Test Equipment Anonymous (TEA) group therapy thread

[Vince]

 

Overjoyed to see that my old junk could be useful ! 

[m k]

I got next set of single sided boards with 3.81 spaced edge connectors.
Edge spacing was 4.1.

Not overly disappointed, it was in the air.

[EggertEnjoyer123]

I took apart my spectrum analyzer because the frequency was slightly off. With a 10 MHz input signal, I got 11.8 MHz on the display.

My spectrum analyzer seems to be open loop (there is no PLL for the YIG oscillator). You can "phase lock" the LO to the nearest 1 MHz using a front panel button though (but it doesn't affect the accuracy of the frequency readout).

After playing around with the YIG oscillator knobs I got the readout to match at 10 MHz and 1800 MHz, but now when I put in a 1 GHz signal it reads 999.1 MHz. I guess you can't do that well with an open loop system. Maybe one of these days I'll get an 8566B to mess around with.

I also had a weird issue where the SA stopped working. I put in a 10 MHz signal at 0dBm and it showed -40dBm. At 100MHz, the difference was 20dB. It worked correctly at higher frequencies and at the higher ranges though. I have no idea what the issue was, but the problem magically disappeared after I took it off the bench to open up the bottom side.

Anyways here are some pictures of the internals.

[AVGresponding]

I also had a weird issue where the SA stopped working. I put in a 10 MHz signal at 0dBm and it showed -40dBm. At 100MHz, the difference was 20dB. It worked correctly at higher frequencies and at the higher ranges though. I have no idea what the issue was, but the problem magically disappeared after I took it off the bench to open up the bottom side.

Anyways here are some pictures of the internals.

Looking at all those hard lines I'd guess a loose or damaged connector.

[wkb]

Or the soldering of the semi-rigid to the SMA connectors, that I have also seen. Very difficult to see typically

[EggertEnjoyer123]

I got three broken spectrum analyzers for free a month ago. All three have the same issue - no firmware IC.

My chip programmer is coming soon. My chips will probably come a lot later because I couldn't find a US seller for them (they are the PA28F400B5T60). The firmware files for this SA (which is a clone of the Aeroflex IFR 2398) are available online, so it should be a pretty easy fix.

Anyways I probably won't have any use for three spectrum analyzers (especially since I already have one). I might keep one and I'll give one to a friend. Not sure what I'll do with the third one.

[tautech]

Looks like a rebrand but whom is the OEM ?
Aeroflex maybe:
https://www.brltest.com/index.php?main_page=product_info&products_id=6942

[Robert763]

LG is the OEM for these. I have an IFR badged 26.5 GHz model.

[Neomys Sapiens]

Not sure what I'll do with the third one.

If you consider selling the third one (working fully), you might drop me a note.

[EggertEnjoyer123]

I received my programmer today in the mail.

First thing I did was back up the calibration on my Tek scope. It was a huge pain in the ass to remove that chip with just a solder sucker but I managed to do it.

So far I don't have any issues with my T48 programmer. What chip should I replace the 32 year old NVRAM with?

[EggertEnjoyer123]

Oh, U too? I bought the one on the pic during my shopping spree.

Now I find myself with Qty 2 HP power meters, a sensor and NO CABLE to connect said sensor to said meters. So basically I am just as stuck as I was with only the meters..

Or maybe worse: I have a sensor I do not know if it works...

Good news: according to people on groups.io, a good VGA cable should work.

https://groups.io/g/HP-Agilent-Keysight-equipment/topic/100358777#137851

[TERRA Operative]

I received my programmer today in the mail.

First thing I did was back up the calibration on my Tek scope. It was a huge pain in the ass to remove that chip with just a solder sucker but I managed to do it.

So far I don't have any issues with my T48 programmer. What chip should I replace the 32 year old NVRAM with?

A FM16W08 FRAM on an adapter PCB.

https://www.pcbway.com/project/shareproject/Dallas_DS1225Y_FRAM_Adapter_3c961bed.html

This is my design, works great in my SG5030.

[Neomys Sapiens]

Finally, my doubts about my TDS5104 have been dissolved by an expert. It is hard to find anyone with as much knowledge about Tek scopes like Mr. Scherer from TMS in Herxheim. I was simply too used to the TDS6xx and TDS3xxx series to understand that the TDS5xxx changes the vertical factor according to the probe used only under certain conditions. And I got a very very affordable calibration on top. When I have it operating again, I will detail what led me to my wrong assumptions. But before I set it onto its place again, I will have to complete a intended construction in the space above. So this will take a few days. But basically, I'm much relieved!

[EggertEnjoyer123]

I received my programmer today in the mail.

First thing I did was back up the calibration on my Tek scope. It was a huge pain in the ass to remove that chip with just a solder sucker but I managed to do it.

So far I don't have any issues with my T48 programmer. What chip should I replace the 32 year old NVRAM with?

A FM16W08 FRAM on an adapter PCB.

https://www.pcbway.com/project/shareproject/Dallas_DS1225Y_FRAM_Adapter_3c961bed.html

This is my design, works great in my SG5030.

Thanks!
Ordered some.

[Vince]

Wow look at that puppy !

A Tek 220 series, always wanted one of those... but they are super sought after over here, so are overpriced and sell literally in the minute.

This is a 222A, the slowest 10MHz version, not the 60MHz 224 version.

I don't check Leboncoin.fr any more as I recently explained, so I didn't even see it when it popped up last evening at 16h50 or so, for free, I mean only 20 Euros, like a  zero is missing or something. However a friend did see it and contacted the seller within an hour. I miraculously live very close to the seller (30+ minutes drive), so my friend contacted me in urgency... so I contacted the seller and at 22H45 I was back home with the thing !

I saw a few YT videos about the thing, but it's the first time I hold one in my hands, so excited ! 

It uses special probes and has two channels, but only one probe was to be found on the pouch on the side. Well at least it's usable. Not sure how cheap and easy it is to find another such probe.. not too hopeful.

It didn't come with the charger either... yet of course in the ad the seller said "scope, it works" (and nothing else...). Go figure. Guy eventually admitted he knows squat about electronic or scopes, and all he meant by "it works" is : " There is a little R&D office at work, that got closed, and their TE was up for grabs, so I assume it must have been working.... ".

So I improvised. Found how to open the battery compartment. Found an original lead-acid Tektronix branded battery inside, flat of course (40mV....), but at least zero leaking, it's sealed. It read "8 volts".
So I unplugged it and replaced it with my lab power supply set to 8Volts.

Scope powers up, yeah ! Drawing about 500mA.

Played with it a bit, all the controls and menus/keypad appear to work fine, yeah.... but... but, the CRT/display has several problems and unfortunately I fear at least some the problems, might be due to internal CRT damage, so it's toast. Well, unless you can find a good CRT for cheap, dream on.

What kills me is that I bet it was indeed working fine at his work place, but that when he picked it up, he mistreated it and the scope took a bad hit, shame.

I can see at least 4 problems with the display :

1) Rotation, the only issue I guess might be electrically or mechanically fixable.

2) Focus problem : the focus is uneven across the screen : there is only narrow vertical tilted band / area that's sharp. Anything left or right of this band is out of focus.

3) Distortion : Easily visible in the upper left corner of the screen, where the readout for CH1 draws a rectangle around the vertical amp setting, to tell you which channel is which. Well the left side of that rectangle looks more like a trapezoid to me...

4) The menus on the right part of the screen, are not entirely on the screen, some of it goes off the screen to the right. quite badly. It's quite bad and I don't see how the  gain  of the horizontal amplifier could have magically gone wrong as bad as that, so again looks more like CRT issue sadly.

So I fear it needs a new CRT. But other than that (and the missing adapter and probe and carry bag) it works fine. So for 20 Euros it's not bad.
It one can find another cheap parts unit with typically toast hybrids but a good CRT... one could make a good scope out of two.

Luckily Tekwiki has the service manual for this thing.

I won't be cracking it open or attempting any troubleshooting or repair, it's not my scope. My friend will get round to visiting me in the coming weeks or months and I will hand him his scope when that happens. Until then... I will keep it safe. Luckily it's tiny so it does not take much space at all, it's not a problem.

[TERRA Operative]

Nice! That price is really cheap!
I made a video a while back on installing 18650 lithium batteries in a 3D printed enclosure.

https://youtu.be/owqpfYs3jsM

[Vince]

Wow, thanks for making that video, excellent ! 

Nice interesting repair, and overjoyed to see such a refined, well developed battery replacement solution, is available off the shelves ! 

[TERRA Operative]

I might even have a spare PCB or two laying around... maayybbee. If you want, I'll have a dig around and see if I still have one.

[Robert763]

Vince, The 222A is a digital 'scope so it might not be a faulty CRT. But it certainly looks like it. A first check would be to feed the X & Y signals to another 'scope in X-Y mode and see what it looks like. The signals are on pins 13 and 14 of P3/J3 between main and powersupply board. (Z is onpin 9) If that looks OK than it's either a powersupply board fault or a faulty PCB.
If it looks bad try the display alignment from the manual.
Manual on Tek website is clearer than the one on tekwiki
https://download.tek.com/manual/222_Service_Manual.pdf

Robert.

[Vince]

Thanks Terra and Robert !

But... as I said, it's not my scope, I am not touching it. I bought it for a friend who asked me not to touch it / open it.
He will work on it himself and do whatever he wants with it... he is a 70+ year old retired electronics design engineer and he likes to do everything his own way, he takes no advice from anyone but a select few people he met decades ago... he is a bit old fashioned and looks down on any info / help I may find on the interweb. If I mention "EEVb......", it triggers him before I have time to finish my sentence...

Getting the scope to power up so I could give it a quick test ride to detect any obvious fault with it was the only planned extent of my interventions on this scope...

Obviously when I finally get one for mySELF, of course I will do all I can to fix it... and would definitely do that battery upgrade, as it's turnkey and polished 



Robert, of course it's digital, but the CRT still has deflection plates and focus/astigmatism control like any analog scope. It's not like the more modern TDS 300/400/500/600/700 series which had a "television" like CRT, with just a big magnetic coil around the neck.
Well, assuming I understood what you had in mind that is...

[factory]

Could it be a problem with the astig control, as the top of the trace is narrow and the bottom is stretched? There is a align test pattern, just had a quick look at the Tek 222 (not A version) CuriousMarc video, would be interesting to see how bad it looks.

P.S. I don't blame Vince for not wanting to work on it, manual is some 200+ pages and it's not his scope.

David

[Vince]

Yes I saw this pattern display routine in Terra's video. I will see if I can get it to show up... I mean it's not easy since the menu options do'nt show up properly on the screen...

I am not touching any trimmer since that would mean opening up the scope and he said not to try to fix it or open it or anything. 
He will investigate the problem by himself hand do whatever he wants with it... the way he wants to do it. He is old now and doesn't like to be told what to do...

[Vince]

David saw your edit.

Again, it's not that I do not WANT to work on this scope, I would LOVE to see if I can fix it, and learn stuff along the way, but my friend clearly, explicitely, firmly told me NOT to attempt any repair on it, and NOT to open it. Said I should not touch it, just keep it safe until we get to meet and I can give him his scope.

It sounded very clear to me... 

[Vince]

OK I managed to get the test pattern, here it is....

Confirms the problems I found earlier, but at least now it's better evidenced.

1) the rotation,
2) the focus problem where only a central vertical band is in focus, and nothing else
3) distortion.

[Robert763]

Sad news
Sphere Research, a big surplus TE and spares seller in Canada is closing down at the end of the year 

From the HPAK groups.io:

"Due to a bad combination  of serious illness and old age,
we will be closing our Sphere business at year end.

We will do our best to provide good service up to the end,
but responses and page updates will be slower.

All our curated parts collections (Tek, HP, Fluke plus fans, semiconductors
and passive parts) are for sale, all offers are welcome. Please contact Susan
at Susan Shawlee <[email protected]>

we have many items not on line, and coming by to see for yourself is really the best plan.
tons of parts are free, plus two out buildings full of free gear. help your self. PLUS a huge shelf full of Tek and HP manuals, take all you want. sorry, we just don't have the resources to ship you this free stuff, it has to be picked up.

Our thanks to the dozens of customers that have already come by in person to help us
clear out parts and equipment, we really appreciate the effort you made on our behalf
with this difficult problem.

We have really enjoyed operating Sphere, and I hope it has been a useful tool for you
to keep your test gear up and running."