Test Equipment Anonymous (TEA) group therapy thread

[med6753]

1st rule when posting, is to check your supporting photos 

At least it's not one of those "accidentally caught my naked large beer belly almost hiding my dick reflection pictures".   

You've been peeping again......

No, it's one of those "what has been seen cannot be unseen". Just like the 90 year old stripper. 

[AVGresponding]

Good news, bad news...


Good news, the stuff I ordered from JPR yesterday arrived today and I got a "second chance" on an ebay joblot.
Bad news, the sparky I did the mains change with on Wednesday has tested positive for covid so I am waiting to see if I have to isolate.


https://www.ebay.co.uk/itm/Electrical-Testers-Fluke-77-Multimeter-Hewlett-Packard-3010R-X3830L-311V-Joblot-/114885837085


Price was £35 shipped.

[Robert763]

Good news, bad news...


Good news, the stuff I ordered from JPR yesterday arrived today and I got a "second chance" on an ebay joblot.
Bad news, the sparky I did the mains change with on Wednesday has tested positive for covid so I am waiting to see if I have to isolate.


https://www.ebay.co.uk/itm/Electrical-Testers-Fluke-77-Multimeter-Hewlett-Packard-3010R-X3830L-311V-Joblot-/114885837085


Price was £35 shipped.

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

[AVGresponding]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

[med6753]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

[Robert763]

Shotgun re-capping will always be a polarised issue (pun intended). Kit from around 20 years ago is very likely to have dodgy electrolytic capacitors. And there are also known specific makes and models. However the electrolytics in older gear, especially the "computer grade" high ripple current units, are likely to be fine and will probably outlive any modern replacement. As long as the chemicals are pure and seals are good then older electrolytics are more reliable due to their size, Thicker foils, thicker separator, more electrolyte.
I change on a case by case basis myself.

[med6753]

Shotgun re-capping will always be a polarised issue (pun intended). Kit from around 20 years ago is very likely to have dodgy electrolytic capacitors. And there are also known specific makes and models. However the electrolytics in older gear, especially the "computer grade" high ripple current units, are likely to be fine and will probably outlive any modern replacement. As long as the chemicals are pure and seals are good then older electrolytics are more reliable due to their size, Thicker foils, thicker separator, more electrolyte.
I change on a case by case basis myself.

Yep, I agree. The aluminum can Sprague electrolytics will probably last 100 years no sweat. But you get the odd man out and I'm not good at picking out who that is. The cardboard Sprague cans are a change out no question. They tend to go dry.

Any tubular electrolytic? Bin it. Of course any wax cap or black beauties. Don't even test. Bin it. And we all know early beaded tants are fails just waiting to happen. Ceramic caps? I've only seen one go leaky. Mica caps? I've never seen one go bad. But the mica caps used in radio IF cans tend to go noisy. Poly caps like those used in the Type 535A and Type 547? Never seen one go bad and I usually don't change them.

And then we have modern equipment both precision and consumer that has all those radial lead caps which sometime are pure garbage.

     

[Andrew_Debbie]

That is indeed impressively bad. 

"Seller refurbished"    Hate to see what the seller's listings were like before.

[tggzzz]

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.[/color][/size][/b]

Many high performance high frequency spectrum analysers have "naked" diode mixers connected directly to the front panel connector. You can imagine that if too much current goes through those small diodes, they stop working.

Hence precautions:

• measure the power before you connect the UUT to the SA
• never have any DC on the signal; a DC block capacitor solves that but may raise the lowest input frequency and won't protect against the transient when a large DC is applied
• while there will be good attenuators inside the SA (between the connector and mixer), it might be advisable to have an external fixed attenuator

RTFM to see what the inputs can actually withstand.

[Cerebus]

[...]
And that's why *I* am not inclined to shotgun caps in old test gear.  YMMV.
[...]

Agree.

Why only shotgun the caps, if you are of that ilk?  You'd have to shotgun every component to be really sure nothing has drifted...  and that essentially means... buying new equipment!

Seems a better plan to verify that the old equipment lives up to its specs...  and only start replacing stuff when it doesn't.

Yeah, the latter is the approach I take. When I get something old but new to me I run it through the manufacturer's stated verification procedure* and if that's good and there aren't (from visual inspection) any obvious time-bombs, bulging electrolytics, RIFAs, etc., then I leave well alone.

I'm quite happy to follow Med et al's shotgunning as a spectator sport, but I wouldn't want to participate.

* If there is a written verification procedure. Being mostly an HP fanboy means that there is always one for HP kit and they're usually easy to reproduce, although sometimes you have to be a little creative if you haven't got all the test gear called out in the verification procedure.

[Cerebus]

1st rule when posting, is to check your supporting photos 

At least it's not one of those "accidentally caught my naked large beer belly almost hiding my dick reflection pictures".   

You've been peeping again......

No, it's one of those "what has been seen cannot be unseen". Just like the 90 year old stripper. 

Hold muh beer. I's a gettin' muh camera.

[Whooshing sound followed by the sound of crickets and the gentle rustling of tumbleweeds]

What? Why is the room suddenly empty?

[Cerebus]

I don't know why you all ran away. I was only going to photograph this:



Got muh boards!

This is the first time I've used JLCPCB and I must say I'm impressed. The quality of these boards is second to none. The only complaint that you could have, if you were being picky, is that the routing on the top edge of the board isn't 100% even - there are a couple of spots, probably where the router bit went into and out of the board, where the routing wavers off line by maybe 100 um. Other than that one minor imperfection they are pristine. Silkscreen is crisp and clear, the holes are accurate, the hot solder levelling is as level as you can expect to get with HASL. This is a 4 layer, 100 x 50 mm board that cost me the grand total of £11.87 for 5 including shipping half way around the world. Ordered on the 24th June, arrived today 10th July using the cheapest and slowest shipping method.

Colour me suitably impressed.

[Kosmic]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

[med6753]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

The last cable guy I had here had no clue as what my stuff was. 

[Brumby]

Typical.  I thought I would have a couple of weeks or so to sort out power options.

Mine arrived today. Def does not appear to be near as much "welder" as yours; but $12 delivered. Decent 12ga Silly-cone wires, already crimped ends and appear well-crimped. It appears they left the buzzer out as "optional" since some folks complained it couldn't be turned off.

   

... ... ...

Not sure if this is a revised design that includes "the cap mod" or not; I need to do the "deep dive" through all the comments and see what leads where.

I've been wondering about the idea of a "cap mod" myself.  Mine has a 2200uF cap across the power input, but the positive also runs directly to one of the welding probes which means this cap will discharge through the weld, providing no real benefit to the control circuitry.

Just watched a video from the same guy I saw testing various boards and he did a mod where the control circuitry was powered from a plug pack (wall-wart) but the welding still done by the high rate battery pack.  In essence, he just ran the the plug pack to the input to the board, with the positive battery lead going straight to the working probe, bypassing the board altogether.  The negative battery/probe connections ran through the board normally.

He seemed amazed that the board fired, having the control and welding circuits separate - but through simple observation you can see the board runs on periodic pulses about a second or so apart.  No magic there.

My approach would be to connect the negative side as normal and run the positive directly from the battery to one working probe, with a diode branching off to the positive input to the board.  This would leave the 2200uF cap to power the control circuitry during zaps.  I expect that should be enough for the job, but I might bump that up a bit ... to be sure.

[Brumby]

The last cable guy I had here had no clue as what my stuff was. 

Years ago one of my sons had an auto sparky over who was trying to show off with his "knowledge" and started talking about an oscilloscope, expecting to befuddle my son.

However the shoe ended up on the other foot when my son not only knew what he was talking about, but that we had one in the house.  Seems the sparky was taken aback - significantly.

.... and I missed it.

[Kosmic]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

The last cable guy I had here had no clue as what my stuff was. 

hehe like the guy that came to change my electricity meter for a wireless digital one. His previous job was manually reading those counters and he was now installing the new one. That was a impressive upgrade for someone with nearly 0 technical skills.

As soon as he left, I went to the basement to check the new meter and quickly realized that something was wrong. They were a loud noise coming from the meter, like a electric buzzing. I quickly ran outside to get him before he left. He had forgotten to secure the terminals in the meter correctly. Hello fire hazard 

[Cerebus]

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

Probably just the North American protectionism thing kicking in, especially with respect to a country that your southern cousins like to cast as the devil incarnate. Iran, or if you prefer Persia, has always had great respect for scholarship and it shows in the quality of their education system and the quality of their graduates. If your Iranian engineer was anything like the Iranian educated folks I've known he was probably better qualified than someone with the ostensibly equivalent qualification from a local institution.

It's a testament to the ingrained Iranian respect for learning that even after the Mad Mullahs took over in Iran the education system remained intact and largely unharmed (It had its hiccups, but that's to be expected). Imagine what would happen to the universities here in the West if the equivalent stripe of Christian fundamentalists took over here. You don't have to imagine hard, because in some places you can see it happening without the the fundamentalists rising to the level of absolute power that the fundamentalists did in Iran.

Also: Persian food is delicious! If you do get hold of an Iranian, get them to cook you their mum's recipe for Dhansak, you will not be disappointed.

However, don't leave Persian blokes alone with your women - I'm looking at you Manek Dubash^*. 

^* As I have mentioned before, Manek is the kind of man who would regularly Google himself, so I fully expect he'll see this in the fullness of time, even though he's not a member here.

[Andrew_Debbie]

ous-(tea)-group-therapy-thread/?action=dlattach;attach=1235081;image[/img]

Got muh boards!

This is the first time I've used JLCPCB and I must say I'm impressed.
Colour me suitably impressed.

I've used them a few times.   Twice the boards had a small amount of what appeared to be contamination during processing.  Showed up as little nicks or spots on the traces.   They were fine, but I was using 10mil trace and space.    Yields might not be 100% at 5mil or 3.5  (which they say they can do)

I've used their SMD assembly service a few times to.   It allows me to use fine pitch parts I would ordinarlily avoid.      It is also a time saver.  Not that I mind soldering 0805 parts, but it is so much faster / easier to have them do it for me.

[Specmaster]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

The last cable guy I had here had no clue as what my stuff was. 

Well now come on be fair, he was only in his 20's, so he had never the stuff in your collection, ask most people what Heathkit are famous for, and they will stare at you like you're bonkers 

[Kosmic]

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

Probably just the North American protectionism thing kicking in, especially with respect to a country that your southern cousins like to cast as the devil incarnate. Iran, or if you prefer Persia, has always had great respect for scholarship and it shows in the quality of their education system and the quality of their graduates. If your Iranian engineer was anything like the Iranian educated folks I've known he was probably better qualified than someone with the ostensibly equivalent qualification from a local institution.

It's a testament to the ingrained Iranian respect for learning that even after the Mad Mullahs took over in Iran the education system remained intact and largely unharmed (It had its hiccups, but that's to be expected). Imagine what would happen to the universities here in the West if the equivalent stripe of Christian fundamentalists took over here. You don't have to imagine hard, because in some places you can see it happening without the the fundamentalists rising to the level of absolute power that the fundamentalists did in Iran.

Also: Persian food is delicious! If you do get hold of an Iranian, get them to cook you their mum's recipe for Dhansak, you will not be disappointed.

However, don't leave Persian blokes alone with your women - I'm looking at you Manek Dubash^*. 

^* As I have mentioned before, Manek is the kind of man who would regularly Google himself, so I fully expect he'll see this in the fullness of time, even though he's not a member here.

The engineering order is really powerful over here. For most (if not all) engineer positions you must be a member of the order. They tried for many years to take control of software engineering but always failed.

[bd139]

I’m glad that failed. That’s be like letting some gun toting nazis in the local synagogue. I say that from experience working with software engineers for the last 30 years.

[mnementh]

Typical.  I thought I would have a couple of weeks or so to sort out power options.

Mine arrived today. Def does not appear to be near as much "welder" as yours; but $12 delivered. Decent 12ga Silly-cone wires, already crimped ends and appear well-crimped. It appears they left the buzzer out as "optional" since some folks complained it couldn't be turned off.

   

... ... ...

Not sure if this is a revised design that includes "the cap mod" or not; I need to do the "deep dive" through all the comments and see what leads where.

I've been wondering about the idea of a "cap mod" myself.  Mine has a 2200uF cap across the power input, but the positive also runs directly to one of the welding probes which means this cap will discharge through the weld, providing no real benefit to the control circuitry.

Just watched a video from the same guy I saw testing various boards and he did a mod where the control circuitry was powered from a plug pack (wall-wart) but the welding still done by the high rate battery pack.  In essence, he just ran the the plug pack to the input to the board, with the positive battery lead going straight to the working probe, bypassing the board altogether.  The negative battery/probe connections ran through the board normally.

He seemed amazed that the board fired, having the control and welding circuits separate - but through simple observation you can see the board runs on periodic pulses about a second or so apart.  No magic there.

My approach would be to connect the negative side as normal and run the positive directly from the battery to one working probe, with a diode branching off to the positive input to the board.  This would leave the 2200uF cap to power the control circuitry during zaps.  I expect that should be enough for the job, but I might bump that up a bit ... to be sure.

Pretty sure these welders rely on that cap to provide at least part of the high-current pulse used to make the weld. The "cap mod" I've read aboot involves isolating the control circuitry from the main power with a diode, then adding a stiffening cap to the isolated portion so that rail doesn't "brown out", causing gate voltage to drop during the pulse.

The theory is that is what causes the fiery doom... when the gate voltage drops during the weld event, the FETs transition from switch-mode to linear mode, and IR goes way up causing kabloomie.

I'm in the middle of aboot 6 different things ATM... I haven't had time to review the board or the comments on the listing yet.

mnem
*tzzzzzt*

[Specmaster]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

The last cable guy I had here had no clue as what my stuff was. 

hehe like the guy that came to change my electricity meter for a wireless digital one. His previous job was manually reading those counters and he was now installing the new one. That was a impressive upgrade for someone with nearly 0 technical skills.

As soon as he left, I went to the basement to check the new meter and quickly realized that something was wrong. They were a loud noise coming from the meter, like a electric buzzing. I quickly ran outside to get him before he left. He had forgotten to secure the terminals in the meter correctly. Hello fire hazard 

Yep, we have lots of similar people over here as well, it all started a few years back when it became the craze for people to be multiskilled. I can't actually remember any incidents like yours though, but I remember a couple of years ago when I had a smart meter installed, that 2 people turned up to do the installation. One was the old meter reader who actually did the physical install, such as it was and the other, an electrician to disconnect and reconnect the tails, which begs the question of why didn't he do it all? Apparently he was training the meter reader to do the whole thing on his own, eventually. Fine until something unexpected happens and then what?   

[mnementh]

You do know that that HP CALAN CATV tester has a 1GHz spectrum analyser function?
It actually works quite well.
 

I wasn't even sure what it was (and didn't bother to google it), I was mainly interested in the Fluke 77 and the Robin insulation tester. The HP was just some bonus weirdness.

I haven't even started to play with the HP 8570A yet; I've no experience with spec-ans, but I believe their inputs are quite fragile? I want to understand what I'm doing before I start poking them.

Since I have found out that CATV cable installers are just Joe Blow's off the street with no electronics training if they can operate that hp then you can.

Often true but not always. Last time I had to upgrade internet, the technician originally came from Iran and had studied in engineering. He unfortunately couldn't work in engineering over here because his formation was probably not recognized and it's a really protected field. Still, he was impressed with my TEA collection and we actually had a chat about Oscilloscope 

The last cable guy I had here had no clue as what my stuff was. 

Well now come on be fair, he was only in his 20's, so he had never the stuff in your collection, ask most people what Heathkit are famous for, and they will stare at you like you're bonkers 

*raises a paw*

DIY home electrocution kits...?  

mnem
*tzzzzt indeed...*