Test Equipment Anonymous (TEA) group therapy thread

[bitseeker]

For completeness, I did another round of probe testing. This time the idea is to submit the probe to a sharp square pulse and observe the rise time, overshoot and general waveform distortions.

...

Conclusion:

• I think everybody should avoid cheap P6100 probes . Even real Hantek probes seem to perform better.
• The cheap active probe is surprisingly a good performer.
• Tektronix probes are generally really good.

For those interested, Part 1 is here: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2416473/#msg2416473

Thanks, Kosmic! I've linked both parts in the POI index.

I'm awaiting my noise generator (just passed customs) so I can hopefully add to the reviews with some Jinhao P6200 probes.

[bd139]

Dang why does the good stuff always turn up on ebay when I am out of budget 

Marconi 2019A buyer collects chelmsford. Price is about right. Perhaps I should swap the DG1022Z for it    But at least that isn't likely to blow an OM module any time soon. Mental gymnastics bad 

[bitseeker]

I knew that DG1022Z wasn't long for bd's world. LOL!

[bd139]

I have come to my senses again and scrapped that idea. That was a close one though!

I shall have to buy something ridiculous at Newbury rally just to keep karma in balance 

[Specmaster]

Dang why does the good stuff always turn up on ebay when I am out of budget 

Marconi 2019A buyer collects chelmsford. Price is about right. Perhaps I should swap the DG1022Z for it    But at least that isn't likely to blow an OM module any time soon. Mental gymnastics bad 

Oooo that is lovely, but sadly out of my budget as well at the moment, TBH, it is really to big as well but it is such a well respected bit of kit that if I could, I'd sneak it into my small lab but SWMBO would instantly spot it Nice and handy for me as well, its only 5 miles away 

[bd139]

Yeah they are rather large.

I found a picture of the one I owned one a few years back which I paid a £10 for which I thoroughly regret selling if I'm honest:



One of the many 465B's that went past my hands on top (for scale)

Edit: the 2019A was picked up from a pretty cool just retired guy in Guildford who was downsizing as his wife had left him for another bloke, so he bought a sports car, found someone 20 years younger than him and chucked all his shit on gumtree for nothing. He had forgotten how to use it so considered it to be broken and a tenner being a fair amount of cash.

[Specmaster]

Yep, sure is large, and to think that I used to work for a Marconi company and regularly played snooker with one of the top engineers from the New Street Marconi factory where large numbers of these were used. If only I was into electronics back then, I reckon I might have gotten one for a song then as well. These days the site is large housing complex 

[tggzzz]

Edit: the 2019A was picked up from a pretty cool just retired guy in Guildford who was downsizing as his wife had left him for another bloke, so he bought a sports car, found someone 20 years younger than him and chucked all his shit on gumtree for nothing. He had forgotten how to use it so considered it to be broken and a tenner being a fair amount of cash.

Don't call me a jammy git in future

What are you going to be looking out for in that field off the M4?

[malagas_on_fire]

Today a old switch that was used to toggle power to a 230V sunoy fan for fume extraction blowed .... this type of switch is very old and due to low separation between Neutral and Phase when swapping the button it arced, RCD tripped

 

[worsthorse]

For completeness, I did another round of probe testing. This time the idea is to submit the probe to a sharp square pulse and observe the rise time, overshoot and general waveform distortions.

It is so much to see people here doing stuff like this.  It it is easy for someone to say, well of course Tek probes are going to be better than brand x or y., especially if brand x or y is made in China.  But to know the quality of the difference is to be able to say whether the difference matters.

Plus I don't feel so bad now about the hours I've put in testing each and every probe I've acquired in the last two treasure hunts before deciding which to keep and which to sell. 

[bd139]

Yep, sure is large, and to think that I used to work for a Marconi company and regularly played snooker with one of the top engineers from the New Street Marconi factory where large numbers of these were used. If only I was into electronics back then, I reckon I might have gotten one for a song then as well. These days the site is large housing complex 

Yeah at least they didn't knock it down entirely like they did with Racal in Bracknell (my father in law worked there for a bit):

Edit: the 2019A was picked up from a pretty cool just retired guy in Guildford who was downsizing as his wife had left him for another bloke, so he bought a sports car, found someone 20 years younger than him and chucked all his shit on gumtree for nothing. He had forgotten how to use it so considered it to be broken and a tenner being a fair amount of cash.

Don't call me a jammy git in future

What are you going to be looking out for in that field off the M4?

Yes that was the pinnacle of jammy gitness that was. Also for an extra fiver I got an amplifier which weighed about 30kg (just wanted the transformers!) and "the scariac" which I got rid of recently as it was too big to manage. Oh and a Harris HF tube amplifier which was taken to local hazardous materials as it was full of beryllium oxide and made an unconvincing and worrying powdery rattling noise.  I remember after that haul I felt like the car was doing a wheelie all the way home 

In the aforementioned field off the M4, I am specifically looking for any Hewlett Packard goodness, otherwise it's open season 

[tggzzz]

Yep, sure is large, and to think that I used to work for a Marconi company and regularly played snooker with one of the top engineers from the New Street Marconi factory where large numbers of these were used. If only I was into electronics back then, I reckon I might have gotten one for a song then as well. These days the site is large housing complex 

Yeah at least they didn't knock it down entirely like they did with Racal in Bracknell (my father in law worked there for a bit):

I had the misfortune to work for Racal SES in 80/81, and they moved us to a site right next to the train station. Three abiding memories of Bracknell:

• the most interesting shop in the centre was Holland and Barrets(!), but only because they sold green lipped mussel pills with zero indication of what they did
• their street market, including food stalls, was underneath one of the ring roads - extra free heavy metals, yummy
• there are good roads out of Bracknell; shame I only had a pushbike at the time

I lasted 3 months at that site, before moving to fenland.

In the aforementioned field off the M4, I am specifically looking for any Hewlett Packard goodness, otherwise it's open season 

Don't think I have anything like that for sale, except a 4GHz 0-110dB attenuator with N connectors.

[bd139]

It has got worse since then if that's any vindication of your decision to escape. The entire manufacturing base has been eviscerated leaving only high tech companies which required skilled staff who don't want to live in Bracknell. Now it's 2nd and 3rd generation poverty, plus lots of cheap new builds. There's some evidence of regeneration, and I apologise for the crudeness of the analogy, but that's really like corn in a turd.

I could really do with a nice attenuator but not one with N connectors as that means I need to buy adapters as I have precisely zero things with N connectors at the moment.

Some TEA activity. I have just realigned the 20/30m filters in the K2 using my HP 400E and TF2015 and set up the S-meter correctly. It's working pretty amazingly - the receiver is so much better than anything Yaesu I've had. Next I will see if I can find the noise source I built for the 7L12 and work out how to align the filters with a sound card and FFT.

[mnementh]

Bean .... you are pure, unadulterated  evil.

   

There. fixed that for ya. 

For completeness, I did another round of probe testing. This time the idea is to submit the probe to a sharp square pulse and observe the rise time, overshoot and general waveform distortions.

The Setup:
The probes are connected to my Lecroy oscilloscope calibration port via a probe-to-bnc adapter. The Calibration port is outputting a square pulse at 2Mhz, 1V, <= 1ns rise time, 25 ns width. Impedance is 1MOhms.

*Every probes as been compensated before running the test.

(SNIP)

Conclusion:

• I think everybody should avoid cheap P6100 probes . Even real Hantek probes seem to perform better.
• The cheap active probe is surprisingly a good performer.
• Tektronix probes are generally really good.

For those interested, Part 1 is here: https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg2416473/#msg2416473

Thanks for carrying forward with this; it's quite illuminating re: the P6100 probes... but I find myself wondering, given the difficulties of sampling in the 1nS neighborhood, how much of the distortion we're seeing is digital artifact...?

Still going. At this point I'm having serious doubts about his mental well-being.

I'm having similar doubts about you, myself... 

mnem
"All the world is mad save thee & me; and oft I have my doubts of thee."

[Mr. Scram]

There. fixed that for ya. 

Thanks for carrying forward with this; it's quite illuminating re: the P6100 probes... but I find myself wondering, given the difficulties of sampling in the 1nS neighborhood, how much of the distortion we're seeing is digital artifact...?
I'm having similar doubts about you, myself... 

mnem
"All the world is mad save thee & me; and oft I have my doubts of thee."

No need to have doubts about my mental well-being. Simply assuming the worst will do.

[tggzzz]

Now I'm pissed off.

I finally got around to looking at my £20 15GHz sig gen on my new 22GHz spectrum analyser. Didn't work, but finally figured out the previous owner had moved SMD resistors to turn off the on-board 100MHz source and use an external sig  gen. Fixed that, and my joy knew no limits.

Came back later, and the dual boot Ubuntu / win7 laptop refuses to get past dropping me into a grub rescue prompt. Bugger, bugger. No, I don't have a win rescue disc.

[0culus]

Now I'm pissed off.

I finally got around to looking at my £20 15GHz sig gen on my new 22GHz spectrum analyser. Didn't work, but finally figured out the previous owner had moved SMD resistors to turn off the on-board 100MHz source and use an external sig  gen. Fixed that, and my joy knew no limits.

Came back later, and the dual boot Ubuntu / win7 laptop refuses to get past dropping me into a grub rescue prompt. Bugger, bugger. No, I don't have a win rescue disc.

What sig gen is it?

I used to have a computer with Windows 7 and Debian on it (separate hard drives). I learned after one disaster where WindBloze ate the Linux disk to unplug the other OS hard disk before doing major updates.

[mnementh]

@   tggzzz

https://www.ultimatebootcd.com/ 

You should still be able to repair your partition table or reprovision the drive for GRUB. If you're built on a RAID, you're probably still well & truly fooked, though. Good luck, my friend.

mnem

[tggzzz]

Now I'm pissed off.

I finally got around to looking at my £20 15GHz sig gen on my new 22GHz spectrum analyser. Didn't work, but finally figured out the previous owner had moved SMD resistors to turn off the on-board 100MHz source and use an external sig  gen. Fixed that, and my joy knew no limits.

Came back later, and the dual boot Ubuntu / win7 laptop refuses to get past dropping me into a grub rescue prompt. Bugger, bugger. No, I don't have a win rescue disc.

What sig gen is it?

LMX2594EVM 15-GHz wideband RF synthesizer with phase synchronization & JESD204B evaluation module  http://www.ti.com/tool/LMX2594EVM I got it at auction along with some other eval kits. Must flog those to SDR fanatics.

I used to have a computer with Windows 7 and Debian on it (separate hard drives). I learned after one disaster where WindBloze ate the Linux disk to unplug the other OS hard disk before doing major updates.

This was a fat finger problem during an ordinary boot Nobody to blame but myself.

[tggzzz]

@   tggzzz

https://www.ultimatebootcd.com/ 

You should still be able to repair your partition table or reprovision the drive for GRUB. If you're built on a RAID, you're probably still well & truly fooked, though. Good luck, my friend.

Yes, I'm hoping that. It is a plain-vanilla laptop that I keep around solely for programs that will only run on Win >XP. I've created nothing useful on it, so in that sense there's nothing to lose.

Thanks for the pointer. I'll look at that once the G&T and sleep deprivation have worn off.

That looks like a political statement

[0culus]

Now I'm pissed off.

I finally got around to looking at my £20 15GHz sig gen on my new 22GHz spectrum analyser. Didn't work, but finally figured out the previous owner had moved SMD resistors to turn off the on-board 100MHz source and use an external sig  gen. Fixed that, and my joy knew no limits.

Came back later, and the dual boot Ubuntu / win7 laptop refuses to get past dropping me into a grub rescue prompt. Bugger, bugger. No, I don't have a win rescue disc.

What sig gen is it?

LMX2594EVM 15-GHz wideband RF synthesizer with phase synchronization & JESD204B evaluation module  http://www.ti.com/tool/LMX2594EVM I got it at auction along with some other eval kits. Must flog those to SDR fanatics.

Neat. Not a cheap board by any means. Any planned applications?

[Kosmic]

Thanks for carrying forward with this; it's quite illuminating re: the P6100 probes... but I find myself wondering, given the difficulties of sampling in the 1nS neighborhood, how much of the distortion we're seeing is digital artifact...?

Technically the scope I'm using (Lecroy DDA-110 / LC574) has a rise time of 0.35nS (1Ghz). It's more than enough to test the poor little P6100 probe. But noise is minimal results are repeatable. Just compare the Kuman to the JinHao waveform, it's identical. Could do a run with averaging if you prefer but the overall distortion are going to be the same.

[Kosmic]

Now I'm pissed off.

I finally got around to looking at my £20 15GHz sig gen on my new 22GHz spectrum analyser. Didn't work, but finally figured out the previous owner had moved SMD resistors to turn off the on-board 100MHz source and use an external sig  gen. Fixed that, and my joy knew no limits.

Came back later, and the dual boot Ubuntu / win7 laptop refuses to get past dropping me into a grub rescue prompt. Bugger, bugger. No, I don't have a win rescue disc.

What sig gen is it?

LMX2594EVM 15-GHz wideband RF synthesizer with phase synchronization & JESD204B evaluation module  http://www.ti.com/tool/LMX2594EVM I got it at auction along with some other eval kits. Must flog those to SDR fanatics.

Neat. Not a cheap board by any means. Any planned applications?

Some sellers from China started offering the LMX2594 in a metal enclosure with oled screen. I'm wondering if it's any good.

https://www.ebay.com/itm/LMX2594-10MHz-15GHz-RF-Signal-Generator-Frequency-Source-Sweep-OLED-Software/113740954230?hash=item1a7b7d3a76:g:FZkAAOSwCuRc0qe0

[mnementh]

Thanks for carrying forward with this; it's quite illuminating re: the P6100 probes... but I find myself wondering, given the difficulties of sampling in the 1nS neighborhood, how much of the distortion we're seeing is digital artifact...?

Technically the scope I'm using (Lecroy DDA-110 / LC574) has a rise time of 0.35nS (1Ghz). It's more than enough to test the poor little P6100 probe. But noise is minimal results are repeatable. Just compare the Kuman to the JinHao waveform, it's identical. Could do a run with averaging if you prefer but the overall distortion are going to be the same.

What's the nominal bit depth when sampling at that speed? I'll admit I'm ignorant of probably at least the last decade of development in DSO tech, but your traces did appear a bit clipped in both axes right around the transition regions; usually a sign that acquisition is operating right at the limits of resolution, which is why I asked.

On the other hand, it's entirely possible I'm misinterpreting what I see in the waveform based on outdated experience and seeing artifact where it isn't.  I mean yeah, still an apples-to apples comparison; the Tek probes and that homebrew FET probe are very clearly better. Just not sure how much better in real-world application.

mnem
Everybody needs something to believe in; I believe I'm gonna go take a nap.

[0culus]

Not strictly Test Equipment, but certainly related to TEA repairs, I purchased this Hitachi/Metabo power screwdriver on Shahriar's endorsement in one of the recent Signal Path episodes: https://www.amazon.com/gp/product/B07L78Y72J/

Looking forward to trying it. Unlike a lot of others, it has a very large selection of clutch settings down to very low torque so it should make disassembly and reassembly of test gear much easier.