Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

The two decade boxes are college lab surplus.  Hopefully they haven’t been abused too badly by students.  I put an LCR meter and walked the dial around and it’s a bit of a mixed bag.  A few values are spot on but most are out, whether a bit high or a bit low.







I haven't taken the screws out and lifted it out of the back case to see what sort of capacitors were used inside and consider if a restuff with closer in value, tighter tolerance capacitors is feasible or desirable.

Next up is the resistance decade box.

These are not standards but substitution boxes, a few years old so will have drifted a bit and as such I don't think that are performing to badly. Not saying however that they couldn't be improved if possible.

[Neomys Sapiens]

For now I am tying to order some BNC - BNC test leads but can't make sense of the subtleties between the various acronyms/norms used to describe them. I am wondering if these norms somehow have a relation ship to the physical presentation of the cable. That is, I don't want the very thick/big diameter black one, I prefer the thin black ones.  Looking at Farnell's offering, pictures and pictures of lots of their cables, I am starting to venture into thinking that the (vanilla) RG58 is the cheaper stuff of all, and has the very thick black form.

The RG58 U and / or C might look like the are black too, but thinner / more flexible.  It seems to be about twice the price of the thicker RG58.

RG316 however clearly (pun intended) seem to the modern super thin transparent cable that we see all over the place. Price wise it seems to be 3 times the price of the thick RG58.

Is that right or does that have nothing to do anything ?! 

Robert did a good walkthrough. I'd like to add that -- in your frequency areas, given the generator you've got and so on, RG series cable is going to be just fine.  What you can find in terms of finished cable is probably not going to be very good. All caveats Robert discussed are going to apply to those cables; also, the connectors will probably be crap. Unless you pay a premium for say Rosenberger or similar.

Before the UK was stoopid enough to leave the Union, I did my best to empty it of old military radios, so I have a small set of Clansman gear. Among those sellers offering radios, there also was spares and parts for sale, so I've got a bunch of extras, including a large stash of .195" BNCs, probably to set me for life: Amphenol straight and angled solder connectors of very high quality.  I complement that with modern .195" cables from reputable manufacturers, like Berkenhoff & Drebes, SSB-Electronic, and Messi & Paoloni. 

I also found Amphenol chassis connectors, NOS NIB(ag) from one of the Israeli tank chock block sellers. (They were very good to deal with, but customs made me think twice; if the company is operating out of areas that aren't part of the original Israel but instead has gone and set up business in occupied areas, at least in Sweden, there are higher customs rates.) From dismantling an IBM SP2 computer, I have a large bag of BNC 50Ω female bulkhead couplers and 30cm jumper cables (The 10Base-2 Control Workstation Ethernet). Also Amphenol. And so on.

I usually don't crimp. I have crimpers, and for things like 75Ω video cable (especially 3G-SDI etc which is 3GHz bandwidth and quite fussy) I probably would, but the reversability of soldering and the PTFE / silicone rubber of the good connectors make them quite reusable. Also, a milspec clamp/solder BNC is going to be pretty water resistant. Not like N connectors, but still pretty good against ingress from rear. (N plugs are typically IP65 mated if solder-and-clamp and good quality.)

If lengths are going to be non-dramatic, that which I've described above will suffice up to UHF without trouble, as long as you stay away from shit connectors like "screened banana with thread" (PL259 "UHF") and Belling-Lee crap. For adapters like to banana et c; you probably mostly need to concern yourself with durability. The adapter situation in and of itself is going to be the main limiting factor for transmission via the interconnection.

I would definitely not recommend buying from SSB-Electronic! They supply total crap whenever it fits their business case, including the most ill-fitting, scratchy, and awkward N connectors I've ever seen!

[tautech]

The two decade boxes are college lab surplus.  Hopefully they haven’t been abused too badly by students.  I put an LCR meter and walked the dial around and it’s a bit of a mixed bag.  A few values are spot on but most are out, whether a bit high or a bit low.







I haven't taken the screws out and lifted it out of the back case to see what sort of capacitors were used inside and consider if a restuff with closer in value, tighter tolerance capacitors is feasible or desirable.

Next up is the resistance decade box.

These are not standards but substitution boxes, a few years old so will have drifted a bit and as such I don't think that are performing to badly. Not saying however that they couldn't be improved if possible.

Take your pick as to which capacitance meter and test frequency is used as to how accurate the values still are in those sub boxes.
I certainly would be changing anything in them until checked with multiple meters.

[Cubdriver]

Yes ideally that's what I would like to do : get a 100m reel of good quality cable, and make my own cables as I need them. Thanks for suggestions on what brand to buy...
Didn't know you could solder BNC connector to make cables.. tought it was only crimped.  Soldering sound more reliable no ? And easier probably, and does not require expensive tooling.
I like that... sell me some cable  and a bag of amphenol solder BNC's ! 

Properly done*, crimped is likely more reliable - it makes a gas-tight connection, and doesn't stiffen the wire the way that solder can if it wicks up into the stranding.  The other challenge with soldering if it's not Teflon cable is to not overheat and melt the dielectric of the center conductor.  That said, most of the BNCs I've used at work in the past (mostly on RG-316) have been solder pin/crimp shield - it's a reasonable compromise, but again unless the dielectric is Teflon (as the 316 is) it can get melty (HDPE insulated coax is a royal bitch to solder!).  It's also fun to get the solder into the tiny hole on the side of the pin without getting a glob on the outside, too, which then must be filed/scraped/melted off in order to get the pin to properly fit into the hole in the connector.  I used to keep needle files and an exacto knife handy, but definitely preferred crimp/crimp overall.

Dies for the common interchangeable ratcheting crimpers aren't usually too terribly pricy, so crimping of BNC connectors is typically less costly than trying to find the specialized crimpers used for, for instance, Molex pins and the like.

Happy New Year, all - let's hope 2022 is better than the past two years have been...

-Pat

* the italicized part is critical here

[AVGresponding]

Still, my scope probes have very thin and flexible cable, like the transparent stuff but black... so I guess this means it must be yet another RG-XYZ norm again ? Which one ?

I use RG174 when I want thin and flexible.

Same here. It's good for up to a low-few GHz (if it's decent quality). It's also way cheaper, and unless you're into high power stuff it's plenty good enough.

I also keep my eye out for clearance stuff from the likes of Rapid, have some nice RG58 SMA-SMA cables from them for not much money.

The two decade boxes are college lab surplus.  Hopefully they haven’t been abused too badly by students.  I put an LCR meter and walked the dial around and it’s a bit of a mixed bag.  A few values are spot on but most are out, whether a bit high or a bit low.







I haven't taken the screws out and lifted it out of the back case to see what sort of capacitors were used inside and consider if a restuff with closer in value, tighter tolerance capacitors is feasible or desirable.

Next up is the resistance decade box.

These are not standards but substitution boxes, a few years old so will have drifted a bit and as such I don't think that are performing to badly. Not saying however that they couldn't be improved if possible.

Take your pick as to which capacitance meter and test frequency is used as to how accurate the values still are in those sub boxes.
I certainly would be changing anything in them until checked with multiple meters.

Dirty/failing switch contacts will have a serious impact on the readings you get as well. I'd give those a damn good clean first, as I'd expect the caps used in these to be film of some sort and reasonably durable.

[GreyWoolfe]

I'm going with the through type of plugs to ensure that the correct cables are in the right positions before crimping as I've never really learnt the knack of getting the wires into the correct slots on the standard plugs. Does anyone else have the same problem?

Used to until I watched how our ISP buddy does it.
Overstrip and manipulate the strands into their correct positions and flex and tweak them between thumb and forefinger until they are all nice and straight and behaving themselves.
Then snip to correct length and offer up the RJ45 plug which should initially slide on with little effort however getting them all the ways home might take a bit of wiggling and shoving.

Did a couple the other day after not having done any for years and they worked out mint. 

I've watched many people do it on video before and I have managed to do it once or twice but only after ruining many plugs  maybe its because I have such big hands or something. When I was working, we used 6 core flat cable for our lighting control networking and never had any trouble terminating those, but make them into a circular cable and I struggle 

I can and have used both types but I do prefer the through type, my Amblyopia and astigmatisms are enough that I have to use my Optivisor to make patch cables.  Many years ago, I used to make patch cords for a part time gig I had so I got used to using the regular connectors.  Age has forced the use of magnification and the use of through connectors eliminates the fuss I have of trying to get the length right, I start long and keep lopping of a a little at a time until it fits right.  Being far sighted and having an issue with depth perception also doesn't help using the regular connectors.  I have large hands also so I don't think that has anything to do with it.  I do overstrip and manipulate the strands into their correct positions and flex and tweak them between thumb and forefinger regardless of the type of connector as I find the cable feeds in easier regardless of the connector used.

[mansaxel]

Yes ideally that's what I would like to do : get a 100m reel of good quality cable, and make my own cables as I need them. Thanks for suggestions on what brand to buy...
Didn't know you could solder BNC connector to make cables.. tought it was only crimped.  Soldering sound more reliable no ? And easier probably, and does not require expensive tooling.
I like that... sell me some cable  and a bag of amphenol solder BNC's ! 

If I start selling them I won't have enough :-D You'll have to look around. Cable, in my experience, is not worth buying second-hand. If it was installed, it probably was outdoors, using shitty connectors that leak, and way too little vulcanizing tape to make up for that. Water-logged coax is bad coax.

Then, of course, soldering coax is not for the sloppy.  Cable prep is with close tolerances, and unless you've got PTFE dielectric, getting the center conductor hot enough to solder will be a challenge. It is very satisfying when you get it right.

The swedish military soldering certification among others has a coax connector test. The requirements are very tough. I don't think I've ever managed to get one that right -- but I've only read the test instructions through, never tried to take the test.

Well it's just for bench use, so I guess at the most, 2 meters graaaand maximum ! I guess most of the time a 1 or 1.5 meter cable, is plenty enough to get from on piece of TE to the next...

That which I've described above will suffice up to UHF without trouble,

As I said in a previous post, I would like at least one good cable so I can shove a few (single digit) GHz down the throat of my 3GHz TDS 694C scope. But other than that, it's going to be slow speed stuff, below one GHz...

It'll likely work quite OK. It can always be improved upon, at cost, and each everyone need to decide where on the slippery slope of diminishing returns they'd like to stake their foothold..

[mansaxel]

@Zucca: (I'm a barbarian and I have fruit in my panna cotta.)

As long is not pineapple on pizza, I can forgive you.

I've had that. It's not the worst thing people put on pizza. The Swedish pizza culture is driven by people from the Balkans; first it was the Italians who took it to Sweden, but then the Greek and after them the Jugoslavians (as it were, back then) took over.  Today, a Swedish pizzeria is operated by immigrants, almost never from Italy, and they serve Kebab, hamburgers, and pizzas. These three kinds of food have cross-bred, and a very common one is the "kebab pizza".   Personally, I rate that below pineapple pizza.

To their credit, most pizzerias today also have a more expensive set of slightly more italian-looking pizzas on the menu. They are more like what you get in Italy, but of course rarely as good.  A select few pizzerias are the real deal; they often have a wood-fired oven built by masons from Napoli, and they churn out thin, crusty pizzas with only the right stuff on.

But, to summarize, there is a distinct swedish pizza style, that has mostly the name common with what's being served in Italy.

And, the most busy day at the pizzerias in Sweden is New Years day. The tradition is that you fix hangover by ordering pizza and watching Ivanhoe on TV. Some swedish TV channel (it varies which) has transmitted Ivanhoe every New Years day since the early 90s. 

There were leftovers of the Panna Cotta (I made 25 portions, for a party with 10 and went over to my parents with two portions to make sure they had a good evening) and there is Recioto left. Also, a rather large portion of one of the wine bottles for dinner (again, Drago from east of Verona) was spared.

I think we can have our home-made pizzas in style. (my recipe currently is tomato sauce, fennel salami, feta cheese, thinly sliced onion and then grated mozarella on top.

[bitseeker]

The two decade boxes are college lab surplus.  Hopefully they haven’t been abused too badly by students.  I put an LCR meter and walked the dial around and it’s a bit of a mixed bag.  A few values are spot on but most are out, whether a bit high or a bit low.







I haven't taken the screws out and lifted it out of the back case to see what sort of capacitors were used inside and consider if a restuff with closer in value, tighter tolerance capacitors is feasible or desirable.

Next up is the resistance decade box.

These are not standards but substitution boxes, a few years old so will have drifted a bit and as such I don't think that are performing to badly. Not saying however that they couldn't be improved if possible.

Take your pick as to which capacitance meter and test frequency is used as to how accurate the values still are in those sub boxes.
I certainly would be changing anything in them until checked with multiple meters.

Dirty/failing switch contacts will have a serious impact on the readings you get as well. I'd give those a damn good clean first, as I'd expect the caps used in these to be film of some sort and reasonably durable.

I second the recommendation on cleaning those switches. The GenRad decade boxes I have needed a good cleaning as well in order to get consistent results. Then, you can see what actually has drifted and, if desired, replace components.

[bitseeker]

Happy New Year. Sorry about your losses, but hope you will be in the TEA more often.

I'm currently working on a Boonton Model 42A power meter given to me. It works but needs some TLC and it's missing a button that I'm designing at the moment. I was just now inspecting one of the boards and it looks like green corrosion on the chopper wires, so I'll be redoing those connections now. 

Gald to see you back here!

Thanks, xrunner. I'm curious to see to what extent your replacement button will go to match the original.

Looking forward to more TEA with y'all.

[Zucca]

@Zucca: (I'm a barbarian and I have fruit in my panna cotta.)

As long is not pineapple on pizza, I can forgive you.

I've had that. It's not the worst thing people put on pizza. The Swedish pizza culture is driven by people from the Balkans; first it was the Italians who took it to Sweden, but then the Greek and after them the Jugoslavians (as it were, back then) took over.  Today, a Swedish pizzeria is operated by immigrants, almost never from Italy, and they serve Kebab, hamburgers, and pizzas. These three kinds of food have cross-bred, and a very common one is the "kebab pizza".   Personally, I rate that below pineapple pizza.

To their credit, most pizzerias today also have a more expensive set of slightly more italian-looking pizzas on the menu. They are more like what you get in Italy, but of course rarely as good.  A select few pizzerias are the real deal; they often have a wood-fired oven built by masons from Napoli, and they churn out thin, crusty pizzas with only the right stuff on.

But, to summarize, there is a distinct swedish pizza style, that has mostly the name common with what's being served in Italy.

And, the most busy day at the pizzerias in Sweden is New Years day. The tradition is that you fix hangover by ordering pizza and watching Ivanhoe on TV. Some swedish TV channel (it varies which) has transmitted Ivanhoe every New Years day since the early 90s. 

There were leftovers of the Panna Cotta (I made 25 portions, for a party with 10 and went over to my parents with two portions to make sure they had a good evening) and there is Recioto left. Also, a rather large portion of one of the wine bottles for dinner (again, Drago from east of Verona) was spared.

I think we can have our home-made pizzas in style. (my recipe currently is tomato sauce, fennel salami, feta cheese, thinly sliced onion and then grated mozarella on top.

In the eraly years in Neaples there were only 3 pizzas:

1- Marinara (tomato & anchoives, NO cheese)
2- Margherita (tomato, mozzarella di bufala campana, basil)
3- Calzone, bigger and folded to increase stuffing capacity. This was the one if you were really hungry.

Anyway the tomato is of course the San Marzano.

Even nowadays the most famous pizzerie in Neaples have a very limited menu (Thank God!)
Example: L'Antica pizzeria da Michele serves only TWO pizzas.
They are so full everyday of people, packed like a board with BGA. Every single day. The line is huge, just order take away and go to the next bar... they will welcome you with a dish a cutlery....

My general rules:

IF (No wood oven) THEN
      (walk away)
ELSE
      IF (they speak italian) THEN
               IF (the pizzas on the tables looks decent) THEN
                       (ask for a seat)
               ELSE
                      (walk away)
      ELSE
             (walk away)
               
 that said I had to confess when I was in Arjeplog for winter testing, I ate rendeer pizza. Mehhh, I did not like it but I could not resist.

[25 CPS]

The two decade boxes are college lab surplus.  Hopefully they haven’t been abused too badly by students.  I put an LCR meter and walked the dial around and it’s a bit of a mixed bag.  A few values are spot on but most are out, whether a bit high or a bit low.







I haven't taken the screws out and lifted it out of the back case to see what sort of capacitors were used inside and consider if a restuff with closer in value, tighter tolerance capacitors is feasible or desirable.

Next up is the resistance decade box.

These are not standards but substitution boxes, a few years old so will have drifted a bit and as such I don't think that are performing to badly. Not saying however that they couldn't be improved if possible.

Take your pick as to which capacitance meter and test frequency is used as to how accurate the values still are in those sub boxes.
I certainly would be changing anything in them until checked with multiple meters.

Dirty/failing switch contacts will have a serious impact on the readings you get as well. I'd give those a damn good clean first, as I'd expect the caps used in these to be film of some sort and reasonably durable.

I second the recommendation on cleaning those switches. The GenRad decade boxes I have needed a good cleaning as well in order to get consistent results. Then, you can see what actually has drifted and, if desired, replace components.

So the test setup:  There's a bunch of information on the screen.  Yeah, the U1733C is running factory defaulted because I didn't null the test leads, so not great.  It's also running at 1 kHz which is a pretty reasonable test frequency.  I didn't move it to any of the extremes like 100 or 120 Hz at the low end or wind it all the way up to 100 kHz.

Now, the phase angle is consistently over 10 degrees off an ideal capacitor which suggests there's some amount of resistive component dragging the vector plus whatever parasitic inductance so switch contacts are a prime suspect here so I several reasons for taking it out of the box.  I'm curious to see what parts they used and how they put it together, and be able to spray out the switch contacts.  The other thing I want to do is get the LCR meter right on to the capacitors if possible and see how the measurements differ compared to going from the banana plugs and switch.

[Cerebus]

I'm curious, what is the search term needed to find those solder on PCB edge pins? We had them on stuff at work and I never found out what they were, in the 15-ish years I worked in the electronics lab.


David

Damn, I found these the other day and thought "I'll have to remember what those are called" and promptly forgot. However like all people good at simulating being clever, I know where to look it up. Hold on ...

"Contacts - leadframe", leastways that's what Digikey has them catalogued.

Weird isn't it? I'm not smart enough to remember what I found out, but I am smart enough to remember where I found it out.

[mnementh]

We're about 10 minutes away from the end of 2021... And now it occurs to me:

I wanna read the gawddamn terms and conditions before I accept delivery on 2022. 

mnem
*raises a glass* Best of luck to all of us in the New Year!

[TERRA Operative]

Yes ideally that's what I would like to do : get a 100m reel of good quality cable, and make my own cables as I need them. Thanks for suggestions on what brand to buy...
Didn't know you could solder BNC connector to make cables.. tought it was only crimped.  Soldering sound more reliable no ? And easier probably, and does not require expensive tooling.
I like that... sell me some cable  and a bag of amphenol solder BNC's ! 

I use Canare crimp connectors for my RG-58A/U BNC needs, really high quality and never had a problem with them. A little bit of cash to set yourself up with tooling, but not too bad considering the cost of some crimpers out there. Plus, the ability to make bespoke cables on demand is great.
Canare don't do connectors for the thinner coax cables though unfortunately, their main deal is broadcast AV stuff.

I'm curious, what is the search term needed to find those solder on PCB edge pins? We had them on stuff at work and I never found out what they were, in the 15-ish years I worked in the electronics lab.


David

Here's the Digikey link for the exact part, that should get you started. It took a bit for me to find them and figure out what they were called too.

https://www.digikey.com/en/products/detail/te-connectivity-amp-connectors/1544210-2/4731536

[wolfy007]

My last save from ewaste bin at work for 2021;

[mnementh]

Oi... spinning rust is sooooo slow... 

Currently updating my old gaming rig (Athlon FX-8350 8-Core 4.0GHz/16GB DDR3-667/XFX RX580 Black Edition) which has been in the trailer unused for 2 years to the latest Win10, so I can have something to peek in here on while I let my son use my i7 laptop on his new 27in/1mS/IPS eSports monitor for his gaming sessions.

Well, and cuz I could. 

mnem
*cellar-dweller dwagon again*

[mnementh]

Happy New Year, or almost new year, to everyone (depending on location)!

Hope you're doing well, or as well as can be under the circumstances. It's been a rough year. Lost some friends and family, and work has been too busy, but I hope 2022 will be better.

What are your goals, TEA or otherwise, for 2022? Mine are to acquire less TE, shrink my repair queue, and spend more time in the forum.

(And catch more typos before submitting a post.)

Mine is to stay at the same address for more than 11 months for a change. And to not start any more international incidents. 

mnem
*heeds Hypnos' siren call*

[0culus]

My last save from ewaste bin at work for 2021;

Dang, that's the sort of thing that requires hours of training at my work. 

[cyclin_al]

 

I mean, it's fairly common on older Tek letter series plug ins to get rid of the UHF connector and replace it with BNC. Because it's a shite connector and annoying to use. Either that or install adapters. That's what I did for my Type O op-amp plug in.

Tek fully converted to BNC in 1963. My Type 535A was built after that date so it's BNC. But I've got plenty of stuff with the UHF connector such as two Type CA plug-in's, a Type 310A, and a Type 503A. I use the UHF to BNC adapters.

Tek even published an article in "Service Scope No.23" with instructions and recommendation to change existing equipment from the UHF (PL259) to BNC connectors.
https://w140.com/tekwiki/wiki/UHF_connector

I found it when reading the manuals for my RM564 and was confused about what a UHF connector was, until I came across that and discovered it was in fact the same as the dreaded PL259...

[cyclin_al]

Interesting enough the bottom right one "Water Fall GFCI" was clearely added after the home was done.
In that line the PE and N (cold/white) were connected together in the main panel. I prefer to keep always separated the PE and N so I disconnected the N from the PE and connected to the N bar.....
N with N and PE with PE in my planet.

Whew!  At least you and I are both from the same planet! 

[cyclin_al]

Happy New Year everyone!

My goal is to get a proper lab space setup and start using my TEA.  Oh, and get that RM564 working and installed in a rack in my lab.

I will also enjoy proper pizza and certain improper pizza 

[Neper]

Happy new year to one and all.

My goal is to throw out a lot of stuff. Too many things I haven't touched for years.

[mansaxel]

I would definitely not recommend buying from SSB-Electronic! They supply total crap whenever it fits their business case, including the most ill-fitting, scratchy, and awkward N connectors I've ever seen!

I've noticed that their connectors have a certain Chinesium feel at times, but do you extend your judgement to the cable too?

[mansaxel]

My last save from ewaste bin at work for 2021;

I'm green with envy. I really could use that at times.