Test Equipment Anonymous (TEA) group therapy thread

[Vince]

Micropross ROM 3000U vintage programmer


NEW EPISODE has just been published !!!  - - - - - > > >


https://www.eevblog.com/forum/repair/vintage-chip-programmer-micropross-rom-3000u/msg4623943/#msg4623943

[minifloat]

And now for something TEA related - fresh from the "Fun with TEA" dept. (in this case, rather the fun with TEC dept.):

That Toellner 7741 audio sign gen looks all the world like an old Philips product.. was it a rebranded Philips then ?! 

No, it isn't. Afaik, Toellner doesn't do brand labeling. If you open one of their devices, you'll always recognize their "style" of mounting the circuit boards into the casing.

That makes it even more odd then... why would they copy the Philips look if that's their own design... I mean I had a quick Google and their products aren't Philips looking... even that 7741. Your particular 7741 is the only they made look like a Philips, how odd !!    Maybe a special order, a prototype... you stumbled upon an extremely rare piece !

Their design changed over time, there's some other function generators that have the same design as mine. You'll find older ones looking different.
The 7741 is a not so common one, indeed. It has a power amplifier built in, and can deliver 63W (iirc) of output power (at 45V peak-to-peak) into the load. Hence the rather low upper frequency.

Hey there, found out Siemens is relabeling Toellner stuff
see https://www.rosenkranz-elektronik.com/de/messgeraete/262320/siemens-7kd2013-8ab
and pic attached
br, mf

[Vince]

ROCHAR A.1466 Niksee DMM



@FACTORY : didn't post about it because I am deep into that vintage EPROM programmer at the moment, but... the guy at Electropuce did send me the manuals.

Original ones as promised, so I got my money's worth.. 50 Euros all in, yeah a bit over x2.5 times what I paid for the meter shipped. But I just love old original manuals.

So the one for the main frame  is thick and complete with a giant single sheet foldout for the schematic, parts list, and theory of operation.
The manual for the plugin however does not have much in int. No schematics but the guy already told me that so no surprise.
It still contains  interesting stuff, all the specs for all ranges, so we know what kind of accuracy we are getting out of this meter.

So if you need something to help you work on your meter, it's there... all in French of course, but I can translate if need be.

[Robert763]

Another PicoScope incoming  Had an offer accepted on ebay for an old ADC212.
www.ebay.co.uk/itm/115665968267
This is a parallel port only 3Ms/s unit so why buy it? Well three reasons
It is 12 bit so good for low frequency FFT spectrum analysis with 80dB dynamic range.
It comes with the unobtainum USB to parallel converter (the parallel ports on Pico products don't work with typical USB to parallel).
It works with the hardware locked automotive software so is a low cost entry into that.

And of course it's TE and I like Picotech kit.

[Swainster]

Time for another Chinese power supply teardown.
This is a 24V 1A power supply. Unlike the other one, this one doesn't have a fan (since it's low power), and it also has no SMD components. One of the displays was not working, and I traced it to a Chinese electrolytic capacitor which had failed short, pulling down the -5V rail. The power supply has a 5V 2A output, and it is achieved by putting 2 voltage regulators in parallel, which is pretty bad design. The capacitor that failed has a red arrow pointing to it on one of the pictures.

Sounds like a satifying repair! I'd just like to point out that Tenma is the house brand of Premier Farnell (i.e. Farnell/Element14/Newark), now part of Avnet, so while this is a rebranded Chinese power supply, you'd have thought that it would be a somewhat reliable and safe one. Those 2 7805s bolted on the base plate, though... nasty. That said, the datasheet shows that the output voltage drops with temperature so maybe they will reach some kind of equilibrium. Hmmm, I feel an experiment coming on...

Edit: After looking at the datasheet a bit more, I think the only way for 2 7805s to work in parallel would be if they were selected. This seems unlikely to be the case so I guess it's just an extremely dodgy design.

[Ice-Tea]

Another PicoScope incoming  Had an offer accepted on ebay for an old ADC212.
www.ebay.co.uk/itm/115665968267
This is a parallel port only 3Ms/s unit so why buy it? Well three reasons
It is 12 bit so good for low frequency FFT spectrum analysis with 80dB dynamic range.
It comes with the unobtainum USB to parallel converter (the parallel ports on Pico products don't work with typical USB to parallel).
It works with the hardware locked automotive software so is a low cost entry into that.

And of course it's TE and I like Picotech kit.

Want some ADC-11's?

**Goes back to cursing the steaming turd that is everything related to USB power delivery in its 6685243 incarnations.**

[Robert763]

No thanks on the ADC11's. One is enough (ooh I just came over all funny)

[Ice-Tea]

I hate those "oeeehhh, no we're classics, no Windooz 10/11 for us" paperweights.

[Specmaster]

Dam and blast, my 40" 2015 vintage 4K smart Samsung TV today has developed 2 blue areas of the screen, top right and top left areas. Currently, its only really noticeable when the background is something like a pale sky. On normal backgrounds it is not normally noticeable, however it is not going to get better without some intervention, for which I don't have the space to do.

I can currently get a Samsung 2022 model for just £399 which has a reasonable specification https://www.samsung.com/uk/tvs/uhd-4k-tv/bu8500-43-inch-crystal-uhd-4k-smart-tv-ue43bu8500kxxu/ and comes with a 6-year warranty. I have never until today had any issues with Samsung TV's, on the other hand I also have a pair of LG monitors which are at least 8-years old and still going strong, but it seems that their TV's only come with a 12-month warranty. Decisions, decisions, what are recommendations, which makes have you all had experiences with?

[Vince]

It's simple Spec. You said you favoured function and bang for buck and only bought things you actually, strictly needed.

So from what you said about your TV, it works plenty fine enough to be used, so just wait until the picture gets so bad that you can't tell if the TV is off or on.

This will save you 400 quid. I thought the Brits had skyrocketing heating bills this winter.... keep your 400 quid to warm your butt this winter.. if you get sick because it's cold and humid in your house, the blue spots in your TV will be the least of your worries.

I have not had a TV since 1997 and I am all the better for it. TEA and a select few YT channels aka the modern TV, is plenty enough to keep me entertained...that plus the lab of course.

I just saved you 400 quid, no need to thank me., I just like to help....

[med6753]

Heathkit IG-18 Audio Generator from local CL. Needed work to get it running properly.



Detail:

https://teanonymous.com/f1/viewtopic.php?t=50

From my prior post. Installed a THD Improvement Kit in the IG-18.

https://teanonymous.com/f1/viewtopic.php?t=88

[TERRA Operative]

If you do buy a new TV, don't buy a Samsung smart TV if you value your privacy.

They are hands-down the worst brand for data mining and advertising.
Even if you don't connect them to your local network, they actively seek out unsecured wireless networks and connect to upload as much data as they possibly can.
If you must get a Samsung and it must be online, then just don't...
Or at least put it behind a pi-hole with a decent router (like an Asus running Merlin WRT firmware) and setup some good strong DNS redirection back to the pi-hole so the Samsung won't try to sneak around the restrictions, which it will try to do.

Better to go get an LG or Toshiba (what I have) or a cinder block, hole in the head, kick in the pants, or anything except a Samsung smart TV!......

[Messtechniker]

In the case of such data blabbers I usually specify as a first measure
for these a fixed IP address and a wrong route to the internet.
i.e. a wrong gateway address. This stops these buggers from
automatically searching the gateway when initially failing to find
a functioning gateway (DHCP).

[Brumby]

If you do buy a new TV, don't buy a Samsung smart TV if you value your privacy.

They are hands-down the worst brand for data mining and advertising.
Even if you don't connect them to your local network, they actively seek out unsecured wireless networks and connect to upload as much data as they possibly can.
If you must get a Samsung and it must be online, then just don't...
Or at least put it behind a pi-hole with a decent router (like an Asus running Merlin WRT firmware) and setup some good strong DNS redirection back to the pi-hole so the Samsung won't try to sneak around the restrictions, which it will try to do.

Better to go get an LG or Toshiba (what I have) or a cinder block, hole in the head, kick in the pants, or anything except a Samsung smart TV!......

I'll have to agree with the privacy comments here....

I had a friend purchase a new Samsung TV and they asked me to help set it up.  In going through the process, I actually scrolled through the mass of T&C's presented on screen and it's all spelled out.   

One excerpt that caught my eye is that the TV "may" take snippets of video and send them back to the mother ship so they can work out what you are watching.  Forget what station you're tuned to or what media file you're playing - it runs of the video data!   

Talk about Big Brother.   

[tggzzz]

I have a Samsung smart TV.

There's a firewall between it and everything else in my house.

I haven't set up a Samsung account. I can't delete channels (shopping, religion etc) from the programme guide. Well, I can - but they reappear after the TV is off then on again. I wonder where the channel preferences are being stored

[TERRA Operative]

Samsung hardware is top claas stuff.

Samsung software is total gutter trash.

All my smart phones have been Samsung, but they have run custom ROM's or seriously neutered stock firmware.
I use ADB Shell to excise the bullshit like cancer.
I'm currently using a Samsung Galaxy Note 20 Ultra that I love, but only after removing a heap of crap amd using Netguard to block the rest. (Netguard, the github version with adblocking, is awesome, if you value privacy you should use it!)
Check my youtube video history for a video on removing the bloat shittery. (Link to my channel in my signature below)

Once you fix the software, Samsung have some good stuff. Too bad they have to ruin it with blatantly privacy infringing crap software.

[Zucca]

My next phone will be used and chosen by the FW supported. I do not want the stock Android anymore.

PS: Do you want/need a cheap LAN MSO scope?
https://www.eevblog.com/forum/buysellwanted/fs-(usplanet-earth)-bitscope-bs44501-mixed-signal-lan-scope-4ch-8-logic/

I added the buy link so my post will not be flagged as not related to electronics.

[Specmaster]

It's simple Spec. You said you favoured function and bang for buck and only bought things you actually, strictly needed.

So from what you said about your TV, it works plenty fine enough to be used, so just wait until the picture gets so bad that you can't tell if the TV is off or on.

This will save you 400 quid. I thought the Brits had skyrocketing heating bills this winter.... keep your 400 quid to warm your butt this winter.. if you get sick because it's cold and humid in your house, the blue spots in your TV will be the least of your worries.

I have not had a TV since 1997 and I am all the better for it. TEA and a select few YT channels aka the modern TV, is plenty enough to keep me entertained...that plus the lab of course.

I just saved you 400 quid, no need to thank me., I just like to help....

When you have others to consider, such as SWMBO and sons also living at home, this get far more complicated than when you're on your own and besides that, not caring a rats arse about TV. If SWMBO can't watch her soaps, life would be intolerable in the Specmaster house, same thing would be the result if football and Formula One is not available to watch as well  .

I have discovered that this purplish tingeing is something that is well known to Samsung and even on their user forums, people are bitching about the problem and Samsung refuse to acknowledge that there is a problem. Once its out of warranty, you're on your own as far as they are concerned. It only seems to happen to the ultra 4K screen although I can't help but wonder if this blight also happens on their 8K screens 

From the research, it seems that the top two brands, which also are bitter rivals are Samsung and LG and it seems that LG are that little bit less expensive, but use the more modern 4 core processor and is also less bloated, some sellers are offering a 55" for just under £300 which seems to be ideal spec wise with 60HZ refresh rate so can handle movement like footballs better than a set with a 50HZ refresh rate.

It also seems to be almost similar costs to replace a panel as that for a brand-new Samsung TV.

[Vince]

Something I don't understand... if you people prevent the "smart" TV from accessing the network / internet... doesn't that keep it from using any of its smart features ?
So it turns it into a "dumb" TV ? So why not buy a dumb TV from the get go and not have to mess around with it ? For marketing reasons I guess a dumb TV would be priced cheaper than a smart one, so you save both money, and hassle. No ?

Or is it that all TV's these days are Smart so there is no way out ? So why do they even bother labeling them "smart" any longer...

Or is it that there are dumb TV's out there but they are marketed to the cheaper end of the market and only available with small and low quality screens ? So if you want a large screen of the best quality possible, you have no choice but make do with a Smart model ?

I have no intention to buy a TV but still interested in keeping in touch with the world none the less, if just so I can laugh / cry at how worse it gets year after year....

Thanks in advance for enlightening me....

[Specmaster]

I don't know for certain, Vince, but I can't help but think that you have answered your own question here, I really don't think that it is possible these days to buy a new TV which is not a smart TV. I remember when you could choose to have either a standard TV or a HD ready TV, then it was HD ready or HD, then it progressed to HD or 4K, also there was of course curved and 3D ones, which now seem to have bitten the bullet.

Now it all seems to be mainly 4K or 8K and, of course, smart ones at that, and all the time, the price is escalating, I just saw a LG 88" 8K tv wait for it...£19,999

https://www.currys.co.uk/products/lg-oled88zx9la-88-smart-8k-hdr-oled-tv-with-google-assistant-and-amazon-alexa-10207545.html

[Vince]

20K for a TV wow... my brain can't even compute the rationale behind that...

[Specmaster]

You're not the only one either, that is stupid money in my book, but of course there are always the elites of this world, the super rich who have so much money that those kinds of prices become change to them 

[TERRA Operative]

Something I don't understand... if you people prevent the "smart" TV from accessing the network / internet... doesn't that keep it from using any of its smart features ?
So it turns it into a "dumb" TV ? So why not buy a dumb TV from the get go and not have to mess around with it ? For marketing reasons I guess a dumb TV would be priced cheaper than a smart one, so you save both money, and hassle. No ?

Or is it that all TV's these days are Smart so there is no way out ? So why do they even bother labeling them "smart" any longer...

Or is it that there are dumb TV's out there but they are marketed to the cheaper end of the market and only available with small and low quality screens ? So if you want a large screen of the best quality possible, you have no choice but make do with a Smart model ?

I have no intention to buy a TV but still interested in keeping in touch with the world none the less, if just so I can laugh / cry at how worse it gets year after year....

Thanks in advance for enlightening me....

Two reasons. Smart TV's are commonly cheaper than dumb TV's, as you are subsidising the purchase cost with your personal data.... And manufacturers will deliberately price smart TV's lower to entice people to buy them so the manufacturer can secure that continuous income stream by selling the data.

And more to this point, it's getting harder and harder to find a flagship dumb TV in the stores too. Consumers want the shiny thing with lots of buttons, so there is that consumer pressure too.

Basically, most people don't even consider, let alone care about, privacy issues when purchasing a TV. Most people just look at the pixel count, panel type and size, and price tag. Not much more thought goes into it beyond that and the manufacturers know it so they capitalise on it.


As for the TE side of things here, I got the Yokogawa 2558 AC volt/current calibrator on the bench. Digikey order arrived so I replaced all the trimpots with multi-turn types to enable me to really get this thing dialled in and accurate.
I also tore it down and thoroughly cleaned it out of dust and stuff. It's looking quite nice now. I just have to reapply some white lines on a few knobs and the front panel is almost perfect. Pics to come.

I also found a 74F74 TTL chip in the B-trigger circuit in my 2235 Tek scope is a bit flakey. Doesn't work properly until it warms up, so I went to my usual chip shop in Akihabara but they are out of stock, so off to Yahoo Auctions to get some.
Luckily the B-trigger is seldom used, only really for the function, so it doesn't impact the normal use of the scope at all. It'll be repaired anyway and that will finally have me a fully calibrated and perfectly working 2235 scope.

And then while testing the option 02 (phase locked loop) board for my Tek AGF5101 arbitrary function generator, I discovered it wasn't working right... I poured over the schematics and photos of the original Tek PCB, and eventually traced the problem to a faulty GAL chip on the CPU board. It's not sending a pulse to tell the MC145145 PLL chip to accept the commands from the data bus, preventing the option board from working.
I guess it was never found before as this output from the GAL is only used for the Option 02 board, so it can be as faulty as can be and it would have no impact at all on a function gen with no option board.
Anyway, I got a rip of a good GAL chip now from a member on the tekscopes groups.io, and some replacement GAL chips from that Digikey order so I'll have a go at fixing that this weekend.

And finally, I got me some busted HP 8481A power sensor heads. I have a 437B power meter and to calibrate it I need a calibrator which is of course stupid expensive...
BUT said calibrator is essentially just a neutered power sensor head minus the thermocouple, instead hooked up to a voltage divider network with a rotary switch to select range and fed from a high accuracy 15.8V power supply. Something that is entirely buildable with a bunch of resistors, a rotary switch, an LM317 vreg and a busted power sensor all stuffed into a box, so that is my new project.
Once it's done I'll make a video for the youtubes and post some photos here too.

[SilverSolder]

20K for a TV wow... my brain can't even compute the rationale behind that...

Too much money printing for too long!

[Peter_O]

I don't have serial TV any more, now using my 32" Computer Monitor for Web TV. The 32" sits on a big svivel arm and I can pull it all the way to the front edge of my desk. Switching from office to easy chair, decent soud from bookshelf speakers and I'm fine. For the more intense sessions there is a 110" beamer screen combo in the middle of my main hifi setup.