis next to the connectors.

OK, your 5245L has definitely had a replacement set of boards, they match what is fitted to my 1840A prefix 5245L, six of 05212-6016 fitted for A10 to A15, one of 05232-6010 fitted for A16 and it has 5245L-4B for A18, ignore A17 as it's a lot newer.


I have manual prefix 716 that covers 05212-6016 (600KC) and 05232-6010 (5MC), can take pictures of the diagrams if needed.

Manual prefix 408 has A17 (5245A-65C) Q9 & Q10 as 1850-0102 = 2N2455.
Manual prefix 716 has A17 (5245A-65C) Q9 as 1850-0158, but no ordinary part given, Q10 same as above (2N2455).

Note: there are minor component value differences on boards with the same part number, this will be most confusing if the manual doesn't cover the prefix of the unit, or if later boards have been fitted. 

Has your 5245L been serviced by hp in the past maybe? and they fitted the newer boards. Then years later someone attempted a repair, by incorrectly swapping boards.

David

Thanks for the offer with the manual schematics, if required I can order the newer artek manual and hope this will be covered. But I doubt I need it.
Tried to measure the pulse at the base of Q9 with a scope and failed, before the capacitor the levels are about 15V and 12.5V with sharp edges, clearly visible on the scope. Removed Q9 again and found no visible scope trigger after the RC. The differentiator is made of C21 with 82p and R52 510R, both measuring OK. This should be a high pass with about 3.8Mc giving short pulses. Maybe have to use a faster scope... I thought that should be OK with a silicon PNP at that stage. 2N2455 has high ft > 600Mc, the PNP I dropped in was a BC557 with about 200Mc, maybe too slow. Will try to change Q10 to a silicon for a test, if this works at that stage I will use the 2N2455 as Q9 for testing.
Just put those 15 pin board connectors in my DK basket, will produce extender boards for testing.

Edit: 1850-0158 is 2N2635 according to -hp- owns part list: http://hparchive.com/PARTS/HP-Parts-List-1973-74.pdf

Here are a couple of pictures from the two manuals showing A17 Q9, seems to be mostly the same apart from R53, will double check against the parts list tomorrow night in case of an error, too late tonight, could we have a picture of the actual board fitted?


David

David, R53 is the same, just that one has it in ohms, the other is shown in k's, 4700 ohms as opposed to 4.7k

[tonyalbus]

Oops i did it again 

Keithley 230 prog. voltage source.. 
now figure out how to pay for dinner for the rest of the mounth... its not that long   

[Specmaster]

Could somebody help me with this addiction? With all the ideas floating around in my head I see me falling into a rabbit hole that costs more and more money.

I think that the "help" that is on offer here may not be be in the best interests of your checking account balance.

This weekend I was hiking with the family and my phone pings. I check it and it's results from a saved search for "Fluke" on craigslist.org. Someone is selling a Fluke 77 with test leads for USD30 ( https://seattle.craigslist.org/est/ele/d/kirkland-fluke-77-multimeter/7398312523.html ). My wife recognized my expression and looked at the screen. "No way!" she said.

"What?" I asked with mock surprise "I'm just looking..."

"You are like a heroin addict looking at different flavors of heroin."

To which the correct diversion should have been "I wasn't aware that heroin came in different flavours, and I wonder how, dear wife, you are so knowledgeable on the subject. Is there something you need to tell me?". Remember, if you want to keep your TEA habit flourishing you occasional have to put SWMBO on the back foot. 

That is bad advice. Never engage a woman in direct back and forth of clever or witty remarks or putting them "on the back foot". Even if you win and achieve the high ground in the end you will lose. Women's egos do not allow them to be beaten at the games that they always play. They will extract revenge when you least expect it. It's part of their DNA. It's much better to let them have their say, acknowledge that they are always right, let their ego be stroked, and let it go. Or make them THINK that. Be more subtle in your activities and hopefully keep it under their radar. Just don't get caught or there will be hell to pay. Yes, this is hard to do when UPS, FedEx, Hermes, or whatever shows up everyday with packages.   

Just have the packages delivered to one of those drop off shops or a locker somewhere. Then you can slip the goodies in the house while she is out at the hairdressers or something 

[Specmaster]

Got the mini 212 pulled apart again. It appears that the issue is the wiring to the socket of the CRT. As you can see it's a tight mess in there. I can tap on the neck of the CRT and make the trace do some dancing. I had already touched up the soldering of the wiring going up to the A2 board prior but apparently that didn't help. So I have to pull the socket off the CRT and check the connections. With the scope pulled apart as shown it doesn't fail. But as soon as you cram everything back together it goes nuts.   

Is it possible that you have a broken wire and when you cram them all together in the case, it makes intermittent contact?

[mansaxel]

Just have the packages delivered to one of those drop off shops or a locker somewhere. Then you can slip the goodies in the house while she is out at the hairdressers or something 

You lot sound like you're all from some 1950's relation comedy. Wife and I have our own money, and when necessary things are paid for, the rest is play money. I don't ask her why, she does not ask me why. I knew the median age is somewhat elevated, but this is ridicolous.

[med6753]

Just have the packages delivered to one of those drop off shops or a locker somewhere. Then you can slip the goodies in the house while she is out at the hairdressers or something 

Exactly. And if your lab is in the cellar, or garage, or attic, or somewhere out of view at her insistence (and probably somewhere she never goes) then she will never know and you're golden.   

I'm so glad I don't have those issues. 

[Specmaster]

Clearly the European options are 'bargains'  eBay auction: #192512640027 this seller has been snorting something on another planet....

Just because it is Fluke XXXx means  asking price to some. Working Fluke 51xx Calibrators are less than all of these.

Well maybe its sort of well, er, our fault because we all go on about how the Flukes are like the holy grail don't we 

[Specmaster]

Just have the packages delivered to one of those drop off shops or a locker somewhere. Then you can slip the goodies in the house while she is out at the hairdressers or something 

You lot sound like you're all from some 1950's relation comedy. Wife and I have our own money, and when necessary things are paid for, the rest is play money. I don't ask her why, she does not ask me why. I knew the median age is somewhat elevated, but this is ridicolous.

Sounds like your wife is a keeper for sure, you struck gold there for sure.

[med6753]

Just have the packages delivered to one of those drop off shops or a locker somewhere. Then you can slip the goodies in the house while she is out at the hairdressers or something 

You lot sound like you're all from some 1950's relation comedy. Wife and I have our own money, and when necessary things are paid for, the rest is play money. I don't ask her why, she does not ask me why. I knew the median age is somewhat elevated, but this is ridicolous.

Sounds like your wife is a keeper for sure, you struck gold there for sure.

I don't have those issues in my current relationship but I certainly have in the past. Her place. My place. Her money. My money. And as you know my "lab" is not hidden away in some dark corner. As soon as you walk in the front door it's in your face. But being that she's a cop she's very astute to changes. She always notices something new. And she teases me about it. But that's the extent of it.