Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

Don’t try and apply reason to these cream faced loons 

Not quite, since they do have their reasons.

Not the same reasons as us, to be sure. It is quite a challenge to work out what their reasons are (frequently emotional at core), and whether they have any basis in reality.

[Specmaster]

Good news ! My HP 3478A works fine after some good cleaning with electronic contact cleaner.
 
Thanks mnementh for his help.
 
 

Surely you didn't have to take the switch apart to use the contact cleaner, did you?

[TorinoFermic]

Quote from: TorinoFermic on Today at 19:14:25

Good news ! My HP 3478A works fine after some good cleaning with electronic contact cleaner.
 
Thanks mnementh for his help.
 
 

Surely you didn't have to take the switch apart to use the contact cleaner, did you?

Oh I did take the switch apart and sprayed some inside it, cleaned up with my qtip many times, then assembled back.

[vk6zgo]

Just got paid this morning so got my baby back again after this year's earlier disaster

After all those years since the TDS210, your new baby still has only 1Gs/s sample rate  Ok so it has colour and 200MHz but seriously I really would have expected a better sample rate 

Yeabut probably for 1/4 the price of TDS when they came out.
SDS2202X-E is the same form factor with 28 Mpts and 2 GSa/s but nearly 2x the price of SDS1202X-E although it does have a pile more features.

Got to be honest I did stare at that for half of yesterday and decided I didn’t need it 

Oh well, you'll just have to do Bode plots the old fashioned way. 

On graph paper, with sharp transitions as calculated?
Of course, frequency response tests are a different thing, & "old school" is still quite meaningful.

[Specmaster]

Quote from: TorinoFermic on Today at 19:14:25

Good news ! My HP 3478A works fine after some good cleaning with electronic contact cleaner.
 
Thanks mnementh for his help.
 
 

Surely you didn't have to take the switch apart to use the contact cleaner, did you?

Oh I did take the switch apart and sprayed some inside it, cleaned up with my qtip many times, then assembled back.

Normally that is not necessary, the switch is loose enough in its housing to allow the contact cleaner to be sprayed in each end and also around the contact pins. The cleaner will normally creep down the pins and the housing into the switch mechanism and then operating the switch a few wipes the contacts clean in conjunction with the cleaner. I know that in the case mnementh he took his apart because there was a spike of metal on one of the contacts that was causing his problem.

[TorinoFermic]

Quote from: TorinoFermic on Today at 20:40:25>Quote from: Specmaster on Today at 20:35:21>Quote from: TorinoFermic on Today at 19:14:25

Good news ! My HP 3478A works fine after some good cleaning with electronic contact cleaner.
 
Thanks mnementh for his help.
 
 

Surely you didn't have to take the switch apart to use the contact cleaner, did you?

Oh I did take the switch apart and sprayed some inside it, cleaned up with my qtip many times, then assembled back.

Normally that is not necessary, the switch is loose enough in its housing to allow the contact cleaner to be sprayed in each end and also around the contact pins. The cleaner will normally creep down the pins and the housing into the switch mechanism and then operating the switch a few wipes the contacts clean in conjunction with the cleaner. I know that in the case mnementh he took his apart because there was a spike of metal on one of the contacts that was causing his problem.

I'll remember it next time I find again the same problem.

[Brumby]

Had a problem using my 3478A yesterday.  Wanted to check a low resistance cable, so wired up for 4 wire and got some curious readings.  Tried 2 wire and it was worse.  Checked my cables and tried again.  Still had stupid numbers.  Rechecked cables and shuffled them around.  Still no joy.


Then I hit the front/rear switch..........   

[med6753]

I'll remember it next time I find again the same problem.

And for future reference Dexoit will even find it's way into supposedly "sealed" pots as long as their design is two dissimilar materials such as plastic and metal. It will soak down into that seam and do a decent job of cleaning the resistive element. But obviously if the pot is one piece welded plastic this method won't work.

[mnementh]

Quote from: TorinoFermic on Today at 19:14:25

Good news ! My HP 3478A works fine after some good cleaning with electronic contact cleaner.
 
Thanks mnementh for his help.
 
 

Surely you didn't have to take the switch apart to use the contact cleaner, did you?

Oh I did take the switch apart and sprayed some inside it, cleaned up with my qtip many times, then assembled back.

Normally that is not necessary, the switch is loose enough in its housing to allow the contact cleaner to be sprayed in each end and also around the contact pins. The cleaner will normally creep down the pins and the housing into the switch mechanism and then operating the switch a few wipes the contacts clean in conjunction with the cleaner. I know that in the case mnementh he took his apart because there was a spike of metal on one of the contacts that was causing his problem.

Well, not quite. I took it apart because I had already sprayed it with 3 different kinds of contact cleaner at least 5 or 6 times and still intermittent contact. Worse yet, I didn’t actually find anything wrong... but it worked perfectly after I scrubbed and sprayed it with food grade silicone spray lube.

It wasn’t until a few days later when I was editing pix I took during the work that I found the one pic right after I’d removed the plunger clearly showing a tiny grain of sand which had gotten in there.

Just proof that sometimes, following a known effective procedure consistently is as important as diag and inspection results. 

In this case, it is my opinion that the switch is made this way on purpose such that it can be serviced this way. I see no good reason not to take advantage of the fact to give it a good scrubbing every once in a while. 

mnem
 

[tautech]

Just got paid this morning so got my baby back again after this year's earlier disaster

After all those years since the TDS210, your new baby still has only 1Gs/s sample rate  Ok so it has colour and 200MHz but seriously I really would have expected a better sample rate 

Yeabut probably for 1/4 the price of TDS when they came out.
SDS2202X-E is the same form factor with 28 Mpts and 2 GSa/s but nearly 2x the price of SDS1202X-E although it does have a pile more features.

Got to be honest I did stare at that for half of yesterday and decided I didn’t need it 

Oh well, you'll just have to do Bode plots the old fashioned way. 

On graph paper, with sharp transitions as calculated?
Of course, frequency response tests are a different thing, & "old school" is still quite meaningful.

Nope like Dave shows in EEVblog #396 – Bode Plotting on Your Osciloscope that I can't seem to link the video. 
Maybe Google can find it. 

[SilverSolder]

Just got paid this morning so got my baby back again after this year's earlier disaster

After all those years since the TDS210, your new baby still has only 1Gs/s sample rate  Ok so it has colour and 200MHz but seriously I really would have expected a better sample rate 

Yeabut probably for 1/4 the price of TDS when they came out.
SDS2202X-E is the same form factor with 28 Mpts and 2 GSa/s but nearly 2x the price of SDS1202X-E although it does have a pile more features.

Got to be honest I did stare at that for half of yesterday and decided I didn’t need it 

Oh well, you'll just have to do Bode plots the old fashioned way. 

On graph paper, with sharp transitions as calculated?
Of course, frequency response tests are a different thing, & "old school" is still quite meaningful.

Nope like Dave shows in EEVblog #396 – Bode Plotting on Your Osciloscope that I can't seem to link the video. 
Maybe Google can find it. 

[mansaxel]

Don’t try and apply reason to these cream faced loons 

Not quite, since they do have their reasons.

Not the same reasons as us, to be sure. It is quite a challenge to work out what their reasons are (frequently emotional at core), and whether they have any basis in reality.

The main issue with them "screening" their mobile phones the way they do, is that they do a pretty bad job of it, but still probably manage to diminish radiation and reception somewhat, at which point the RBSS will command the phone to increase TX power. 

Analogous, when they NIMBY RBSSen, they're effectively creating a situation where their own phone will constantly run with higher transmit power. Of course, this "worse battery time" (which is the only actual observation they'll make) will be seen as the Government commanding the phone.  When in reality it is a 25yo piece of shitty code, frustrated by impeded radio coverage planning, trying to keep up.

(RBSS == Ericsson lingo for "mobile tower"; I did consultant work there, 20 years ago)

[bitseeker]

Well, I got that sort-of wrong.

There I was thinking I'd have a nice little resistance box to put on the shelf on top of my HP3468a and new Agilent 34410A. And, ... not quite ...



I'll have to build a shelf for that pit prop.

Still, at least they are 0.03% resistors, 2mOhm switches, and 25mohm excess resistance.

No problem. Fixed that for ya.

[bitseeker]

Recently on other pages, something stupid happens:



        

I do like the accent of this bloke, very understandable.

What a load of snowflakes. What is the point of a mobile phone to anyone if it is always wrapped in tin foil, it is not going to receive any phone calls 

Phone calls? What are those?

[bitseeker]

Public Service Announcement

All HP 3478A owners:

• Clean your front/rear switch
• Replace your RIFA caps
• Back up your cal data
• Check your SRAM battery voltage (replace as needed; see also #3)

Everyone else: Don't forget when the next item on your auction watchlist ends. 

[tonyalbus]

Public Service Announcement

All HP 3478A owners:

• Clean your front/rear switch
• Replace your RIFA caps
• Back up your cal data
• Check your SRAM battery voltage (replace as needed; see also #3)

Everyone else: Don't forget when the next item on your auction watchlist ends. 

3. is a problem, i have that keysight adapter..installed 1,5 GB of keysight crap...on the adress of the DMM (11 in my case) only one meter connected, i see lot of devices?? but none is detected..
anyone a tip how to do this?

[Zucca]

Cuz I tend to test what I build. Also I can write any test gear off my taxes.
I submit some ideas for improvement from time to time, and my employer gives me an appropriate bonus if those ideas materialize. I tend to test those ideas at home, build up my knowledge, and people have a hard time smart assing me on my job.
For this I use some adequate test gear which I can get at a reasonable price, which I resell after my tests are complete and if I don't use it anymore.

Which also means that I have several RTX cards sitting here; they would make a good mining rig if not for the electricity bill.

Since my next project will involve machine learning and speech to text  plus OCR I will need some of those cards, but not all of them. I'll probably try to do one training in CUDA and one in OpenCL, pythonize it, try to move it to a Pynq and get it to work on one of those autonomous Zynq Ultrascale boards. If that works out I will not need all those RTX cards any more.

Some of them are populating those PCs that I have sitting here idling around.

The original Asus blew in one of my tests, probably because of a fan failure. Asus swapped it out within 3 days, but by that time I had another replacement.

Cool job, same as mine sort of. I like 0% political discussions and 100% technical stuff.
You can't mess around with me, either it works or not, ...and yes of course I measured it (after a while they stop asking that...  ).
Enjoy your 4 weeks away, I am already missing the TEA girl.

PS: One day I would like to know what you think about ECC Ram, I still don't have a clear opinion on that stuff.

[Zucca]

3. is a problem, i have that keysight adapter..installed 1,5 GB of keysight crap...on the adress of the DMM (11 in my case) only one meter connected, i see lot of devices?? but none is detected..
anyone a tip how to do this?

Screenshots?

[Robert763]

<SNIP>
[/quote]

Well, not quite. I took it apart because I had already sprayed it with 3 different kinds of contact cleaner at least 5 or 6 times and still intermittent contact. Worse yet, I didn’t actually find anything wrong... but it worked perfectly after I scrubbed and sprayed it with food grade silicone spray lube.

It wasn’t until a few days later when I was editing pix I took during the work that I found the one pic right after I’d removed the plunger clearly showing a tiny grain of sand which had gotten in there.

Just proof that sometimes, following a known effective procedure consistently is as important as diag and inspection results. 

In this case, it is my opinion that the switch is made this way on purpose such that it can be serviced this way. I see no good reason not to take advantage of the fact to give it a good scrubbing every once in a while. 

mnem
 
[/quote]

As a rule you should NOT use silicone lubricants on contacts. If there is any arcing at the contact Silicon Dioxide (glass) can form ruining the contact. Some contaminants can also cause silicone to form solid insulating layers on contacts. If you get even tiny amounts of silicone near contacts it can cause issues. One case was the UK Post Office Telephone exchanges (Old Strowager type) where thy had problems eventually traced to the floor polish changing to have silicone wax in it.

A good grease lubricant for contacts is petrolum jelly  "Vaseline". Mixing in a little oil based contact cleaner makes it even better.

[bd139]

Just got paid this morning so got my baby back again after this year's earlier disaster

After all those years since the TDS210, your new baby still has only 1Gs/s sample rate  Ok so it has colour and 200MHz but seriously I really would have expected a better sample rate 

Yeabut probably for 1/4 the price of TDS when they came out.
SDS2202X-E is the same form factor with 28 Mpts and 2 GSa/s but nearly 2x the price of SDS1202X-E although it does have a pile more features.

Got to be honest I did stare at that for half of yesterday and decided I didn’t need it 

Oh well, you'll just have to do Bode plots the old fashioned way. 

On graph paper, with sharp transitions as calculated?
Of course, frequency response tests are a different thing, & "old school" is still quite meaningful.

Nope like Dave shows in EEVblog #396 – Bode Plotting on Your Osciloscope that I can't seem to link the video. 
Maybe Google can find it. 

Probably similar to this (which I did ages ago) to get a frequency vs log power plot





Apparently my hooky homebrew spectrum analyser is arriving today or tomorrow. I'm rather excited to see what steaming pile of crap I bought for my money now 

[tautech]

Probably similar to this (which I did ages ago) to get a frequency vs log power plot

Didn't you post that a while back ?
Looks familiar. 

[bd139]

Yeah long time ago now.

[tautech]

Yeah long time ago now.

So dipping the toes into RF eh ?

Review coming ?

[McBryce]

Public Service Announcement

All HP 3478A owners:

• Clean your front/rear switch
• Replace your RIFA caps
• Back up your cal data
• Check your SRAM battery voltage (replace as needed; see also #3)

Everyone else: Don't forget when the next item on your auction watchlist ends. 

Is there any easy way of backing up the cal data? I replaced the battery last year (without losing the cal data), but it would be nice to have it stored safely somewhere else.

McBryce.

[Zucca]

PS: One day I would like to know what you think about ECC Ram, I still don't have a clear opinion on that stuff.

Interesting here.