Test Equipment Anonymous (TEA) group therapy thread

[25 CPS]

The batteries are exposed because I originally was going to use the two meters to cross check each other but the Agilent did not like that one bit and freaked out with an A-Err message and beeping when measuring the battery connected to the Fluke at the same time the Fluke was measuring the battery connected to the Agilent.  The Fluke didn’t care but the U1252A didn’t like that cross connected arrangement at all so a bench power supply connected to both solved that problem.

This does not surprise me at all. Come on - the analogy of two surgeons operating simultaneously on each others guts is the kindest picture which I can find for this experiment! All other analogies involve livestock keeping neighbours with unmentionable predilections.

Actually, it totally surprises me.  A-Err on the Agilent is intended to warn you that the test leads are in the current jack when the function knob is not on one of the current ranges to prevent you from accidentally short circuiting something through the meter:



The leads were in the correct set of jacks and the meter was alternating between showing the expected 9V and change, and throwing the error and this was repeatable going between measuring the battery powering up the Fluke and the DC off the power supply which raises questions about differences between the input side of the meters and why the Agilent consistently enters this state with leads in the correct sockets while the Fluke operates without any issue while performing the same measurement test.

[0culus]

Type 547 vertical mod is half done. I got the NTE parts I needed. Q1109 is replaced, and D1109 is replaced with a 110V zener. D1114 is added (used a 1N4007, which is overkill, but I have them on hand from when the Type 585A needed rectifiers replaced). Hopefully the new vertical output transistors will be here this week, so I'll be able to get my workhorse back up and running this weekend.

[Cerebus]

Actually, it totally surprises me.  A-Err on the Agilent is intended to warn you that the test leads are in the current jack when the function knob is not on one of the current ranges to prevent you from accidentally short circuiting something through the meter:



The leads were in the correct set of jacks and the meter was alternating between showing the expected 9V and change, and throwing the error and this was repeatable going between measuring the battery powering up the Fluke and the DC off the power supply which raises questions about differences between the input side of the meters and why the Agilent consistently enters this state with leads in the correct sockets while the Fluke operates without any issue while performing the same measurement test.

Doesn't necessarily surprise me. Some meters can generate quite significant current spikes on their inputs while measuring from switching artefacts (e.g. range switching, even actual input sampling). On high quality, high precision bench meters there are quite a lot of loops jumped through to stop the meters from doing this and to make them present a constant effective impedance to the input signal even though the signal may be being switched left, right and centre, connected to an ADC, disconnected from the ADC while it auto-zeroes, connected again and so on.

What the 27 is like in this regard I don't know, I've never measured it taking a measurement and given its generation and relatively low input impedance (10M is nothing) it's quite likely that it does produce some loading/unloading current spike artefacts on its input.

Given what's becoming the reputation for HP handheld meters having rather poor EMI rejection I'm not surprised that the HP is the one getting its knickers in a twist.

[med6753]

Type 547 vertical mod is half done. I got the NTE parts I needed. Q1109 is replaced, and D1109 is replaced with a 110V zener. D1114 is added (used a 1N4007, which is overkill, but I have them on hand from when the Type 585A needed rectifiers replaced). Hopefully the new vertical output transistors will be here this week, so I'll be able to get my workhorse back up and running this weekend.

Make certain that the collector (case) of Q1109 isn't shorted to the chassis. I discovered mine was because I had the fiber shoulder insulator slightly askew. (Yes, found it BEFORE power up. ) 

[0culus]

Type 547 vertical mod is half done. I got the NTE parts I needed. Q1109 is replaced, and D1109 is replaced with a 110V zener. D1114 is added (used a 1N4007, which is overkill, but I have them on hand from when the Type 585A needed rectifiers replaced). Hopefully the new vertical output transistors will be here this week, so I'll be able to get my workhorse back up and running this weekend.

Make certain that the collector (case) of Q1109 isn't shorted to the chassis. I discovered mine was because I had the fiber shoulder insulator slightly askew. (Yes, found it BEFORE power up. ) 

I aligned the rubber grommets and the insulator and then tested with a multimeter. All is well on that front. 

[vk6zgo]

[ Attachment Invalid Or Does Not Exist ] [ Attachment Invalid Or Does Not Exist ]

In case of Rohde&Schwarz they sold Tektronix equipment as a distributor in Germany back then, placing an own label on the equipment. "Rohde & Schwarz Vertriebs-GmbH" is the sales company for Germany.

Yes. Two examples (NAWTS):

A T912:
https://www.ebay-kleinanzeigen.de/s-anzeige/tektronix-t912-von-rohde-schwarz/1853152201-168-3411


A D54:
https://www.ebay-kleinanzeigen.de/s-anzeige/oscilloscope-oszilloskop-analog-rohde-schwarz/1169411519-168-6900


The D54 is looking nice. Is it worth to have a closer look? Or is the T912 the better device?

Edit:
Thought again about the D54. I have some doubts, that it is a Tek scope. I was misleaded by the red knobs and the layout. Telequipment - never heard of that company. Can someone illuminate me? Thanks.

Telequipment was a British scope manufacturer that was acquired by Tektronix in 1966.  They produced scopes more intended as service grade instruments for repair shops and the like, as opposed to the more lab-grade Tek scopes.  That kinship explains the family resemblance you noted.

https://w140.com/tekwiki/wiki/Telequipment

-Pat

Even the little Telequipment "Serviscope" from well before the acquisition followed the Tek pattern , with the Red & black knobs, although the tube position looked a bit more typically "British".

[vk6zgo]

It's not unusual for TE to be owned by rival manufacturers, I'm sure one of my Keithley meters has a Fluke asset sticker on it, and one of my Fluke 8300A's has a TI asset number, though I suppose they aren't/weren't direct competitors for bench meters.

In case of Rohde&Schwarz they sold Tektronix equipment as a distributor in Germany back then, placing an own label on the equipment. "Rohde & Schwarz Vertriebs-GmbH" is the sales company for Germany.

Hmmm... is that ironic...?

Or just a reminder that once upon a time, businesses actually occasionally operated in a cooperative manner...?

mnem
Which would be its own, much sadder irony... 

There was quite a lot of that!

Rohde & Schwarz & Wandel und Goltermann had some of their equipment designed to interface with each other.
Siemens TV transmitters had Rohde & Schwarz exciters integrated into them

Dodge & International used the same cabs for their forward control trucks in Oz for years.

Before that, Dodge/Fargo/DeSoto trucks shared the same cabs with the Brit designed Ford Thames & Morris Commercial in Oz.

[vk6zgo]

In case of Rohde&Schwarz they sold Tektronix equipment as a distributor in Germany back then, placing an own label on the equipment. "Rohde & Schwarz Vertriebs-GmbH" is the sales company for Germany.

Yes. Two examples (NAWTS):

A T912:
https://www.ebay-kleinanzeigen.de/s-anzeige/tektronix-t912-von-rohde-schwarz/1853152201-168-3411


A D54:
https://www.ebay-kleinanzeigen.de/s-anzeige/oscilloscope-oszilloskop-analog-rohde-schwarz/1169411519-168-6900


The D54 is looking nice. Is it worth to have a closer look? Or is the T912 the better device?

Edit:
Thought again about the D54. I have some doubts, that it is a Tek scope. I was misleaded by the red knobs and the layout. Telequipment - never heard of that company. Can someone illuminate me? Thanks.

Telequipment was a British scope manufacturer that was acquired by Tektronix in 1966.  They produced scopes more intended as service grade instruments for repair shops and the like, as opposed to the more lab-grade Tek scopes.  That kinship explains the family resemblance you noted.

https://w140.com/tekwiki/wiki/Telequipment

-Pat

It also has a familial connection a little closer to home... bd139's mom was a assembly line debugger (IIRC) at Telequipment:

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3492346/?topicseen#msg3492346

mnem
 

That must have been "de bugger of a job"!

[vk6zgo]

Mini 212, round 4.

PSU board, batteries, and CRT reassembled. It is a tight fit and gonna get even messier when the other 2 boards are installed.



And here's an example of the documentation not matching the board. The trace routing to R141. Those 2 orange tants. One is a 1uf/35V, the other is a 1uf/50V. I'm not sure which one is which and there's a 50% chance of getting it wrong resulting in smoke. So I'll wait until assembled and powered up then measure voltage on each. In the meantime changing out the other tants on this board. The main board is still to do and I have to figure out how to get access to the solder side.

If they are both 1uF caps, why not replace both with 1uF /50v?
That is what would almost certainly have been done if they needed replacement during the instrument's service life.

[AVGresponding]

Also consider this as well, there is the possibility that the person you know might well have parted company with Sinclair under a cloud for some reason if that is the case, is he going to be 100% honest about his relationship with Sinclair, I think not.

People, not person, and both worked for Amstrad after the Sinclair properties they worked for were sold to Amstrad. (If you really want to hear some bad-mouthing, ask either of them about Alan Sugar.) So much for that theory. It's rather unfair to character assassinate people you don't know and ascribe ill motives to them just because their actual first hand experience of Sinclair doesn't accord with your rose-tinted view from a distance.

Whereas a sample size of two makes for a robust analysis?

[dl6lr]

I'll leave it up to you to discover more about the man himself, but I must say, the image many have of him, does not actually match the reality.

Being given that "the reality" is always a subjective value, the man can be charming in a lot of situations whereas he will be a choleric person in others. And even persons you know well can be disturbing different in other environments.

[mansaxel]

Whereas a sample size of two makes for a robust analysis?

Superficially, twice as good.

Taken into account the circumstance that those two were working relations rather than one-time encounters, there is a considerable lever effect on top, making the "two" sample size much greater than twice as good.

Whether one may chose to disagree with the aardvark or not, one must acknowledge that he does put some thought-out effort into strengthening his case.

[mansaxel]

Add one to the "long string of purchases for projects", "supposed" Matsushita BBD IC's. They come in pairs, one MN3207 which is the actual capacitor array, and one MN3102 which is the clock chip.  Since they were less than 1USD per chip shipped from the Middle Kingdom, the idea that they might be real is bordering on silly. 

Matsushita stopped making the originals in 1999, and since chips of that family are used in modulation stomp boxes "as made famous by men who made goodpopular music and then killed themselves" the actual stock of the parts must have dwindled fast. There are as-such marked clones, and I've paid my dues to the "respectable clone" trade, by buying some of those, branded "Beiling Shanghai". Beiling and Coolaudio are the two current cloners, the latter being a vertical integration in music industry giant Behringer (the company that today owns the British crown jewels Midas, Klark-Teknik and Turbosound.    )

These chips are much more of a gamble, just to find out if there is any meat to the argument that some clones are better than other clones.

On the positive side I notice that the transport company, "Orange Connex" which sounds like a cross between a phone company and a railway mismanager apparently can sneak the little white plastic padded bags past the Postnord protection racket and that I thus avoid extra VAT and a SEK75 handling fee. Or this might be an effect of Ebay VAT rule complicance. 

Now I just need to fail to find the rest of the components in my bins and drawers, order them anew from Mouser, only to find that I already had 52% of them while trying to sort the new purchases into my "system". 

[med6753]

If they are both 1uF caps, why not replace both with 1uF /50v?
That is what would almost certainly have been done if they needed replacement during the instrument's service life.

Of course that's the obvious answer and I considered doing that. But for accuracy and for record keeping I want to know who's right so I can apply any appropriate paperwork changes.

[mansaxel]

On the positive side I notice that the transport company, "Orange Connex" which sounds like a cross between a phone company and a railway mismanager apparently can sneak the little white plastic padded bags past the Postnord protection racket and that I thus avoid extra VAT and a SEK75 handling fee. Or this might be an effect of Ebay VAT rule complicance. 

It is the VAT rules at work; I looked again at the purchase details and there it is. I must say I like this better than having the shipment delayed, mauled, delayed a bit more and then held ransom by Postnord.

[vk6zgo]

Even the little Telequipment "Serviscope" from well before the acquisition followed the Tek pattern , with the Red & black knobs, although the tube position looked a bit more typically "British".

Here is the pix I tried to attach before (I found an online converter from tfif to jpeg.)

[med6753]

Even the little Telequipment "Serviscope" from well before the acquisition followed the Tek pattern , with the Red & black knobs, although the tube position looked a bit more typically "British".

Here is the pix I tried to attach before (I found an online converter from tfif to jpeg.)
(Attachment Link)

They apparently exploited that gap between Heathkit and Tektronix. Telequipment stuff is rare here and I've never seen one in the flesh.

[srb1954]

They apparently exploited that gap between Heathkit and Tektronix. Telequipment stuff is rare here and I've never seen one in the flesh.

You haven't missed much.

I used a number of different Telequipment scopes during my university days and early career and I can't say I particularly liked any of them. Their performance wasn't anything wonderful and they were a PITA to work on when repairs had to be done.

[Neper]

... I'm no longer willing to put other people's repair jobs ahead of my own projects on the bench once those three committed once are finished up and out the door.

My final red line was crossed when a remote acquaintance asked if I would be so nice to have a look at a minor problem his girlfriend was having with her stereo amp. Surely something I could fix in a few minutes. I agreed to have a look.

On the day, she arrived with an amp of some cheap chain store house brand, the thing was a total wreck and looked as if it had been buried under a dungheap which wasn't far from reality - she owned a pub. Switches had lost their click stops, the volume pot was broken and there were a number of black spots on the PCB.

When I suggested we'd better put this thing out of its misery she got all upset. "Well, thanks for nothing, Mister Electronics Wizard!"

My workbench hasn't seen anything that wasn't my own, ever since.

[srb1954]

Yes. Two examples (NAWTS):

A T912:
https://www.ebay-kleinanzeigen.de/s-anzeige/tektronix-t912-von-rohde-schwarz/1853152201-168-3411


A D54:
https://www.ebay-kleinanzeigen.de/s-anzeige/oscilloscope-oszilloskop-analog-rohde-schwarz/1169411519-168-6900


The D54 is looking nice. Is it worth to have a closer look? Or is the T912 the better device?

Edit:
Thought again about the D54. I have some doubts, that it is a Tek scope. I was misleaded by the red knobs and the layout. Telequipment - never heard of that company. Can someone illuminate me? Thanks.

The T912 would better overall than the D54 particularly if they are priced nearly the same. However, T912 is a storage scope so there is a greater risk that the tube is burnt, which is perhaps why the seller didn't show a trace on the T912.

[jonovid]

Even the little Telequipment "Serviscope" from well before the acquisition followed the Tek pattern , with the Red & black knobs, although the tube position looked a bit more typically "British".

Here is the pix I tried to attach before (I found an online converter from tfif to jpeg.)
(Attachment Link)

update-  here is two images of my TV repair oscilloscope its the dusty one

I have one of them old 1950s single channel TV repair oscilloscopes too. its exactly the same at your Image. made in the UK if I remember
and its has banana plug inputs on the rear of the case.
My scope has a failed sweep generator circuit so is useable but still shows a dot in its green CRT.
so the HT is ok. I have had  mine for about 30 yrs. and it was used to test audio befor it got a bad thump one day that may have
damaged a valve in the sweep generator circuit. do hope its not a damaged plate inside the CRT tube.   

[Brumby]

Heads up Aussie AVO nuts. Short time auction eBay auction: #115030471572

Location is about an hour's drive each way for me .... but I already have one AVO.  Not really looking for another.

ONE  , You're not trying hard enough, I've got six of them here, 4 model8 MKV and earlier Avo's all in working order and another model 8 MkV that is a parts mule.

I am constrained by a lack of space to limit myself far more than I might like.  My limitation is based on what I can reasonably use ... and multiple AVOs doesn't represent much value in this direction.




Buuuuuuut ... then ....... it does have that hefty current shunt ...   

[Robert763]

... I'm no longer willing to put other people's repair jobs ahead of my own projects on the bench once those three committed once are finished up and out the door.

My final red line was crossed when a remote acquaintance asked if I would be so nice to have a look at a minor problem his girlfriend was having with her stereo amp. Surely something I could fix in a few minutes. I agreed to have a look.

On the day, she arrived with an amp of some cheap chain store house brand, the thing was a total wreck and looked as if it had been buried under a dungheap which wasn't far from reality - she owned a pub. Switches had lost their click stops, the volume pot was broken and there were a number of black spots on the PCB.

When I suggested we'd better put this thing out of its misery she got all upset. "Well, thanks for nothing, Mister Electronics Wizard!"

My workbench hasn't seen anything that wasn't my own, ever since

The killer for me was when I found out that a "friend" who was asking for help with repairs was actually touting for work and charging other people for the repair.   guess help is better than expecting me to do all the work. But still a cheek. The final straw was when he put a mark-up on an item I asked him to add to an order he was doing...........

[med6753]

Even the little Telequipment "Serviscope" from well before the acquisition followed the Tek pattern , with the Red & black knobs, although the tube position looked a bit more typically "British".

Here is the pix I tried to attach before (I found an online converter from tfif to jpeg.)
(Attachment Link)

update-  here is two images of my TV repair oscilloscope its the dusty one

I have one of them old 1950s single channel TV repair oscilloscopes too. its exactly the same at your Image. made in the UK if I remember
and its has banana plug inputs on the rear of the case.
My scope has a failed sweep generator circuit so is useable but still shows a dot in its green CRT.
so the HT is ok. I have had  mine for about 30 yrs. and it was used to test audio befor it got a bad thump one day that may have
damaged a valve in the sweep generator circuit. do hope its not a damaged plate inside the CRT tube.

That reminds me a lot of this.

[Specmaster]

Also consider this as well, there is the possibility that the person you know might well have parted company with Sinclair under a cloud for some reason if that is the case, is he going to be 100% honest about his relationship with Sinclair, I think not.

People, not person, and both worked for Amstrad after the Sinclair properties they worked for were sold to Amstrad. (If you really want to hear some bad-mouthing, ask either of them about Alan Sugar.) So much for that theory. It's rather unfair to character assassinate people you don't know and ascribe ill motives to them just because their actual first hand experience of Sinclair doesn't accord with your rose-tinted view from a distance.

Now who is not reading what was written? I'm NOT character assassinating anyone, you are reading far more into what I wrote than was there or implied. You tried to cast doubts on the words of Ruth Bramley in that interview with her, also to the best of my knowledge, you have never met him, instead relying on what some people have told you.

I'm not naive enough to believe that all the well documented awards given to Sinclair are the results of Sir Clive personally, but are the results of his team doing their very best to turn his vision into reality. It was also well known that he had a temper, and was even portrayed in the earlier video I posted a link to, just has Alan Sugar, who you also named and shamed in your reply. I also have met Alan when he had premises in Dalston, again, I have over the years owned many Amstrad devices, again, designed and built down to a price point so do not stand comparison against better specified, more expensive competition that only those with more disposable income could afford!

Both Sugar and Sinclair have achieved far greater things than either of us have managed to do, so in my book, they will be well remembered in history, while we will not. Infact  it is perfectly conceivable that maybe, without Sinclair, the BBC Micro might not have come about or indeed ARM processors which is today used in loads of devices, so they all form part of the legacy left behind by Sir Clive Sinclair