Test Equipment Anonymous (TEA) group therapy thread

[beanflying]

Five overpriced BWD Mini Labs in the UK...

That's what they call "mini"?

 

3+ Decades ago they were in widespread use in Tech Schools and some Uni's locally. Common as muck and by todays (and even back then) a very average Spec. Reason to buy one is a stack of us have used them way back when  As to 'worth' $100 max just for nostalgia.

[med6753]

Little puzzle for you amp nuts
Shed stereo Sony STR-DE-485 after a couple hours starts randomly rattling relays yet with no ill effect on the output. 

Now it's autumn occasionally it goes into Protect mode however after some 20 mins ON and after a power cycle works perfectly fine...until next time. As the thing is top vented I guess there will be a good layer of crud and dust on the PCB so I reckon just some TLC will sort the Protect mode but whaddabout the rattling relay ?

Remember that's the exact same unit I worked on for my brother almost 2 years ago which also had an intermittent protect mode. Never did track down the exact cause. I pulled the main board out and resoldered the output transistors plus any suspicious looking joints, especially in the PSU area. Ran it for several days with no fails. Returned it to my brother and last I heard it was working fine.

No I didn't but a jog of the memory cells rings a bell. Thanks.
But strange that the random rattling relay has no ill effect on sound or the display...zip, nuthing, nada !

Here it is....

[xrunner]

Five overpriced BWD Mini Labs in the UK...

That's what they call "mini"?

 

3+ Decades ago they were in widespread use in Tech Schools and some Uni's locally. Common as muck and by todays (and even back then) a very average Spec. Reason to buy one is a stack of us have used them way back when  As to 'worth' $100 max just for nostalgia.

Oh yea I'm just kidding. It's a cool little TEA item.

There I go using words that describe small things. 

[xrunner]

Here it is....

Darth Vader's stereo amp? 

[SilverSolder]

Here it is....

Darth Vader's stereo amp? 

I like the design - someone spent  lot of time on that! 

[factory]

An example of the opposite of the packaging we see all to often from sellers of gear on the bay (and, for that matter, all too often from Amazon, too).  I went to weld the broken end of my friend's lawn mower handlebar yesterday and discovered that the battery in my auto darkening helmet had moved on to the big charger in the sky.  It's a lithium coin cell, so for starters I looked on Amazon to see if it would be easier to order it than to make a special trip to the store to get one.  Found it there; for $3.46 shipped next day to my door it was a no brainer.  It'd be almost that in gas to go to and from the store to buy one.  It arrived this morning.  In a 6 x 9 x 5" box (~155 x 225 x 125mm for you metric types), cushioned with 8 air pillows.



Perhaps it needed to be packaged that way due to shipping regs (it sports a UN3090 battery warning sticker on the side), but I was quite surprised and expected it to show up in a padded envelope.  Less than $3.50 packed like that and delivered next day HAS to be a loss leader for them!

-Pat

I find that packaging method from Amazon Amascum offensive too, people then think these crappy air pockets are suitable for packing delicate and/or heavy items with sharp corners. Then you get items damaged like this once good condition hp 809B after all the pockets pop and the item is rattling around for the rest of the journey. 


David

[bd139]

Oof that hurts to look at.

Got to say that the only problem I’ve had with packing quality and amazon was the idiot trying to stuff something through the letter box that won’t fit. Can’t remember what it was but they delivered a replacement the next day  .

Just had to return that Mac mini to them after video ram failure. After 5 months got full refund no questions asked. Can’t beat that. Credit card in positive balance now though 

[med6753]

Oof that hurts to look at.

Got to say that the only problem I’ve had with packing quality and amazon was the idiot trying to stuff something through the letter box that won’t fit. Can’t remember what it was but they delivered a replacement the next day  .

Just had to return that Mac mini to them after video ram failure. After 5 months got full refund no questions asked. Can’t beat that. Credit card in positive balance now though 

Positive experience with the one time I had to return something to Amazon. A scarf bought for the Lady Cop. She wasn't thrilled with it so I contacted Amazon to return. They said keep it and full refund.

And positive proof women are fickle. Later on she decided it wasn't so bad after all and started using it. 

[Bad_Driver]

Little puzzle for you amp nuts
Shed stereo Sony STR-DE-485 after a couple hours starts randomly rattling relays yet with no ill effect on the output. 

Now it's autumn occasionally it goes into Protect mode however after some 20 mins ON and after a power cycle works perfectly fine...until next time. As the thing is top vented I guess there will be a good layer of crud and dust on the PCB so I reckon just some TLC will sort the Protect mode but whaddabout the rattling relay ?

I have a STR DB 925, 930, 940 running for about 20 years now in my house.
The 925 suffered in the beginning from a over heating 15 V LDO since the heat sink was to small.
And this was the reason for very strange behavior like yours.

The 930 has blown the fuses with a big bang after 15 years since there was a short between one of the Sanken transistors
and the big heat sink. The isolation layer between transistor and heat sink seem to got porous so I renewed all.
The 940 runs without any problems every day now with my home cinema system - 5 channels is enough for me.

All receivers from this good old time before they start with D-class power amps seem to be very reliable.

[factory]

Oof that hurts to look at.

Got to say that the only problem I’ve had with packing quality and amazon was the idiot trying to stuff something through the letter box that won’t fit. Can’t remember what it was but they delivered a replacement the next day  .

Just had to return that Mac mini to them after video ram failure. After 5 months got full refund no questions asked. Can’t beat that. Credit card in positive balance now though 

Trouble is that so many people think their packaging methods are acceptable for sending out heavy/delicate stuff and when you forget to remind that one ePay seller you end up with trashed items. Quite frankly it's about time they started printing proper packaging instructions on the boxes for when 1D10T users re-use their boxes.

I've got some pictures somewhere of a small 1920's dynamo that was sent in a John Lewis kettle box almost the same size as the item, it arrived totally destroyed as the cast alloy parts were broken/smashed, even had the makers name pressed into the thin foam from when it got dropped on the way. 

David

[med6753]

Little puzzle for you amp nuts
Shed stereo Sony STR-DE-485 after a couple hours starts randomly rattling relays yet with no ill effect on the output. 

Now it's autumn occasionally it goes into Protect mode however after some 20 mins ON and after a power cycle works perfectly fine...until next time. As the thing is top vented I guess there will be a good layer of crud and dust on the PCB so I reckon just some TLC will sort the Protect mode but whaddabout the rattling relay ?

I have a STR DB 925, 930, 940 running for about 20 years now in my house.
The 925 suffered in the beginning from a over heating 15 V LDO since the heat sink was to small.
And this was the reason for very strange behavior like yours.

The 930 has blown the fuses with a big bang after 15 years since there was a short between one of the Sanken transistors
and the big heat sink. The isolation layer between transistor and heat sink seem to got porous so I renewed all.
The 940 runs without any problems every day now with my home cinema system - 5 channels is enough for me.

All receivers from this good old time before they start with D-class power amps seem to be very reliable.

Well, I was not impressed with the quality of construction of that receiver compared to what Sony used to produce. The chassis didn't have a bottom plate so I could access the solder side of the main board. So I had to pull the entire unit apart. But they are not alone. Many other brands have gone the same cheap route.

[Robert763]

Little puzzle for you amp nuts
Shed stereo Sony STR-DE-485 after a couple hours starts randomly rattling relays yet with no ill effect on the output. 

Now it's autumn occasionally it goes into Protect mode however after some 20 mins ON and after a power cycle works perfectly fine...until next time. As the thing is top vented I guess there will be a good layer of crud and dust on the PCB so I reckon just some TLC will sort the Protect mode but whaddabout the rattling relay ?

Remember that's the exact same unit I worked on for my brother almost 2 years ago which also had an intermittent protect mode. Never did track down the exact cause. I pulled the main board out and resoldered the output transistors plus any suspicious looking joints, especially in the PSU area. Ran it for several days with no fails. Returned it to my brother and last I heard it was working fine.

No I didn't but a jog of the memory cells rings a bell. Thanks.
But strange that the random rattling relay has no ill effect on sound or the display...zip, nuthing, nada !

The relay is probably part of the AV input switching. With the tuner selected (electronic switching) the relays won't affect the sound.

[Bad_Driver]

Little puzzle for you amp nuts
Shed stereo Sony STR-DE-485 after a couple hours starts randomly rattling relays yet with no ill effect on the output. 

Now it's autumn occasionally it goes into Protect mode however after some 20 mins ON and after a power cycle works perfectly fine...until next time. As the thing is top vented I guess there will be a good layer of crud and dust on the PCB so I reckon just some TLC will sort the Protect mode but whaddabout the rattling relay ?

I have a STR DB 925, 930, 940 running for about 20 years now in my house.
The 925 suffered in the beginning from a over heating 15 V LDO since the heat sink was to small.
And this was the reason for very strange behavior like yours.

The 930 has blown the fuses with a big bang after 15 years since there was a short between one of the Sanken transistors
and the big heat sink. The isolation layer between transistor and heat sink seem to got porous so I renewed all.
The 940 runs without any problems every day now with my home cinema system - 5 channels is enough for me.

All receivers from this good old time before they start with D-class power amps seem to be very reliable.

Well, I was not impressed with the quality of construction of that receiver compared to what Sony used to produce. The chassis didn't have a bottom plate so I could access the solder side of the main board. So I had to pull the entire unit apart. But they are not alone. Many other brands have gone the same cheap route.

It depends from the model, the devices I have were in this old years the highest models in the QS class.
Tautechs one was lower priced.

[factory]

Anybody in need of a 1N829A?
I've bought a lot of two diodes from this seller (NAWTS) and they are looking genuine.

https://www.ebay.com/itm/252700801494

Cheaper to buy new ones here 

https://uk.farnell.com/american-power-devices/1n829a/diode-zener-two-terminal-6-2v/dp/1651543

Yes, but when you are located in Germany, one cannot by at Farnell as a private person.
Mouser has them as well: https://www.mouser.de/_/?Keyword=1N829A&bws=1 but for some nostalgic and silly reasons I wanted the ones from Motorola. 
Yeah, perhaps not my smartest buy.   

Unless you find some cheap and have time to test them & reject them if they are not as described, I would only buy those temperature compensated reference zeners from a known reliable source.
We had some 1N827 bought from a grey market supplier at work, a thermal test proved they weren't any good and cleaning off the markings revealed something like C6V2, a regular spec cheap zener.  In the bin they went as work never seemed interested in sending crap back.

David

[bd139]

Oof that hurts to look at.

Got to say that the only problem I’ve had with packing quality and amazon was the idiot trying to stuff something through the letter box that won’t fit. Can’t remember what it was but they delivered a replacement the next day  .

Just had to return that Mac mini to them after video ram failure. After 5 months got full refund no questions asked. Can’t beat that. Credit card in positive balance now though 

Trouble is that so many people think their packaging methods are acceptable for sending out heavy/delicate stuff and when you forget to remind that one ePay seller you end up with trashed items. Quite frankly it's about time they started printing proper packaging instructions on the boxes for when 1D10T users re-use their boxes.

I've got some pictures somewhere of a small 1920's dynamo that was sent in a John Lewis kettle box almost the same size as the item, it arrived totally destroyed as the cast alloy parts were broken/smashed, even had the makers name pressed into the thin foam from when it got dropped on the way. 

David

Yes there’s an art to it.

My father ran an import/export business for two decades and taught me how to package stuff properly. I’ve never had a single outgoing item damaged by any carrier. Lost or stolen yes but not damaged.   

[BU508A]

Five overpriced BWD Mini Labs in the UK...

That's what they call "mini"?

 

Yes.
Because this is "maxi"   

[xrunner]

Yes.
Because this is "maxi"   

Yea I've seen his work area. I always envisioned the whole shebang collapsing and imagining the rescue team cutting through all the thousands of pounds of equipment to find a squashed Mr. Carlson. 

[mansaxel]

Because this is "maxi"   

And I immediately spot the 428B. Because that is my favourite instrument.

[factory]

Snagged this Telemeter LCR Databridge 6401 beast as consolation price, I was hoping for the HP from zhoffler, but it went for crazy money  .
The UK fellas, do you know anything about it, any service manual ?

Cheers,
DC1Mc

Used the AIM version of that one at work a lot, we never had any problems with it.
Now have two of the Racal 9343M versions from a member on the UK vintage radio forum, I believe he acquired them from the Ramco auctions a few years ago, they seem to have sold a fair amount recently too.


David

I've seen that the HW is different, 5 digits instead of 4, most likely the insides are different as well, so no (easy) 10KHz for me  , but if you sometimes open one of them and make some nice detailed PCB pictures it will be great, also if you can read the EEPROMS it will be better, and perfect if you want to part of, or exchange one against his lower spec brother, you know, diversity is our strength .

 Cheers,
 DC1MC

I've never seen inside of one of these LCR bridges until now, the AIM 401 at work never had any problems & had cal seals so we had no good reason to be opening it up.  No longer have access to the stuff at work so would be interested in seeing a teardown of the 6401 version.

Insides of the 9343M (same as 451, 6451?) are quite different when compared with the service manual for the 9341 (same as 401, 6401 ?), also their seems to be a lack of service information for the 9343M versions.

Some teardown pictures from the one that is in use (other is in storage), the board is labelled as made by AIM & the EPROM has 6451 (the OEM model?) written on it and no I don't have anything here for reading programmed IC's.


Top half of the main board and nearby the Z80 one of the radial Philips caps has been replaced with an axial version.


PSU section with toroid transformer and linear regulators.


Lower half of the main board with four-connection test plates and most of the analog circuitry.


Trio of reference grade resistors.


The digital comms board in the sloping base section.


The only part that needed adjustment, this glued on piece had slid down slightly over the years, now moved back to where it should be.


Edit: the forgotten display board. 

Even this has a couple of a extra spaces for LED's, must be another variant that uses those.



The back of the board gives no doubt that the OEM for these LCR data-bridges is AIM.


Probably need to sell the one in storage, as I have quite a few more LCR meters here, including the Wayne Kerr B900 that arrived recently.

David

[tggzzz]

I bought a Tek 465 replacement CRT from a fleabay vendor. I picked up in person and he let me have my first Tek 485 for £50. He was completely open about its fault, which was a pig to diagnose since I could only do two tests in 24 hours

He had a shack like that, only about 3 times the depth and full of Tek/HP equipment. Plus a farm outbuilding with less well maintained kit.

[AVGresponding]

Yes PSU ripple had crossed my mind however the main amp PSU seems to be working fine as it's still driving the 5 speakers without hum or noticeable distortion and able to blast us out of a 4 car garage when Pink Floyd get played and you crank it right up ! 

So check how the lower voltage auxiliary supplies are generated. Might be a separate winding (with failed bridge rectifier) or some nasty dropper resistors from main amp voltage causing local hot spots on the PCB and nearby components failing ...

Yep all simple stuff you would normally spot with a little experience....spose I should go looking for a SM....oh hang on I've already got one on my Manual folder ! 

If it's a single sided board, check for broken solder joints. Mechanical or thermal stress makes them unreliable.

This was my first thought also.

Little puzzle for you amp nuts
Shed stereo Sony STR-DE-485 after a couple hours starts randomly rattling relays yet with no ill effect on the output. 

Now it's autumn occasionally it goes into Protect mode however after some 20 mins ON and after a power cycle works perfectly fine...until next time. As the thing is top vented I guess there will be a good layer of crud and dust on the PCB so I reckon just some TLC will sort the Protect mode but whaddabout the rattling relay ?

Remember that's the exact same unit I worked on for my brother almost 2 years ago which also had an intermittent protect mode. Never did track down the exact cause. I pulled the main board out and resoldered the output transistors plus any suspicious looking joints, especially in the PSU area. Ran it for several days with no fails. Returned it to my brother and last I heard it was working fine.

No I didn't but a jog of the memory cells rings a bell. Thanks.
But strange that the random rattling relay has no ill effect on sound or the display...zip, nuthing, nada !

The relay is probably part of the AV input switching. With the tuner selected (electronic switching) the relays won't affect the sound.

Also my first thought... beaten to the punch once again due to having to work overtime. At least it means I can continue to afford to feed my habit...



If anyone was bidding on the Fluke 8300A with the mV/Ohms converter option, #sorrynotsorry.

At least it arrived well packed, and bloody quickly too, less than 48 hours after the hammer fell. Initial impressions are it's quite clean. Then I looked at the back, and uh-oh... this isn't factory, surely...


What the... oh, and there's no continuity from the earth pin to the case. Given the gauge of the wire, any earth fault would likely see it behave like a fuse.   
Turns out it's only connected to the trafo shield and not earth. Can't call them a gorilla, as from what I understand, those animals are quite intelligent. I've made a temporary repair with a bit of 2.5mm² green/yellow equipment wire, soldered to places you should really use crimp terminals. At least it's safe now.

Readings are not too bad. Interestingly it agrees exactly with the 289 if you use the 1V range, looks like the mV converter needs tweaking, and the neon range indicator isn't working. It's closer on the main meter ranges generally. Ohms is ok, though the last digit wouldn't settle, maybe my setup is too noisy.


Looks like overload on ohms is indicated by a max reading?




Here are a few pics of the damage to the PM 5193. The use of the Philips monitor box to ship it would be amusing if it weren't so ridiculously undersized. Only the industrial nature of its construction saved it from serious damage. Even the front fascia is metal, none of that usual Philips disintegrating plastic rubbish.

[factory]

Poms are very quiet...where are they all.....lockdown finished and they're all down at the pub ! 

Now back at work and after a week or two I'm now back to being too tried in the evenings to do much (fatigue I get with my poor health), it sucks I can't view the forum at work till I choose a cheap data SIM for my phone, it's supposed to have a second SIM slot. Think that may be the best option and just chuck the second SIM & choose another if & when better deals are available.

Still got a lot of catching up to do.

David

[SilverSolder]

Poms are very quiet...where are they all.....lockdown finished and they're all down at the pub ! 

Now back at work and after a week or two I'm now back to being too tried in the evenings to do much (fatigue I get with my poor health), it sucks I can't view the forum at work till I choose a cheap data SIM for my phone, it's supposed to have a second SIM slot. Think that may be the best option and just chuck the second SIM & choose another if & when better deals are available.

Still got a lot of catching up to do.

David

I bring my own laptop to work,  and use my phone as a wifi hotspot to connect it to the Internet,  if I need a fix! 

[AVGresponding]

Am currently trying to decide whether or not to bid on some Weston cells. They are from a so-far reliable vendor, which also happens to be a calibration lab, and appear to be sans-thermometers, so no worries about the mercury in those, but there are still some pretty nasty chemicals in there, and then there's the distinct possibility they won't like being shipped, even if they aren't EOL which is the obvious reason for selling them...

[factory]

Forgot to post this last week, job lot of vintage boat sinker grade TEA (in the US) including; a hp 738BR, 200SR, 739AR voltmeter calibration set (and yes hp did offer these three together in a rack as K02-738BR, first one I've seen for sale), Genrad capacitor measuring rack, Fluke 760A meter calibrator and another rack of cal standards? from Optimation Inc that I don't recognise.
https://www.ebay.com/itm/353436335733



David

We used an Optimation like that one at Wavetek about 1970 to do AC calibration on their differential voltmeters. Didn't depend on to for a calibrated output voltage but measured with a Holt thermal converter for accuracy. Don't know where you would find the oversized banana plugs for the HV output these days.

Did you not mean a high current output?  Those connectors were also used on the high current section of the Rotek calibrator at work and on some Fluke/Ballantine transconductance amplifiers, I'm sure they would be something still available, but probably not cheap.

David