Test Equipment Anonymous (TEA) group therapy thread

[McBryce]

[...], Gould had a built in printer option, but I'm not sure if it was pen based or thermal, as I never used one.

I had a Gould 1604. It had a pen based printer on top. I never found the pens for this printer...

This scope was a bit drifty, depending on temperature. So I removed the useless printer, and replaced it with a slowly rotating 12cm fan:


IMG_4647-Gould_1604_met_fan-2000pix.jpg

This cured almost all of the drift.
Also, now I could reduce the speed of the original fan in the back. This made the scope almost silent.

regards, Gertjan.

Maybe the Gould 940 I had, had a pen plotter not a thermal printer. It's a long time since I had it and I never tried to use the printer, but the scope had a colour screen, so it's highly possible.

McBryce. 

[factory]

Apparently Gould used both depending on the model, some have a thermal printer and others use a pen plotter (made by Alps?), you can identify this if it has a "pen change" button.
https://www.vintage-radio.net/forum/showthread.php?p=999313

The pens are common to various things such as old computers and medical equipment, example of replacement pens here at a medical supply webshop; https://www.evident-shop.de/en/diagnostics/plotter-pens/249/plotter-pens/pencil-assortment-in-the-colours-red-blue-green-black

David

[Gertjan]

Apparently Gould used both depending on the model, some have a thermal printer and others use a pen plotter (made by Alps?), you can identify this if it has a "pen change" button.
https://www.vintage-radio.net/forum/showthread.php?p=999313

I checked my notes. Yes it was Alps:

Make:  Alps
Type:   PCA 104 plotter
           assy no. 477190

Print mechanism:  Alps PTMPG2335A
                           741320

regards, Gertjan.

[nonius_]

Ouch, Gertjan, it hurts to see the modification to that scope....

Wasn't it possible to somehow make your own pens for it? (from Bruynzeel fineliner pens for example) Shouldn't be too hard to bodge a pen, I'd expect? And nowadays, with 3D printers, the sky is the limit anyway.

If it had been my oscilloscope I'd have tried everything to make the printer operable again. Have never seen a scope with built-in printer myself. Would be pretty unique to have such a thing in the shop.

[dazz1]

I now declare the Tektronix TDS 350 and the Fluke PM3394A alive.
Both scopes 30 years old.  Both spent the last 10 years in an abandoned storage unit.  Just like you see on those terrible TV programmes, only this is a true story.

The TDS 350 appears to be 100% operational.  As a vintage fully digital scope, it is quite good.  There are a lot of menu options hiding behind the simple user interface.  If had had more than 1k memory depth, it could be a keeper.   

The PM3394A has a fault that makes the display jump in size (shrink) by about 1% every 7 seconds or so.  It is like something is building up voltage, then breaking down.  If the fault is in the HV section, it could be a challenge to find.
Also the unobtainium lamp for the graticule is blown.  I have a LED solution to that.

So now I am moving onto the next item of test equipment to resurrect. 

[tautech]

I now declare the Tektronix TDS 350 and the Fluke PM3394A alive.
Both scopes 30 years old.  Both spent the last 10 years in an abandoned storage unit.  Just like you see on those terrible TV programmes, only this is a true story.

The TDS 350 appears to be 100% operational.  As a vintage fully digital scope, it is quite good.  There are a lot of menu options hiding behind the simple user interface.  If had had more than 1k memory depth, it could be a keeper.   

The PM3394A has a fault that makes the display jump in size (zoom) by about 1% every 3-5 seconds or so.  It is like something is building up voltage, then breaking down.  If the fault is in the HV section, it could be a challenge to find.
Also the unobtainium lamp for the graticule is blown.  I have a LED solution to that.

Numerous blue Phillips caps inside Dazz ?
Quite renown for their shortish service life but you have a good ST42 tweezer to check their values and ESR. 

[dazz1]

Numerous blue Phillips caps inside Dazz ?
Quite renown for their shortish service life but you have a good ST42 tweezer to check their values and ESR. 

Lots of brown electrolytics.  A few pale blue ?solid? electrolytics.  No time to stop and fault find. I have more vintage gear to resurrect.  I am just grateful the magic smoke stayed hidden.   

[tautech]

Numerous blue Phillips caps inside Dazz ?
Quite renown for their shortish service life but you have a good ST42 tweezer to check their values and ESR. 

Lots of brown electrolytics.  A few pale blue ?solid? electrolytics.  No time to stop and fault find. I have more vintage gear to resurrect.  I am just grateful the magic smoke stayed hidden.   

IIRC the old blue axials were the first to go.

[dazz1]

IIRC the old blue axials were the first to go.

All are single ended radial wires. 
My thoughts are to create those symptoms, it has to be a fault related to driving the CRT rather than a data or signal fault.  If it is HT related, then a failing multiplier could be the cause.  It could also be any component in the CRT circuit partially breaking down.

[Gertjan]

Ouch, Gertjan, it hurts to see the modification to that scope....

Wasn't it possible to somehow make your own pens for it? (from Bruynzeel fineliner pens for example) Shouldn't be too hard to bodge a pen, I'd expect? And nowadays, with 3D printers, the sky is the limit anyway.

If it had been my oscilloscope I'd have tried everything to make the printer operable again. Have never seen a scope with built-in printer myself. Would be pretty unique to have such a thing in the shop.

Hi nonius,

Even if the printer was functional, I would not use it. What use is a print on a cash register roll?
To use  it  in documentation, or show it on the web, I would have to photograph or scan it....
So why bother with the intermediate step of printing, instead of taking a photo of the screen directly?

On the other hand, the modification was very useful.
Before the modification, the scope was drifty. Focus, DC offset of the traces, and all kinds of settings where drifting. More so during the first hour. It was quite irritating while using the scope.
After the modification, the drifting was almost gone, and the scope was much more pleasant to use.

To ease your hurt, I did make the modification reversible. The alu plate with fan is mounted with the same four screws, as were used for mounting the original plotter.


I traced the root cause of the drifting to the drift of the ±12V power supplies. These were running rather hot. I managed to improve things with better components etc. But a real solution would need a complete redesign. Or better cooling.


A point in favour for the built-in plotter: I remember it had four coloured pens. While the screen was green only.

regards, Gertjan.

[wkb]

Yes I did watch the video. My post is addressed to make people aware that in general instant film is not entirely dead, as was suggested.

[AVGresponding]

Numerous blue Phillips caps inside Dazz ?
Quite renown for their shortish service life but you have a good ST42 tweezer to check their values and ESR. 

Lots of brown electrolytics.  A few pale blue ?solid? electrolytics.  No time to stop and fault find. I have more vintage gear to resurrect.  I am just grateful the magic smoke stayed hidden.   

IIRC the old blue axials were the first to go.

IIRC the old blue axials were the first to go.

All are single ended radial wires. 
My thoughts are to create those symptoms, it has to be a fault related to driving the CRT rather than a data or signal fault.  If it is HT related, then a failing multiplier could be the cause.  It could also be any component in the CRT circuit partially breaking down.

iirc the psu's in these are notoriously problematic. I recently commented on "Blue Bastards" in another thread, hope there aren't too many in it. Time to check the HV diodes by the sound; remember they have somewhat more than a 600-700mV drop...

[dazz1]

My thoughts are to create those symptoms, it has to be a fault related to driving the CRT rather than a data or signal fault.  If it is HT related, then a failing multiplier could be the cause.  It could also be any component in the CRT circuit partially breaking down.

iirc the psu's in these are notoriously problematic. I recently commented on "Blue Bastards" in another thread, hope there aren't too many in it. Time to check the HV diodes by the sound; remember they have somewhat more than a 600-700mV drop...

I had enough problems with 2x Philips PM3070 scopes I built a power supply dummy load.  I had hoped I could easily repurpose this for the Fluke PM3394.  I had expected the PM3394 to basically be an upgraded version of a PM3070, but it is a completely different scope. 

The PM3070 had an invisible crack in a HV diode.    The fault on the PM3394 causes the display to expand about 1%-2% every 7 seconds or so, like a saw tooth oscillator.  Shrinks slowly, then jumps.  It affects both horizontal and vertical deflection.   Something somewhere is failing.   Could be thermally cycling.   

My hypothesis is that is it is something affecting the beam acceleration voltage.  A decrease in the acceleration voltage will cause greater beam deflection for given Horizontal &Vertical deflection voltages.  After studying the circuit diagram (I haven't done that yet), I would look halfway between the CRT and the power supply.  Probably the input to the voltage multiplier diodes.    Assuming the multiplied output is regulated, I would look at the feedback error signal and the reference.   I would be looking for a saw tooth wave form.

The other fault I need to fix is to replace the blown graticule lamp with an LED. I actually make use of an illuminated graticule.   

[factory]

Yes the earlier Philips scopes were notorious for SMPS PSU failure, they also seemed to change the design slightly with every new scope over the years. The PM3055 at work was no exception, it used to have problems starting the PSU, which of course never got fixed, it eventually died several years later blowing the mains fuses, the cal department decided the transformer was shorted and declared it BER, which I think was code for I can't be bothered trying to fix this.
I've since acquired my own, it has the same problem, but haven't got round to working on it.

The PM3394A pictures on the previous page show mostly brown Chemi-Con capacitors, the 1000uF 35V of these is notorious for peeing all over the PSU board in HP scopes & logic analyzers. It also shows at least one small diameter Philips radial cap, I've had those fail short circuit in the past.
But I've not heard of any problems with the this model of Philips scope, maybe they aren't old enough to show problems yet, another thread on here does recommend giving the HV section a clean, it's very dirty in the picture, probably not helped by being right by the fan.
Also the deflection PCB had some areas that were a bit baked, with a mention of applying new thermal paste to some parts & checking for dry joints.

https://www.eevblog.com/forum/repair/fluke-philips-pm3394a-combiscope-preventive-maintenance/msg3445504/#msg3445504

David

[factory]

Yes I did watch the video. My post is addressed to make people aware that in general instant film is not entirely dead, as was suggested.

I've edited my post, as I wasn't clear enough to only refer to the scope camera film, not general purpose Polaroid film which is still used for photography. Can't say I've seen anyone use one since the 1990s and film photography is not a hobby I want to start either.

Even if they did build new machinery to reproduce the specialist size/type & high speed films for scope cameras, I can't imagine it would be sell well enough to cover the machinery & production costs.

David

[nonius_]

To ease your hurt, I did make the modification reversible. The alu plate with fan is mounted with the same four screws, as were used for mounting the original plotter.

Fair enough, Gertjan

A thermal printer is indeed less useful but I understand that there are also variants with a small plotter. That'd be amazing to have in an oscilloscope, for me. But I have a soft spot for such technology where mechanical engineering and electronics are combined.

[tautech]

Yes the earlier Philips scopes were notorious for SMPS PSU failure, they also seemed to change the design slightly with every new scope over the years. The PM3055 at work was no exception, it used to have problems starting the PSU, which of course never got fixed, it eventually died several years later blowing the mains fuses, the cal department decided the transformer was shorted and declared it BER, which I think was code for I can't be bothered trying to fix this.
I've since acquired my own, it has the same problem, but haven't got round to working on it.

The PM3394A pictures on the previous page show mostly brown Chemi-Con capacitors, the 1000uF 35V of these is notorious for peeing all over the PSU board in HP scopes & logic analyzers. It also shows at least one small diameter Philips radial cap, I've had those fail short circuit in the past.
But I've not heard of any problems with the this model of Philips scope, maybe they aren't old enough to show problems yet, another thread on here does recommend giving the HV section a clean, it's very dirty in the picture, probably not helped by being right by the fan.
Also the deflection PCB had some areas that were a bit baked, with a mention of applying new thermal paste to some parts & checking for dry joints.

https://www.eevblog.com/forum/repair/fluke-philips-pm3394a-combiscope-preventive-maintenance/msg3445504/#msg3445504

David

And that thread leads to this thread where the fault Dazz has might also just be a loose/dirty/arcing PDA anode cap:
https://www.eevblog.com/forum/repair/crt-scope-trace-scale-affected-by-intensity-pm3394/

[nonius_]

Those Philips scopes are indeed notorious for their electrolytic caps. Had to replace many of them in the powersupply of my PM3055, plus a few more on the XYZ-board, before it sprang back to life.

There's a pretty long thread on a Dutch electronics forum where one persistent repairer is trying to resuscitate a particularly maltreated pwersupply. Impressive to see the many problems with it (many of which were caused by another repairer who made a small error by installing one of the replacement caps reversed. That caused quite a cascade of other failures).

https://www.circuitsonline.net/forum/view/171020

[Zoli]

Since we're on page 5555, I would put up an image of an HP5555, but it's a PDA

[Cyclotron]

Since we're on page 5555, I would put up an image of an HP5555, but it's a PDA

I was trying to figure out what you meant. Then I realized I had configured my settings to 50 posts per page so it doesn't appear to me that we have reach 5555 just yet.  Or, I'm just a time traveler form the past, or maybe you're a time traveler from the future?  What are the PPMs like in the future?

[McBryce]

Since we're on page 5555, I would put up an image of an HP5555, but it's a PDA

Here's 5 555's instead.

McBryce.

[factory]

Since we're on page 5555, I would put up an image of an HP5555, but it's a PDA

At least HeaP appear to have not recycled an old HP model number for that PDA, well from what I can see in the HP manual fiche index, 5554A (a preamplifier) however was a valid HP TE number, really surprised no-one has posted a picture of their 5554A on the previous page (for those either not logged in, or on the forum default setting).

David

[TERRA Operative]

Started on the journey to hopefully mod my Valhalla 2724A Resistance Standard with an LED display.

https://www.eevblog.com/forum/projects/valhalla-2724a-resistance-standard-vfd-to-led-display-conversion/msg6269122/#msg6269122


Yet another project on the pile of projects.....

[dazz1]

I am now the owner of a Tektronix 3001 GPX Logic Analyser.  When I first saw it, with a B&W curvy CRT, I thought it was 1980's vintage.  The IC dates it to 1994, so only 32 years old.

The LA also came with most of a matching kit of adapters to PLCC chips.  I suspect this is not a very common accessory.

I haven't been in the same room as a old school logic analyser since 1985 at University.  These are very rare where I live.

Some might think of asking why would I need a logic analyser that was probably obsolete before it left the factory.  To that I would say, I want it therefore I need it. 
It is the digital version of an oscilloscope and a perfect complement to my growing collection of oscilloscopes and other odd-ball instruments. 

Haven't put power on it yet.  The single pod is broken.  I am looking for pods and clips to buy if any one knows someone who wants to sell.    I see a lot of parts for these on e-bay.  I presume a lot have been scrapped to e-waste.  I imagine the market for obsolete old logic analysers is quite small.  Lots of sellers and not many buyers.

[TERRA Operative]

Do want those IC clips!