Test Equipment Anonymous (TEA) group therapy thread

[hughtmccullough]

Specmaster,
Back in September last year you mentioned that you had been able to get an improved scan of the DSA511/524 service manual.  I too have on of these adapters, actually a DSA524 and hope to get round to working on it.  Would you mind sharing the manual that you received?
Also, you mentioned you wanted some information on the front panel.  A while back I was able to contact a very helpful guy called Chris Wood who sent me some information which included an improved calibration routine and also a diagram that showed which pins on IC412 and IC416 you should see changing for each of the buttons and pots on the front panel. I could return the favour by sharing this if you think it would be useful.

[tautech]

Yeah, I guess the world is slowly but surely opening up again so things can start moving more easily to make parts cheaper for us.

I don't see pricing coming down anytime in the near future but competition is driving service.
Twice in a month big FedEx packages have taken just 7 days from Shenzhen to NZ.   

Getting to grips with your new SA ?

[Ice-Tea]

Just got my PP bill.

Sweet baby Jesus.

Wait til you get the shipping quote...

They're actually quite reasonable and competent. I guess your mileage may vay if you buy one or two pieces. Which is one of the reasons I tend to go big 

[AVGresponding]

Discord is up, like a The Mission song

[Vince]

Question : does anyone know where I could buy these things ?

Some time ago I bought x4 100MHz Tek probes NOS in their little still sealed pouch with manual and all accessories... for cheap.

The quality of the crocodile clip on the ground lead is so disastrous that I am now wondering if these probes were not modern chinese counterfeits, hence the chinese quality of the ground clip.

Problem : the spring in the alligator clip is extremely stiff. So much so that you pretty much need both hands to force it to open.
Then when you release it, the spring action is so weak, almost non existent, that it takes several seconds for the two jaws to come into contact, and when they do there is not enough force left to actually close them shut completely. You have to finish the job yourself, force them to close for good.
Needless to say that with zero clamping force, it can't even grab a tiny wire. Each time I want to do that I have to force the jaws by hand to get them to clamp the wire.

It's TE probing... hell.

I am hoping these ground leads are generic enough in the probe world, that some companies out there sell them, with a decent quality, and for not too much money hopefully.. given what it is ! 

So if you know where to get decent ones of those, please speak up ! 

Sank u vary mush.

[Brumby]

Vince, I've had similar problems with cheap alligator clips.  I found the problem was the PVC boot - it doesn't like stretching, especially when cold.  When you open the jaws, it seems to me that the boot shrinks a bit at the point where you squeeze and when you release, the spring action of the clip has to work against the boot to stretch it out again in order for the jaws to close with any force.  My experience is that it will eventually get there - but waiting is intolerable.

If I'm in a gorilla mood, I might give the back of the boot a little  stretch to help temper my "impatience".

[Peter_O]

Question : does anyone know where I could buy these things ?
[...]

Haven't tried these, but the clamp looks different at least.

https://www.datatec.eu/en/pmk-890-400-015-ersatzteile-fuer-probes

[TERRA Operative]

I've been known to replace the alligator clips. There's a Japanese company that makes nice gold plated ones that have teeth that actually line up properly and a soft boot that prevents the issues you are seeing.

Yeah, I guess the world is slowly but surely opening up again so things can start moving more easily to make parts cheaper for us.

I don't see pricing coming down anytime in the near future but competition is driving service.
Twice in a month big FedEx packages have taken just 7 days from Shenzhen to NZ.   

Getting to grips with your new SA ?

I've been getting my head around the basic functions by calibrating and adjusting my function generators. It's working quite well so far, I just have to work on the idiot pressing the buttons a bit more.

[tautech]

Yeah, I guess the world is slowly but surely opening up again so things can start moving more easily to make parts cheaper for us.

I don't see pricing coming down anytime in the near future but competition is driving service.
Twice in a month big FedEx packages have taken just 7 days from Shenzhen to NZ.   

Getting to grips with your new SA ?

I've been getting my head around the basic functions by calibrating and adjusting my function generators. It's working quite well so far, I just have to work on the idiot pressing the buttons a bit more.

OK, good. Do you have it 10 MHz referenced ?

Recommend you go into System and change screenshots to Normal and Preset to Factory and boot up to Last settings. Then using the blue Preset it's a factory default evicting any hidden settings (there are plenty) and each time you boot it it's how it was at shutdown so to carry on with a project.

[Vince]

Vince, I've had similar problems with cheap alligator clips.  I found the problem was the PVC boot - it doesn't like stretching, especially when cold.  When you open the jaws, it seems to me that the boot shrinks a bit at the point where you squeeze and when you release, the spring action of the clip has to work against the boot to stretch it out again in order for the jaws to close with any force.  My experience is that it will eventually get there - but waiting is intolerable.

If I'm in a gorilla mood, I might give the back of the boot a little  stretch to help temper my "impatience".

Thanks people for your feedback.

Brumby was right on the money it seems !

To confirm or deny, I pulled / slid the boot all the way backward, to uncover completely the alligator. Well, turns out that a free alligator is a very healthy one ! It can now bite really well, plenty enough springiness and clamping force ! The alligator clip works just fine... great 

I tried "working" the PVC boot for 5 minutes with my fingers, to see if I could instill some life/elasticity back to it, but zero luck. It looks like it's stiff and shrunken for good...

The boot is not strictly necessary to probe stuff, since the exposed metal is ground, no risk of getting zapped. However the boot is useful nonetheless I find.. makes it easier to operate the clip one handed, otherwise fingers tend to slide over the clip, it's not reliable grip. Plus, the boot reduces significantly the amount of exposed metal, which helps a lot in avoiding accidental contact with adjacent pins or component leads... which is valuable...

So I guess I will be looking at purchasing new ground leads for my probes, given that I don't quite see how I could replace that boot with a new one without having to cut the lead....

[Robert763]

I bought back the HP 5090A from storage, it behaves much the same, loop volts works and a lack of signal, or maybe it's the Philips RF gen that isn't working properly. 



The power indicator is dead, 100Kc output functions OK, but 10Mc output is faulty, after running it for a while, I noticed the mains transformer seemed excessively hot. Checking later the mains power consumption was around 27W, manual states 8W. 

Later I disconnected the secondary from the PSU board, with no load the power only dropped to 21W. 
Think this one is terminal, one secondary winding measured at 39.6V, the other at 22V (must have shorted turns), need to find another one to restore.





Robert do you still have the 5090A & 5090B, would you be interested in selling them to me?

David

Yes I still have them. Not 100% sure of their exact location at the moment  I've been shifting a lot of stuff around. They are pretty heavy to post, do you just want the power transformer?
I'll have a look for them tomorrow, they are in one of 3 places.

Thanks Robert, complete would be preferable, they are quite small & a bit lighter compared with some other HP TE that arrives here.

The converter board from JLC is now in the UK (with Evri) , still need to order a couple of parts from Mouser for it.

David

Hi,
Located the 5090A,
PM me if still interested.

Robert.

[Zoli]

...
So I guess I will be looking at purchasing new ground leads for my probes, given that I don't quite see how I could replace that boot with a new one without having to cut the lead....

Think about to replace the alligator clips with mini grabbers; some sets(ebay, amazon) are coming in colours, so you can match the scope's channels colour code 

[Vince]

There are no colour codes on my scopes BNC inputs, only the fancy modern stuff has such a luxury ! 

[TERRA Operative]

Yeah, I guess the world is slowly but surely opening up again so things can start moving more easily to make parts cheaper for us.

I don't see pricing coming down anytime in the near future but competition is driving service.
Twice in a month big FedEx packages have taken just 7 days from Shenzhen to NZ.   

Getting to grips with your new SA ?

I've been getting my head around the basic functions by calibrating and adjusting my function generators. It's working quite well so far, I just have to work on the idiot pressing the buttons a bit more.

OK, good. Do you have it 10 MHz referenced ?

Recommend you go into System and change screenshots to Normal and Preset to Factory and boot up to Last settings. Then using the blue Preset it's a factory default evicting any hidden settings (there are plenty) and each time you boot it it's how it was at shutdown so to carry on with a project.

I have a Leo Bodnar GPSDO (and a HP 5065A that I'll get working one day) but I just need to buy/scavenge/build a distribution amplifier still.

I made the settings as you suggested, but I'm not sure what the blue preset is? I can choose 'Def', 'Last', and 'User'.

[Swake]

Somehow I got trapped in the transistor curve tracer matrix and these things popup on aliexpress, taobao and the like sites: QT 2A (several versions); WQ4830; XJ4834A. I didn't expect this.

[Vince]

Wow incredible, thanks for that, didn't know about these things !

So the Tek curve tracers are so sought after but rare and expensive and hard to fix / find parts for that..... the chinese thought there is enough demand to flog "clones" of them ?! 

Interesting.... makes the genuine old Tek even more valuable, now I can say " I have got a REAL one, not a chinese copy ! "   

Well that said I guess just like the cheap chinese scopes, I guess people find these curve tracer to their liking. There is something for every one....

[tautech]

I made the settings as you suggested, but I'm not sure what the blue preset is? I can choose 'Def', 'Last', and 'User'.

Blue Preset button is top right on the front panel and the settings to determine how it works are in the System menu.
It's something you will use often so take a minute to set it up as you want/need it.
I leave mine on Default.
For a preferred custom setup set it to User but first Factory default/Preset it then make the settings you want associated to it and then select User to Preset.

[factory]

The converter boards for my 200kHz HP 5090A 5090B off air receivers arrived during the week, spent yesterday afternoon moving TE around and transferring some TE into storage.
Put an order in for the 7660 IC, some caps & some other bits from Mouser last night, not managed to get much done on the board today, as I was doing some tests on my HP 5300B to help with a repair thread on another forum.

Got most of the resistors fitted to the converter board this evening, need to look for some 4k7s as I forgot to pick some out last weekend.

P.S. made a note to increase the size of the + symbol for the small caps, for the silkscreen, next time I use Kicad, this is the first board I've had made, hopefully Vince will be happy as it's not blue. 

David

[TERRA Operative]

I made the settings as you suggested, but I'm not sure what the blue preset is? I can choose 'Def', 'Last', and 'User'.

Blue Preset button is top right on the front panel and the settings to determine how it works are in the System menu.
It's something you will use often so take a minute to set it up as you want/need it.
I leave mine on Default.
For a preferred custom setup set it to User but first Factory default/Preset it then make the settings you want associated to it and then select User to Preset.

Ah ha, I see now. Got it, thanks!

[vk6zgo]

There are no colour codes on my scopes BNC inputs, only the fancy modern stuff has such a luxury ! 

'
Wouldn't they all have to be green?

[TERRA Operative]

The converter boards for my 200kHz HP 5090A 5090B off air receivers arrived during the week, spent yesterday afternoon moving TE around and transferring some TE into storage.
Put an order in for the 7660 IC, some caps & some other bits from Mouser last night, not managed to get much done on the board today, as I was doing some tests on my HP 5300B to help with a repair thread on another forum.

Got most of the resistors fitted to the converter board this evening, need to look for some 4k7s as I forgot to pick some out last weekend.

P.S. made a note to increase the size of the + symbol for the small caps, for the silkscreen, next time I use Kicad, this is the first board I've had made, hopefully Vince will be happy as it's not blue. 

David

You got some interesting routing on that board...


I'll be making a PCB order soon myself, gonna get blue for mine to match the original PCB's in the thing.

[Brumby]

There are no colour codes on my scopes BNC inputs, only the fancy modern stuff has such a luxury ! 

'
Wouldn't they all have to be green?

It took me a second to get that.   

[Robert763]

There are no colour codes on my scopes BNC inputs, only the fancy modern stuff has such a luxury ! 

'
Wouldn't they all have to be green?

It took me a second to get that.   

No some are all blue...

[Vince]

The converter boards for my 200kHz HP 5090A 5090B off air receivers arrived during the week,
[...]
hopefully Vince will be happy as it's not blue. 

David

I like you enough that I feel I owe you the truth.

I didn't even know violet existed ! .. but now that I am confronted with it, I have to make it clear : I hate it even much more than blue ! 

Main problems with blue is that it looks completely anachronistic in last century's electronics, which is what I deal with.
Also, blue reminds me of blue LEDs and backlight that I hate with a passion words can't even begin to describe.

After 20 years of blue, I see that it's now progressively coming of fashion now replaced with a new fashion, for white LED.
White looks much less ugly / shocking / damaging / stressful to my eyes, however it has one huge problem, not esthetics but functional... I find that every time I am confronted with consumer stuff that use while LED, like my work laptop and it's base station.... my brain simply does not register white. I simply don't notice if it's on or not. the fact that they make the white very dim and covered with a diffused doesn't help.
It seems like they engineered it 100% to look nice (to the marketing guys at least), but forgot it's main goal : be NOTICED and convey information to the user !

[Vince]

There are no colour codes on my scopes BNC inputs, only the fancy modern stuff has such a luxury ! 

'
Wouldn't they all have to be green?

You lost me... non-native here. For my defense even native Terra Operative didn't get it right away, so that makes me feel a little less stupid.

Now will someone please explain it to me....