Test Equipment Anonymous (TEA) group therapy thread

[Neomys Sapiens]

Hi guys and gals! Have a splendid and less infectious new year!

[DH7DN]

Happy New Year from Germany :-)

Goals in 2022: More Test Equipment

[Neper]

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.

[Vince]

Vince
A useful Coax chart I posted is in this thread:
https://www.eevblog.com/forum/testgear/quality-test-cable-rg58-alternative/

BTW, forget about using the thin flexible probe cables, they are not 50 Ohm rated and are lossy to help manage reflections.

Thanks for the link. Chart useful indeed, I have it in a safe place now...
Thread over there is... well, in just a handful of posts they managed to throw more cable types/norms than I can count, it's overwhelming. Clearly a whole can of worms in its own right... not qualified to go into that.
I do gather from the though, that important things are improved/ doubled screening for better signal integrity, losses which limit use at very high / Shahriar like frequencies (not my world...), and that having a stranded inner core is more important to achieve cable flexibility, than having a thin/small diameter cable. RG58 with stranded core apparently makes people happy for use on the bench as a test lead. So I should bed happy too I guess...
And foil shielding not good for test cables as won't last long on the bench, foil will deteriorate. Need braided shielding.


For now all I wanted was a quick answer to what is a decent general purpose affordable get me started with basic stuff... cable.
Seems RG58 'C' suffix is a good default choice, so will go with that for now.

Then later on if I get smarter and do fancy stuff that requires specific spec for thjis or that...then I will worry about what cable type is best for whatever it is that I want to achieve.
I guess the most likely scenario is if I get rich and can afford test gear to venture at several GHz, then maybe RG58 might have too much loss to be bearable. We shall see.

for now I am not into fancy RF stuff, so RG58 should do it I guess...

Well I do have a 3GHz scope, a TDC 694C, so I might want to get a cheap PLL like Factory AVGresponding just did, and sweep from 2 to 4GHz to see how it does, plot its bandwidth response out of curiosity, just for fun. But that's about as far as my "RF" needs are likely to go for the foreseeable future....

[Specmaster]

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.)

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!

What was the year of manufacture, do you know? I've this kind of thing before and mains cables made between 1965 and 1971 and this article relates.
https://www.voltimum.co.uk/articles/green-goo-0

[srb1954]

Later I got one of these Advance RF signal generators from the same source that also had the dreaded Belling-Lee coax sockets, but as these were pretty common at the time, I was able to source new replacements to replace the clapped ones on the generator, from the same shop that sold me the generator.

I've got one of those Advance E2 generators as well. Surprisingly good frequency accuracy and stability for its age but the output attenuation is wildly inaccurate at lower output levels.

I blame the Belling-Lee output connector for the excess RF leakage at low output levels.

[Cerebus]

Well it's either 2022 or the revolution has finally arrived. It sounds like small arms fire and shelling outside!

Happy new year folks.

[mansaxel]

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.

[Specmaster]

Wishing you all a Happy New Year.

Goals for 2022, apart from scoring more interesting, TE is still seeing you all here at the end of the year, will be the best possible outcome for us all.

[xrunner]

What was the year of manufacture, do you know? I've this kind of thing before and mains cables made between 1965 and 1971 and this article relates.
https://www.voltimum.co.uk/articles/green-goo-0

Thanks. I suspect it was made in early 1980s I unsoldered those wires and stripped back the insulation just now and it doesn't look all that great, but it's a lot better than what I saw exposed. Anyway enough of that thing for this evening.

HAPPY NEW YEAR!

[factory]

Vince
A useful Coax chart I posted is in this thread:
https://www.eevblog.com/forum/testgear/quality-test-cable-rg58-alternative/

BTW, forget about using the thin flexible probe cables, they are not 50 Ohm rated and are lossy to help manage reflections.

Thanks for the link. Chart useful indeed, I have it in a safe place now...
Thread over there is... well, in just a handful of posts they managed to throw more cable types/norms than I can count, it's overwhelming. Clearly a whole can of worms in its own right... not qualified to go into that.
I do gather from the though, that important things are improved/ doubled screening for better signal integrity, losses which limit use at very high / Shahriar like frequencies (not my world...), and that having a stranded inner core is more important to achieve cable flexibility, than having a thin/small diameter cable. RG58 with stranded core apparently makes people happy for use on the bench as a test lead. So I should bed happy too I guess...
And foil shielding not good for test cables as won't last long on the bench, foil will deteriorate. Need braided shielding.


For now all I wanted was a quick answer to what is a decent general purpose affordable get me started with basic stuff... cable.
Seems RG58 'C' suffix is a good default choice, so will go with that for now.

Then later on if I get smarter and do fancy stuff that requires specific spec for thjis or that...then I will worry about what cable type is best for whatever it is that I want to achieve.
I guess the most likely scenario is if I get rich and can afford test gear to venture at several GHz, then maybe RG58 might have too much loss to be bearable. We shall see.

for now I am not into fancy RF stuff, so RG58 should do it I guess...

Well I do have a 3GHz scope, a TDC 694C, so I might want to get a cheap PLL like Factory just did, and sweep from 2 to 4GHz to see how it does, plot its bandwidth response out of curiosity, just for fun. But that's about as far as my "RF" needs are likely to go for the foreseeable future....

Erm I don't have any cheap PLL thingies, maybe confused with AVGresponding and the cheap & faulty ADF 4351-based RF-gen he bought recently.
I did however buy the HP 8616A (1.8-4.5GHz) recently for £35 plus postage, just needed a replacement side frame & that knob still needs gluing back together. Also got a HP 8614A (0.8-2.4 GC) for not too much a few years back.

P.S. happy new year.

David

[Kosmic]

Holy crap, I can't believe some of what I'm reading here. It's actually getting borderline ridiculous. 

This Heath OL-1 did not originally have that BNC connector. Someone in the past installed it.

Did it "ruin" the "originality" of the instrument? In strictest terms yes. Does this Smurf give one wit? Absolutely not. But believe it or not some dumb ass did suggest that perhaps I might want to remove it and patch the hole. Yea, right. Not happening. 

Did it actually increase the usability of the instrument? Absolutely which is why it was installed.  In my mind that beats "originality" and this Smurf is not running a museum. 

P.S. Most museum pieces look great but don't freaking work. My stuff may have some rough edges but it all works. 

I did something similar on my Keithley 610CR. Removed the awful UHF connector and installed a proper Triax connector instead. I have 0 regrets 



BTW, Happy new year everyone!!

[Vince]

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.

[..] 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. 

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 lengths are going to be non-dramatic,

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...

[Vince]

[...} so I might want to get a cheap PLL like Factory just did [..]

Erm I don't have any cheap PLL thingies, maybe confused with AVGresponding and the cheap & faulty ADF 4351-based RF-gen he bought recently.

Oops sorry ! 

[factory]

Later I got one of these Advance RF signal generators from the same source that also had the dreaded Belling-Lee coax sockets, but as these were pretty common at the time, I was able to source new replacements to replace the clapped ones on the generator, from the same shop that sold me the generator.

I've got one of those Advance E2 generators as well. Surprisingly good frequency accuracy and stability for its age but the output attenuation is wildly inaccurate at lower output levels.

I blame the Belling-Lee output connector for the excess RF leakage at low output levels.

If you think the Belling-Lee is bad, just look at the crap Taylor (aka Windsor) used for the RF output connector on the 65 series signal generators. Picture is not of mine, but from the web, the other half is similar to the plugs used for old radio batteries.


My Windsor 65C of course has two replacement Bellend-Lee connectors, which one day I will replace with the crappy original two pin socket, the audio output should be a 1/4" jack socket too. I didn't know it at the time, but this was the first item of TE I ever acquired.


David

[Kosmic]

And let's not talk about GR connectors. What a nightmare they are. 

They actually perform a lot better than BNC though. They can reach 9GHz and normally SWR is really low.

A old marketing flyer from Genrad https://www.ietlabs.com/pdf/Datasheets/874.pdf

[factory]

Currently waiting on parts for the Type 1A4 plug-in and the two Type 547's so this would be a perfect time to re-visit an old project. Install of the upgraded rectifier board in the 212 mini scope. I know I promised TERRA Operative that I would get this done by Christmas but I never expected to have a windfall of 5 plug-in's and 2 scopes to take up all my time.

Anyway, here's the built up board with the components installed. Those 2 additional parts are fuses for the battery packs. My packs already have fuses so these are spares.

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

[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.

[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.

[Vince]

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.

Boy what wrong with the guy who designed this box ?! Labeled in uF but all values are SUB-uF !  So many zeros... was that a test to see if students could get their mental math right ?! 
Why not label them in pF and nF to make it easy and quick to read... or if it's super old, from the era where they did not know what a nF was, at least they could have labeled it in uuF for pF ranges, like they used to do back then, and OK use 0.xxx uF for the nF range like they did.

I think it's a box for sadistic teacher that like to torture their students... 

[Neomys Sapiens]

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

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

Zucca, Zucca, you should know better than give your weakness away like that! Now, if you cross us, or if you do your home wiring wrong, or whatever you will do to incur our wrath - we might feel compelled to have a global, distributed Pizza Hawaii pigout and post visual evidence of it? (maybe aggravating it by wearing Bersaglieri hats?)

[Zucca]

I suggest you run a 3 conductor cable (L1, L2, N) for both of your circuits (the bare ground is not counted).  You can get greater flexibility of having both 120 V ( L1-N or share the load with L2-N) and 240V (L1-L2) available.

All the target locations has already 120V don't need the N, still I plan to run L1, L2 and PE.

For my (hopefully soon) future lab, I am thinking of running a 120 V circuit from a 15A DFCI (dual arc and 5mA ground fault protection) breaker for any DUT.
Along with that would be a 240V circuit from a 15A EFCI (equipment protection: arc fault but only 10mA ground fault) for lots of lab equipment (15A L1-N plus 15A L2-N = 30A total at 120V), and the possibility of having 240V available for future use. 

Note, that a 240V DFCI breaker is not available, otherwise I would have chosen that.
Note2, in the current supply chain circumstances, a DFCI is much cheaper than a GFCI (5mA ground fault protection)... at least locally in the GWN.

I did some homework, I did not know what a DFCI is.
Yeah we have the same arc detection in Europe too, but I personally to not trust them too much.
There were rumors they will trip for no real problems...

IMHO the real deal is to prevent the arc with nice and high quality equipment, and I am sorry what I see in USA compared with EU is disappointing.
In my new US home two (not one) switches were busted and I had to replace them.

I never saw a switch fail in europe in 20 years I lived there. Maybe I was lucky but when I have an US switch in my hands it looks cheap made....
No wonder you have some arc problems in those switches....
So maybe arc detection make sense for USA stuff, but I will connect only Hager to my 220VAC so I should be safe without an arc detector.

EDIT:  forgot to mention it.  A bunch of your breakers are labelled GFI (GFCI in the GWN), but those are just regular breakers.  A GFCI breaker would have a white coloured test button.  I assume that it means there are GFCI protected receptacles on the circuit.  With a new-to-you place, it might be worth checking whether or not that is the case.

Ah yes, those lines are going to GFCI plugs, not sure why the ele. mexican put "GFCI" in the label, it is rather confusing.
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.

[med6753]

Currently waiting on parts for the Type 1A4 plug-in and the two Type 547's so this would be a perfect time to re-visit an old project. Install of the upgraded rectifier board in the 212 mini scope. I know I promised TERRA Operative that I would get this done by Christmas but I never expected to have a windfall of 5 plug-in's and 2 scopes to take up all my time.

Anyway, here's the built up board with the components installed. Those 2 additional parts are fuses for the battery packs. My packs already have fuses so these are spares.

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

IDK but I'm sure TERRA Operative could tell you.

[Zucca]

Zucca, Zucca, you should know better than give your weakness away like that! Now, if you cross us, or if you do your home wiring wrong, or whatever you will do to incur our wrath - we might feel compelled to have a global, distributed Pizza Hawaii pigout and post visual evidence of it? (maybe aggravating it by wearing Bersaglieri hats?)

well... I am not alone in this fight
Anyway, real italians would prefer to go to prison for 3 days instead to eat a tropical fruit (?) on a pizza.

Challege accepted, if I wire my home right... you have to wear this....

[Neomys Sapiens]

@Zucca: rest assured, at least I would be severely tasked with getting it down.