Test Equipment Anonymous (TEA) group therapy thread

[srb1954]

Had a go at my old-style PG506 again. Something appears to be pulling the 5V rail down and subsequently killing all the power in the unit.

Possibly a shorted tantalum as there are a few on the +5V supply rail. However, most seem to be 20V rated so they are perhaps a little less likely to fail than as seen in the normal Tek practice of applying 15V onto a 20V rated tanatlum. Another possibility is a faulty over-voltage crowbar SCR Q45 and/or its sensing Zener VR45. A fault in either of those would take the +5V supply down.

You could perhaps differentiate between the two types of faults by checking with an ohmmeter - a shorted tantalum would immediately show up as a low resistance whereas the crowbar SCR might not be triggered or stay latched on when tested with an ohmmeter.

 

[Mad Axeman]

Am I the only one who finds the name Supernova a bit oddly chosen for a PAT tester?

The earlier models were just called Seaward Nova. When they brought out a new model with lots more features it became the SuperNova. There's a couple on fleabay at the moment. People are asking stupid money for what they are 

[m k]

Am I the only one who finds the name Supernova a bit oddly chosen for a PAT tester?

No.

On the other hand, maybe it's a brightness of the final wisdom of the situation.

[TERRA Operative]

Had a go at my old-style PG506 again. Something appears to be pulling the 5V rail down and subsequently killing all the power in the unit.

Possibly a shorted tantalum as there are a few on the +5V supply rail. However, most seem to be 20V rated so they are perhaps a little less likely to fail than as seen in the normal Tek practice of applying 15V onto a 20V rated tanatlum. Another possibility is a faulty over-voltage crowbar SCR Q45 and/or its sensing Zener VR45. A fault in either of those would take the +5V supply down.

You could perhaps differentiate between the two types of faults by checking with an ohmmeter - a shorted tantalum would immediately show up as a low resistance whereas the crowbar SCR might not be triggered or stay latched on when tested with an ohmmeter.

I've checked the tants and they all seem fine, and checking resistance across the 5V rail gives me a good few hundred ohms (over 400 ohms IIRC).

I'll check the crowbar circuit to see what's up, I have a couple Peak testers, so I can check all the things pretty easily.

[Robert763]

I have a Supernova too. And a PAT100i. The Supernova is a great bit of TE.
I hadn't looked at PAT guidance recently and was surprised (not) to see that IET have updated their Code Of Practice again. Now they are calling it ISITEE (in service inspection and test of electrical equipment) and trying to cover more fixed equipment. Last time thay did an update was because thay were told it it was too onerous with too frequent testing etc.
I really was initally surrised that the latest edition does no require the high current earth bond test for class 1 items. They say "emprical evidence" shows it does not detect many faults. I guess they have removed the test rather than admit the testers that can't do it are no good. I've seen plenty of  mains leads where the earth was down to a strand or two and could have fused before a 13A fuse. It may be rare but the consequences are high.

It's been officially known as ISITEE for quite some time, as you say, to cover more non portable stuff. I think the 'next test due' date was removed from the stickers at the same update. I can see the point in that though. The general public see the next due date and assume it's fine. A bit like a car MOT. It could have been tested 11 months ago but the sticker says it's not due so it must be fine. I agree with you on the earth bond. I much prefer a 10 or 25A test. As you say, if it's down to a couple of strands a good high current will sort it out. I'm pretty lucky, the only PA Testing I do is for the guys in the team I work for. Just the stuff on their vans. It does makes a change from my day job crawling all over generator transformers at power stations. There is no way I could spend my life doing PAT. I do like pulling the testers apart though. Just swapped the data backup battery on a Metrotest MPAT 60 as there was nothing interesting on TV.

I suspect they are playing the numbers game and relying on the fact that class 2 is increasingly more prevalent, at least outside of commercial/industrial kitchens etc.

We're currently refurbing a sports centre, and obviously one of the first orders of business is to get temporary 110V power and lighting set up. We use LED festoon these days, and boy does it save on the number of transformers...
Anyway, we set some apprentices to put it up, with instructions to drill walls and cut the festoon and fit IEC 60309 plugs and couplers to rejoin them, rather than running the cables through doorframes where they stop fire doors from closing, jam doors, and the cable gets crushed. After they finished, I was in the toilets washing my hands and glanced up at the end of a live festoon cable, only to see it had been terminated into a plug...

Several years ago I was asked to look a somthing in production and the guy got out the test box. Ive got a metal bodied 3 pin MALE connector in my hand sorting out the tangled cables. I identified the far end of the cable just as he was about to plug the 13A plug in 
 So I promply took the 13A plug off and cut the other end off too. Why oh why would anyone use a £180 worth of mil-spec connector that is downright lethal (it wasn't even a scoop-proof one) instead of a £10 IEC 60320 C13/14?

[factory]

I have ended up with a bit of a list of parts I need for stuff. If anyone has any of these parts, please let me know!

- #4-40 x 0.375 (3/8") pozi flat head/countersunk screw - Bottom right front panel screw on my late PG506

Closest I've got here, for some reason I don't seem to have many #4 flat head screws, need to check the thread pitch.

David

[factory]

Done a bit of the forbidden subject on here today "woodwork", or in this case veneered recycled toilet paper board  , the Marconi signal generator was missing one of the plywood strips that are glued inside the outer case, soon made a replacement from a off-cut of board.


It's all back together now, just need to make a replacement for the missing voltage selector plate, that prevents the mains voltage switch from being accidentality changed. Only other thing I've done was fix the seized AM % modulation control.

It seems to be working fine on both AM & FM, testing a random old trannystor radio.


David

[Mad Axeman]

AAAARRRGGGHHHHHHHHH...............................
I've done it again. I've just bought a 'spares or repair' Kewtech KT77. Not sure what state it's in but I couldn't resist. I have promised myself that I'm going to sell one of my fully working KT77s though, maybe, perhaps, well, we'll see.

[jxjbsd]

From the present point of view, it is a small and beautiful toy. Of course, as an analog oscilloscope, its performance is good.

[Peter_O]

HP3312A from 1975

Many of you contributed to the knob scew size and knob cleaning questions.

Meanwhile I've ordered small allen keys mm and inch both.

Best fit is a 0.9mm metric one.

And an old Oral B toothbrush with soapy water did the grease.

Before and after. 

(Huh? Something has changed. My normal approach to get images into the text doesn't work anymore. I always postet with attachements and then edited the post afterwards by adding image hypertext and copying the graphic's link from graphic's context menu below.

[BU508A]

HP3312A from 1975

Many of you contributed to the knob scew size and knob cleaning questions.

Meanwhile I've ordered small allen keys mm and inch both.

Best fit is a 0.9mm metric one.

And an old Oral B toothbrush with soapy water did the grease.

Before and after. 

(Huh? Something has changed. My normal approach to get images into the text doesn't work anymore. I always postet with attachements and then edited the post afterwards by adding image hypertext and copying the graphic's link from graphic's context menu below.

Works for me:



Code:

Code: [Select]

[img height=150]https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/?action=dlattach;attach=1732313;image[/img]

[Specmaster]

Am I the only one who finds the name Supernova a bit oddly chosen for a PAT tester?

The earlier models were just called Seaward Nova. When they brought out a new model with lots more features it became the SuperNova. There's a couple on fleabay at the moment. People are asking stupid money for what they are 

Its probably because of the added "super" to the name that  makes sellers think its worth a lot more.

[Ero-Shan]

It's all back together now, just need to make a replacement for the missing voltage selector plate, that prevents the mains voltage switch from being accidentality changed. Only other thing I've done was fix the seized AM % modulation control.

It seems to be working fine on both AM & FM, testing a random old trannystor radio.


David

Looks good, nice job.

While the old tube radio is back in a mostly working state, wouldn't it be a shame not to use some of the test gear that was acquired for just this purpose?

So I damaged my already hurting-as-hell back even more by heaving up the Anritsu signal gen onto the bench today. Only to find it being in a rather bad mood. The one time you actually need it, it won't work? After switching it on with the rear power switch, the standby LED came on, faded to black, came on, faded to black, ... Also, there was some clicking of relays.
I put the service manual on my tablet, opened the sig gen and started to measure. The voltages after the rectifiers where a bit lower than expected, but the regulated ones where fine. And sure enough, the standby LED was now steadily lit. While I had noticed that there was no more clicking, the LED was shining away from me. Seems to work fine now. Just a rough startup after months of negligence? Tsk. While I had it open, I used the opportunity to check the memory backup battery. It's still fine at 3.1 volts.

Of course I have no balun to connect the 50 Ω unbalanced output of the Anritsu to the 300 Ω balanced input of the FM tuner, so I cobbled something together that I will never show to anyone  . Haven't done a lot of testing yet. It took me some time to realize that the radio did indeed see the carrier signal - it was just about 7 MHz off of its expected spot on the scale; hadn't looked that far away (until I finally did; it found radio stations, it had to be somewhere!).

So the old space heater with sound output seems to work with FM, but fine is not exactly the word I'd choose to describe it.

Wish mine worked as well as yours ...

[Ero-Shan]

Just received one of DC1MC's "Blue Beauty" AR488. Thanks DC1MC, I'd never been able to solder at your level of quality!



And here it is amidst its inferior brethren.

[ Specified attachment is not available ]

But will I ever actually use it? Only time will tell ...

[DC1MC]

Just received one of DC1MC's "Blue Beauty" AR488. Thanks DC1MC, I'd never been able to solder at your level of quality!

(Attachment Link)

And here it is amidst its inferior brethren.

(Attachment Link)

But will I ever actually use it? Only time will tell ...

That's the trifecta of GPIB interfaces  , no device could resist it, but please do use our forum baby with the glorious "software that can log from many multimeters", or even Putty !!!

 Cheers,
 DC1MC

P.S> Stil a number of colorful AR488 available for good homes.

[BU508A]

Speaking of old steam radios: isn't this a beauty? An old sound studio from the 50's  (NAWTS)



https://www.ebay-kleinanzeigen.de/s-anzeige/roehrenradio-roehrenverstaerker-philips/2376588975-172-9191

[BU508A]

Related to Neomys Sapiens hint:

So, I would be very interested in the Telefunken lab books.

 

[Ero-Shan]

Related to Neomys Sapiens hint:

So, I would be very interested in the Telefunken lab books.

 

You're not the only one. This will not end cheap. Or should I forfeit them?

[BU508A]

Related to Neomys Sapiens hint:

So, I would be very interested in the Telefunken lab books.

 

You're not the only one. This will not end cheap. Or should I forfeit them?

I was afraid of something like this. Actually, I don't want a wild bidding war, but this book set is extremely tempting. There is already a first bid.

[Andrew_Debbie]

BBC Archives Phase 3 auction is less then 2 days away.   Not much pure TE this time.  There are a 3 or 4 analog Tektonix 'scopes.  The prices are already beyond what I'd pay for them.

I'm watching this Nagra T1 --> https://www.ppauctions.com/lot/177840/lot-339, some of  the other reel-to-reels --> https://www.ppauctions.com/lot/177833/lot-332 as well as the 'scopes.   

[ch_scr]

Just received one of DC1MC's "Blue Beauty" AR488. Thanks DC1MC, I'd never been able to solder at your level of quality!

(Attachment Link)

And here it is amidst its inferior brethren.

(Attachment Link)

But will I ever actually use it? Only time will tell ...

That's the trifecta of GPIB interfaces  , no device could resist it, but please do use our forum baby with the glorious "software that can log from many multimeters", or even Putty !!!

 Cheers,
 DC1MC

P.S> Stil a number of colorful AR488 available for good homes.

This seems like an contagious affliction, similar to voltnuttery or the enchanting glow of nixies. But I must say, with newer TE (that responds to IDN) and on linux (with the integrated USB TMC driver) I now prefer the xyphro UsbGPIB, as it allows to individually identify devices on the driver level and one is not bound to the fickle nature of "USB serial port identity's". Now with these, one's also bound to use one device per adapter - but then, it sure almost "feels like" (and handles like, with e.g. pyVISA) it came with USB from the factory!

[Wolfgang]

Just received one of DC1MC's "Blue Beauty" AR488. Thanks DC1MC, I'd never been able to solder at your level of quality!

(Attachment Link)

And here it is amidst its inferior brethren.

(Attachment Link)

But will I ever actually use it? Only time will tell ...

That's the trifecta of GPIB interfaces  , no device could resist it, but please do use our forum baby with the glorious "software that can log from many multimeters", or even Putty !!!

 Cheers,
 DC1MC

P.S> Stil a number of colorful AR488 available for good homes.

This seems like an contagious affliction, similar to voltnuttery or the enchanting glow of nixies. But I must say, with newer TE (that responds to IDN) and on linux (with the integrated USB TMC driver) I now prefer the xyphro UsbGPIB, as it allows to individually identify devices on the driver level and one is not bound to the fickle nature of "USB serial port identity's". Now with these, one's also bound to use one device per adapter - but then, it sure almost "feels like" (and handles like, with e.g. pyVISA) it came with USB from the factory!

Hi, does this part cooperate with Keysight IO Libraries ? I have a 3458A, an 34401A and a 34420A, and so far I was using the Keysight GPIB/USB converters. They work fine, but they are really bulky and extend far in the back of not too small instruments. I did not really like the NI adapter due to its increadible driver bloatware approach.

Thanks
  Wolfgang

[ch_scr]

It is an IVI compliant device, and shows up on a pc that has only extremely basic IVI drivers installed. So I'd say pretty sure it "just works". Haven't looked into how far this actually integrates into the commercial software, but would be glad to send you one to try out! Shoot me a pm if interested.

[med6753]

Wanted to pass this along. I nearly got scammed with this Type G plug-in project. Something to watch out for on future TE purchases.

https://teanonymous.com/f1/viewtopic.php?t=125

[Vince]

Geez glad you checked the tubes before trying it in a scope, could have done any kind of damage to the plugin or scope 

Glad it ended well overall.

And why is it the forum fails to display any and al images starting a few hours ago ?

Avatar pictures don't show up, attached images don't show up.... or is it just me ?