Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

That has to do with the frequencies the circuit is optimized for; they use actual Kelvin wiring up to the alligator clip. Many folks have modded them for true Kelvin operation using 75Ω coax from laptop WiFi antennae.

I assume you're considering the LCR45 combined with the ESR+/ESR70?

I've been using an ESR+ since they were brammy-spankin' pre-order new. So like (looks at shipping label on bottom of box, which makes handy tool case) 9 years. Effing awesome, pain-free tool. Quick & accurate, plus it automatically discharges DUT (abuse rating +/-275V!!!); ideal for its intended purpose, which is repair bench diag work. In all honesty, it is probably my prior experience with the ESR+ that has held me back from fully educating myself on the proper usage of the DE-5000; it's so much easier to just grab the ESR+ and get a quick answer.

I don't have the LCR45, but I expect it to be similarly excellent. If you need both feature sets and still can't make yourself buy the DE-5000, then I think the pair would be an awesome one-two punch for the majority of general-purpose diag work.

Maybe you should get the LCR45 and tell us what you think, so we can all have a similar evaluation?

mnem
 

[bd139]

Yes I was looking at the ESR70 as well but the thing is I don't usually actually bother measuring ESR. I just feel like I should. I usually get a feeling for which caps are shafted and just swap them out. So I'm not sure I need one yet.

The LCR45 does the job and has the right specifications so I supposed it's probably a good compromise.

While I like the look for DE-5000, and it does both, I'm not so sure about the whole shipping, customs, reliability, quality side of it. I know people who've returned peak stuff out of warranty and got it fixed for example. DE-5000 works out slightly more expensive and returns and problems are £££.

I shall mull for a few mins. It's 4pm here and cut off for Rapid (cheapest UK reseller) is 6pm...

Edit: quick one - this is what I'm currently doing to measure inductance ...

I take an RC with known C measured with the 87V and "ring it" with the AWG with a square wave, then measure the frequency:



Then plug the thing into ((1/2*pi*f)^2)/C to get L.

[mnementh]

Well, speaking as someone who's done bench work for a living... ESR measurement IS an indispensible tool. Jobs like med's Sony receiver there... I look at the PVC heat-shrink on those caps, which from years of experience I know is NOT what they're supposed to look like (the heat-shrink should come right up to the edge of the can) tells me they're highly suspect. The ESR+ is THE TOOL for that; THE definitive answer.

I see the difference being this: ESR+ for electrolytic caps and testing MMLC caps for poor ESR, the LCR45 for ceramic/mylar, etc and small-med value inductors.

mnem
 

[bd139]

Yeah it's definitely 100% required if you're doing professional service but for me it's not a big issue or a budgetary issue to just throw new caps at something as a precaution. I know the suspicious ones as well. They tend to look a bit like Mr Creosote 

I'm building high Q LC filters with this LCR45 so in theory that's the ideal thing for the job. I'm going to have to build some custom inductors with pot cores for that.

[med6753]

Well, speaking as someone who's done bench work for a living... ESR measurement IS an indispensible tool. Jobs like med's Sony receiver there... I look at the PVC heat-shrink on those caps, which from years of experience I know is NOT what they're supposed to look like (the heat-shrink should come right up to the edge of the can) tells me they're highly suspect. The ESR+ is THE TOOL for that; THE definitive answer.

I see the difference being this: ESR+ for electrolytic caps and testing MMLC caps for poor ESR, the LCR45 for ceramic/mylar, etc and small-med value inductors.

mnem
 

As I said the other day those caps are OK. They simply have a mylar label going around the can and it does NOT project over the top of the can. I've never seen caps labeled like that before and they have no brand name on them.   

[mnementh]

Yeah it's definitely 100% required if you're doing professional service but for me it's not a big issue or a budgetary issue to just throw new caps at something as a precaution. I know the suspicious ones as well. They tend to look a bit like Mr Creosote 

I'm building high Q LC filters with this LCR45 so in theory that's the ideal thing for the job. I'm going to have to build some custom inductors with pot cores for that.

Hmmm...

Tell you what. Give me a DigiKey BOM of inductors and caps that you'd trust to be reasonably close to advertised spec, that you'd like to see tested with the DE-5000. I'll order the BOM and run the gauntlet on 'em, then post results here.

This is something I've been meaning to do for a while now. 

mnem
 

[med6753]

Speaking of this POS Sony. It's back together and burning in. So far no issues but my Brother said sometimes it will go for hours before going into protect. We'll see.

And it is truly a POS. It has almost NO bass response. Perhaps that's deliberate because most folks connect a sub but still compared to my older stuff it sounds terrible.

 

[bd139]

Hmmm...

Tell you what. Give me a DigiKey BOM of inductors and caps that you'd trust to be reasonably close to advertised spec, that you'd like to see tested with the DE-5000. I'll order the BOM and run the gauntlet on 'em, then post results here.

This is something I've been meaning to do for a while now. 

I haven't got a BOM off the top of my head. For precision capacitors I use Vishay MKP1839 1%. Decent Q, usually bang on. Warning they are stupid expensive - $5-10 each. But TBH the cheap green blobs from Tayda/China are pretty good believe it or not but you have to bin them yourself hence the LCR45. I buy 100 mylar films for the price of one MKP1839 and get 5-6 within 1% of the value. Good tradeoff. Source: https://www.taydaelectronics.com/capacitors/polyester-mylar-film-capacitors/0-1uf-100v-5-mylar-film-capacitors.html . Pretty good caps the green ones I have to say. Supposedly microphonic but I can't reproduce that.

Inductors I wind my own usually because decent tolerance inductors are $20+ a go. Got a metric ton of old Mullard and Epcos pot cores.

[mnementh]

Well, speaking as someone who's done bench work for a living... ESR measurement IS an indispensible tool. Jobs like med's Sony receiver there... I look at the PVC heat-shrink on those caps, which from years of experience I know is NOT what they're supposed to look like (the heat-shrink should come right up to the edge of the can) tells me they're highly suspect. The ESR+ is THE TOOL for that; THE definitive answer.

I see the difference being this: ESR+ for electrolytic caps and testing MMLC caps for poor ESR, the LCR45 for ceramic/mylar, etc and small-med value inductors.

mnem
 

As I said the other day those caps are OK. They simply have a mylar label going around the can and it does NOT project over the top of the can. I've never seen caps labeled like that before and they have no brand name on them.

It's not mylar; it's thin PVC (as opposed to the usual polyolefin) and it should go all the way up to the edge of the can, but not over the top. This design of cap is a "thing" I've seen a lot of in the last 10-15  years or so. If you've tested them and they're okay, fine.  I didn't mean to cast aspersions upon your diag skillz.

mnem
The Marcus says "moo!"

[med6753]

No offense taken.  Just pointing out that they tested OK and are a weird labeling scheme. 

[mnementh]

Speaking of this POS Sony. It's back together and burning in. So far no issues but my Brother said sometimes it will go for hours before going into protect. We'll see.

And it is truly a POS. It has almost NO bass response. Perhaps that's deliberate because most folks connect a sub but still compared to my older stuff it sounds terrible.

It's a DTS receiver. By default, all outputs will be configured as "Small speaker" for the pedestal speakers & subwoofer system that usually ship with the receiver. All speaker outputs will be processed through a 12-24dB active crossover set at at 80-180Hz High-Pass. You CAN change this in the setup for most such receivers made in the last 20 years.

mnem
 

[med6753]

Speaking of this POS Sony. It's back together and burning in. So far no issues but my Brother said sometimes it will go for hours before going into protect. We'll see.

And it is truly a POS. It has almost NO bass response. Perhaps that's deliberate because most folks connect a sub but still compared to my older stuff it sounds terrible.

It's a DTS receiver. By default, all outputs will be configured as "Small speaker" for the pedestal speakers & subwoofer system that usually ship with the receiver. All speaker outputs will be processed through a 12-24dB active crossover set at at 80-180Hz High-Pass. You CAN change this in the setup for most such receivers made in the last 20 years.

mnem
 

Ah yea.....you might be right. I reset it back to factory default and it's probably defaulted to the pedestal speakers. And yes, I can be changed but I'm not gonna screw with it. If I fixed the protect problem it's going back to it's home ASAP. 

[mnementh]

No offense taken.  Just pointing out that they tested OK and are a weird labeling scheme. 

What's the ESR? I'd expect less than 0.1Ω on those if they're healthy.

They are weird, I'll agree. I suspect the printed PVC heat-shrink is supposed to be a built-in "telltale" for prolonged heat exposure, but that's just an educated guess.

mnem
 

[med6753]

No offense taken.  Just pointing out that they tested OK and are a weird labeling scheme. 

What's the ESR? I'd expect less than 0.1Ω on those if they're healthy.

They are weird, I'll agree. I suspect the printed PVC heat-shrink is supposed to be a built-in "telltale" for prolonged heat exposure, but that's just an educated guess.

mnem
 

6800uf, 72V and their ESR was just at 0.1 ohm so they were "OK" but not great.

[bd139]

AFAIK ESR is higher on larger caps due to the material size, which is why you tend to bus smaller ones so that sounds about right.

[mnementh]

Speaking of this POS Sony. It's back together and burning in. So far no issues but my Brother said sometimes it will go for hours before going into protect. We'll see.

And it is truly a POS. It has almost NO bass response. Perhaps that's deliberate because most folks connect a sub but still compared to my older stuff it sounds terrible.

It's a DTS receiver. By default, all outputs will be configured as "Small speaker" for the pedestal speakers & subwoofer system that usually ship with the receiver. All speaker outputs will be processed through a 12-24dB active crossover set at at 80-180Hz High-Pass. You CAN change this in the setup for most such receivers made in the last 20 years.

mnem
 

Ah yea.....you might be right. I reset it back to factory default and it's probably defaulted to the pedestal speakers. And yes, I can be changed but I'm not gonna screw with it. If I fixed the protect problem it's going back to it's home ASAP. 

Ummm... *cringe* ...and if you keep it that way, you won't be testing "under load". No high temps at the finals, no heating up on those caps, no resultant voltage "sag" and random speaker protection faults...

You also want to check with bro to make sure he's using correct impedance speakers and not paralleling speaker sets. Those protection faults may just be the amp protecting itself from a 2-6Ω load when it should be 8Ω. 

mnem
Yes, as often as not, with consumer electronics, diag work includes diag-ing user faults as well.

[mnementh]

No offense taken.  Just pointing out that they tested OK and are a weird labeling scheme. 

What's the ESR? I'd expect less than 0.1Ω on those if they're healthy.

They are weird, I'll agree. I suspect the printed PVC heat-shrink is supposed to be a built-in "telltale" for prolonged heat exposure, but that's just an educated guess.

mnem
 

6800uf, 72V and their ESR was just at 0.1 ohm so they were "OK" but not great.

Ewww... okies...

I was thinking typical value in the neighborhood of 4700/50V, which would be 0.08-0.06Ω... so shift that a decimal over. More like 0.03-0.01Ω, at least with my ESR+. 

mnem
 

[med6753]

I had the same thought and decided to change it full range speakers. The bass response still sucks. 

I did talk to my bro about the speakers he had connected. The factory speakers that came with it and connected properly.

Yes, the ESR should be lower but it works and I ain't changing them.

[mnementh]

AFAIK ESR is higher on larger caps due to the material size, which is why you tend to bus smaller ones so that sounds about right.

Ehhh.... depends. If they have the thicker snap-in lugs, then the ESR still drops pretty linearly with size & voltage. But with large values above 4700uF or so and regular wire leads, yeah. That tends to be an issue.

mnem
The only constant is change.

[tggzzz]

Edit: quick one - this is what I'm currently doing to measure inductance ...
I take an RC with known C measured with the 87V and "ring it" with the AWG with a square wave, then measure the frequency:
Then plug the thing into ((1/2*pi*f)^2)/C to get L.

Don't forget that the frequency of oscillation shifts depending on the damping factor / quality factor.

[mnementh]

I had the same thought and decided to change it full range speakers. The bass response still sucks. 

I did talk to my bro about the speakers he had connected. The factory speakers that came with it and connected properly.

Yes, the ESR should be lower but it works and I ain't changing them.

Fair enough... those caps are probably $10-20 ea by the time you get 'em in hand. 

Some DTS systems STILL crossover at 40-60Hz even when set to large speakers; they want to shift that high-current subwoofer load outside the receiver so they can keep their specs looking good.    I'd still let it cook for a good long while in "Large speaker" mode before I call it okay. I used to use a cluster of cheap 1Ω/10W cement resistors on a big heat sink, set up to approximate two 6Ω loads with shunting at 10:1 ratio so I could cook a stereo or amp at high-ish power and still hear myself think.

You really can't call it "poor bass response"; you don't have the full system in play as it's intended to be used. Just think of it as a bi-amped system with the LP amp built into the subwoofer.

mnem
 

[neo]

Can i ask you lot a tube question?



Coming out of pin 3 it says max 150, i'm wondering just what the hell means? I'm almost certain it isn't a voltage rating. Maybe i should just stick to SS rectification 

[GregDunn]

Yes, as often as not, with consumer electronics, diag work includes diag-ing user faults as well.

When I was in college, a friend of my parents wanted my help with a pair of speakers he owned.  The problem was that when he hung them on the walls, they sounded terrible - distorted, no bass, etc.  They were a very nice pair of 60s KLH acoustic suspension bookshelf-sized units.  They did indeed sound awful, so I asked him to take one down in order that we could look at it.

He had cut a huge hole in the rear of the cabinet so he could hang it on a hook.

[PA0PBZ]

Coming out of pin 3 it says max 150, i'm wondering just what the hell means?

mA?

[med6753]

Can i ask you lot a tube question?



Coming out of pin 3 it says max 150, i'm wondering just what the hell means? I'm almost certain it isn't a voltage rating. Maybe i should just stick to SS rectification 

What is that from? That's a indirectly heated full wave rectifier that has a 6.3V filament and separate cathode. Very unusual. Most rectifier tubes are 5V filament with directly heated filament functioning as the cathode. And I don't recognize that basing. Does it say "B9A" ? Not in my RCA Receiving Tube Manual. Need more info. What is the tube type? 

Edit.....Looks like a 6X4 Rectifier. Max load on that tube is 90ma.

2nd edit, Nope...not a 6X4. The basing doesn't match.