Test Equipment Anonymous (TEA) group therapy thread

[Robert763]

I saw this coil around resistor construction in vacuum tube circuits but never in semiconductor ones.

As BD139 says it is a lossy inductor. They were used in valve circuits because they had no real resonances and thus stopped parasitic oscilations. One reason you don't see them often in modern circuits is because the resistor has to be non inductive e.g. carbon composition.
I have used them to fix an EMC issue on a piece of aircraft kit that was basically an Amiga 500 in a box. It would not pass EMC emissions testing and everytime the stuck a capacitor on a signal coming out of the screened box the emissions just came out somewhere else. I was sked to look at it and could see the whole 5V supply was "hot" from about 21.3 MHz to over 200MHz with spurs every 7.09Mhz.
My fix was a pair of10R 2W carbon composition resistors with a single layer of 0.5mm wire wound over the body and connected in parallel. One in the 5V positive and one in the return (it had an isolated DC-DC converter). Their designer could not believe it worked. The issue was the very low RF impedance of the converter output generating high RF currents in the supply wiring that then coupled into everything else. The lossy chokes directed the RF energy into the resistors where it was converted to heat. The designer had tried inductors alone but thay just generated high RF voltages that also "escaped". Lossy ferrite sleeves do the same thing but not so well.

[bd139]

Quick RF pr0n. Marconi 2022E RF board with can removed. Notable quantity of duff OM345's in there  (at least IC10 so far )



Edit: at least it hasn't had any hams in there already!

[Robert763]

The external bias resistor bodge fix cures most OM345 failures

[Saskia]

got the crossovers from my Quadral Montan back. A friend of mine who does nothing but developing speakers took a look and found the fault. 2 crapacitors (MKP) were blown, those were sitting in the signal path of the leaf tweaters causing them to not tweet.

He swapped them out for some ott capacitors:

https://www.hificollective.co.uk/catalog/audyn-capacitors-mkp-plus-cap.html

but those are not really over the top (40€ for 2 plus work is actually quite reasonable), but look at this:
Vince, take your heart pills ...
https://www.hificollective.co.uk/catalog/audyn-capacitors-true-copper-max-cap.html

[bd139]

The external bias resistor bodge fix cures most OM345 failures

That's good enough for some of the OM345's in there like the PLL divider preamps but not ones in the RF path. Overkill solution coming in...

[Saskia]

let's play a game.
Spot the gorilla, umm, idiot, umm failure ...

[Saskia]

Hint: the previous owners spent 2500 on repairs ...

[mansaxel]

No new test gear around here for a while, aside from picking up one of those Micsig 700V differential probes. Those things, by the way, are fairly nice and are a very handy utility for the price.

But.. I think I need to join "Hand Tools Anonymous" now. For some reason my addiction has shifted to wrenches, ratchets, hex bits, screwdrivers, etc. lately. Damn Youtube "tool review" channels. Every time I start watching those I find out about some new tool brand I wasn't familiar with and immediately a thread kicks in somewhere in my brain going "Hey, I need to buy some of their stuff to try out."  Now I have a whole box full of Icon and Tekton wrenches, Vessel screwdrivers, Wiha screwdrivers, etc. 

Dagnabit. How am I supposed to afford more test gear as long as this keeps up?!?  Then again... what other test gear could I possibly need? OTOH, what other hand tools could I possibly need?

 

The Facom R1Pico very compact ratchet set has won the heart and desire of everyone who's laid hands on it. If you have an addiction problem, don't look at it. If you have a sensible interest in high-quality tools, by all means.

(The fact that Stanley has bought Facom makes me nervous. I think that Stanley should stick to wood planes and breaker bars, and not be buying up fine tool companies and brand-rape them. Like Crap-On with Bahco. (And Bacho with Sandvik and Belzer, someone from Germany is going to complain, pretty soon... )

[GreyWoolfe]

20% of any Bernstein, Erem or Lindstrom catalogue content.
25% of any Wiha, Wera, Knipex, Xcelite, PB or OK/Jonard catalogue content
as well as 10 hand tools not included in the above which represent a new value of 100$ or € each.

I don't know about the exact percentages, but I definitely have Lindstrom, Wiha, Wera, Knipex, and Xcelite stuff in my toolbox(es).  Not sure I have anything that retails for more than $100 each though. Which is probably a Good Thing. 

The most of anything I have is Xcelite 99. I probably have a few dozen driver bits about 7 handles including 3 of the ooooold skool ratcheting handles that I paid way too much money for.  Bought them all used, paid $35 USD for 1 and $55 USD apiece for the other 2.  Xcelite lives on my workbench, in my 2 toolkits in the company van and in my rifle case.  I have a bigger rolling tool chest in my office than I have seen in some peoples' garage when we are doing the yard sale thing.  I have learned though that military legal size 4 drawer filing cabinets make great corded power tool storage.

[mansaxel]

Quick RF pr0n. Marconi 2022E RF board with can removed. Notable quantity of duff OM345's in there  (at least IC10 so far )



Edit: at least it hasn't had any hams in there already!

Is it "the usual resistor" in the OM345 that's gone in your case too?

This sounds like right fettlish:

https://www.viehl-radio.de/homeda/vlf/reparatur%20om345.pdf

[Saskia]

Replacement transformer for the one lost during moving.
Needed for the Terminator 2 pinball rebuild (2500 pieces 3d puzzle)

Cost for replacement was 300 quid ...

[duckduck]

I saw this coil around resistor construction in vacuum tube circuits but never in semiconductor ones.

As BD139 says it is a lossy inductor. They were used in valve circuits because they had no real resonances and thus stopped parasitic oscilations. One reason you don't see them often in modern circuits is because the resistor has to be non inductive e.g. carbon composition.
I have used them to fix an EMC issue on a piece of aircraft kit that was basically an Amiga 500 in a box. It would not pass EMC emissions testing and everytime the stuck a capacitor on a signal coming out of the screened box the emissions just came out somewhere else. I was sked to look at it and could see the whole 5V supply was "hot" from about 21.3 MHz to over 200MHz with spurs every 7.09Mhz.
My fix was a pair of10R 2W carbon composition resistors with a single layer of 0.5mm wire wound over the body and connected in parallel. One in the 5V positive and one in the return (it had an isolated DC-DC converter). Their designer could not believe it worked. The issue was the very low RF impedance of the converter output generating high RF currents in the supply wiring that then coupled into everything else. The lossy chokes directed the RF energy into the resistors where it was converted to heat. The designer had tried inductors alone but thay just generated high RF voltages that also "escaped". Lossy ferrite sleeves do the same thing but not so well.

So the carbon comp resistor is not connected to anything?

EDIT:

Recently bought this ( https://www.kctool.com/wera-056490-tool-check-plus-bit-ratchet-set-with-sockets-metric/ ), along with an insulated screwdriver set from Wera.

[Vince]

got the crossovers from my Quadral Montan back. A friend of mine who does nothing but developing speakers took a look and found the fault. 2 crapacitors (MKP) were blown, those were sitting in the signal path of the leaf tweaters causing them to not tweet.

He swapped them out for some ott capacitors:

https://www.hificollective.co.uk/catalog/audyn-capacitors-mkp-plus-cap.html

but those are not really over the top (40€ for 2 plus work is actually quite reasonable), but look at this:
Vince, take your heart pills ...
https://www.hificollective.co.uk/catalog/audyn-capacitors-true-copper-max-cap.html

 

I am so thankful not to be an audiophile or phool, it means I don't need expensive stuff to actually enjoy my music. The emotions I get from music / singers have little to do with the technical "perfection" of this or that. Imagine if you could love your wife or husband only if he / she were perfect. Perfectly shaved, perfect hair, perfect skin, perfect clothes, perfect eyes, perfect voice, perfect job, perfect everything... you would never be happy with him/her. Tragic.

I am perfectly happy with 50 cents capacitors in my speakers, or whatever is in them...

[bd139]

Quick RF pr0n. Marconi 2022E RF board with can removed. Notable quantity of duff OM345's in there  (at least IC10 so far )



Edit: at least it hasn't had any hams in there already!

Is it "the usual resistor" in the OM345 that's gone in your case too?

This sounds like right fettlish:

https://www.viehl-radio.de/homeda/vlf/reparatur%20om345.pdf

Been there and evaluated that. That’s plan A.

Plan B is I already engineered a complete replacement module using an MMIC and ordered parts 

[Saskia]

got the crossovers from my Quadral Montan back. A friend of mine who does nothing but developing speakers took a look and found the fault. 2 crapacitors (MKP) were blown, those were sitting in the signal path of the leaf tweaters causing them to not tweet.

He swapped them out for some ott capacitors:

https://www.hificollective.co.uk/catalog/audyn-capacitors-mkp-plus-cap.html

but those are not really over the top (40€ for 2 plus work is actually quite reasonable), but look at this:
Vince, take your heart pills ...
https://www.hificollective.co.uk/catalog/audyn-capacitors-true-copper-max-cap.html

 

I am so thankful not to be an audiophile or phool, it means I don't need expensive stuff to actually enjoy my music. The emotions I get from music / singers have little to do with the technical "perfection" of this or that. Imagine if you could love your wife or husband only if he / she were perfect. Perfectly shaved, perfect hair, perfect skin, perfect clothes, perfect eyes, perfect voice, perfect job, perfect everything... you would never be happy with him/her. Tragic.

I am perfectly happy with 50 cents capacitors in my speakers, or whatever is in them...

oh, the speakers they go in were bloody expensive, and the amp driving them has enough oomph to warrant putting 800V rated caps in there.
and 40€ to revive 2000€ speakers is still absolutely within reason, he did not charge 2500 € for a jumper wire. So I'll fix those speakers and can use them again, driving them with a very nice stereo set.

If you need some stereo equipment just let me know. I often have some stuff I can be talked into parting with.

[Wolfgang]

If its a parasite stopper (common in tube circuits) the resistor is in parallel with the coil.
Otherwise its a *coil former* . I personally never saw something like this in the wild.

[Vince]

GPIB FUN

Sorry for the late reply, to all who are helping with that... been baby sitting that old computer for 3 hours while trying to install Windows2000. Now back on TEA to report....

RAM : do'nt know what it is for sure, BIOS says nothing, only the totla capacity that's installed. However looking at them in the flesh, they look "modern"... and the user manual says they are 164 pin SDRAM.

Also says as I said earlier, that the motherboard can take only 32MB sticks. There are two slots available, so 64MB max, which is what there is presently, so no room for improvement there.


@ Robert : thanks for digging out that CD ! You won't need to ship it though (lucky you).. because that random ISO I just downloaded, did the trick, and it didn't even ask me for license key or anything or the sort... strange, but hey not complaining of course.

So here goes, 3 hours shrunk in a few lines (hopefully) :

- Entered the BIOS to make sure the CD Drive was in the boot sequence, before the hard drive. It was, good.
- PC none the less refuse to boot from the CD drive...
- Tried with my WinXP install CD, which I know boots fine... no joy. So there must be some kind of H/W problem within the CD driver itself, my luck !  Told you I was cursed...
- So I start Win95 instead, and the Win2000 CD auto starts ! It asks :" I detect you have an older version of Windows, do you want to upgrade ?"
- Yeah ! Don't need to boot from the Cd, I can install it from Win95 instead !!! 
- So I did that. It copied a few files quickly on the HDD, then rebooted.
- It booted from the HDD and started a text mode installer, yeah... looking good.
- Asked what partition I wanted to use... the 2GB HDD is split in two 1GB partitions. Was worried 1GB might not be enough for Win2000, so I tried to merge both partitions (hence wiping win95 in the process of course). but that failed. The partitioning too was not capable enough to allow for that. It let me delete the second partition, but not delete the first one !  So, no choice, had to recreate the second partition and format it, which took a while in itself. So, since I was stuck with 1GB partition, I might as well leave Win95 alone and install Win2000 on the second partition, hoping there would be enough space.

So I did that, and after about 2 hours, it succeeded ! Yes, look at that...
SO now I have boot loader to select Win95 on the first partition, or Win2000 on the second partition.
Right there Win2000 is cool. A "normal" windows refuses to install on anything other than the first partition, and won't install a boot loader. It thinks it's the only OS in the world...
So happy with that indeed. 

So I started Win2000 for the first time... and was surprised that it booted in a "normal'" time, was not slow. No worse than Win95, perfectly acceptable.
The desktop/ GUI loads up just fine, doesn't feel slow. Mouse pointer is responsive, Start menu as well... loading apps is OK too. Looked at the System Monitor, it says only 50% of the RAM is being used.

Looking at the splah screen during startup, it looks like the version I have is " Server Family ".

At boot it keeps poping-up an assustant with a dozen tabs asking me to configure a trillions server/network related things. Not understanding any of it, I skip this part...
It also tried to scare me during the install : " I detect that this computer has already be assigned at least one dynamic IP address".

ME : " Well, good, I assume that's ADSL box talking to the computer automatically and giving it an IP address, that's great, it works !!! "

Computer : " NO, DUMB ASS !!! Dynamic IP is BAD, you need this computer/ Server to have a STATIC  IP for thigns to work properly ! Here is the config dialo, please make the necessary changes immediately ! ".

Eh ?! 

I guess a static IP is good for a server indeed... makes it easier for the clients to find you... but I didn't care, and wanted the dynamic IP to work, so since I do'nt know what I am doing, I said " Sorry get lost, I will keep my dynamic IP ".

Computer : " You're a fool, but if that's what you want !! "

Then it asked me some more stuff I have no clue about : " What licensing scheme do you want ? Per client or per seat ?? "

Me : WHAT ?! 

I chose the second option, " Per seat ", because I like a good seat, thinking if that was the wrong answer hopefully the guys on TEA can help me fix that later on....

So eventually it installed and I could start test driving it, because to my amazement as I said, the GUI  / Desktop is actually plenty responsive enough to be usable.
Actually I didn't even see, during boot, an option asking me if I wanted to start in console mode rather than loading the desktop... maybe you need to press F8 like with Win95 ?!...

Lots of goods news :

- Just like on Win95, the Network / ADSL Box attache USB stick is visible out of the box in the explorer 

- 3COM Ethernet card works out of the box as well.

- The Matrox Millenium Graphics card I added in that computer, works right away as well

- USB works as well ! Tried a USB stick, works just fine !! 

I guess that's all because Win2000 is a bit newer than 95, so there are more drivers built-in.

Tried Internet Explorer, but no joy, just like Netscape in Win95, it fails to load websites other than google.com
However since Win2000 is 4 or 5 years newer than Win2000, maybe there is a web browser that can actually work on this platform ?
I need to Google to see what is the most recent browser that can run on W2K, and give that a try.
It's W2K version 5.00.2195, if that's any help.


OK !!!

So let's now see if TEKTOOL will work or not now ! As the saying goes... hoping for the best but expecting the worst... place your bets !

Stay tuned...be right back...

[Specmaster]

let's play a game.
Spot the gorilla, umm, idiot, umm failure ...

Plug J137 back in and bingo 

[mnementh]

It's basically usually just a very low Q inductor / RFC.

Just ordered a pile of shit from Mouser 

Yeah; I'm being molested right now by DigiKey...   

mnem
I shall be destitute by morning.

[Saskia]

umm, no. look at the jumper wire and the trace that is burned away. a new power board ist 350€, a pinball repair company charged them 2500 for that jumper wire.
The could at least have repaired the trace properly

[Vince]

oh, the speakers they go in were bloody expensive [...]
and 40€ to revive 2000€ speakers is still absolutely within reason,

Ah yes, it makes sense 
I was looking at the biggest one in the list, the one that costs like 1,000 Euros a pop !

If you need some stereo equipment just let me know. I often have some stuff I can be talked into parting with.

Thanks...but I my budget is next to nil compared to your world, I can't afford Saskia-approved stuff ! 
I may replace my amplifier at some point. The one I got, a Sony F261R cost me 10 Euros, defective. Fixed it for... free. All that was wrong with it were cracked solder joint on the speaker connectors.... now works just fine.
It's a piece of junk all in one integrated amplifier (an STK chip IIRC) but works fine.
The plastic front panel looks and feel cheap, that my main gripe with it.
One day I will try to find one with a better quality front panel, and maybe more exciting internal, like a toroidal transformer and discrete transistors rather than a big do it all power IC.
Typically early '90s stuff. and black. Hopefully with schematics available.
Yamaha something, or whatever decent brand for the masses.
No, don't vomit Saskia... it's horrible to your ears I am sure, but it's just fine for mine 

I have good friend in Germany in Augsburg who likes to restore old tube amps, and designs and makes his own I believe. He offered many years ago to give me one. Might give that a try...
He too has mega expensive speakers. I visited him once, he had a pair of very, very tall speakers. Can't remember the details / brand / model, but I remember he said they cost 50,000... 
He has an impressive collection of vinyl records as well, I remember... it's all 20 year old memories, I visited him only once (it's almost 1,000kms away...).
Also, he uses an old glowing Tek scope to work on his amps !!    A 547 IIRC,  maybe a 545 can't remember.

[Vince]

umm, no. look at the jumper wire and the trace that is burned away. a new power board ist 350€, a pinball repair company charged them 2500 for that jumper wire.
The could at least have repaired the trace properly

I am in the wrong business for sure... I will start a Pinball repair business right away !!! 

[Specmaster]

got the crossovers from my Quadral Montan back. A friend of mine who does nothing but developing speakers took a look and found the fault. 2 crapacitors (MKP) were blown, those were sitting in the signal path of the leaf tweaters causing them to not tweet.

He swapped them out for some ott capacitors:

https://www.hificollective.co.uk/catalog/audyn-capacitors-mkp-plus-cap.html

but those are not really over the top (40€ for 2 plus work is actually quite reasonable), but look at this:
Vince, take your heart pills ...
https://www.hificollective.co.uk/catalog/audyn-capacitors-true-copper-max-cap.html

 

I am so thankful not to be an audiophile or phool, it means I don't need expensive stuff to actually enjoy my music. The emotions I get from music / singers have little to do with the technical "perfection" of this or that. Imagine if you could love your wife or husband only if he / she were perfect. Perfectly shaved, perfect hair, perfect skin, perfect clothes, perfect eyes, perfect voice, perfect job, perfect everything... you would never be happy with him/her. Tragic.

I am perfectly happy with 50 cents capacitors in my speakers, or whatever is in them...

Agreed on every level. I doubt that many people can really tell the difference between a Hi-Fi system that costs just a few hundred and one that costs a few thousand in a blindfold test. Some people just love to flaunt the fact that they have money.

[Neomys Sapiens]

20% of any Bernstein, Erem or Lindstrom catalogue content.
25% of any Wiha, Wera, Knipex, Xcelite, PB or OK/Jonard catalogue content
as well as 10 hand tools not included in the above which represent a new value of 100$ or € each.

I don't know about the exact percentages, but I definitely have Lindstrom, Wiha, Wera, Knipex, and Xcelite stuff in my toolbox(es).  Not sure I have anything that retails for more than $100 each though. Which is probably a Good Thing. 

The most of anything I have is Xcelite 99. I probably have a few dozen driver bits about 7 handles including 3 of the ooooold skool ratcheting handles that I paid way too much money for.  Bought them all used, paid $35 USD for 1 and $55 USD apiece for the other 2.  Xcelite lives on my workbench, in my 2 toolkits in the company van and in my rifle case.  I have a bigger rolling tool chest in my office than I have seen in some peoples' garage when we are doing the yard sale thing.  I have learned though that military legal size 4 drawer filing cabinets make great corded power tool storage.

It will probably water your eyes when I tell you that I bought the BIG Xcelite foldout toolkit complete for 35€+postage. It had a very blurry picture of the incomparable ugly brown case and was titled 'old american toolkit'. It was completely unused, with the protective cushioning still in place.
Since then, I converted it further with a US pattern hammer, a set of Craftsman ignition wrenches, several of the premium quality Xcelite pliers and tweezers, a GCE alignment tool kit and a NSN-specified inhex kit and drift punch kit. I also have the option of removing the fixed nutdrivers, as I have found both metric and imperial Series 99 kits. Also added some stuff from Ullman, a Milspec Weller kit for 115V and another Weller iron for 230V.
Last thing I need for it are the series 99 torx blades. And I have a HP DMM with Muller and Pomona accessories residing in it.
Voila - totally American, aren't we?

[Specmaster]

umm, no. look at the jumper wire and the trace that is burned away. a new power board ist 350€, a pinball repair company charged them 2500 for that jumper wire.
The could at least have repaired the trace properly

Oh yes, now I see it  . I suppose the company thought about the callout charge, time taken in checking everything out and then knowing how to fix it quickly and move onto the next sucker. I mean, don't forget that today its all about the fat cats getting fatter quicker, it's an obsession about money and much you of it you can get.