Test Equipment Anonymous (TEA) group therapy thread

[Cubdriver]

nice stack.

gonna' go out on a limb here and say that you don't have any lab cats.

Whatever you do don't let go of the limb.

I have 10

Alessa, Garfield, Midge, Moses, Fluffy, Venus also called Boxtops, Romulus, Remus, Lazarus and Caesar

Damn!  And here I thought I was bad with SIX of 'em!!   

 

-Pat

[neo]

nice stack.

gonna' go out on a limb here and say that you don't have any lab cats.

Whatever you do don't let go of the limb.

I have 10

Alessa, Garfield, Midge, Moses, Fluffy, Venus also called Boxtops, Romulus, Remus, Lazarus and Caesar

Damn!  And here I thought I was bad with SIX of 'em!!   

 

-Pat

Well i had 5 but then Alessa had a litter, she hasn't kept one alive yet therefore Venus, Romulus, Remus, Lazarus and Caesar are all miracle cats. You just can't get rid of miracle cats

[neo]

If nobody minds me asking a stupid question.

https://www.mouser.com/ProductDetail/Sunon/ME80151V1-000U-A99?qs=%2fha2pyFadui8Jilq6D1XTjg9ehLYfd0wJAcSmlBvK5o%3d

Hows that for a replacement fan in the 2465B?

I'm fairly sure the size is right, i know the voltage is right, it's relatively quiet and has enough airflow to match the original. Plus maglev instead of bearings so it'll live a long time.

[Cubdriver]

Well i had 5 but then Alessa had a litter, she hasn't kept one alive yet therefore Venus, Romulus, Remus, Lazarus and Caesar are all miracle cats. You just can't get rid of miracle cats

 

Miracle cats FTW!

-Pat

[Cubdriver]

If nobody minds me asking a stupid question.

https://www.mouser.com/ProductDetail/Sunon/ME80151V1-000U-A99?qs=%2fha2pyFadui8Jilq6D1XTjg9ehLYfd0wJAcSmlBvK5o%3d

Hows that for a replacement fan in the 2465B?

I'm fairly sure the size is right, i know the voltage is right, it's relatively quiet and has enough airflow to match the original. Plus maglev instead of bearings so it'll live a long time.

What's in there now?  Best thing is to try to find the datasheet of the existing fan and the new, and compare the static pressure vs. airflow curves.  As long as the new one is equal or better as far as volume at a given static pressure, it should be fine as a replacement.

-Pat

[neo]

Miracle cats FTW!

-Pat

I wonder if you've noticed that at a certain point i ran out of ideas and began using either biblical or mythological names?

What's in there now?  Best thing is to try to find the datasheet of the existing fan and the new, and compare the static pressure vs. airflow curves.  As long as the new one is equal or better as far as volume at a given static pressure, it should be fine as a replacement.

-Pat

All i know is this a B model therefore it uses a "standard computer fan" and that someone used a similarly speced one and reported good results.

[djos]

Cats are much smarter than they let on. Be afraid. Be very afraid.

My cat doesn't go anywhere near my workshop thankfully - that's what I call a smart cat. 

[Cubdriver]

Cats are much smarter than they let on. Be afraid. Be very afraid.

My cat doesn't go anywhere near my workshop thankfully - that's what I call a smart cat. 

I will frequently hear things being batted about on the floor during the night, and when I get up to investigate will discover one of them (usually Pixel) is playing with something such as a resistor or switch or LED that she got from the bench.    I still think that they absconded with my solder sucker, and that I will someday find it, under something, at the far end of the house.  I finally gave up and bought another...

-Pat

[Cubdriver]

Miracle cats FTW!

-Pat

I wonder if you've noticed that at a certain point i ran out of ideas and began using either biblical or mythological names?

What's in there now?  Best thing is to try to find the datasheet of the existing fan and the new, and compare the static pressure vs. airflow curves.  As long as the new one is equal or better as far as volume at a given static pressure, it should be fine as a replacement.

-Pat

All i know is this a B model therefore it uses a "standard computer fan" and that someone used a similarly speced one and reported good results.

I did notice the names.  Naming them can be tough.  It took about a month for me to name the three siblings (Gilmore, Pixel, and Beaker).

As for the fan, I still think it might be best to get the model number from the one in there now and try to compare.

-Pat

[Brumby]

WIFI in full swing.     

[djos]

Cats are much smarter than they let on. Be afraid. Be very afraid.

My cat doesn't go anywhere near my workshop thankfully - that's what I call a smart cat. 

I will frequently hear things being batted about on the floor during the night, and when I get up to investigate will discover one of them (usually Pixel) is playing with something such as a resistor or switch or LED that she got from the bench.    I still think that they absconded with my solder sucker, and that I will someday find it, under something, at the far end of the house.  I finally gave up and bought another...

-Pat

I think my Cat is also even lazier than most due to her age (~10 i think).

[capt bullshot]

Talking of lubrication, here is the Wigan kebab (aka Pie Barm) with a carefully selected matching wine.

For our friends in the North American former colonies, substitute the locally available equivalent, Ripple or Thunderbird. I'm not sure what the former Antipodean former colonists use to fill this bibularian hole.

Hey, wait, does this label say Buckfast Abbey, near Buckfastleigh in the vincinity of Dartmoor? Been there, drunken that quite a long time ago (around 1985, afair), been there again ten years ago, the whole abbey was turned into a real tourist trap. Remember having seen large stainless steel casks while my first stay there (had a guest room within the main monastery building) where the monks made this stuff from whatever ...

[bd139]

Buckfast turns you into a ned. 

At basically the biological equivalent of red bull and cheap vodka.

[bd139]

Nice item if anyone is near Bury st Edmunds (nice day out that sitting in the gardens with a receiver getting stared at by all the old people who think you are trying to blow the place up)

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F292493374803

I would go and get this myself but I honestly can’t be arsed.

[capt bullshot]

Buckfast turns you into a ned. 
 bull and cheap vodka.

Had too look up this with urbandictionary ...
Thank god, once I tasted this stuff while my first stay, I've never touched Buckfast Tonic Wine (afair the stuff was labeled) again. I was really tempted to pour the rest of my glass after the first mouthful, but I was playing nice to Father Sebastian.

[bd139]

That’s the stuff. It’s nasty. Historically in the U.K., most of the beers and wines were brewed by religious folk and I suspect this is so they had control. He who controls the spice controls the ... err chavs.

[Ero-Shan]

When I repaired my DC505A last autumn I wanted a decent signal generator rather badly. So now that I have one, I was able to check the counter a bit better. While it started off about 1.2 kHz high, the displayed frequency went down rather nicely after an hour's warm-up (DC505A has the OCXO option). I was hoping that the two would be close, but didn't expect that:



Granted, maybe another hour later it might have fallen a wee bit below 265.0000, but I didn't wait and and don't really mind. It's just nice to see the two agree.

I have to admit, though, that finding the trigger level to make it count was a bit finicky. Probably still something lurking (but I definitely don't want to take that DC505A apart again!).

[bd139]

That's pretty good!

I've got a bunch of stuff from QRP Labs arriving some time in the next week so will bodge up a GPSDO with it. I'm interested to see how accurate my TF930 is. I don't think it'll be anywhere near that!

[capt bullshot]

When I repaired my DC505A last autumn I wanted a decent signal generator rather badly. So now that I have one, I was able to check the counter a bit better. While it started off about 1.2 kHz high, the displayed frequency went down rather nicely after an hour's warm-up (DC505A has the OCXO option). I was hoping that the two would be close, but didn't expect that:



Granted, maybe another hour later it might have fallen a wee bit below 265.0000, but I didn't wait and and don't really mind. It's just nice to see the two agree.

I have to admit, though, that finding the trigger level to make it count was a bit finicky. Probably still something lurking (but I definitely don't want to take that DC505A apart again!).

These Anritsu Sig Gens apparently have an OCXO that requires some time to warm up from a quite large frequency offset, Having warmed up all the stuff, their reference frequency is quite accurate (matching up to 8 digits with the CMU200 ref out, DC503A in A/B ratio mode with one digit overflowing).
BTW that TM504 rack made me wonder ... Did you by chance photograph mine? I've got a similar looking one (FG504, FG50_can't remember the last digit, DC503 (with these nice pixie LEDs), DC503A (one more digit), both w/o OCXO, alas.

[mnementh]

Joyous news! My 2465B arrived today and it works! I mean the fan sounds like a dying cat but the thing displays a trace.

So should i replace electrolytics as well as fan or just the fans?

Just a note, thats a 480 MHz sine wave on a 400MHz scope. Damn this thing is nice.

Rebuilding the DC-DC converter in these is always a good idea; also get the fan fixed ASAP as a failed or poorly performing fan can take the pure unobtanium U800 with it.

Here's a good rundown on rebuilding the converter that I found pretty accessible: https://bradthx.blogspot.com/2014/01/tektronix-2445b-capacitor-replacement.html?m=1

IIRC from my Googling back when, the 2465A & B use a 24CFM/12V/80mm fan. There's a pic and some discussion in this thread: https://www.eevblog.com/forum/testgear/a-new-fan-for-a-tektronix-2465/

A common "cause of death" in all 2465s is the EAROM/NVRAM battery; when it dies, all calibration data is lost and she is history until recalibrated and then you lose the cal as soon as you turn it off. The solution on older models like mine is to replace the battery on the A5 board; however the 2465B just HAS to be different. It stores this data in a Dallas DS1225Y BBSRAM, which has the battery internal inside the IC. The common fix is to carefully desolder the chip, read the data, then reprogram another DS1225Y with that data, and install a low-profile socket for the IC. You'll need a universal programmer and the correct socket for this.

You can find much discussion here (actually, the whole thread is a goldmine of information): https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/30/

Really in-depth discussion of mostly experimental methods of salvaging the DS1225:

http://www.worldphaco.com/uploads/TEKTRONIX_2465b_OSCILLOSCOPE_CALIBRATION___REPOWERING_THE_DS1225.pdf


Cheers,


mnem
*Off to another work order*

[neo]

Joyous news! My 2465B arrived today and it works! I mean the fan sounds like a dying cat but the thing displays a trace.

So should i replace electrolytics as well as fan or just the fans?

Just a note, thats a 480 MHz sine wave on a 400MHz scope. Damn this thing is nice.

Rebuilding the DC-DC converter in these is always a good idea; also get the fan fixed ASAP as a failed or poorly performing fan can take the pure unobtanium U800 with it.

Here's a good rundown on rebuilding the converter that I found pretty accessible: https://bradthx.blogspot.com/2014/01/tektronix-2445b-capacitor-replacement.html?m=1

IIRC from my Googling back when, the 2465A & B use a 24CFM/12V/80mm fan. There's a pic and some discussion in this thread: https://www.eevblog.com/forum/testgear/a-new-fan-for-a-tektronix-2465/

A common "cause of death" in all 2465s is the EAROM/NVRAM battery; when it dies, all calibration data is lost and she is history until recalibrated and then you lose the cal as soon as you turn it off. The solution on older models like mine is to replace the battery on the A5 board; however the 2465B just HAS to be different. It stores this data in a Dallas DS1225Y BBSRAM, which has the battery internal inside the IC. The common fix is to carefully desolder the chip, read the data, then reprogram another DS1225Y with that data, and install a low-profile socket for the IC. You'll need a universal programmer and the correct socket for this.

You can find much discussion here (actually, the whole thread is a goldmine of information): https://www.eevblog.com/forum/testgear/tektronix-2465b-oscilloscope-teardown/30/

Really in-depth discussion of mostly experimental methods of salvaging the DS1225:

http://www.worldphaco.com/uploads/TEKTRONIX_2465b_OSCILLOSCOPE_CALIBRATION___REPOWERING_THE_DS1225.pdf


Cheers,


mnem
*Off to another work order*

OK
The fan is good then.
Found that sight independently and because of it decided to do a full recap, using that parts list.
As for the Dallas DS1225Y BBSRAM....... 


Me trying to tinker with that is a scary proposition but if i have to i guess i have to. Will https://www.ebay.com/itm/TL866CS-Universal-EPROM-EEPROM-USB-FLASH-Programmer-MiniPro-BIOS-AVR-AL-PIC-SP-/141978692525 work for the universal programmer?

EDIT: After seeing the price of a DS1225Y.... Ow... owww.. owwdammit OWWW!

[nixiefreqq]

i have replaced dallas ram chips in the hp54502a  (and other 5450x scopes) with standard sram, a separate battery controller chip, and a coin cell.

BUT........ that hp series has built in self calibration, so there is no need to copy the cal data stored in the old nvram.

see details at the link below:

www.eevblog.com/forum/repair/hp-54502a-nvram-substitute/msg1402374/#msg1402374

 

[tggzzz]

Potential technique, based on you not caring about the chip, only on the data in it.

Use the exerciser routine to dump the contents of the ram to the screen. Video the screen, make sure it is readable, save video in a safe place, and forget about it.

If you ever need to, find another ram or ram equivalent, and only then load the caldata. "Ram equivalent" could be anything, e.g. an MCU with onboard seldom, or even a prom.

[bitseeker]

Cats are much smarter than they let on. Be afraid. Be very afraid.

My cat doesn't go anywhere near my workshop thankfully - that's what I call a smart cat. 

Or they do when you're not looking. It's quite fun to see what they're up to when they think you can't see them. Then, make some noises and they'll quickly pretend that they weren't breaking any rules. Too funny.

[Neomys Sapiens]

There is always this option if you are really desperate or a slightly eccentric Islander 

What is a 'PAIN HAMBURGER'? At which point does it become painful? Also, it's sort of cruel - you need food urgently (if not, you wouldn't resort to opening MREs) and they throw a dare at you.