Test Equipment Anonymous (TEA) group therapy thread

[med6753]

Well bugger today. Outcome of fluffing around inside scopes = zero. Still the same number of broken scopes.  Anyone want to buy some broken scopes? I'm fed up of broken scopes now. 

Why can't you feed an identical signal into both Channel 1 and 2 and then compare them signal stage by stage? I would figure in real quick time you'll find out where channel 1 is losing gain.

 

Plus also this is a proper screwing and an example of why I don't buy anything from the US. This applies to test gear as well which is of interest to the group...

"made in USA" Elecraft K2 (zero rated for duty):

Direct conversion from USD to to GBP price ...... £620
After screwing by shipping, customs and UPS .... £866 (takes 7 days)
If I buy from euro official reseller ..................... £905 (takes 14 days)
If I get all the options I want ........................... £1333 (takes 7 days)

I did a finger in the air inventory cost for the whole thing in parts and boards cost from JLCPCB and Farnell here in UK.

£385 for all optioned parts delivered to my door tomorrow.

To build the entire receive chain only from scratch is around £55. Most of the fluff is the uC, hardware, boards, panels etc.

And that idea is going down the crapper 

That sucks. And what happens after you guys go Brexit? 

[mnementh]

   They'll essentially be a Push me-Pull you trying to fuck itself. 

mnem
Modern Life...

[med6753]

LMFAO! Good one mnem. 

[Specmaster]

Well bugger today. Outcome of fluffing around inside scopes = zero. Still the same number of broken scopes.  Anyone want to buy some broken scopes? I'm fed up of broken scopes now. 

Why can't you feed an identical signal into both Channel 1 and 2 and then compare them signal stage by stage? I would figure in real quick time you'll find out where channel 1 is losing gain.

 

Plus also this is a proper screwing and an example of why I don't buy anything from the US. This applies to test gear as well which is of interest to the group...

"made in USA" Elecraft K2 (zero rated for duty):

Direct conversion from USD to to GBP price ...... £620
After screwing by shipping, customs and UPS .... £866 (takes 7 days)
If I buy from euro official reseller ..................... £905 (takes 14 days)
If I get all the options I want ........................... £1333 (takes 7 days)

I did a finger in the air inventory cost for the whole thing in parts and boards cost from JLCPCB and Farnell here in UK.

£385 for all optioned parts delivered to my door tomorrow.

To build the entire receive chain only from scratch is around £55. Most of the fluff is the uC, hardware, boards, panels etc.

And that idea is going down the crapper 

That sucks. And what happens after you guys go Brexit? 

At least another 14% will be added to the total WTF! [emoji107]

Edit:
And to think that we have been lied to as well as apparently we will be "better off" after Brexit 

[med6753]

Speaking of scopes. No projects today. So.......fire'em all up and surround yourself with analog goodness.

This is the 465B with the fubar Channel 2 but as shown Channel 1 is fine. The 2465 below it is starting to make it's Seimen's fan motor audible so at some point I'll have to tear it down and lubricate it. No big deal, it has no options so teardown is easy. A few hours, done.



Old faithful 2465 DMS. This is the unit that nearly 4 years ago gets the credit or the blame for starting me down that TEA rabbit hole. I was basically inactive at the time and my brother had this scope and asked me if I wanted it. The rest is history.



The 7603N burning in more plug-ins in anticipation of the soon to arrive 7704. That will put me forever deeper in the rabbit hole.




Damn the electric bill 

[tautech]

No I've got a 465 as well

Currently have a 475A, 465, 2235 and TDS210

4, only 4 ? 

Got more than that in just one model ! 

Then there's the five CRO's and a busted TDS1202B stashed waiting for that rainy day that never seems to arrive. 

[Specmaster]

That 2465 DMM is a nice unit and to hell with the electric bill, its all adding to the space heating and keeping you warm and snug 

[med6753]

That 2465 DMM is a nice unit and to hell with the electric bill, its all adding to the space heating and keeping you warm and snug 

It's 13 C outside and sunny. Snow melting like hell. I'm actually tempted to open the windows and blow the stink out.   

[bd139]

Well bugger today. Outcome of fluffing around inside scopes = zero. Still the same number of broken scopes.  Anyone want to buy some broken scopes? I'm fed up of broken scopes now. 

Why can't you feed an identical signal into both Channel 1 and 2 and then compare them signal stage by stage? I would figure in real quick time you'll find out where channel 1 is losing gain.

Done that. It's after or in the channel switch unfortunately. My arsedness has declined to zero suddenly so I've shelved it until it returns. I'm having a real problem with arsedness at the moment!

That sucks. And what happens after you guys go Brexit? 

Full idiocracy!

[tautech]

Nice collection of Tek classics Med.
The 500 is a storage model right ?

My buddy scored a non-storage one a few years back and some gorilla had been at that too, this time it was the PSU and the ape had no idea what he'd been doing. 
For the sake of the right bulk rectifier caps and a other few bits and bobs it was up and running without messing with Cal. 

[med6753]

Nice collection of Tek classics Med.
The 500 is a storage model right ?

Which one are you referring to? None of them are storage scopes.

[med6753]

Well bugger today. Outcome of fluffing around inside scopes = zero. Still the same number of broken scopes.  Anyone want to buy some broken scopes? I'm fed up of broken scopes now. 

Why can't you feed an identical signal into both Channel 1 and 2 and then compare them signal stage by stage? I would figure in real quick time you'll find out where channel 1 is losing gain.

Done that. It's after or in the channel switch unfortunately. My arsedness has declined to zero suddenly so I've shelved it until it returns. I'm having a real problem with arsedness at the moment!

I'm sure you checked this but are you positive you didn't mix up the attenuator blocks? 

[bd139]

Well bugger today. Outcome of fluffing around inside scopes = zero. Still the same number of broken scopes.  Anyone want to buy some broken scopes? I'm fed up of broken scopes now. 

Why can't you feed an identical signal into both Channel 1 and 2 and then compare them signal stage by stage? I would figure in real quick time you'll find out where channel 1 is losing gain.

Done that. It's after or in the channel switch unfortunately. My arsedness has declined to zero suddenly so I've shelved it until it returns. I'm having a real problem with arsedness at the moment!

I'm sure you checked this but are you positive you didn't mix up the attenuator blocks? 

Yeah 1v in both channels leads to 500mV deflection.

And before anyone says anything yes I did set up the termination on my generator properly (and checked it with the TDS210 )

[tautech]

Nice collection of Tek classics Med.
The 500 is a storage model right ?

Which one are you referring to? None of them are storage scopes.

Oh Ok. Right it's a 7000 series. 

[tautech]

Well bugger today. Outcome of fluffing around inside scopes = zero. Still the same number of broken scopes.  Anyone want to buy some broken scopes? I'm fed up of broken scopes now. 

Why can't you feed an identical signal into both Channel 1 and 2 and then compare them signal stage by stage? I would figure in real quick time you'll find out where channel 1 is losing gain.

Done that. It's after or in the channel switch unfortunately. My arsedness has declined to zero suddenly so I've shelved it until it returns. I'm having a real problem with arsedness at the moment!

I'm sure you checked this but are you positive you didn't mix up the attenuator blocks? 

Yeah 1v in both channels leads to 500mV deflection.

And before anyone says anything yes I did set up the termination on my generator properly (and checked it with the TDS210 )

With the correct 0V point ?

[bd139]

Yes.

It’s soemthing related to the channel switch I think. Possibly diff resistor. Will trace it out another day.

Need it practice some CW as a priority as I have cocked up the last two QSOs

[tautech]

Yes.

It’s soemthing related to the channel switch I think. Possibly diff resistor. Will trace it out another day.

Need it practice some CW as a priority as I have cocked up the last two QSOs

Oh good, don't we like a good brain teaser ! 
Keep us posted.

[bd139]

I shall indeed.

Ended up making a 3s2p battery pack out of a duff NOS laptop battery and some shit from China.

Now charging the thing. Not done much charging of NiMh packs so don’t own a charger. Manufacturer, Panasonic, says CC-CV 4A/12.6V. Fingers crossed. Making the PL154 supply do some work for a change! No fire yet.

[mnementh]

If you're not balancing, you'll want to keep current below 1/2C. Laptop cells are good for 2.2-2.6AH at most usually. The ones that rate higher capacity usually do so at damaging current rates and discharge levels; often as short as 500 cycle lifetime.

mnem
*tzzzt*

[beanflying]

I shall indeed.

Ended up making a 3s2p battery pack out of a duff NOS laptop battery and some shit from China.

Now charging the thing. Not done much charging of NiMh packs so don’t own a charger. Manufacturer, Panasonic, says CC-CV 4A/12.6V. Fingers crossed. Making the PL154 supply do some work for a change! No fire yet.

Keep it under 1.35V a cell on charge is a reasonable thing. While they don't have much of a memory issue like NiCads they improve their capacity with a few cycles and some use. Constant Current charge of 1/4C will always be safe. You will find the voltage get above 1.35 when they become close to charged. Rubbery numbers but safer than none EDIT 1/2C will be fine too but I am conservative with unknown cells 

Plenty of options here Farnells have stock of a chunk of them https://www.google.com/search?client=firefox-b-d&q=texas+instruments+nimh+ic

[mnementh]

Laptop cells=Lixx=4.2V terminal/cell.

CC up to ~4V/Cell; CV at 1/10-1/100C to terminus.

mnem
*poot!*

[bd139]

Sorry being a dumbass here. It’s a Li-ion 18650 pack not NiMh. I’ve got a BMS board on it which has overcharge and balancing.

Cells are Panasonic NCR18650. Datasheet https://engineering.tamu.edu/media/4247819/ds-battery-panasonic-18650ncr.pdf

I’ll get shot but when I stripped the pack down I snipped it so there were tags left, poked it in a 2x3 cell spacer frame thing and soldered new nickel strips on. Don’t have spot welder. You can get in and out very fast with the Metcal

[beanflying]

Well that is a bit different 

Constant current up to 1C V keep it to a safe 4.1V/cell maximum then reduce it to 1/4C max to 4.2V/cell Birddog Charger. Cheep Cheep Rough Rough 

Edit first Coffee now consumed I can read more carefully 

[mnementh]

Didn't I just say that? Except keep it under 1/10C to terminus if not balancing.

I solder tabbed cells all the time. Sometimes untabbed ones too. 150W GT7 makes short work of soldering to most cylindrical cells.  Makes short work of cauterizing too.

mnem
Yes, I know this from personal experience. 

[beanflying]

Was below required caffeine level to read proper like 

My 10,000's took in 5300 overnight and I found my kwality connection swinging in the breeze had ended the charge Looks like they will come up to a reasonable number so time to use that TI search for myself