Test Equipment Anonymous (TEA) group therapy thread

[Vince]

Forgive the dumb question, but why not just put that tool in a vice to squeeze it smoothly instead of hammering it ?! 
The smooth progressive action of the vice would be kind to the lug wouldn't it.

I mean a real big/full size garage vice of course, not the tiny vice we use in the lab, that goes without saying !

[AVGresponding]

Interesting the first comment....

I like to solder all my lugs on for an even better connection.  And in the example at the end where you cut through the 4 - 0 lug, you chose a location where it had not been crimped thereby showing an uncrimped gap inside.  Not a nice demonstration.  Solder has always been superior to crimp, throughout the history of cable lug use.  Not sure where you went to school but we actually tested crimped vs soldered connections for resistance and noticed failures in current draw tests.  The solder, when done correctly always produced better results than crimps when done correctly.  In most applications, either will suffice.  However, for pure results solder wins.  Silver based solder is 5% more conductive than copper (copper 100%, silver 105% using copper as the standard conductor).  Heating wire tends to distort the insulator so care must be used.  I like to use a wet rag to cover the insulation near the end or an cooling paste which is available from most HVAC wholesalers.  Silver requires a bit more heat than propane, though so most opt for the crimp.  We're talking about the purest method here...in real life and in most situations the crimp will suffice.  Its important to know the composition of the lug being used as well.  Some are made of aluminum while some are copper and other's copper with a tinned coating.  Best to choose one with copper, either bare or tinned, since aluminum tends to oxidize over time which creates friction within the lug.  I've seen 'em glowing red like a toaster element from bad connection.  I got about 50 years experience in this subject.

Ok, I just got around to watching the video, and there are three points I care to make.

1. That fly was the star of the show, it trolled the **** out of him!   

2. He didn't crimp the lug correctly, and it wasn't because it was a cheap tool. You do NOT crimp to the tip of the wire, you only ever crimp BEHIND it. This is so the conductor forms a wedge in front of the crimp, preventing any realistic possibility of the cable pulling out of the crimp.

3. That was a crimp only lug. The ones that are intended for crimp or solder have a relief hole at the front, like the second one he sectioned.

[Cerebus]

Talking of ginger and white cats. About 30 minutes ago the living room curtains twitched and about five feet off the ground a furry ginger and white face poked through them. We're not on the ground floor, and we don't have a ginger and white cat. Window now shut to keep the furry burglar out.

See, now that was a missed opportunity - you could have had a ginger and white cat, but you blew it! 

They make excellent lab assistants.
 

-Pat

No, I could have had Madam (Madam of the furry variety, not Madam of the human variety) telling him to "GET OUT AND STAY OUT!" in the time honoured  claws and teeth fashion. She is not a fan of Ging (as we call him, to differentiate him from the similar looking Mr. Baker, also of the neighbourhood). He has snuck into the house several times recently, but so far he's been lucky or calculating enough to have done so only when Madam has been out. He's a stray/feral and will happily sit and look at me through a pane of glass, but won't let me get closer than about two feet if there isn't a pane of glass separating us.

[bd139]

Madam of the furry variety, not Madam of the human variety

Fortunately that was (furry && !human) and not (furry && human) 

[mnementh]

Forgive the dumb question, but why not just put that tool in a vice to squeeze it smoothly instead of hammering it ?! 
The smooth progressive action of the vice would be kind to the lug wouldn't it.

I mean a real big/full size garage vice of course, not the tiny vice we use in the lab, that goes without saying !

Because of how they work. To correctly crimp any crimp, you need to squeeze evenly from all sides at once. This kind of crimper was devised as a half-measure, to get a maybe-OK half-assed crimp without spending the big bucks on a proper industrial crimper. The core problem is that the action doesn't only compress, but rather is a wedge that acts to split as much as it does to compress.

Because of this, it relies on the integral strength of the lug to "get away with doing it wrong". With the race to the bottom in everything, including making things like lugs of the thinnest material we can get away with, you can't count on that anymore.

mnem
Just say "No, thank you" to crappy crimpers, no matter how cheap or expensive they are.

[mnementh]

Interesting the first comment....

I like to solder all my lugs on for an even better connection.  And in the example at the end where you cut through the 4 - 0 lug, you chose a location where it had not been crimped thereby showing an uncrimped gap inside.  Not a nice demonstration.  Solder has always been superior to crimp, throughout the history of cable lug use.  Not sure where you went to school but we actually tested crimped vs soldered connections for resistance and noticed failures in current draw tests.  The solder, when done correctly always produced better results than crimps when done correctly.  In most applications, either will suffice.  However, for pure results solder wins.  Silver based solder is 5% more conductive than copper (copper 100%, silver 105% using copper as the standard conductor).  Heating wire tends to distort the insulator so care must be used.  I like to use a wet rag to cover the insulation near the end or an cooling paste which is available from most HVAC wholesalers.  Silver requires a bit more heat than propane, though so most opt for the crimp.  We're talking about the purest method here...in real life and in most situations the crimp will suffice.  Its important to know the composition of the lug being used as well.  Some are made of aluminum while some are copper and other's copper with a tinned coating.  Best to choose one with copper, either bare or tinned, since aluminum tends to oxidize over time which creates friction within the lug.  I've seen 'em glowing red like a toaster element from bad connection.  I got about 50 years experience in this subject.

Ok, I just got around to watching the video, and there are three points I care to make.

1. That fly was the star of the show, it trolled the **** out of him!   

2. He didn't crimp the lug correctly, and it wasn't because it was a cheap tool. You do NOT crimp to the tip of the wire, you only ever crimp BEHIND it. This is so the conductor forms a wedge in front of the crimp, preventing any realistic possibility of the cable pulling out of the crimp.

3. That was a crimp only lug. The ones that are intended for crimp or solder have a relief hole at the front, like the second one he sectioned.

IMO the amount of cable he stripped would go well into the shoulder of the lug, so beyond where he made the first crimp, as you suggest it should be.

BUT... if you're going to double-crimp as he did (there are arguments for and against... not gonna get into that here) you should do the first crimp at the END of the lug, not at the shoulder. This ensures you have the wedge/plug you're trying to make correctly formed BEFORE you make the second crimp.

You should try to avoid having your second crimp overlap the first; this ensures that the wedge/plug you're talking about forms BETWEEN the two crimps, and the second crimp really is only "for good measure".

mnem
Oh, and right on aboot the fly... that made for some good cinema there.

[mnementh]

Talking of ginger and white cats. About 30 minutes ago the living room curtains twitched and about five feet off the ground a furry ginger and white face poked through them. We're not on the ground floor, and we don't have a ginger and white cat. Window now shut to keep the furry burglar out.

Had that with a tabby cat here a few months back. Was just sitting at the desk and it came and brushed my leg. I crapped myself as we don’t have a cat  . I shovelled it back out of the window it came from. 

As much as I hate cats, the poor bugger was hit by a car a couple of weeks back and didn’t make it 

Better watch out bd... we might start thinking you actually have a soul or summat... you know, something left that hasn't been eaten by all your redheads... 

mnem

[Zoli]

Forgive the dumb question, but why not just put that tool in a vice to squeeze it smoothly instead of hammering it ?! 
The smooth progressive action of the vice would be kind to the lug wouldn't it.

I mean a real big/full size garage vice of course, not the tiny vice we use in the lab, that goes without saying !

Because of how they work. To correctly crimp any crimp, you need to squeeze evenly from all sides at once. This kind of crimper was devised as a half-measure, to get a maybe-OK half-assed crimp without spending the big bucks on a proper industrial crimper. The core problem is that the action doesn't only compress, but rather is a wedge that acts to split as much as it does to compress.

Because of this, it relies on the integral strength of the lug to "get away with doing it wrong". With the race to the bottom in everything, including making things like this of the thinnest material we can get away with, you can't count on that anymore.

mnem
Just say "No, thank you" to crappy crimpers, no matter how cheap or expensive they are.

He meant to say:
"If you have the jaws, you can use the vise." 

[mnementh]

*groaaaannnnn...*

mnem
"critical hit from horrible pun... too weak to lob soggy ol' boots..." *passes out with a whimper*

[AVGresponding]

Interesting the first comment....

I like to solder all my lugs on for an even better connection.  And in the example at the end where you cut through the 4 - 0 lug, you chose a location where it had not been crimped thereby showing an uncrimped gap inside.  Not a nice demonstration.  Solder has always been superior to crimp, throughout the history of cable lug use.  Not sure where you went to school but we actually tested crimped vs soldered connections for resistance and noticed failures in current draw tests.  The solder, when done correctly always produced better results than crimps when done correctly.  In most applications, either will suffice.  However, for pure results solder wins.  Silver based solder is 5% more conductive than copper (copper 100%, silver 105% using copper as the standard conductor).  Heating wire tends to distort the insulator so care must be used.  I like to use a wet rag to cover the insulation near the end or an cooling paste which is available from most HVAC wholesalers.  Silver requires a bit more heat than propane, though so most opt for the crimp.  We're talking about the purest method here...in real life and in most situations the crimp will suffice.  Its important to know the composition of the lug being used as well.  Some are made of aluminum while some are copper and other's copper with a tinned coating.  Best to choose one with copper, either bare or tinned, since aluminum tends to oxidize over time which creates friction within the lug.  I've seen 'em glowing red like a toaster element from bad connection.  I got about 50 years experience in this subject.

Ok, I just got around to watching the video, and there are three points I care to make.

1. That fly was the star of the show, it trolled the **** out of him!   

2. He didn't crimp the lug correctly, and it wasn't because it was a cheap tool. You do NOT crimp to the tip of the wire, you only ever crimp BEHIND it. This is so the conductor forms a wedge in front of the crimp, preventing any realistic possibility of the cable pulling out of the crimp.

3. That was a crimp only lug. The ones that are intended for crimp or solder have a relief hole at the front, like the second one he sectioned.

IMO the amount of cable he stripped would go well into the shoulder of the lug, so beyond where he made the first crimp, as you suggest it should be.

BUT... if you're going to double-crimp as he did (there are arguments for and against... not gonna get into that here) you should do the first crimp at the END of the lug, not at the shoulder. This ensures you have the wedge/plug you're trying to make correctly formed BEFORE you make the second crimp.

You should try to avoid having your second crimp overlap the first; this ensures that the wedge/plug you're talking about forms BETWEEN the two crimps, and the second crimp really is only "for good measure".

mnem
Oh, and right on aboot the fly... that made for some good cinema there.

You shouldn't crush the wedge at all. Copper has a very low elastic limit, and if you do that you lose the benefit of having a wedge.

[bd139]

Talking of ginger and white cats. About 30 minutes ago the living room curtains twitched and about five feet off the ground a furry ginger and white face poked through them. We're not on the ground floor, and we don't have a ginger and white cat. Window now shut to keep the furry burglar out.

Had that with a tabby cat here a few months back. Was just sitting at the desk and it came and brushed my leg. I crapped myself as we don’t have a cat  . I shovelled it back out of the window it came from. 

As much as I hate cats, the poor bugger was hit by a car a couple of weeks back and didn’t make it 

Better watch out bd... we might start thinking you actually have a soul or summat... you know, something left that hasn't been eaten by all your redheads... 

mnem

If it's any consolation, I only spent about 3 seconds in that state of mind and my mind immediately turned into this dude and the possibilities of murdering my neighbour with a flying cat at 2AM at the window.

[mnementh]

Interesting the first comment....

I like to solder all my lugs on for an even better connection.  And in the example at the end where you cut through the 4 - 0 lug, you chose a location where it had not been crimped thereby showing an uncrimped gap inside.  Not a nice demonstration.  Solder has always been superior to crimp, throughout the history of cable lug use.  Not sure where you went to school but we actually tested crimped vs soldered connections for resistance and noticed failures in current draw tests.  The solder, when done correctly always produced better results than crimps when done correctly.  In most applications, either will suffice.  However, for pure results solder wins.  Silver based solder is 5% more conductive than copper (copper 100%, silver 105% using copper as the standard conductor).  Heating wire tends to distort the insulator so care must be used.  I like to use a wet rag to cover the insulation near the end or an cooling paste which is available from most HVAC wholesalers.  Silver requires a bit more heat than propane, though so most opt for the crimp.  We're talking about the purest method here...in real life and in most situations the crimp will suffice.  Its important to know the composition of the lug being used as well.  Some are made of aluminum while some are copper and other's copper with a tinned coating.  Best to choose one with copper, either bare or tinned, since aluminum tends to oxidize over time which creates friction within the lug.  I've seen 'em glowing red like a toaster element from bad connection.  I got about 50 years experience in this subject.

Purely from a resistive point of view that may be true, but overall I don’t think it is - solder will wick into the wire, and turn at least some of it, right where it emerges from the terminal, effectively into a solid conductor - right where it’s anchored and going to be subjected to the most stress.  What breaks first when subjected to vibration - solid wire, or stranded wire?

Properly made crimps are mechanically sound, more resistant to vibration than soldered ones, and gas tight.

https://workmanship.nasa.gov/lib/insp/2%20books/links/sections/201%20General%20Requirements.html#:~:text=Crimping%20is%20an%20efficient%20and,design%20application%20and%20connectivity%20requirements.

I’ll stick with crimping, thankyouveryplease…

-Pat

Edit to add:  copied from the first paragraph of the link above:
Crimped Terminations
Crimping is an efficient and highly reliable method to assemble and terminate conductors, and typically provides a stronger, more reliable termination method than that achieved by soldering.

No. Just no.

Solder joints are more difficult to do correctly, but when done so are almost always the better choice. The vibration point is a good one, but not really applicable for a home solar PV installation, unless you live directly above a seriously active tectonic fault zone.

I tend to agree... having done gazillions of soldered lugs personally. I'll make a exception for crimping a solderable lug if one does a crimp right at the end of the lug (or a couple mm inboard if it's a lug with no flare), then fill the shoulder with solder. The crimp will ensure you don't have to worry about the solder wicking up the cable.

mnem
Look! I contributed something positive to the discussion!

[mnementh]

What kind of soldering (station?) are you using for thick cables?   Our everyday 80 W soldering station wont cut it, right?   

You need napalm...

Even on 4-aught lugs, a propane torch is more than enough. You dip the stripped end in rosin flux, heat the lug right around the back of the shoulder, then when the flux smoke starts shooting out the hole, you start feeding in solder. Reheat as needed to finish the solder joint.

Some will tell you to feed solder until you see it drip out the back; I look for solder to be just starting to wick right at the end of the lug but still mostly copper, as I always finish with heavy-thickness heat-shrink, preferably the sealant-impregnated kind.

Y'all can argue aboot that one if you like... IMO, if your wires are breaking at the solder joint due to vibration, it means you haven't properly applied your D-straps close enough to the end of the wire to support it as it needs.

mnem
 

[AVGresponding]

Yeah, if your application has major vibration issues you should really be taking extra care with cable routing and strain relief.

[Robert763]

So I finally got around to trying out the recently purchased R&S FSH-Z1 power sensor that goes with my FSH3 SA.
All looked good so what to use as a reference power source? First thing I grabbed was an old HP 435A power meter.
As most will know these have a built in 0dBm (1mW) reference at 50 MHz. As this was an old meter that I'd never tested before I did a basic check to make sure there was no DC on the output using the trusty Fluke 8060A There wasn't any DC but switching the meter to AC showed 2.5V RMS at 50Hz  . I'm gussing the main smoothing cap(s) have gone. I think that 435A will become a donor.
So I set up the R&S CMS-33 comms test set as a source.
All looks good. There is a ~0.5dB difference from the set output setting but this is well within the the specification of the CMS-33.
So we need a third measurement or refence to find exactly what is Watt.
Enter the HP 432A and not one but two 478A thermistor sensors (about £20,000 worth at current Keysight list prices)
Bill, Dave and the two Doctors would be happy - perfect agreement . Test at -5dBm shown I did check other points.

More interstingly, while the FSH-Z1 is specified for 10MHz to 8GHz some testing shows that it is perfectly good all the way down to 500kHz 

[mnementh]

...You should try to avoid having your second crimp overlap the first; this ensures that the wedge/plug you're talking about forms BETWEEN the two crimps, and the second crimp really is only "for good measure".

mnem
Oh, and right on aboot the fly... that made for some good cinema there.

You shouldn't crush the wedge at all. Copper has a very low elastic limit, and if you do that you lose the benefit of having a wedge.

The wedge does form if you do the 2nd crimp far enough away; it forms between the 2 crimps. A mm wide and deep (less, really) is all the wedge needs be to provide more than adequate mechanical strength. When I talk of the 2nd crimp being "for good measure" it is to increase the contact area under compression for lowest resistance, not mechanical strength.

These are not brake cables or the like; mechanical strength does not need to be that much in engineering terms to be stronger than any mechanical stress it should ever experience.

mnem
 

[mnementh]

54621D is here. 

mnem
*disappears into the dwagon-cave*

[AVGresponding]

...You should try to avoid having your second crimp overlap the first; this ensures that the wedge/plug you're talking about forms BETWEEN the two crimps, and the second crimp really is only "for good measure".

mnem
Oh, and right on aboot the fly... that made for some good cinema there.

You shouldn't crush the wedge at all. Copper has a very low elastic limit, and if you do that you lose the benefit of having a wedge.

The wedge does form if you do the 2nd crimp far enough away; it forms between the 2 crimps. A mm wide and deep (less, really) is all the wedge needs be to provide more than adequate mechanical strength. When I talk of the 2nd crimp being "for good measure" it is to increase the contact area under compression for lowest resistance, not mechanical strength.

These are not brake cables or the like; mechanical strength does not need to be that much in engineering terms to be stronger than any mechanical stress it should ever experience.

mnem
 

You haven't seen how some "engineers" rag on cables connecting big batteries in big strings... you'd think the prospect of instant death if there's a serious short would moderate their behaviour, but as the old saying goes "familiarity breeds contempt".

If you do the arithmetic, you'll see that even a single crimp will have more surface contact area than the cable CSA. I'm not saying it's inherently bad, I'm just saying I prefer the guaranteed mechanical strength over the possible few nano-ohms difference a second crimp makes.

Mostly these things will only make a difference in edge cases; I routinely "crimp" 10-95mm² lugs with my trusty 2PH and a hammer (only if I don't have a proper crimper to hand and it needs to be done NOW. Bigger than 95mm² and I need a hydraulic crimper which I don't have, so those have to wait until it gets hired). Haven't burned any buildings down yet.   

[Neomys Sapiens]

What kind of soldering (station?) are you using for thick cables?
Our everyday 80 W soldering station wont cut it, right?

I've got the Weller WSD151 with the WSP150 iron,but I found that the high-capacity tips for the WSP80 cover most situations well.In the company we have a special JBC (HDE+T470) with up to 250W. But both aquisitions were motivated more by SMD power electronics and RF connectors than cables.

[factory]

I thought you won one of the 180 series SA mainframes, in the last PP auction, it should work in the SA mainframe, just some of the later ones haven't got the scope cal outputs, as they were made long after the scope modules became obsolete.
I'm I the only one on here with some 180 scopes in my collection?

David

I have a 181 here.


Lab Cat looking none too pleased with the poor probe compensation:


-Pat

A quick warning note for anyone with a HP 181T, 181A oscilloscope mainframe or spectrum analyzer display section (or older 141T,141S,141A), beware there is no protection for the storage CRT with excessive intensity, particularly in normal mode, where you can't see the trace bloom with high intensity setting, the storage mesh is often damaged on these from previous owners not RTFM, or clueless sellers that just turn every control to max until a trace appears. 

Warning from 141T manual, need to add the 181 warning (aka, use Write & avoid Norm for setting intensity).


Another warning, when buying unknown condition 180/181 series mainframes, check the PSU is working correctly, before trying with known good plug-ins, as there was a mention of damage to the plug-ins from a faulty PSU.

Some of mine.....

David

I noted the same warning in the Tektronix RM564 manual ... which I still have not got round to powering it up.  Eventually.... some day

I just want to note for the record that that photo was taken in rather dim lighting, so the phone camera horribly overexposed the appearance of the trace on the scope - it wasn’t set to eye-searing, screen-melting intensity despite the fact that it may seem to be.  Also note how bright the pilot light looks, and how dimly lit everything else is in comparison.  No CRTs were harmed in the production of that photograph. 

-Pat

I guessed that you were trying to get the best possible picture of your fuzzy whiskered friend.

The comment about the storage CRT, was intended for those not familiar with these old analog storage CRT based scopes (not Cubdriver), I try to add it everytime these are discussed, to try and get the information out there, so it can help newcomers & clueless house-clearer/trader type ePay sellers.
If I remember correctly, the 180series pdf manuals scanned by Agilent genitAl Technologies are complete unreadable shite, also the warning sticker is not always present.

David

[factory]

Another grey box* red box (for a change) arrived today. 


*I often get the comment "not another grey box" when large parcel(s) arrive.

David

[mnementh]

The wedge does form if you do the 2nd crimp far enough away; it forms between the 2 crimps. A mm wide and deep (less, really) is all the wedge needs be to provide more than adequate mechanical strength. When I talk of the 2nd crimp being "for good measure" it is to increase the contact area under compression for lowest resistance, not mechanical strength.

These are not brake cables or the like; mechanical strength does not need to be that much in engineering terms to be stronger than any mechanical stress it should ever experience.   mnem   

You haven't seen how some "engineers" rag on cables connecting big batteries in big strings... you'd think the prospect of instant death if there's a serious short would moderate their behaviour, but as the old saying goes "familiarity breeds contempt".

If you do the arithmetic, you'll see that even a single crimp will have more surface contact area than the cable CSA. I'm not saying it's inherently bad, I'm just saying I prefer the guaranteed mechanical strength over the possible few nano-ohms difference a second crimp makes.

Mostly these things will only make a difference in edge cases; I routinely "crimp" 10-95mm² lugs with my trusty 2PH and a hammer (only if I don't have a proper crimper to hand and it needs to be done NOW. Bigger than 95mm² and I need a hydraulic crimper which I don't have, so those have to wait until it gets hired). Haven't burned any buildings down yet.   

I think we've both come to a similar understanding of what's important when making heavy-ass cables (heavy ass-cables def need to be made for mechanical strength FIRST  ) ; just coming at it from different directions. I spent a fair bit of time doing scale RC drag racing, where fractions of a ohm do make a difference you can see on the clock, then working on big forklifts as a young mechanic... so I'll just say it can matter. 

When you say "rag on cables", I'm guessing you mean something different than I would? Over here, to "rag on" something means to "frequently, repeatedly denigrate" whatever it is... ie "In the TEA thread, we always rag on RIFAs and tants!"

So from the context, I'm guessing you mean something like "to put it on carelessly" or to "assemble poorly and without regard for proper procedure"...? 

mnem
*luggable... barely*

[Zucca]

Yes I was right, we can talk for pages and pages about crimping a big cable.
This is the only place that can happen so flawlessly.

Fantastic performance gang! Many thanks!

My major concern is now the power company: will they let me interconnect my solar/battery system IF I do not plan to sell back the energy to them?
All what I need is to stay passive as I am now....no change in my current contract.
I sent already an email... I am scared to read their response.

[Robert763]

Another grey box* red box (for a change) arrived today. 


*I often get the comment "not another grey box" when large parcel(s) arrive.

David

Racal SA 540 Universal counter
Edge lit readout
£38

[tautech]

Forgive the dumb question, but why not just put that tool in a vice to squeeze it smoothly instead of hammering it ?! 
The smooth progressive action of the vice would be kind to the lug wouldn't it.

I mean a real big/full size garage vice of course, not the tiny vice we use in the lab, that goes without saying !

With a little care you can indeed make very serviceable crimps in a vise if you know how.
Not so much with the smaller cable sizes however in a permanent installation where there will be zero vibration or rarely a need to disconnect it, then bucket type lugs, those without a opening at the bottom of the bucket then soldering on crimps works just fine however a cleaner job is done with a Propane torch rather than Oxy/Acetylene.

Crimps in the vice with commercially or homemade lugs really need a reasonably heavy wall lug to withstand the compression as only 2 sides of the crimp are contacted on.
First you need a crimp that well matches the cable size and then the Hex head of a bolt or stout nut for just one of the Hex faces to be squeezed into the side of the barrel of the crimp to leave a deep rectangle pressed into the crimp.
I've used this method with 100% success over many decades on heavy welder leads and with a couple of layers of shrink sleeve for strain relief it's a quick solution if you don't have some blowtorch handy or your sparky mate with the good crimpers has gone AWOL.

Edit
However care must be taken where one might do such non-standard procedures so to properly consider the risk to life, limb or property.