Test Equipment Anonymous (TEA) group therapy thread

[tggzzz]

How does the multiplexing work for channels 3&4 with that control setup ? 

They're not without compromise. Channels 3 and 4 are 0.1+0.5v/div only and sweep only after 1/2 sweep alternatively in pairs. Extra two channels are handy for digital and monitoring but that's about it.

On the 24x5 scopes, channels 3 & 4 are traditionally regarded as trigger channels that appear on the screen - and can be used for digital.

[bd139]

Got it already. Looks reasonable condition. Will have it on the bench shortly. Currently in Greggs procuring hot goodies.

[bd139]

Yep definitely bust. C608/609 are likely culprit on CRT board. Got the right parts in stock already so will swap them over quick. Fingers crossed (or zapped)

[Specmaster]

Got it already. Looks reasonable condition. Will have it on the bench shortly. Currently in Greggs procuring hot goodies.

Good catch, hopefully, looks like a really useful bit of kit complete with cursors and all the shit eh. Is it as fast as the old Rigol?

[bd139]

Got it already. Looks reasonable condition. Will have it on the bench shortly. Currently in Greggs procuring hot goodies.

Good catch, hopefully, looks like a really useful bit of kit complete with cursors and all the shit eh. Is it as fast as the old Rigol?

Exactly. Found the culpit already. C608 has green legs.

It's got more bandwidth but it has no memory depth compared to the rigol. You need to treat it like an analogue scope with cursors and measurement stuff really. It does slow sweeps / roll though with 2MHz bandwidth which is fine for watching PLLs lock etc. The UI is much faster. Bear in mind it has a pretty slow m68k processor in it. X-Y mode is analogue speed unlike the rigol which was a turd there.

[Specmaster]

Check that froggy cap out of the window then. Looks like your 3rd and 4th channels are much the same as those on my Iwatsu which is either .03v or 1v per division, still better then only having 2 channels.

[tggzzz]

Currently in Greggs procuring hot goodies.

Oxymoron alert!

[bd139]

Currently in Greggs procuring hot goodies.

Oxymoron alert!

Hahaha. I agree. Other half's choice. I suggested Carluccios. Posh McDonalds

Check that froggy cap out of the window then. Looks like your 3rd and 4th channels are much the same as those on my Iwatsu which is either .03v or 1v per division, still better then only having 2 channels.

Bastard has been replaced. Think I won!



Noted some more problems, hopefully surmountable:

1. Self cal is way out. I'll run that process through on it. It's offsets mainly which drift anyway.
2. Fan is really noisy as it's dying. Standard 80mm 12V panasonic jobby so will pick one up somewhere.
3. Second soft button on the display isn't working. Probably needs cleaning.

[bd139]

Quick video of the interface to give you an idea how fast these are. Bear in mind 1994 date of manufacture.

This is doing auto rise time measurement on a 10ns ish rise square wave.

Please excuse the shit quality of the video

[Specmaster]

Currently in Greggs procuring hot goodies.

Oxymoron alert!

Hahaha. I agree. Other half's choice. I suggested Carluccios. Posh McDonalds

Check that froggy cap out of the window then. Looks like your 3rd and 4th channels are much the same as those on my Iwatsu which is either .03v or 1v per division, still better then only having 2 channels.

Bastard has been replaced. Think I won!



Noted some more problems, hopefully surmountable:

1. Self cal is way out. I'll run that process through on it. It's offsets mainly which drift anyway.
2. Fan is really noisy as it's dying. Standard 80mm 12V panasonic jobby so will pick one up somewhere.
3. Second soft button on the display isn't working. Probably needs cleaning.

Great job, 2 and 3 should be simple jobs, 2 sounds like a standard 80mm PC fan and 3 could have suffered liquid damage and Simon Spiers paints the membrane with silver paint where the carbon should be and that seems to work well.

[tggzzz]

Currently in Greggs procuring hot goodies.

Oxymoron alert!

Hahaha. I agree. Other half's choice. I suggested Carluccios. Posh McDonalds

Carluccio's ain't cheap - so yo've gained both brownie points and cash for more silicon goodies

[bd139]

Indeed good point.

Found the issue with the button not working. Track is broken on the button PCB where it rests on the mount. Bodge wire incoming...

Channels 2 and 4 are however, unfortunately, dead by the looks. Hmm. Might be a similar issue.

[tggzzz]

2. These things have no bugs at all. None at all. Not one. Literally the only thing in the universe!

They can still mislead you, in a way that is certainly infelicitous.

From memory, and without checking the exact scope type...

You are looking at/for eye-diagrams for digital signals (e.g. LSTTL and observing a 10ns risetime), so the persistance is infinite. The input signal is noisy/variable, so the eye diagram should be "thick".
Set to "show samples as dots - don't connect the samples with lines" display mode. The eye diagram is what you expect.
Set to the default "connect the sample dots with lines". The eye diagram limits are now much wider.

The reason is the realtime sampling rate is much lower than the repetitive sampling rate, and joining the dots produces lines crossing areas where the signal doesn't actually go.

Unfortunately changing anything resets the display mode to the default "connect the dots" mode, so you are forever changing the mode back.

[bd139]

I think all digital scopes have the ability to mislead you. You need to be aware of how and why for each particular model.

Have started a repair thread for this one:

https://www.eevblog.com/forum/testgear/hp-54602b-oscilloscope-problems-repair/msg1422133/

[kj7e]

With my new 5346A i have two capacitor questions,
A, where ARE They? Manual list 46 and i don't see anything even resembling a tantalum.
B, Assuming i find any, are they old enough to deserve mandatory replacement?

Also i wouldn't mind the scenery in NZ, but all the fun bits are here. 

You mean your 3456A?  Send me a PM, I have a few extra of the hard to find caps (there are two).  Don't worry about the 1uF tantalum's.  Yes, you should replace all the large electrolytics (8 caps total).

Here is where I did mine and I included Digikey part numbers;
https://www.eevblog.com/forum/testgear/fluke-8505a-vs-hp-3456a/25/

[orin]

Solid copper earth bar, 2" braid on the left ties it directly to a 8' ground rod in the shop floor just below it. 

That's what I call half a ground ! 

From my rural experiences, a ground like that just won't cut it for our high powered mains electric fence units.
My preference has been for a 20ft length of galv 20mm/3/4'' ID water pipe.
Threaded one end to allow fitment of 2x 90⁰ elbows/bends to allow connection of a garden hose and water supply while thrusting the whole thing up and down and bit by bit down to full length into the ground.
Pneumatic water hammer action allows it to get down fairly quick in most soils that don't have hard aggregates.
5-10 mins is typical installation time.
The greatest benefit is the lowest end is generally always below the water table.

Yeah, real vicious critters you need to keep in down there...  that is a NZ flag, right?

Bonus points for identifying the location.

BOI or Coromandel ?

Puponga hilltop, January 2013.  #1 on the map in this brochure.

http://www.doc.govt.nz/Documents/parks-and-recreation/places-to-visit/nelson-marlborough/farewell-spit-brochure.pdf

[bitseeker]

Tiddlers. 

Mine from last year.

Awesome catch! Sashimi for days and days. Yum!

Maybe I can try catching something the next time I go there. We drove around both islands for a couple weeks, but there's still more to explore.

Slope Point, NZ is the most southern location on our planet I've been to so far and Denali National Park, Alaska, the most northern.

[tautech]

Maybe I can try catching something the next time I go there. We drove around both islands for a couple weeks, but there's still more to explore.

You ain't kidding !

I've been lucky to be self employed for a good hunk of my life and we've have traveled heaps around little ol' NZ but there's still a lot to see. When relatively newlywed we spent 5 weeks in the South Island but there was still bits we couldn't get to. I've missed my chance now (too old) to do some of the great high country hunting we have, instead opting for some of the easier country in the central North Island and locally.
Gimme a yell and drop by.......

[Brumby]

I think all digital scopes have the ability to mislead you. You need to be aware of how and why for each particular model.

FTFY

[bitseeker]

we've have traveled heaps around little ol' NZ but there's still a lot to see.

Yeah, NZ is like the US with compression: lots to see in smaller space.

Gimme a yell and drop by.......

Will do. I hope to visit Oz at some point, too.

[Mr. Scram]

So, after letting the disappointment of the tangerine TF930 subside I've weighed my options and hatched a plan. Now, this is known to be dangerous, so two steps back and don't stare into the light. I figured I had a number of options.

*Chuck it and forget it
*Sell it and do the same
*Buy another one to ease the pain
*Use the Retrobright method to restore the device

Initially, I was inclined to opt for the first two or three options. After testing it and finding that it all seems to work properly, as far as I can tell at least, I came around a bit. Maybe the Retrobright method was viable. Unfortunately, I found out that this method isn't as permanent as you'd hope. It works, but after a few years some discolouration returns. Areas with uneven discolouration, like where stickers protected the case from light, also return uneven. That would make it a fair amount of work for a questionable return. Closer inspection also showed that the bezel has started to crack. I was about to revert to The Chucking when I remembered something.

Someone on here once talked about the TTi cases being ugly, but spare parts being available through RS. As a cursory search didn't turn up anything on the RS site, I decided to simply call TTi. A girl with the most incomprehensible accent picked up the phone. After explaining what I was calling for I was once more greeted by a jumble of vowels, this time with an upward inflection at the end of it. At this point I felt the prickle of sweat on my brow and started to look for an exit, but I collected myself and, after some hesitation, I hazarded "yes please". This turned out to be the correct answer, as I got transferred to a cheerful lad speaking human words. The darkness lifted, and memories of syntactical languages came flooding back.

After explaining the reason I was calling I was told that yes, they did in fact did sell spare parts. Good news. After a brief exchange of details I was promised to be sent an email. Sure enough, within moments I received a message. An upper case shell, lower case shell and front bezel would cost me a grand total of about 23 pounds plus shipping. Great news. After suffering through buying spares for Weller and Fluke gear, it was great to find I wouldn't have to sell off my other nephew this time. Not gouging customers. What a novel idea.

Considering the affordability of spares, the plan is to replace the entire outer shell. The front panel does not seem to be yellowed as much, and might even not be touched at all. Only a few tiny spots are covered by the bezel and knob, but these don't seem to be any more white than the rest, suggesting it still has its original colour. Even a mark I had taken for a ding turned out to disappear after some scrubbing. It probably was a pencil mark. This means that despite the rest of the shell being in a sorry state, the front panel is essentially pristine. The back panel isn't entirely clean, but close enough to it. The rest I can replace.
 
It's going to cost me a few quid and I'm not quite there yet, but the prospect of restoring the TF930 to almost brand new is very exciting indeed. Getting the runt was a stroke of bad luck, but it could have been much worse. Thanks TTi, for not being cunts.

[Specmaster]

So, after letting the disappointment of the tangerine TF930 subside I've weighed my options and hatched a plan. Now, this is known to be dangerous, so two steps back and don't stare into the light. I figured I had a number of options.

*Chuck it and forget it
*Sell it and do the same
*Buy another one to ease the pain
*Use the Retrobright method to restore the device

Initially, I was inclined to opt for the first two or three options. After testing it and finding that it all seems to work properly, as far as I can tell at least, I came around a bit. Maybe the Retrobright method was viable. Unfortunately, I found out that this method isn't as permanent as you'd hope. It works, but after a few years some discolouration returns. Areas with uneven discolouration, like where stickers protected the case from light, also return uneven. That would make it a fair amount of work for a questionable return. Closer inspection also showed that the bezel has started to crack. I was about to revert to The Chucking when I remembered something.

Someone on here once talked about the TTi cases being ugly, but spare parts being available through RS. As a cursory search didn't turn up anything on the RS site, I decided to simply call TTi. A girl with the most incomprehensible accent picked up the phone. After explaining what I was calling for I was once more greeted by a jumble of vowels, this time with an upward inflection at the end of it. At this point I felt the prickle of sweat on my brow and started to look for an exit, but I collected myself and, after some hesitation, I hazarded "yes please". This turned out to be the correct answer, as I got transferred to a cheerful and lad speaking humans words. The darkness lifted, and memories of syntactical languages came flooding back.

After explaining the reason I was calling I was told that yes, they did in fact did sell spare parts. Good news. After a brief exchange of details I was promised to be sent an email. Sure enough, within moments I received a message. An upper case shell, lower case shell and front bezel would cost me a grand total of about 23 pounds plus shipping. Great news. After suffering through buying spares for Weller and Fluke gear, it was great to find I wouldn't have to sell off my other nephew this time. Not gauging customers. What a novel idea.

Considering the affordability of spares, the plan is to replace the entire outer shell. The front panel does not seem to be yellowed as much, and might even not be touched at all. Only a few tiny spots are covered by the bezel and knob, but these don't seem to be any more white than the rest, suggesting it still has its original colour. Even a mark I had taken for a ding turned out to disappear after some scrubbing. It probably was a pencil mark. This means that despite the rest of the shell being in a sorry state, the front panel is essentially pristine. The back panel isn't entirely clean, but close enough to it. The rest I can replace.
 
It's going to cost me a few quid and I'm not quite there yet, but the prospect of restoring the TF930 to almost brand new is very exciting indeed. Getting the runt was a stroke of bad luck, but it could have been much worse. Thanks TTi, for not being cunts.

That's good news and it shows why TTi are held up as being a quality manufacturer but who's products are sometimes thought to be old models that should be replaced to keep inline with others. They clearly take the view that customer is king and if it ain't broke, don't fix it. Give them a medal for sterling service to their customer's, well done TTi.

[bitseeker]

That's a great solution and at a reasonable cost. Amazing. Seems like you should go for it.

[Cubdriver]

Wow!  That's very nice to hear!  Great news.

-Pat

[bd139]

TTi are one of the best manufacturers out there IMHO. They are also one of the only that still do their manufacturing in the native country too. No cost cutting