Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

I just had to post a pix of it all back together with the covers installed and in the corner running a burn-in. To think twice I came close to throwing it into the bin. This definitely has been my most difficult restoration and it's extremely satisfying to see it up and running.

BTW, I did get new batteries for the 212 scope.

Great job on this, we all knew that you would be victorious in the end 

[Vince]

You might want to do a Google search for the basic principle of a wobulator.

I just searched for the manual for this thing, lucky me I found it (rare for Metrix stuff of any vintage...), attached below. A nice manual too (by French standards that is...) = 60 pages of goodness ! Complete with schematics, block diagram, how to operate it as well as principle of operation, and good quality scans to boot, perfectly legible ! 

Just skimmed the surface for a few seconds but it's already starting to make more sense ! 
Robert and ShakalNokturn helped a good deal too !

So now it's clear that it's a very specialized bit of kit, a test set for TV service techs, which I have therefore no business owning! Let's be honest... this thing is wasted if it stays with me, I just have zero use for it yet it takes an awful lot of space. The only good thing to do is sell it to someone who actually is into old TV stuff, and could appreciate this NIB piece of test gear....

So yeah. Manual helps for sure.

So basically the middle part of the isntrument, they call the "Wobulator". Generated the HF "carrier" + some frequency modulation on top of it hence as Robert said the term "Wobble". Teh amount of Wobble is controlled by that knob that gives your a few fixed spans up to 20MHz.  So for starters I need to get that working !

Then the left part of the instrument, they say it generates "markers". There two kinds you chan choose from. A marke for sound, and another marker for video. Markers are at a fixed frequency, 1MHz and 10Mhz. Can't remember which is sound and which is video.
The "biscuits" one can shove into the big rotating switch, do not define the carrier/ HF frequency. They are there to provide the two sound and video markers. So for example I have the biscuit for Channel #7 on my particular instrument. That means that the biscuit I have will generate a marker at the carrier Frequency for channel #7 + 1MHz and another marker at carrier + 1MHz. That's why the biscuit is made of two identical looking sections, each with their own Quartz crystal.

Then,  CRT/ scope section of the instrument, is supposed to display the amplitude vs frequency response of the TV set under test, so I guess it should look like a LPF Bode plot or something ? A horizontal part then a negative going slope on the right hand side ?!
Will try to find videos of a Wobulator in action to confirm...

That also means I need an old TV set to to wire to this Wobulator if I want it to display what it's supposed to display, pfff... how practical. Need to find a way to get round that...

Anyway, armed with this manual hopefully I should be able to fix it... or at the least have a fait go at it.
Decision is also made to sell this puppy so it can go to someone who deserves it more than I do. Hopefully I will make some profit in the process and that will allow me to buy a similar vintage Metrix boat anchor (love the look of them), but this time a general purpose RF generator with general purpose modulation features, that I can actually make use of and enjoy...

[Cerebus]

Testing the preliminary fixed TA520 by measuring the wander of a cheap GPS module PPS output vs. the True Position GPSDO PPS output - or fine arts japanese technology vs. rock solid HPAK:

TA520 and 53131A - the perfect team for timenuttery

Just a FYI based on my experiences with the 53132A so far. If the 53131A with the HS oven option behaves the same as the 53132A with the US option oven it needs several days of standby/power on to reach ultimate stability. The OCXOs are the same design, just different grades with the US being picked out and given the appropriate part number, so I expect they do. Worth noting if you're really going to get into it, not worth noting if something of the close order of 1 ppb/day drift isn't going to bother you because you're just doing relatively short term comparative measurements.

[25 CPS]

Yes - my mistake there - it was 135 MOhms in that one test with the far end open circuit, not GOhms.

That's more like sensible values, yes.    If you'd had GΩ in a bit of dirty, humid cordage, that would have been something.

My Wee Megger example yielded 250MΩ for buried cable, which is satisfactory, with margin: The Swedish (probably EU) rules establish a pass/fail insulation resistance of 1KΩ per volt of system voltage. As we're running 400VAC phase/phase voltage, I had to get above 400*1000 Ω which as noted I did, with a wide margin. If I'd been anywhere close, I'd think twice about why and perhaps would not have recommissioned the cable. Measurement voltage of course also needs to surpass the system voltage, and the Megger at 500V (verified) will satisfy that too. What it does not achieve, of course, is safety to IEC 61010-1... 

I didn't know the 1 KOhm/Volt was a codified standard.  It's been an accepted practice I've seen pretty much everywhere so I wouldn't be surprised if it turns up in a lot of standards, actually.

I forgot to mention that part of the reason for demonstrating all the wireless connectivity stuff was to show what I had in mind for getting instrumentation set up on some tramcars in railway museums to get some objective measurements on controller and motor performance especially on newer ones that have automatic acceleration and dynamic braking.

That is seriously cool.

There was a lot of discussion between myself and a couple of friends, including one who is a mechanical engineer and is soft on the electrical side of things, about the supposed "300 A ammeter" that was being used at one railway museum to set up streetcars because he wanted to buy one for himself to take to each museum he volunteers at.  This prompted a whole discussion of how what this one museum gave him to use wasn't really an ammeter, it was a voltmeter with a dial scale that reads out in amps and it's used with a built in current shunt on the tramcar that has its output routed to a set of test points in a box in the passenger area.

Anyways, this prompted a whole discussion about how we could throw some of my modern instrumentation at the problem in different ways.  I worked out what the acceleration, braking, and coasting currents equated to in terms of voltage output from the shunt and suggested that what we could do is set up a multimeter on the shunt test points as well as a clamp meter on the motor feed that passes through the shunt and we could observe both at the same time on the remote logging display and see if they agree.

They should be pretty close.  If not, there's a possibility that the shunt got overheated and damaged at some point.  Every time someone does a controller setup and plugs in the meter to the test points, the working assumption is that the current shunts on each of these tramcars is still giving accurate output but truth be told, nobody's ever checked to make sure that this really is the case.  The other variation of the theme is to replace the remote logging display with a tablet running the Keysight Meter Logger app which has the computer meter function where you can multiply the voltage being read off by the DMM on the current shunt's test points and multiply it by the mV/A ratio of the current shunt and have it directly display the output in amps.  Unfortunately, the U1115A remote logging display doesn't have this feature while the tablet app does.

[Kosmic]

If anybody is looking for some voltnut connectors. Seller is in Germany, shipping is pretty cheap even for Canada.

https://www.ebay.com/itm/304161839776

[Robert763]

Don't forget about it, is almost time  !!!

https://www.ebay.de/itm/373727179675




Cheers,
DC1MC

Don't want it...

GOOD!

It's not moving a lot. You might be able to get a good deal.

Hope you got Gixen setup and ready 

It moved - £460 

[Kosmic]

Yes it was funny everybody waited at the end.

Anybody got it ? I guess not since it was pretty expensive in the end.

[Saskia]

did some work over the weekend.
Pinball backbox, Fish Tales to be exact.
Sanded it down and went at it with Polyester filler. Brought it back into shape (reconstructed the edges, ...), then sanded, used filler, sanded, .... you get the idea.

Fortunately I had decent equipment that a friend of mine loaned to me:
This:
https://www.festool.de/produkte/holzbau/exzenterschleifer/576329---ets-ec1505-eq-plus
and this:
https://www.festool.de/produkte/saugen/absaugmobile/574983---ctm-36-e-ac-230v
and this:
https://werkzeugstore24.de/festool-ansetzhilfe-ah-es-ets-etsc-205316.html?gclid=Cj0KCQjwtMCKBhDAARIsAG-2Eu_Fz0RHL-wikWUIcOq3jffdTXweHcPAs4BZ0EzG9D5sp1Bbfv3fXvwaAsPiEALw_wcB with the corresponding 125mm sander. Still took about 20 hours to rebuild that box. Next one will be faster ...

The box now has its first primer coating, additional final filler/sander stage will follow. After that it will be decal time, then the old backbox content can be moved.

In other news I just got the ok for a major pinball mayhem.
Will get 3 pinballs for 2000€, a Flintstones, a BS Dracula and a Grand Lizard (?) ...
Given today's pb pricing that is extremely good.

[tggzzz]

Don't forget about it, is almost time  !!!

https://www.ebay.de/itm/373727179675




Cheers,
DC1MC

Don't want it...

GOOD!

[color]

It's not moving a lot. You might be able to get a good deal.

Hope you got Gixen setup and ready 

It moved - £460 

Bloody hell. I'm rich Mine didn't have the NVRAM failure the last time I turned it on.

[factory]

Probably didn't have borked ohms ranges either.

David

[mansaxel]

If the Fluke is is as good as the Agilent 34401A they sold me, I'll be quite happy:

(this is one of the occasions where a Fluke 27 compares well to a 34401A)

It will be.

[dl6lr]

I did some digging just now because the seller's name looked familiar so I went back through my purchase history and, sure enough, he's there.  Remember those new-old-stock US Navy surplus Agilent 34401A meters that turned up on eBay last year?  It was the same seller who had those so I'm pretty confident buying one of those Flukes.  That's why anainstr looked familiar.

If the Fluke is is as good as the Agilent 34401A they sold me, I'll be quite happy:

Yes, I remember the seller too. This was my first 34401A
Now something puzzles me about the eBay GSP: If I prepare a lower offer, the shipping and tax is estimated higher than in the original ad? Can someone shed some light on this?

[mansaxel]

I didn't know the 1 KOhm/Volt was a codified standard.  It's been an accepted practice I've seen pretty much everywhere so I wouldn't be surprised if it turns up in a lot of standards, actually.

TBH I did not pay the ISO / SIS protection racket for a PDF file containing the definition, because my IETF ethos is a bit too strong. I had to go on secondary sources, which in fact say, as you indicate, 1KΩ / Volt being a rule of thumb, not specifically stating it's a standard.

There was a lot of discussion between myself and a couple of friends, including one who is a mechanical engineer and is soft on the electrical side of things, about the supposed "300 A ammeter" that was being used at one railway museum to set up streetcars because he wanted to buy one for himself to take to each museum he volunteers at.  This prompted a whole discussion of how what this one museum gave him to use wasn't really an ammeter, it was a voltmeter with a dial scale that reads out in amps and it's used with a built in current shunt on the tramcar that has its output routed to a set of test points in a box in the passenger area.

Anyways, this prompted a whole discussion about how we could throw some of my modern instrumentation at the problem in different ways.  I worked out what the acceleration, braking, and coasting currents equated to in terms of voltage output from the shunt and suggested that what we could do is set up a multimeter on the shunt test points as well as a clamp meter on the motor feed that passes through the shunt and we could observe both at the same time on the remote logging display and see if they agree.

They should be pretty close.  If not, there's a possibility that the shunt got overheated and damaged at some point.  Every time someone does a controller setup and plugs in the meter to the test points, the working assumption is that the current shunts on each of these tramcars is still giving accurate output but truth be told, nobody's ever checked to make sure that this really is the case.  The other variation of the theme is to replace the remote logging display with a tablet running the Keysight Meter Logger app which has the computer meter function where you can multiply the voltage being read off by the DMM on the current shunt's test points and multiply it by the mV/A ratio of the current shunt and have it directly display the output in amps.  Unfortunately, the U1115A remote logging display doesn't have this feature while the tablet app does.

Sounds you need to take the lab on the rails. We've got a pretty extensive streetcar operation downtown that is partially run by a commercial branch of the Historical Streetcar Society. You can end up in a 1911 streetcar for your work commute, or in a very modern one , a bit depending on what they feel like running. 

Edit: Better english.

[Cerebus]

There's a new Signal Path up if anyone's interested:

[factory]

Well I now have the crusty hp 207A sweep oscillator & 3480B voltmeter from Chelford, didn't go back through Peover Superior this week, instead a detour to Macclesfield to fill the van with more stuff from my Grandparents estate. On the way back the A534 Wheelock bypass got blocked by some mangled vehicles & the police had closed the road, had to turn back & go another way. 

Anyway here is the first of the crusty hp relics, the 207A sweep oscillator.


Cleaned up the label a little.



Inside it's not as bad as I thought, I managed to free up the various shafts without too much difficulty, only the short section of shaft at back is rusty.



Underneath it's fairly clean, apart from a few rusty nuts & the exposed E section lamination of the output transformer, all the vacuum bulbs are intact too.



It did come with the covers & fuse cap (3A fitted  ), it was removed while I was evaluating it, I cut off the mains cord as it needs replacing along with the terminal strip. Serial number is 00355.


Final picture for the moment, two of the three EOL Sprague bumble bombs. 


David

[mnementh]

A new seller has popped up on ebay in the UK. They seem to have a lot of NOS TE spares. For example a Fluke 8060A front case moulding.
Rather than linking to an item which will disappear in time, here is his user info
www.ebay.co.uk/usr/stiff-3268

Doesn't seem to be pricing parts like they're made of gold just cuz they're shiny, too. Should be someone we can do bidnezz wid'd.

mnem
 

[mnementh]

I just had to post a pix of it all back together with the covers installed and in the corner running a burn-in. To think twice I came close to throwing it into the bin. This definitely has been my most difficult restoration and it's extremely satisfying to see it up and running.

BTW, I did get new batteries for the 212 scope.

*flies past, stealing all med's little yellow caps and cackling all the while*

Seriously... good work. You slugged it out and won.

Yeah, we saw the Tenergy packs in the previous pic. Fit 2 into one set of endcaps, by the looks. 

mnem
 

[Specmaster]

Heads up guys, new Solartrons listed on eBay


https://www.ebay.co.uk/itm/373733849156


https://www.ebay.co.uk/itm/373733837529

[AVGresponding]

Don't forget about it, is almost time  !!!

https://www.ebay.de/itm/373727179675




Cheers,
DC1MC

Don't want it...

GOOD!

It's not moving a lot. You might be able to get a good deal.

Hope you got Gixen setup and ready 

It moved - £460 

Yes, all the serious bidders waited for the dying seconds. It went way past what I was prepared to risk on something that's potentially unfixable.

[mansaxel]

Final picture for the moment, two of the three EOL Sprague bumble bombs. 

I'm positive you can sell them to someone who claims point-to-point wired guitar amps is more reliable than PCB's. And make a profit.

[AVGresponding]

Heads up guys, new Solartrons listed on eBay


https://www.ebay.co.uk/itm/373733849156


https://www.ebay.co.uk/itm/373733837529

Yes, from the same seller as the 7081. The 7071 may or may not be working, the 7061 looks like it may well be borked, you picked the wrong pic...

[mnementh]

did some work over the weekend.
Pinball backbox, Fish Tales to be exact.
Sanded it down and went at it with Polyester filler. Brought it back into shape (reconstructed the edges, ...), then sanded, used filler, sanded, .... you get the idea.

Fortunately I had decent equipment that a friend of mine loaned to me:
This:
https://www.festool.de/produkte/holzbau/exzenterschleifer/576329---ets-ec1505-eq-plus
and this:
https://www.festool.de/produkte/saugen/absaugmobile/574983---ctm-36-e-ac-230v
and this:
https://werkzeugstore24.de/festool-ansetzhilfe-ah-es-ets-etsc-205316.html?gclid=Cj0KCQjwtMCKBhDAARIsAG-2Eu_Fz0RHL-wikWUIcOq3jffdTXweHcPAs4BZ0EzG9D5sp1Bbfv3fXvwaAsPiEALw_wcB with the corresponding 125mm sander. Still took about 20 hours to rebuild that box. Next one will be faster ...

The box now has its first primer coating, additional final filler/sander stage will follow. After that it will be decal time, then the old backbox content can be moved.

In other news I just got the ok for a major pinball mayhem.
Will get 3 pinballs for 2000€, a Flintstones, a BS Dracula and a Grand Lizard (?) ...Given today's pb pricing that is extremely good.

I remember GL... relatively intuitive game mechanic, easy to learn... mostly symmetrical playfield with dual ramps. Set up fast, a really good knock-em-down muscle-memory workout with multiball. I think the lizard was "inspired" by Zool from Ghostbusters. Or maybe other way around... 

You get the new art or the old?

      

mnem
 

[Saskia]

the old one. Needs fixing tho. Blows a fuse when powering up ...
the BSD and the GL are dead. But that does not keep me ... the Flintstones is working and will sell for more than 2k ...

[mnementh]

I did some digging just now because the seller's name looked familiar so I went back through my purchase history and, sure enough, he's there.  Remember those new-old-stock US Navy surplus Agilent 34401A meters that turned up on eBay last year?  It was the same seller who had those so I'm pretty confident buying one of those Flukes.  That's why anainstr looked familiar.

If the Fluke is is as good as the Agilent 34401A they sold me, I'll be quite happy:

Yes, I remember the seller too. This was my first 34401A
Now something puzzles me about the eBay GSP: If I prepare a lower offer, the shipping and tax is estimated higher than in the original ad? Can someone shed some light on this?

IIRC, there's a field in the GSP processing forms where the seller can add a fee for their time filling out the form.  Then tax is calculated including that fee.

mnem
 

[mnementh]

the old one. Needs fixing tho. Blows a fuse when powering up ...
the BSD and the GL are dead. But that does not keep me ... the Flintstones is working and will sell for more than 2k ...

Good deal. Once you play the GL, you might like it better than the Fishtales and keep it instead. I liked the newer art, and not just because it doesn't look like it fell out of an old issue of Spider-Man; the little green reptile-girl became the subject of more than a few a schoolboy fantasies. 

mnem
Ehhh... raging hormones, frustrated by social norms. The single biggest driving force of all civilization.