Test Equipment Anonymous (TEA) group therapy thread

[GreyWoolfe]

SNIP
BTW never buy a Dell precision 5550. Horrid horrid thing. They tried to copy Apple at every stage and fucked it up massively. I’d be really pissed off if I’d paid for it.

Personally I always thought that Dell was a shit show anyway, I don't think that from all the computers I've had the pleasure of working (as in repairing), none have been such bad performers as Dell's. I have been given a Dell Dimension 5520 tower that currently sits under my desk/bench that I was supposed to be returning into a games machine to play my many games that need windoze XP or 7 to run on. The thing it is still sitting there 2 years later, I can't be arsed to do it because it will be a disappointment I'm sure.

I have a T5500 here that I paid $50 for.  Tossed in a couple of hard drives I had and another $24 for more memory.  I am running Win10 Pro 64 bit and use it as email/surf/youtube and netflix.  Works absolutely fine for my modest needs and kept the solid metal chassis from being recycled.  Before this job, I worked for a certified Dell service provider, 1999-2004.  I repaired thousands of them, both desktops and laptop.  They were certainly better than the Compaq and Packard Hell computers I serviced through 3rd party warranty contracts.  My first 2 company laptops on this job were Dells and they did get the job done.  Now I have a Lenovo T460 and do like it better.  I used to be all Dell but now I have some scrapped out HP Z210 SFF computers.  I don't have demanding needs so I like keeping the old girls working and out of the landfills.

[Robert763]

I've got an older T5400 in the workshop. Apart from being a bit power hungry it does a good job. 2x Quad core 3.5GHz Xeons, 32GB ECC RAM 1TB HDDs, reasonable graphics card Win 7 pro 64 bit. cost was less than nothing. I rescued 5 of them from WEEE. Two were very dirty with noisy fans so they donated CPUs and RAM to others The remaining two were passed on.
I did invest in a SSD for it recently and it is now even faster and rock solid. It's not on all the time so the power consumption is not really an issue.

[Specmaster]

SNIP
BTW never buy a Dell precision 5550. Horrid horrid thing. They tried to copy Apple at every stage and fucked it up massively. I’d be really pissed off if I’d paid for it.

Personally I always thought that Dell was a shit show anyway, I don't think that from all the computers I've had the pleasure of working (as in repairing), none have been such bad performers as Dell's. I have been given a Dell Dimension 5520 tower that currently sits under my desk/bench that I was supposed to be returning into a games machine to play my many games that need windoze XP or 7 to run on. The thing it is still sitting there 2 years later, I can't be arsed to do it because it will be a disappointment I'm sure.

I have a T5500 here that I paid $50 for.  Tossed in a couple of hard drives I had and another $24 for more memory.  I am running Win10 Pro 64 bit and use it as email/surf/youtube and netflix.  Works absolutely fine for my modest needs and kept the solid metal chassis from being recycled.  Before this job, I worked for a certified Dell service provider, 1999-2004.  I repaired thousands of them, both desktops and laptop.  They were certainly better than the Compaq and Packard Hell computers I serviced through 3rd party warranty contracts.  My first 2 company laptops on this job were Dells and they did get the job done.  Now I have a Lenovo T460 and do like it better.  I used to be all Dell but now I have some scrapped out HP Z210 SFF computers.  I don't have demanding needs so I like keeping the old girls working and out of the landfills.

For my own personal use, I prefer to assemble my own from propriety parts and have so far only stuck with AMD CPU's as they have the best bang per buck. May not have been the fastest available unlike today when they are.

[Cerebus]

11. The trackpad has really poor palm rejection meaning you have to constantly hold your hands like a spider legging it.

[Cerebus]

What's the max CAT class for an AWG24 ethernet cable? I am wondering if I can find a CAT7 with AWG24...

It doesn't work like that. What makes a cable Cat-whatever is whether it meets the appropriate set of criteria in ISO/IEC 11801 for a number of parameters like NEXT at a specific frequency, insertion loss and so on.

As far as current carrying capacity is concerned all Ethernet twisted pair signalling uses a 1V differential signal into 100 ohms characteristic impedance, so the nominal current is only 10 mA. That means that you can realise a Category whatever in cabling with as small a copper cross section as you like as long as it meets the AC criteria. DC criteria over a maximal cable run are likely to be met with anything so long as the cross sectional area isn't so small that it's ridiculous BUT if you're running power as well - either PoE or -48V telco power then I'm talking bollocks and of course you have a more stringent set of DC criteria to meet. All else being equal, the only place cross sectional area is going to bother you is having conductors that are fat enough to properly terminate in the pushdown blocks in wall plates, patch panels and so on.

If you're trying to cram as much Ethernet as you can into a small duct/conduit, consider installation cable that bundles several multipair cores into one overall sheath - most of the bulk in Ethernet twisted pair cables is in the outer sheath. I've done this before where I had to retrofit Ethernet into an office with narrow ducting buried in concrete floors. I could easily get a four way installation cable into a duct that only had room for one and a half standard Cat-5 strands. The downside is that the multiway cabling is relatively expensive and minimum reel sizes can push the cost up further.

[bd139]

11. The trackpad has really poor palm rejection meaning you have to constantly hold your hands like a spider legging it.

Appropriately that’s about it 

But you have a proper one which is unnecessary to employ spiders to operate 

[Robert763]

The Advance OS250 'scope arrived today - in a very battered Walkers crisp (potato chip) box with a bit of small bubble wrap and some bags of air 
Let it warm up gently to room temperature and then turned it on.    no trace, just a faint blob to the left side of the screen. it responds slightly to the focus and X position controls but no sweep and no response to any Y controls. On power off you briefly get a brighter half round spot in center of screen. Either a supply has gone or the CRT electrodes have been damaged. 
I've messaged the seller and asked for permission to open it up and check voltages.

[TERRA Operative]

On my current theme of building test equipment, I just finished building a tester to test my test equipment. yo dawg.....
Took me a while to get it just right, but it all clicks together just nicely.

Behold, the latest creation! A Tek TM500 mainframe tester!
Works well too which is a surprise....

youtube.com/watch?v=Afwqtc6Fxd4

[bd139]

The Advance OS250 'scope arrived today - in a very battered Walkers crisp (potato chip) box with a bit of small bubble wrap and some bags of air 
Let it warm up gently to room temperature and then turned it on.    no trace, just a faint blob to the left side of the screen. it responds slightly to the focus and X position controls but no sweep and no response to any Y controls. On power off you briefly get a brighter half round spot in center of screen. Either a supply has gone or the CRT electrodes have been damaged. 
I've messaged the seller and asked for permission to open it up and check voltages.

I fixed one of them in the 90s if I remember correctly. Was power supply. Think it was fairly easy to work on as well. Made in Hainault. Remember that!

[mnementh]

hp scopes have trouble triggering in ALT mode? Lame. 

you wanna' provide some context for that?   

Yeah... not sure I believe that's the scope rather than imperfect isolation between the two channels on a $99 arb. Take a look at the measured frequency.

mnem
 

[AVGresponding]

@Robert763 I have my eye on a more modern unit on Deutsche fleabay but I expect it'll exceed my price range. Oh well...

What do you want / need to measure / detect? I may have something suitable available.
 PM me if you like.

Pure curiosity rather than a specific use case.

[Saskia]

prick ebay buyer (the one with the bloody camera). Buyers remorse. Fuck him.

[bd139]

prick ebay buyer (the one with the bloody camera). Buyers remorse. Fuck him.

Another one?! Appears to be a crapfest at this time of year. Not selling between Nov 1st to Feb 1st now. Fuck ‘em all.

[Saskia]

yarp.

[bd139]

Joy. I’m getting to the point I’m going to start restricting spending to new stuff only that I’m going to use until it’s throughly rinsed of all value. Everything else seems to have some annoying as fuck human interaction around it 

[BU508A]

Joy. I’m getting to the point I’m going to start restricting spending to new stuff only that I’m going to use until it’s throughly rinsed of all value. Everything else seems to have some annoying as fuck human interaction around it 

What a surprise ...     


+++ This message has been written on a newly installed Linux machine, running perfectly well on hardware from Saskia.    +++

Edit:

Code: [Select]

BU508A@merkur:~$ cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 158
model name      : Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
stepping        : 10
microcode       : 0xde
cpu MHz         : 800.099
cache size      : 9216 KB
physical id     : 0
siblings        : 6
core id         : 0
cpu cores       : 6
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 22
wp              : yes

Code: [Select]

BU508A@merkur:~$ cat /proc/meminfo
MemTotal:       16343184 kB
MemFree:        10657260 kB
MemAvailable:   13590968 kB

[Robert763]

@Robert763 I have my eye on a more modern unit on Deutsche fleabay but I expect it'll exceed my price range. Oh well...

What do you want / need to measure / detect? I may have something suitable available.
 PM me if you like.

Pure curiosity rather than a specific use case.

I have some small pager style units that are usable. I need to hack the software so the user can reset it etc. and you will have to sort out a battery cover but it's cheap.  Same as this old listing (not mine)
www.ebay.co.uk/itm/Pocket-radiation-meter-geiger-counter-dosimeter-SAIC-PD-2i-Missing-battery-cover/164454610279
The issue with the PD2i is that it's a "dumb user" type and can't be reset, have alarms set or mode changed by the user. Depending how they were set up (special programmer and software) if they reach a ceartin threshod they lock out and alarm. I change mine to the PD12i which is the skilled user version with full control from the user buttons. Does both dose rate and total dose with alarms. Will easilly detect a Radium luminised instrument etc.   
If you want a traditional meter this one os OK
www.ebay.co.uk/itm/Geiger-Counter-Radiation-Detector-Dosimeter-Eagle-CO-96-1979/143893208654
it has a "hotdog" GM probe and also a low energy scintillaton probe. The microphone is nothing to do with it.
I sold it about 8 yeras ago and it has comme on ebay through a house clearence. Don't pay more than £70 though, I can do you a similar looking, but plastic cased, RM5 and a GM tube probe for that. 
If you want to DIY I have HV PSU and amplifier PCBs and various GM tubes and scintillation probes

[mnementh]

I like butterflies.

mnem

[Ice-Tea]

Heh. Spotted some nixies in "the midnight sky" at about 1h33m or so

[Saskia]

cleaning up 3100 spam emails from ebay ... D'oh

[Robert763]

So I had a closer look at the OS250. Tube seems to have shifted slightly which is a worry. However lets do logical fault finding.
Raw DC supplies, all 3 OK.
Regulated supplies, HT and -20V OK, +20V is at 5.2V
Go to check at pass transistor Tr32 and found transit damage, broken lead on transistor.
A combination of bad design - transistor mounted to chassis with leads soldered to PCB hih stranded ch has no local support, Bad installation - 90 degree bend in lead and finally bad packing.
Quick bit of soldering with stranded wire link and it works! Tube has shifted and rotated. Ws able to moveit bck but it probably had foam packing hat has decayed. I'll look at that later.
Think I'll still ask for a partial refund, packing was not up to scratch.

[bd139]

Good catch. Racal had a (shitty) solution for that. Splay the transistor legs out then solder inch long wires between them and the board. Ugh.

[kleiner Rainer]

And now for something completely different: Dads first multimeter (and mine)

This, my friends, is a Siemens und Halske Multizet, made in the fifties in Berlin-Siemensstadt in the "Wernerwerk" factory. It has been in our family since then. Dad got it during his apprenticeship as an electrician. He later went on to become an airforce NCO and after that a service technician and programmer for Sperry Rand/Univac/Unisys up to his retirement. The meter survived my first experiments with electrons fifty years ago and still works. Nice feature: there is a button on the left side that when pressed allows to zero the ohms range without bridging the jacks.

Sorry for the picture quality, during the visit at my parents house I only had my smartphone camera to take pictures.


Greetings,

Rainer

[factory]

An update on the repair of the battered Racal 9839 UHF frequency meter, all the IC's are OK, but it turned out six of the number tubes were faulty, most of those required more than 250V on the Megger to get a faint glow, one required more than 500V, a few of the leads have some rust where they meet the glass seal, making me think the neon inside is contaminated with air.

Luckily I had purchased a few spare five digit boards years ago, when they were still reasonably priced, I re-tested those boards yesterday using the connector I had made up, one of those tubes was also faulty.
Six of the good tubes were de-soldered & fitted to the 9839 board, as well as the missing IC's, I removed the IC sockets & repaired the damaged traces at the same time.






After cleaning the board & refitting it, the counter is now fully working on the 40MHz to 560MHz range. And mostly working on the 10Hz to 60MHz range, but the sensitivity seems poor, I'll clean the connectors & pot tomorrow to see if it can be improved or if there is a fault.
The highest the Racal will count is around 574MHz.


David

[med6753]

So the gray screen filter for the Type 535A arrived at my local PO at 5:35 AM this morning....or so sez the tracking. I just got back from taking Jo home at 17:05. Naturally I expected to see it delivered. No package. 

Go on line. My PO didn't even make an attempt to deliver it, and it arrived plenty early enough to make it out for delivery. I got 2 words for them:

FUCKING ASSHOLES

And every time I have issues with them the only response I get is "I apologize".