Test Equipment Anonymous (TEA) group therapy thread

[med6753]

My faith in USPS has been restored. The wayward package went from Phillipsburg NJ to Albany NY distribution center, then to Newburgh NY distribution center, and to my PO this morning. So as long as my local PO doesn't fumble it I should have the package today. 

I hope, it will not turn out like this:


 

LMAO.  Thanks, I needed that. 

[Neomys Sapiens]

Keysight has sent a link to the new AN-90 "The Power Handbook", now focussing on PS applications.
https://www.keysight.com/zz/en/assets/3121-1101/application-notes/The-Power-Handbook.pdf

They mention the 'old An-90', focussing on PS design.
Does anybody know a source? 

If you PM me, I could mail it to you.

[AVGresponding]

the postman just rang. twice ...

Got a Keithley 2000 in the mail. Sender information plus serial number intakt. boots wo errors. Selftest gets to 400, then asks me to insert 4 wire short which I don't have. Last calibration was in 2010. Cosmetically it looks a shitload better than the 2700. Display ok, no covers missing.

cost was 155 Pesos incl postage

It's easy enough to make a 4-wire short if you have 4 spare banana plugs. The self tests you're missing are unlikely to be hiding a major fault, fortunately.


Wago 4mm banana plugs ftw:





Here's a pic that demonstrates the mental capacity of some of our painters:



The room in question is a sub-mains, which has the DB (3ph 64 way) for the full floor, run off a canalis. Great place to store flammable materials.   

[GreyWoolfe]

Med, hate seeing you go down that road.  I was heading there myself, Mrs GreyWoolfe was convinced I was heading there also.  I was up to 1000 mg of Metformin, twice a day, Glipizide was next.  Her kicking my tail to join her on weight watchers was my saving grace.  For us, all it took was a change in eating habits.  Lean meats, lots of veg and fruits, beans and lentils(dried and done in the pressure cooker to our recipe) and almost no simple carbs.  mnem, we do enjoy the occasional Mission carb balance tortilla ourselves.  We have found quite acceptable substitutes; zoodles for pasta, Quest protein chips made with psyllium husk instead of flour replaced potato chips, chicken sausage instead of pork sausage.  We do some plant based protein alternatives.  My favorite is MorningStar Farms chorizo crumbles with my eggs and oat bran in the morning.  No fried/greasy food and no processed sugar and we read the labels on everything.  No fast food.  It took weeks to get used to healthy eating and I fought it every step of the way.  A year later, no measuring of food except the pasta sauce for zoodles.  We eat proper serving sizes and I try to eat 5 times a day, 3 meals and 2 snacks.  Just did blood work for hematology/oncology and fasting blood sugar was 100 and my primary care took me off metformin 2 months ago.  A1C from 7.9 to 5.1. Yes, I still monitor my blood sugar every day, once a day-that's all Medicare will pay for as I am not insulin dependent.  And, honestly, I am not exercising much, as the monthly chemotherapy shots keeps me in a constant state of serious fatigue( zero testosterone in my system) and at the end of the day it's hard to do much of anything.  Most days, it's enough getting through work.  Looking forward to November when I get my last shot.  Hopefully, I will be able to get my life back on track and not be so tired.  Still down 133 pounds as of this morning, 385 to 252.  Thankfully, we have each other to hold us accountable and to encourage.  She is down 75.  We are planning to go out to dinner tomorrow for our 17th anniversary.  I will probably have what I usually have when we do go out to dinner, which is very rare now.  A salad, dressing on the side, keep the bread/roll and topped with a grilled protein of some sort, no appetizers or dessert. I like going to places that have all you can eat salad bars.

We both tried multiple diets and failed at all of them, some spectacularly.  Changing our lifestyle and eating habits has corrected much.  Mrs GreyWoolfe has had irritable bowel syndrome with diarrhea, IBS/D for years.  Without the fat and sugar in our diet, she has had to add a fiber substitute so she doesn't become constipated.  It is great to shop at wally world for cheap pants/polo shirts for work since I shrink out of clothing every couple of months.  No more big and tall stores with their outrageous prices.  I would encourage you to try healthy eating, no diet for a couple of months before going on insulin.  Friends and family that have ended up on insulin have had the same side effect, sugar craving which is a huge no-no.  Best of luck, med.  Fight the good fight.

Thanks for the encouragement. Weight for me is not an issue. I'm only 7 pounds above my target weight of 170 - 175 pounds. Type 2 Diabetes runs in my family on my Mother's side. And I've been lucky enough to carry on the tradition. I knew sooner or later I was going to be insulin dependent no matter what I did with my diet or weight. But I will continue a very low carb routine to avoid large blood sugar spikes. And small portions to keep the weight off. When I was working I had no problem keeping the weight off. As soon as I retired 10 pounds suddenly got packed on. But now that I doubled down on the diet it's slowly coming back off.     

Same thing here, mom and oldest sister were type 2 and one of mom's brothers was insulin dependent but didn't manage it well and he died alone in the bathtub.  He was there for 3 days before my aunt called the police because she hadn't heard from him.  I am hoping to keep status quo now.  Seeing what friends and family go through, though admittedly, they don't manage it well is all the encouragement I need.  The friend takes her blood sugar 5 times a day, she has serious issues(vision and kidney damage) as she was misdiagnosed for years.  Son in law refuses to be compliant.  He has diabetic retinopathy and diabetic neuropathy, having had multiple surgeries on his eyes and has lost 2 toes so far and almost lost a 3rd  plus has stents in his legs trying to improve circulation.  That is why I now fight the good fight to keep from going down that path.  Getting old truly sucks.  The person who coined the phrase getting old gracefully needs a full comprehensive and continuous beating.  There is no gracefully, you get old kicking and screaming every step of the way.

[Kosmic]

Another victim of the "lamp maker".

https://www.ebay.com/itm/194996457051

[AVGresponding]

Another victim of the "lamp maker".

https://www.ebay.com/

I could forgive this if the resistor decades were used to control the brightness of the lamp

[med6753]

Another victim of the "lamp maker".

https://www.ebay.com/

I could forgive this if the resistor decades were used to control the brightness of the lamp

You are too generous. They should be beaten to a pulp with the lamp. 

[Cerebus]

Here's a pic that demonstrates the mental capacity of some of our painters:



The room in question is a sub-mains, which has the DB (3ph 64 way) for the full floor, run off a canalis. Great place to store flammable materials.   

You've got to make allowances for what years of sniffing paint, solvents and thinners have done to the poor darling's brains, it's gonna be like Swiss cheese in there. They ought by now, like some people with dementia, be under Court of Protection supervision and not allowed out on their own but only with adult supervision. 

[Cerebus]

Another victim of the "lamp maker".

https://www.ebay.com/

I could forgive this if the resistor decades were used to control the brightness of the lamp

You are too generous. They should be beaten to a pulp with the lamp. 

... from the inside out!

[Brumby]

I could forgive this if the resistor decades were used to control the brightness of the lamp

You are way too generous.  I couldn't.

[m k]

Couple Bio Pharma sets in Exeter, UK.
https://www.allsurplus.com/asset/2237/20372
https://www.allsurplus.com/asset/2235/20372

[tggzzz]

Another victim of the "lamp maker".

https://www.ebay.com/

I could forgive this if the resistor decades were used to control the brightness of the lamp

You are too generous. They should be beaten to a pulp with the lamp. 

No, no, no. They should be allowed to choose which orifice it will be inserted into.

[mnementh]

Driver frozen up is a very common failure mode; I've replaced more than I can count. 

That's when the recone kit comes out. Such things do exist. I've done more JBL 2220 and 2225 15" drivers than I can count. Although, for a simple 6" car woofer, not likely to find one. Aftermarket foam surrounds, though.  That is a thing.

Get a pair of cheap aftermarket 4Ω speakers the right size and replace both so the sound is the same. If that speaker measures 2Ω DCR, actual impedance will be a bit higher; more like 2.5-3Ω. Inversely, a 4Ω impedance speaker will usually measure 3-3.6Ω DCR.

2Ω might be a battered 4Ω too. I've done a few in-door replacements, and there's one coming up soon here. What I usually do, is to go to used parts dealers and buy from scrapped cars. For a lot of non-wear items (and a good deal wear items too) this is a very convenient and cheap way to prolong the life of your car.  In Sweden, there's a common online database service for about 150 dealers where you can search on mfr part number and find who's got it. Very, very effective and convenient.

Under any circumstances, in most cases using a lower impedance speaker will do nothing except decrease max volume a bit and make the amp run a bit cooler.

Now, lowered impedance, if we for a while play "DC == AC" simplification game, means more current. More current usually means hotter transistors. The limiting factor for output power is rail voltage, which will set an output level at which clipping happens. In an ideal amplifier, half the load impedance means double current at a fixed max voltage, doubling the output power, and making the amp run hotter. Less than ideal amplifiers usually mean that the power supply can't supply enough current, or the transistors won't deal with the power levels, placing a limit on how low load impedance safely can be.

I'm quite bad at electronics, and I only have professional user experience of power amplifiers, but this is what I learnt during perhaps 20 years doing such things on and off.

So, how come you predict the amp will run cooler? And then we've not discussed any passive crossover point moving because the impedance is a part of the filter..

Yeah, reconing isn't going to fix a voice coil rusted fast. Also very NCE for a cheap factory speaker. Spec indicated that cost was a concern, so I recommended replacing with a set of cheap aftermarket drivers. 

No, the speaker is labeled 2Ω as well. It is not normal for a speaker to read the same DCR as it is labeled; impedance is, as you know, dynamic loading.

Yeah, that was a brain-fart on my part plain & simple. I was thinking "higher impedance will just lower the speaker loading, etc..." and completely failed to error check before I posted.  I've gone back and corrected, tho it still feels a wee bit clunky due to trying to fit into existing post.

Under any circumstances, in most cases using a lower impedance speaker will do nothing except higher impedance speaker will do nothing except lower speaker loading and decrease max volume a bit, which will make the amp run a bit cooler.

In my experience, the real-world difference in replacing a 6-8" driver (in a car door; if it were in a tuned enclosure, a different story altogether) with another that is 1Ω different impedance is in most cases not going to be something you can even hear. He might even be able to get away with replacing just the one speaker, but most likely there would be a difference in perceived volume.

As for the crossover... a lot of things to consider.

If it uses a passive X-O, there would be a theoretical difference in response, yes... but in real-world sound quality, the difference will likely not be great due to the fact of not being in a sealed/tuned enclosure (the car door). If I were REALLY concerned about the audio fidelity (like when I used to do dB drags and such), I'd replace the whole shebang with a name-brand component set and use the crossover that came with it.

However... another thing to consider... a lot of the OEM "premium sound" setups use bi-amp and even tri-amp drive, with active crossover in the frontend. There you'd be looking at very little difference between a 3Ω speaker and one with nominal 4Ω impedance.

If that speaker is actually supposed to be 2Ω, then yes... could be a noticeable difference, particularly in relative volume. But myself, as this is just gramma's grocery getter, I'd probably try a cheap pair of aftermarket drivers first and see if I could get decent sound out of 'em.

mnem
 

[mnementh]

I officially underestimate how dangerous lead is... EDIT: on the other hand

The safety section contains a classic! (And presumably the orange safety specs allow better visibility through clouds of vapourised flux)

Oooooh... is it time for THE CRINGE again...?



mnem

[mansaxel]

Yeah, reconing isn't going to fix a voice coil rusted fast. Also very NCE for a cheap factory speaker. Spec indicated that cost was a concern, so I recommended replacing with a set of cheap aftermarket drivers. 

No, it is not likely available. But if it were, it would fix the voice coil too; because recone kits come with new voice coils. Just need to clean out the old gunk.

No, the speaker is labeled 2Ω as well. It is not normal for a speaker to read the same DCR as it is labeled; impedance is, as you know, dynamic loading.

Oh, it was labeled 2Ω, that is another thing. 

Yeah, that was a brain-fart on my part plain & simple.

OK, no problemo.

In my experience, the real-world difference in replacing a 6-8" driver (in a car door; if it were in a tuned enclosure, a different story altogether) with another that is 1Ω different impedance is in most cases not going to be something you can even hear.

<snip>

As for the crossover... a lot of things to consider.

If it uses a passive X-O, there would be a theoretical difference in response, yes... but in real-world sound quality, the difference will likely not be great due to the fact of not being in a sealed/tuned enclosure (the car door). If I were REALLY concerned about the audio fidelity (like when I used to do dB drags and such), I'd replace the whole shebang with a name-brand component set and use the crossover that came with it.

Yeah, most likely. I'm just nit-picking.  Dragons like that, I've decided!

[AVGresponding]

I remember some years back investigating one of the door speakers in my 205, which had started to "fart" quite badly. I habitually drove my sound system very hard and so was expecting some damage to the front suspension, maybe even some torsional distortion of the cone.
What I found was that the entire front suspension had disintegrated, the cone just flapping around on its voice coil suspension!   

I fitted some nice Alpines and never looked back. In fact, I took the speakers back out when I scrapped the car, still have them...

[mnementh]

Yeah, reconing isn't going to fix a voice coil rusted fast. Also very NCE for a cheap factory speaker. Spec indicated that cost was a concern, so I recommended replacing with a set of cheap aftermarket drivers. 

No, it is not likely available. But if it were, it would fix the voice coil too; because recone kits come with new voice coils. Just need to clean out the old gunk.

Yeah, most likely. I'm just nit-picking.  Dragons like that, I've decided!

 HAHAHAHAHA!!!   Yeah, there's prolly a grain of truth in that. I wouldn't come to eevBlog if tweren't so.

Yeah, you're right... if a kit was available, and you could get the rust cleaned out... but then you'd have the problem of it wanting to rust up again in no time. Ugggh.

I've paid my dues on that whole rigamarole; can't count the number of kits I've had to throw on a shelf and hope they get used at a later date because the vendor info was wrong or incomplete so I had to guess, and when it arrived the VC or spider wasn't exactly right. Anymore, if a speaker needs more than a new dome or surround, I give it wide berth.

mnem

[mnementh]

...The person who coined the phrase getting old gracefully needs a full comprehensive and continuous beating.  There is no gracefully, you get old kicking and screaming every step of the way.

OWWWWW! Watch where you're kickin', muthafucka!!!   

mnem
*certifiable old punk*

[AVGresponding]

Fair warning for the forgetful among us; Discord screeching in your ear in 3 hours or less

[Specmaster]

Driver frozen up is a very common failure mode; I've replaced more than I can count. 

That's when the recone kit comes out. Such things do exist. I've done more JBL 2220 and 2225 15" drivers than I can count. Although, for a simple 6" car woofer, not likely to find one. Aftermarket foam surrounds, though.  That is a thing.

Get a pair of cheap aftermarket 4Ω speakers the right size and replace both so the sound is the same. If that speaker measures 2Ω DCR, actual impedance will be a bit higher; more like 2.5-3Ω. Inversely, a 4Ω impedance speaker will usually measure 3-3.6Ω DCR.

2Ω might be a battered 4Ω too. I've done a few in-door replacements, and there's one coming up soon here. What I usually do, is to go to used parts dealers and buy from scrapped cars. For a lot of non-wear items (and a good deal wear items too) this is a very convenient and cheap way to prolong the life of your car.  In Sweden, there's a common online database service for about 150 dealers where you can search on mfr part number and find who's got it. Very, very effective and convenient.

Under any circumstances, in most cases using a lower impedance speaker will do nothing except decrease max volume a bit and make the amp run a bit cooler.

Now, lowered impedance, if we for a while play "DC == AC" simplification game, means more current. More current usually means hotter transistors. The limiting factor for output power is rail voltage, which will set an output level at which clipping happens. In an ideal amplifier, half the load impedance means double current at a fixed max voltage, doubling the output power, and making the amp run hotter. Less than ideal amplifiers usually mean that the power supply can't supply enough current, or the transistors won't deal with the power levels, placing a limit on how low load impedance safely can be.

I'm quite bad at electronics, and I only have professional user experience of power amplifiers, but this is what I learnt during perhaps 20 years doing such things on and off.

So, how come you predict the amp will run cooler? And then we've not discussed any passive crossover point moving because the impedance is a part of the filter..

Yeah, reconing isn't going to fix a voice coil rusted fast. Also very NCE for a cheap factory speaker. Spec indicated that cost was a concern, so I recommended replacing with a set of cheap aftermarket drivers. 

No, the speaker is labeled 2Ω as well. It is not normal for a speaker to read the same DCR as it is labeled; impedance is, as you know, dynamic loading.

Yeah, that was a brain-fart on my part plain & simple. I was thinking "higher impedance will just lower the speaker loading, etc..." and completely failed to error check before I posted.  I've gone back and corrected, tho it still feels a wee bit clunky due to trying to fit into existing post.

Under any circumstances, in most cases using a lower impedance speaker will do nothing except higher impedance speaker will do nothing except lower speaker loading and decrease max volume a bit, which will make the amp run a bit cooler.

In my experience, the real-world difference in replacing a 6-8" driver (in a car door; if it were in a tuned enclosure, a different story altogether) with another that is 1Ω different impedance is in most cases not going to be something you can even hear. He might even be able to get away with replacing just the one speaker, but most likely there would be a difference in perceived volume.

As for the crossover... a lot of things to consider.

If it uses a passive X-O, there would be a theoretical difference in response, yes... but in real-world sound quality, the difference will likely not be great due to the fact of not being in a sealed/tuned enclosure (the car door). If I were REALLY concerned about the audio fidelity (like when I used to do dB drags and such), I'd replace the whole shebang with a name-brand component set and use the crossover that came with it.

However... another thing to consider... a lot of the OEM "premium sound" setups use bi-amp and even tri-amp drive, with active crossover in the frontend. There you'd be looking at very little difference between a 3Ω speaker and one with nominal 4Ω impedance.

If that speaker is actually supposed to be 2Ω, then yes... could be a noticeable difference, particularly in relative volume. But myself, as this is just gramma's grocery getter, I'd probably try a cheap pair of aftermarket drivers first and see if I could get decent sound out of 'em.

mnem
 

Yeah, I knew that you had the running cooler bit, arse backwards, so I ignored that to save the dwagons blushes. After market speakers would be a bit of a pig to fit due to way these speakers are constructed and location in the door. The woofer is in a reasonably sealed enclosure of their own, so need the replacements to be precise same size and depth etc to form the enclosure between the door card and the door.

So I have located on eBay the normal standard fitment speakers for the Superb, identical in overall dimensions etc except for the magnet, which is slightly smaller going by the photos, I can't think that just 1 will make that much difference, but to safe, I'm going swap both front speakers over to standard ones. I'll keep the good uprated one just in case there is a noticeable difference, ready for refitting in the event I come across another one like it.

Problem is that there are no sellers on eBay that has 2 of them, so I have submitted 2 offers, 1 one of which has been accepted and I've paid already, so I'm just waiting to hear if the one will be accepted, if not I may just try and get away with just the 1 speaker, after all, it will be far better than what I have currently

The power amp sits under the front passenger seat and judging by the huge multipin plug and loom going to it, it will be a tri-amp x 4.

At the moment I'm just fed up not being able to hear any bass coming from the left front door, especially when playing some of Pink Floyd and Phil Collins tracks where the stereo effect on bass is really pronounced.

[mnementh]

Empirical Engineering at its finest. 

mnem
 

[Specmaster]

I officially underestimate how dangerous lead is... EDIT: on the other hand

The safety section contains a classic! (And presumably the orange safety specs allow better visibility through clouds of vapourised flux)

Oooooh... is it time for THE CRINGE again...?



mnem

Don't ya just hate the smell of burning flesh 

[Specmaster]

Empirical Engineering at its finest. 

mnem
 

I didn't trust that German supplier as they claimed to have both types of speakers in stock at the same price  and with the same photos  and yet part numbers were different, mine is 3T0035411J and the standard speaker is 3T0035411A. Then there was the hassle of possible import duty and returning it if it was faulty or damaged, or even, as I suspect, claiming they have when they only have 1 and hoping no one notices 

[Specmaster]

Fair warning for the forgetful among us; Discord screeching in your ear in 3 hours or less

Yeah, I'm hoping to be there, if only on the text channel, the youngest's monitor has just shot itself, so I'm being pressured to go and see if I can resurrect that now, as well getting a curry takeaway for dinner.

[mnementh]

...Problem is that there are no sellers on eBay that has 2 of them, so I have submitted 2 offers, 1 one of which has been accepted and I've paid already, so I'm just waiting to hear if the one will be accepted, if not I may just try and get away with just the 1 speaker, after all, it will be far better than what I have currently

The power amp sits under the front passenger seat and judging by the huge multipin plug and loom going to it, it will be a tri-amp x 4.

At the moment I'm just fed up not being able to hear any bass coming from the left front door, especially when playing some of Pink Floyd and Phil Collins tracks where the stereo effect on bass is really pronounced.

Yeah, factory car audio follows the same fundamental law of service-ability as all other technology:

"Good, Cheap, Easy. Pick any two."

Bet you a dollar that's because they replaced one that failed in exactly the same way as yours with a pair of aftermarket drivers and are trying to recoup a little of that investment.

It may very well be a "design flaw" with your vehicle; well, something that fails consistently in a certain way due to the design of the car or the speaker. I remember back in the day, the Chrysler K-cars would always blow out the left-front speaker; the other 3 almost never failed. 

mnem