Author Topic: Test Equipment Anonymous (TEA) group therapy thread  (Read 2857992 times)

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Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19325 on: November 08, 2018, 02:19:03 pm »
No Unit To be Seen, or NUTS.

 :-+ :-+ :-+
True story. A medium sized software company I was working for about 15 years ago, someone fell off a boat at a boat party and drowned. Everyone in tears the next morning so I cheerfully said "hey we don't have to buy as many Windows CALs next refresh now". This stopped me being invited to any social events. Tactical move that played off well that.
You brutal bastard.
Beat me to it. I was about to say that was utterly BOFH-worthy.  :-DD

Quote from: bd139
You're too nice. I'd keep it out of spite.  >:D
Yep, I think I would as well unless you have to sign for it.
The public record has to state that it will be returned  8)

I would HOPE that I needed to sign for it... which I would do quite dutifully, in someone else's name.

If signature is required, then there HAS to be a tracking number, and the seller will know you got it. And since the seller failed, over the course of several weeks, to provide said tracking while the sale was open, if he dared to claim receipt of goods, I would then deny said alleged receipt and report his ass to eBay for fraud.  >:D

Why would this normally mild-mannered tinkerdwagon be such an unmitigated Simon T. ? Making them pay the Assh'o Tax.  :-DD

mnem
“I like your Christ, I do not like your Christians. Your Christians are so unlike your Christ.” ― Mahatma Gandhi
« Last Edit: November 08, 2018, 02:23:13 pm by mnementh »
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19326 on: November 08, 2018, 02:25:02 pm »
That's just shows how good these Flukes are as I doubt that has been calibrated for years and possibly even never since it left the factory. Fix the display and you've a good meter there for sure, I'll be watching your progress with the display closely in case I ever need to the same thing. :-+

Indeed. This one is date coded latest 1981. Probably not opened other than to remove the batteries I suspect looking at it.

I'm going to re-engineer this to reconfigure the LM317 for around 2.8v or so constant voltage rather than constant current. This should adequately emulate a couple of charged NiCads. Should be simply a case of replacing the current source resistor with something suitable and adding another one from adj to ground. And probably a reasonable sized tant where the NiCad terminals are so the regulator doesn't go mental. Going to do some voltage measurements first though and work out how to do this without being too creative and causing buggeration and inability to return it to its natural state if I so desire in the future.

Edit: might be easier to stuff a fat zener where the battery was as well.

“I like your Christ, I do not like your Christians. Your Christians are so unlike your Christ.” ― Mahatma Gandhi

Quote of the day that. Having some problems with some Christians this week. Alas I'll leave that for another forum.

Quote from: bd139
You're too nice. I'd keep it out of spite.  >:D
Yep, I think I would as well unless you have to sign for it.
The public record has to state that it will be returned  8)

I would HOPE that I needed to sign for it... which I would do quite dutifully, in someone else's name.

If signature is required, then there HAS to be a tracking number, and the seller will know you got it. And since the seller failed, over the course of several weeks, to provide said tracking while the sale was open, if he dared to claim receipt of goods, I would then deny said alleged receipt and report his ass to eBay for fraud.  >:D

Why would this normally mild-mannered tinkerdwagon be such an unmitigated Simon T. ? Making them pay the Assh'o Tax.  :-DD

I doubt it's going to turn up at this point. Something I ordered from China got here first.

BTW credit card is cleaned out and £0 now so it's drone-o-clock time ;)

True story. A medium sized software company I was working for about 15 years ago, someone fell off a boat at a boat party and drowned. Everyone in tears the next morning so I cheerfully said "hey we don't have to buy as many Windows CALs next refresh now". This stopped me being invited to any social events. Tactical move that played off well that.
You brutal bastard.
Beat me to it. I was about to say that was utterly BOFH-worthy.  :-DD

I got the nick name Gene at one company, after Gene Hunt (possibly c**t as well  :-DD)



If you haven't seen the TV series Life on Mars or Ashes to Ashes, worth a watch.
« Last Edit: November 08, 2018, 02:34:41 pm by bd139 »
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19327 on: November 08, 2018, 03:09:02 pm »
Random trick I found on the 8010A. If you short common to mA terminal it will hold the reading until the short is removed thus avoiding paying good money for the touch-hold probe :)

Neat.
 

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19328 on: November 08, 2018, 03:14:55 pm »
They are generic displays. Work to get them in requires quite a bit of re-engineering. Basically you remove the old bezel and cut it down so the new display fits then patch the display leads to the existing edge or the IC pins with kynar.

https://www.bitsbox.co.uk/index.php?main_page=product_info&cPath=172_182&products_id=2354

I’ll demonstrate when I get all the bits together. It’s not pretty I warn you :)

Backlight might be an option. I may try that. I’m sure I can sneak 20mA off the 5v line.

Edit: here’s one someone else did: https://billingtonrepairs.wordpress.com/repairs/fluke-8010a-lcd-replacement/

Looks to me like if you used Kynar or fine magnet wire, you could probably bring them all right out the bottom left corner, and not need to drill all those holes. Is there other modding required to make it fit in the bezel, or just a little silicone abuse?

Oh... it looks like he modded the LCD carrier to accept the DIL LCD, and is using the bundles of wires to provide pressure against the bezel... Hmmm. I'd probably try to do some foam mounting tape or somesuch.

My experience tells me that if your LCD doesn't have a diffuser panel underneath, you'll play hell getting any kind of BL to light up worth a damn; trying to get the light to diffuse properly through a 1-2mm thick aperture is ummm... painful. That said... many of these generic LCDs have a semitransparent reflective coating on the back, and if you add a diffuser and 4-6 super-bright LEDs (two or 3 on each end seems to work best with homemade diffusers), you CAN get a passable BL out of it anyways.

   I HAVE modded this BL Kit from HobbyKing to a number of other applications; a few considerations for best results:

1)Peel the reflective Mylar tape from the edge and save it so you can reapply it after you cut the diffuser to size with a Dremel Saw or coping saw.

2) Peel the white sheets from front and back before cutting, then cut to size with scissors afterwards.

3) Apply masking tape (preferable as less likely to leave residue) or clear shipping tape to acrylic panel to protect surface while cutting.

4) Do NOT apply the included double face tape between diffuser and LCD; it shows through.

5) Unsolder the pigtails from the LED PCB before you start cutting; they'll break off anyways, and it's easier to get clean pads on the PCB without melting stuff.

The LED PCB has two 0603 LEDs in parallel; it will draw approx 22-25mA at 13.8V with OEM 470Ω ballast. I've driven these to 40mA with no problem; 30ma is my usual target. The blue one has VF of 2.52 (I just checked); will need a ballast of 68-100Ω at 5V.  Green and white will be very close to same; they disco-ed the red kit ages ago.

White Kit here:   Blue Kit here:   Green Kit here:

Good luck, and *~ Happy Hacking! ~*

mnem
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« Last Edit: November 08, 2018, 05:03:39 pm by mnementh »
 

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19329 on: November 08, 2018, 03:57:42 pm »
I would HOPE that I needed to sign for it... which I would do quite dutifully, in someone else's name.

If signature is required, then there HAS to be a tracking number, and the seller will know you got it. And since the seller failed, over the course of several weeks, to provide said tracking while the sale was open, if he dared to claim receipt of goods, I would then deny said alleged receipt and report his ass to eBay for fraud.  >:D

Why would this normally mild-mannered tinkerdwagon be such an unmitigated Simon T. ? Making them pay the Assh'o Tax.  :-DD

I doubt it's going to turn up at this point. Something I ordered from China got here first.

BTW credit card is cleaned out and £0 now so it's drone-o-clock time ;)

Yeah, that's my take as well.

In all honesty, I'd probably pay the guy out-of-channel if it DID arrive; it is SO unlikely I'd want to at least reward the attempt at good faith, even if the execution was utterly craptacular. Which I actually did a few weeks ago; an order for some now-no-longer-available-on-fleaBay R4 ROM adapters that showed up two months late direct from the fab in Taiwan.    :palm:  I was glad to actually get them; I had written the whole project off, so I felt it was bad Karma not to at least pay for them.

PM me with what you want to fly... or maybe you want to start out with a Sim. My fave so far is Liftoff (Steam); I'm trying out VelociDrone when I finally get my wireless Sim dongle ironed out. I need to program a whole new model profile for it.

mnem
*Back into hell*
 

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19330 on: November 08, 2018, 05:36:09 pm »
That's just shows how good these Flukes are as I doubt that has been calibrated for years and possibly even never since it left the factory. Fix the display and you've a good meter there for sure, I'll be watching your progress with the display closely in case I ever need to the same thing. :-+

Indeed. This one is date coded latest 1981. Probably not opened other than to remove the batteries I suspect looking at it.

I'm going to re-engineer this to reconfigure the LM317 for around 2.8v or so constant voltage rather than constant current. This should adequately emulate a couple of charged NiCads. Should be simply a case of replacing the current source resistor with something suitable and adding another one from adj to ground. And probably a reasonable sized tant where the NiCad terminals are so the regulator doesn't go mental. Going to do some voltage measurements first though and work out how to do this without being too creative and causing buggeration and inability to return it to its natural state if I so desire in the future.

Edit: might be easier to stuff a fat zener where the battery was as well.


   Got room to stuff one of these along with something like a 602060 LiPo cell?

That's typically 600-800mAH. Then just use the USB as your power adapter.

mnem
*Idle thoughts over a liverwurst sandwich*
 

Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19331 on: November 08, 2018, 05:41:49 pm »
Good luck, and *~ Happy Hacking! ~*

Interesting ideas with the display backlight. Thanks for taking the time to write this up. I'm going to skip this one and will grab a module next time I order from bitsbox and do some experimentation.

I've looked at the existing display module now and shone some light down the side and forget it. That won't work. Also attempts to remove the reflector from the back caused the entire display to bleed out finally killing it dead. New module arriving tomorrow

I would HOPE that I needed to sign for it... which I would do quite dutifully, in someone else's name.

If signature is required, then there HAS to be a tracking number, and the seller will know you got it. And since the seller failed, over the course of several weeks, to provide said tracking while the sale was open, if he dared to claim receipt of goods, I would then deny said alleged receipt and report his ass to eBay for fraud.  >:D

Why would this normally mild-mannered tinkerdwagon be such an unmitigated Simon T. ? Making them pay the Assh'o Tax.  :-DD

I doubt it's going to turn up at this point. Something I ordered from China got here first.

BTW credit card is cleaned out and £0 now so it's drone-o-clock time ;)

Yeah, that's my take as well.

In all honesty, I'd probably pay the guy out-of-channel if it DID arrive; it is SO unlikely I'd want to at least reward the attempt at good faith, even if the execution was utterly craptacular. Which I actually did a few weeks ago; an order for some now-no-longer-available-on-fleaBay R4 ROM adapters that showed up two months late direct from the fab in Taiwan.    :palm:  I was glad to actually get them; I had written the whole project off, so I felt it was bad Karma not to at least pay for them.

PM me with what you want to fly... or maybe you want to start out with a Sim. My fave so far is Liftoff (Steam); I'm trying out VelociDrone when I finally get my wireless Sim dongle ironed out. I need to program a whole new model profile for it.

mnem
*Back into hell*

Yeah if it does turn up and it's as described, you can re-pay the seller if you want. I don't have a problem with that to be honest. If it turns up and it's junk I'm keeping it as a public service to stop it getting back on the market again. It has been sold and returned already apparently looking at the guy's feedback.

I'm going to learn the expensive way. Simulators aren't the same as doing the real thing :)

edit: more 8000 series pr0n. Cleaned the 8012A up. This is before I yanked the display module out. Neither have been calibrated AFAIK and they match the calibrated 87V spot on after all these years!

« Last Edit: November 08, 2018, 05:43:54 pm by bd139 »
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19332 on: November 08, 2018, 07:04:21 pm »
Fitted new power plug and sockets to the Technics amp to replace the ones I broke trying undo them  :palm: and connected the speakers and switched on with volume downed low, buzz from the right speaker and then silence. Then I noticed smoke coming from the speaker  :palm:

Yep, I forgot the seller did say not to connect the amp to speakers that I wanted to keep, so now I'm looking for replacement speakers because I joined forces with bd and smoked my speakers when I should have used a dummy load first  :scared:

Looking likely that the IC power amp module is short circuited internally.  |O
« Last Edit: November 08, 2018, 10:37:27 pm by Specmaster »
Who let Murphy in?

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Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19333 on: November 08, 2018, 07:14:43 pm »
Interesting ideas with the display backlight. Thanks for taking the time to write this up. I'm going to skip this one and will grab a module next time I order from bitsbox and do some experimentation. I've looked at the existing display module now and shone some light down the side and forget it. That won't work. Also attempts to remove the reflector from the back caused the entire display to bleed out finally killing it dead. New module arriving tomorrow


I'm going to learn the expensive way. Simulators aren't the same as doing the real thing :)
Don't give up hope on the BL yet. The new module may have one of the semi-transparent reflectors as I mentioned earlier. Shine a flashlight from the back; if it lights up, you've got a good chance.

As for sims... they're not perfect yet, but they're really close now. Since we now have Sims which will interface with your TX just like a real quad, they're an excellent way to train the muscle memory you need to get good. They're cheap, and unlike a real quad, "Getting back in the air" is a push of a button, NOT 5-15 minutes in the pits.

Sims still are no substitute for a real quad... but they ARE an important part of a balanced practice regimen. You want to do BOTH, and there's no good reason not to.

https://youtu.be/FlJkmt0ozAQ

Steele tends to ramble sometimes... but he's one of the first to make quadcopters a thing, and he knows his shit. Everything in this video is the truth; just watch out for his prejudice in favor of ߃. He was one of their ßeta testers for like... EVER.  ;)


mnem
"The universal warrior uses all tools at his disposal; to do less would be to invalidate his own existence."
 

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19334 on: November 08, 2018, 07:52:54 pm »
In Other news...

   A quick heads-up... something that just blew me away.
A few days ago I needed a bunch of cheap extension cords; they were available as an "add-on" for a good price on Amazon, so I built up an order to get to the minimum. Among the many things I bought was the YinYoo KZ ZSE dual driver earbuds for the wallet-shattering price of $5.99.  ;) I'd link to the page on Amazon for you, but since they sold out, it now links to a higher tier YinYoo product for $24. Chinglish ad copy set aside, they have some pretty impressive specs for any sub-$30 headphones, so I decided to give 'em a try for only $6. I got the blue ones. ;)

 I know, I'm weird... but when I listen with phones, I still prefer an iPod.  :o One of the caveats of every iPod I've ever owned is that if you enable ANY EQ of any sort, the iPod drops Max Volume by 3-10 dB. Period. Nothing you can effing do about it short of running it through an external amp. (You headphone tube-amp weenies can eat my shorts... I need to be able to do shit when I jam out and damage my eardrums!  :-DD ) Finding a set of phones that actually sound good on default EQ is a bit of a hassle; hence all the rage for all these uber-expensive headphones nowadays.

Anyhoo... these things are freaking amazing for a $6-8 set of earbuds; they easily blow away my decade-long favorite Creative EP-630 "budget headphones" when playing with my many iPod Nanos. Where the 630s have good bass and crisp, balanced highs, they've always been just a little thin on mid; which especially with female vocalists can really hurt the presence. Also, the 630s aren't capable of handling the full output of any of my iPods on anything really dynamic; you'll hear the driver start to waffle at around 80% volume, then they start to cavitate and drop off a cliff of distortion.

These have everything the 630s lack... easily 5-10hz lower bass response, more volume at the same level, and they actually show you where the iPod comes up short and they can take more... 90-95% volume or so the drumbeats hammer hard, and mids are still full and bright but you start to hear the HF clipping in the D-A converter  (or the original sampling; the difference doesn't matter) but there's no waffling and everything else is TIGHT.

Yeah, there are a lot of earphones out there that can do this... but I haven't come across any as good as the ~$25 EP-630s for the money, and certainly not for $6-8.

No wonder Amazon is trying to make them disappear!

mnem
woohoo! woohoo!  :scared: woohoo! woohoo!
« Last Edit: November 08, 2018, 07:58:03 pm by mnementh »
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19335 on: November 08, 2018, 08:13:57 pm »
A man after my own heart, I love the deep bass and ear buds normally don't deliver this but I looked on the UK Amazon site and we have the same ones here ranging between £10.99 and £11.99 a pair depending who the seller is. Anyway, I decided to get a pair based on your review and the reviews of customers who seem to be backing your views and also the makers claims. They are also noise cancelling as well according to the blurp and I get mine in my hands on Saturday. Thanks for the heads up.  :-+
Who let Murphy in?

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Online Vgkid

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19336 on: November 08, 2018, 08:19:08 pm »
For cheap headphones with good bass , I like my mee-elecectronics m6. Good to work out with as well.
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19337 on: November 08, 2018, 11:10:56 pm »
Update on the Technics Amp, as is usual with modern amps, there is provision for 2 sets of speakers, A and B, when it smoked one of my speakers it was the right speaker on set A so just put a couple of multimeters on the speaker outputs for set A, inputs open, volume at zero left output reads just a few mV, fine, right out reads 36.5v. connected meters to terminals for set B, selected set B both outputs read a few mV, perfectly fine so somewhere along the line switching set A in connects the output directly across one side of the supply rail.  Back down the rabbit hole again looking for solder bridges etc, on the main board which the only part of the amp that the 37V rails are to found is between the power supply and the power amp IC so it should be fairly easy to spot and yet I didn't see anything wrong when I inspected it before :palm: 

This is another situation that calls for multiple meters, 4 in this case to monitor all the speaker terminals at the same time, 7 if I was to monitor all the supply rails of +37, -37 and +4.6v so its true when they say you can never have enough meters   :-DD :-DD :-DD
« Last Edit: November 08, 2018, 11:14:27 pm by Specmaster »
Who let Murphy in?

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Offline bd139

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19338 on: November 09, 2018, 12:45:30 am »
Ouch. That’s a pain in the arse :( ... let us know if you find the solution.

Shitty evening here too. Spent the entire evening trying to get that 475A to trigger but it just lollops along and sweeps every few seconds when it pleases them goes to sleep for a bit. Not tants either as have checked every damn one. Not tunnel diodes either as I put them in the 465 and that worked.

Going to bed now. Probably have nightmares about sweep circuits now.
 

Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19339 on: November 09, 2018, 12:58:15 am »
A man after my own heart, I love the deep bass and ear buds normally don't deliver this but I looked on the UK Amazon site and we have the same ones here ranging between £10.99 and £11.99 a pair depending who the seller is. Anyway, I decided to get a pair based on your review and the reviews of customers who seem to be backing your views and also the makers claims. They are also noise cancelling as well according to the blurp and I get mine in my hands on Saturday. Thanks for the heads up.  :-+

Yeah, "Noise-Cancelling" in this case means "completely sealed in the ear canal"; this is always 90% of the battle for good bass. The silicone mushroom tips on these are a bit firm, but still just on the good side of the comfortable range. I tried the small tips, but they didn't make a good seal and they sounded horrible.

   Be prepared, the stems reach a bit further into the ear than most single-driver buds; this is good, as it offsets the slightly heavy weight. I can only imagine what the $24 ones with the aluminum shell feel like... probably something like Uhura's honey-dipper sticking out both ears.  :-DD

Update on the Technics Amp, as is usual with modern amps, there is provision for 2 sets of speakers, A and B, when it smoked one of my speakers it was the right speaker on set A so just put a couple of multimeters on the speaker outputs for set A, inputs open, volume at zero left output reads just a few mV, fine, right out reads 36.5v. connected meters to terminals for set B, selected set B both outputs read a few mV, perfectly fine so somewhere along the line switching set A in connects the output directly across one side of the supply rail.  Back down the rabbit hole again looking for solder bridges etc, on the main board which the only part of the amp that the 37V rails are to found is between the power supply and the power amp IC so it should be fairly easy to spot and yet I didn't see anything wrong when I inspected it before :palm: 

This is another situation that calls for multiple meters, 4 in this case to monitor all the speaker terminals at the same time, 7 if I was to monitor all the supply rails of +37, -37 and +4.6v so its true when they say you can never have enough meters   :-DD :-DD :-DD

Not to be the bearer of bad news, but again... these usually run their outputs BTL, so no hardware switching involved. It's most likely a 4-channel amplifier IC, and one output is shorted internally. I've seen it a thousand times... dumbass hooks up underrated speaker "just for a second"; blows the motor apart in the speaker, which shorts against the magnet core and burns out the channel.  :-BROKE

I sure hope I'm wrong and it's just a shorted cap somewhere, but not likely.  :-\

In response to your earlier question about revisions... With Sanyo monolithic ICs, IIRC letter revisions are USUALLY a packaging variant; offset legs vs inline, or regular pinout vs "mirror" pinout. Number revisions... like a -110 or -220, are usually a power rating or maximum voltage rating variant of the same circuit.

As usual: YMMV, DQMOT, INAL, WTFBBQ?, DILLIGAF?!?  :bullshit:

mnem
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« Last Edit: November 09, 2018, 01:05:17 am by mnementh »
 

Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19340 on: November 09, 2018, 01:00:33 am »
Update on the Technics Amp, as is usual with modern amps, there is provision for 2 sets of speakers, A and B, when it smoked one of my speakers it was the right speaker on set A so just put a couple of multimeters on the speaker outputs for set A, inputs open, volume at zero left output reads just a few mV, fine, right out reads 36.5v. connected meters to terminals for set B, selected set B both outputs read a few mV, perfectly fine so somewhere along the line switching set A in connects the output directly across one side of the supply rail.  Back down the rabbit hole again looking for solder bridges etc, on the main board which the only part of the amp that the 37V rails are to found is between the power supply and the power amp IC so it should be fairly easy to spot and yet I didn't see anything wrong when I inspected it before :palm: 

This is another situation that calls for multiple meters, 4 in this case to monitor all the speaker terminals at the same time, 7 if I was to monitor all the supply rails of +37, -37 and +4.6v so its true when they say you can never have enough meters   :-DD :-DD :-DD

I thought I saw some smoke signals coming from the East. Between you and BD139 you are the magic smoke kings.  :-DD
An old gray beard with an attitude.
 
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Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19341 on: November 09, 2018, 01:07:42 am »
Cain't blame him for this one; it came that way. The seller even warned him aboot it. ;)

mnem
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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19342 on: November 09, 2018, 01:13:45 am »
@bd139 ooh er, it seems that we both have good and bad days at the same time, like bloody twins  :-DD

I'm beginning to suspect at this late hour that its one of those poxy connectors, one of these that you push multi core flat ribbon cable (with solid cores) into and push down a locking tab to secure the cable in, this bastard in fact (not sure what those sockets are called)


And this here is one that I broke in trying release the cables so I had to solder in on the main board and the transformer terminal board, 2 x 4 pin headers and source this premade lead with the 4 colours to replace the power supply lead to the system. I suppose I could always do the same on the the other cable (which connects the A/B speakers selector switch and the headphone socket to the main board), I have the headers but not found anyone that has similar 7 pole leads that I could use.
« Last Edit: November 09, 2018, 01:25:36 am by Specmaster »
Who let Murphy in?

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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19343 on: November 09, 2018, 01:26:38 am »
Cain't blame him for this one; it came that way. The seller even warned him aboot it. ;)

mnem

My Irish ancestors were always spinning tales. Truth be told it was the drink.  :-DD

Ever see the book of Irish Superstitions?  It's thicker than the Holy Bible.  :o ;D
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Online mnementh

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19344 on: November 09, 2018, 01:33:59 am »
Aye, and probably more truth innit.  :-DD

mnem
My great granma Edwards told me the truth aboot them Scots and their bagpipes; The Irish gave it too'em as a joke, aaand they never caught on.  >:D

 

Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19345 on: November 09, 2018, 01:48:21 am »
@mnementh Yes it is a bloody power amplifier in a IC but only a 2 channel one that is as you correct assumed, BTL and it is the only item that takes the full supply rail voltage of 37V +ve and -ve. I don't believe that the IC is shorting out internally as the outputs are taken through speaker selector switches which are mounted on the front panel and are connected via that flat 7 core cable. It also connects the headphone socket, nothing else is carried via that 7 core cable, it's just output from the amp IC 2 channels in and then 2 x 2 channels coming out again to speakers A and B. No permanent voltage should be but I was reading 36V on right channel, on the A setting, B setting appears to be fine.

If the IC was internally shorted then operating the A B speaker selector would move this 36V from Ch1 R to Ch2 R but it isn't. Anyway, its late now and I'm toddling off to bed for some well earned sleep, got to be up early tomorrow to collect Mother in Laws flower plants for her, and then shoot off doing a 40 mile round trip collecting more audio gear and a set of speakers to replace my smoked ones. I'll look into this more tomorrow.
Who let Murphy in?

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Offline Specmaster

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19346 on: November 09, 2018, 01:53:20 am »
Update on the Technics Amp, as is usual with modern amps, there is provision for 2 sets of speakers, A and B, when it smoked one of my speakers it was the right speaker on set A so just put a couple of multimeters on the speaker outputs for set A, inputs open, volume at zero left output reads just a few mV, fine, right out reads 36.5v. connected meters to terminals for set B, selected set B both outputs read a few mV, perfectly fine so somewhere along the line switching set A in connects the output directly across one side of the supply rail.  Back down the rabbit hole again looking for solder bridges etc, on the main board which the only part of the amp that the 37V rails are to found is between the power supply and the power amp IC so it should be fairly easy to spot and yet I didn't see anything wrong when I inspected it before :palm: 

This is another situation that calls for multiple meters, 4 in this case to monitor all the speaker terminals at the same time, 7 if I was to monitor all the supply rails of +37, -37 and +4.6v so its true when they say you can never have enough meters   :-DD :-DD :-DD

I thought I saw some smoke signals coming from the East. Between you and BD139 you are the magic smoke kings.  :-DD
Yeah smoke maybe but no bright orange fireball with it, at least there wasn't at my end of the double act  :-DD :-DD
Who let Murphy in?

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Online med6753

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19347 on: November 09, 2018, 01:59:05 am »
In other news....

The Rigol DMM with it's dead LCD display has been fully refunded.

The Siglent SDM3055 has been ordered from Saelig and will be here in a few days. I got the 6% EEVBlog discount however I didn't realize that Saeling was located in New York. And since I'm in New York had to pay sales tax which is 6.25% so it completely wiped out the discount.  :palm: :--
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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19348 on: November 09, 2018, 02:03:29 am »
In other news....

The Rigol DMM with it's dead LCD display has been fully refunded.

The Siglent SDM3055 has been ordered from Saelig and will be here in a few days. I got the 6% EEVBlog discount however I didn't realize that Saeling was located in New York. And since I'm in New York had to pay sales tax which is 6.25% so it completely wiped out the discount.  :palm: :--
Bugger !
Maybe the USA shop price shipped from Ohio might have worked out better ?  :-//
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Offline bitseeker

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Re: Test Equipment Anonymous (TEA) group therapy thread
« Reply #19349 on: November 09, 2018, 02:33:34 am »
Majorly Elusive Test Equipment Relocation

Misplaced Equipment Temporary Elusiveness Reaction

Missing Equipment Torment Endlessly Recurring
MET.  :-+

No Unit To be Seen, or NUTS.

 :-+

 :-+ :-+ :-+


OK, the results thus far: one vote for MET, two for NUTS.

Any other votes (or new candidates)?
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