Test Equipment Anonymous (TEA) group therapy thread

[RoGeorge]

Ok unwrapped. Well this is not a good start. It has the AN/USM-486 sticker on it. Fair enough. US labelled.  Methinks oh fuck it's 120V set up. Well it is indeed!

And I find this inside.





Fingers crossed the fuse went before anything else did. Going to buzz it out quickly and strap it to a 5V supply and see what the deal is. If it survived it, it might give me a bit more confidence on buying that other one 

It's pretty tidy though which is good news.

Edit: transformer is melted 

That's how come that a wire makes metal beads before melting, like the ones seen in the melted fuse pic:





More about "unduloids"

[mnementh]

Well that was most disappointing. I blew up all of the capacitors and was greeted maximally with a “pfft” and that was it. No booms. 

Inadequate applied voltage. My preferred means of capacitor grenading involves a salvaged microwave transformer. 

mnem
      It's THE LAW!!!

[factory]

Just drill them out and screw the cans back in?

No way am I going to do that and risk getting metal shavings everywhere. I'll do it only if it requires replacement of a defective unit....or the POS burns to cinders....whichever occurs first.   

Fuck HP. 

Just take steps to minimise the risk, like using a vacuum cleaner to suck the shavings out as you drill 

Nope, I have something else in mind. Stay tuned. 

Grease/Vaseline ?

A vac is what I was going to suggest, and you can make a custom nozzle with card to get it small and high flow very close to your drill site.

I'd advise against vaseline for anything other than really low speed stuff as it's likely to melt and provide zero help. General purpose lithium grease is ok for low speed stuff, but high speed it'll throw swarf off with the centripetal forces.

EDIT: You can use a neodiddelyum magnet on ferrous stuff, but rivets are usually aluminium in my experience.

I've had the aluminium ones that fell out of a HP 1900A I bought that turned out to have been drowned. 
Some HP stuff has brass rivets, but the plating hides this. Also the paxolin spacers are easy to crack/break if drilling them out.

David

[factory]

Well that was most disappointing. I blew up all of the capacitors and was greeted maximally with a “pfft” and that was it. No booms. 

Inadequate applied voltage. My preferred means of capacitor grenading involves a salvaged microwave transformer. 

mnem
(Attachment Link)    It's THE LAW!!!

Mains AC should help  , see around 22.40 to 27.00 in this Shango066 TV recap video and recapping it did not fix the fault.
https://youtu.be/gqcdyyKp8GY?t=1360

David

[mnementh]

I know bd... He started with mains AC. Now it's time for the good stuff. 

mnem
 

[bd139]

Was 70V DC wrong way round at half an amp. Buggers usually let go fine at that.

[bd139]

Ok unwrapped. Well this is not a good start. It has the AN/USM-486 sticker on it. Fair enough. US labelled.  Methinks oh fuck it's 120V set up. Well it is indeed!

And I find this inside.





Fingers crossed the fuse went before anything else did. Going to buzz it out quickly and strap it to a 5V supply and see what the deal is. If it survived it, it might give me a bit more confidence on buying that other one 

It's pretty tidy though which is good news.

Edit: transformer is melted 

That's how come that a wire makes metal beads before melting, like the ones seen in the melted fuse pic:





More about "unduloids"

That was rather interesting that was. Thanks for posting 

[Cerebus]

Further to us discussing the other day whether you can leave feedback after a case is closed on eBay. I just had to force a refund out of a seller that sent 'not as described' crap (it was what they said, but was so borked as not to fit the description). They tried all the usual crap that it typical of some  Chinese vendors - discount and keep ("no it isn't any use"), emails outside eBay "can't refund with case open" (screen shotted and added to case photos) and so on. So, they are definitely getting negative feedback. They finally caved and refunded - immediately after I copied their external emails outside eBay into the case, funny that.

Anyway, refund has been paid, and this is what it looks like at the moment pre-feedback:



I wonder if people who thought that they couldn't leave feedback simply missed the entry because it had moved to "Returns and Cancelled Orders" or some other sub-category other than the headline "Orders" list.

Negative feedback now successfully left.

[bd139]

This is a cool looking mini scope: https://www.ebay.co.uk/itm/264005789638

[Neomys Sapiens]

all the Tek TM500 modules are popping up recently.

I've got that oscillator too. It's a really smooth device, and its tone is very, very good, plus I like that it's got a balanced output.  In the same frame it is paired to a very sick distorsion analyser, an AA501A, but I'm suspecting its no more than aging pains.

What's the trick to get a module out of the frame if the handle is broken?

Edit: Found this thread and subsequently ordered a cable...

I did use the following trick, which is applicable if the remaining part of the lever is visible and functional:
With a pin vise and a small drill bit, a hole is drilled into the plastic of the remaining lever. Then I screwed a plastic screw of sufficient lenght into this hole. In one case, it is still in place, acting as a substitute pull tab. In another case, where the pull tab was found in the package, I used the screw after removal of it's head to repair the pull tab with a matching hole drilled in the broken part and a drip of epoxy adhesive.

[Neomys Sapiens]

Goodie box from Sphere came today...pics later. I got a really pristine Tek 191, the transistors I need to repair my second HP 3444A plugin, and the usual Sphere bag of extra goodies.

And here it is. The 191 works great. Recently calibrated, and looks exceptionally clean outside and in.

Here's my three. One of these days I suppose I'll spring for a Type 184. But after reading the frustrations You and Worsthorse had with the high frequency circuits I'm not sure I want that aggravation... 

Nice! I'd say the type 184 isn't that bad as long as the example you find doesn't require extensive repairs. Mine boiled down to a bad Nuvistor and a bad socket on the the 500 MHz board. I robbed that board from worsthorse's parts unit he sent me and that solved that problem.

I adjusted the crystal oven to 5 decimal places using my 53310A modulation domain analyzer (which is fed from the GPSDO). This provides far more than sufficient accuracy for an analog scope time base. The most fiddly part by far was getting the mutually coupled inductors on that board adjusted right. This requires much care and patience (and a fast oscilloscope...I used my 7104 for this).

Your hand being present is enough to detune this circuit, so it becomes a matter of trying to find the adjustment that works better once you move your hand away!  And the big horse shoe shaped one has B+ on it so do not ground it with your hand!!!

   

I suspect that may be the exact use case for which Tek designed the big one in this set I got from Neomys Sapiens; it's 300mm long. 

mnem
I have 30cm and I know how to handle it. 

Oh man. I wish I had that set. I used an insulated Wera screwdriver to help me manipulate it from a safe distance. If I had had a large noninductive tool it probably would have made the adjustments a lot easier to see too.

Ok, what now? I DID explicitly wait for your and 'horses answers, which did not come. I have only a spare set of the three scewdriver-like tools of different lengths. I will look at their condition later.

[Cerebus]

   

I suspect that may be the exact use case for which Tek designed the big one in this set I got from Neomys Sapiens; it's 300mm long. 

mnem
I have 30cm and I know how to handle it. 


Oh man. I wish I had that set. I used an insulated Wera screwdriver to help me manipulate it from a safe distance. If I had had a large noninductive tool it probably would have made the adjustments a lot easier to see too.

This seems a prime candidate for 3DP.

Hmm, probably not. With most 3DP materials I suspect that would come out like a wet noodle.

More a case of "Slap a bit of Delrin in the lathe". Oh..., no lathe.

Grease/Vaseline ?

A vac is what I was going to suggest, and you can make a custom nozzle with card to get it small and high flow very close to your drill site.

I'd advise against vaseline for anything other than really low speed stuff as it's likely to melt and provide zero help. General purpose lithium grease is ok for low speed stuff, but high speed it'll throw swarf off with the centripetal forces.

EDIT: You can use a neodiddelyum magnet on ferrous stuff, but rivets are usually aluminium in my experience.

I'd opt for one of those little hand jeweller's type drills that you scoot up and down. Mine's buried so I have to resort to an 'Internet pic':

[med6753]

The Type 3A74 4 channel vertical plug-in is fixed. The new NTE160 transistor did the trick.

One more plug-in to fix. A Type 3A6 Vertical.

[TorinoFermic]

Well that was most disappointing. I blew up all of the capacitors and was greeted maximally with a “pfft” and that was it. No booms. 

I am sure I could make these caps blow at 1000 DC once my Keithley 236 arrives and gets upgraded to 237.

[AVGresponding]

Well that was most disappointing. I blew up all of the capacitors and was greeted maximally with a “pfft” and that was it. No booms. 

In the words of mnem, "tzzzzzt":
https://www.ebay.co.uk/itm/Consort-Bioblock-Scientific-Microcomputer-Electrophories-Power-Supply/293670154493



That wee scope you linked is nice, shame it's in the land of mad shipping prices.

[Cerebus]

Those can run to 100s of watts, so very "tzzzzzzzt".

[Cerebus]

This reminds me of someone, but quite who momentarily escapes me:

[tonyalbus]

ever tried this ADF4351 with display?

[tonyalbus]

Not doing a Dave .... it is a Tony... does it work for you guys... just trying some stuff...

[Cerebus]

This is a cool looking mini scope: https://www.ebay.co.uk/itm/264005789638

It's a bit "Star Trek, during the movies but before TNG" looking. Not sure if I like it or loathe it.

As to whether it looks useful or not, I've got to give that a big thumbs up. If it was in the UK at that price I'd be seriously considering dropping the money on it.

[bd139]

Yes indeed. It’s totally “Japan” as well if you know what I mean.

[Robert763]

Well that was most disappointing. I blew up all of the capacitors and was greeted maximally with a “pfft” and that was it. No booms. 

In the words of mnem, "tzzzzzt":
https://www.ebay.co.uk/itm/Consort-Bioblock-Scientific-Microcomputer-Electrophories-Power-Supply/293670154493



That wee scope you linked is nice, shame it's in the land of mad shipping prices.

Note that the Electrophoresis type supplies are designed for biology lab use and have safety features including earth leakage detection on both positive and negative outputs that make them hard to use as regular power supplies.

[Cerebus]

Not doing a Dave .... it is a Tony... does it work for you guys... just trying some stuff...

I've watched all of two minutes so far, so this isn't anything like a fair summation, or even a comment on the content. BUT, too many "erms", "errs" and "ahhs". I know that's it's difficult not to do, but the thing is that all those noises that would go unnoticed during a face-to-face conversation really distract one during watching a recording.

A trick that works for some people is to talk just a little bit slower than normal so that your brain has slightly longer to catch up with what you are trying to say. Like I say, works for some people, not for all. Perhaps try it to camera, play it back and see if it works for you.

My two cents. I'll try and find time to watch the whole thing later and say something a little more constructive (no promises, I've a zillion things to distract me today).

[Specmaster]

100uf 6.3v x5
10uF 16v x2
47uF 16v x1
22uF 16v x1

All need to be low profile <8mm long. 10uF ones need to be <= 5mm diameter.

Check yours is the same though before hand as there are a few variants with different configurations.

What about the little brown bastards hiding under the display?

[mnementh]

Further to us discussing the other day whether you can leave feedback after a case is closed on eBay. I just had to force a refund out of a seller that sent 'not as described' crap (it was what they said, but was so borked as not to fit the description). They tried all the usual crap that it typical of some  Chinese vendors - discount and keep ("no it isn't any use"), emails outside eBay "can't refund with case open" (screen shotted and added to case photos) and so on. So, they are definitely getting negative feedback. They finally caved and refunded - immediately after I copied their external emails outside eBay into the case, funny that.

Anyway, refund has been paid, and this is what it looks like at the moment pre-feedback:   

I wonder if people who thought that they couldn't leave feedback simply missed the entry because it had moved to "Returns and Cancelled Orders" or some other sub-category other than the headline "Orders" list. Negative feedback now successfully left.

No; this isn't what I was talking about. I've had a few such clusterfucks where once the refund was done, the transaction was removed from my purchase history as if it had never happened; I could only bring it up by ticking the "Show Hidden Items" box, and even then, there were no actions available to me.

No idea why, how, or if it is something that has changed in over a year since my last really shitty fleaBay transaction.

mnem
"It's all shit; pick a layer and dive in." ~mom