Test Equipment Anonymous (TEA) group therapy thread

[Zucca]

Anybody in need of a Keysight 34470A or a Picoammeter Keithley 6485/E?  NAWTS

34470A (calibration date March 2020, warranty til 1st of June 2023, 2475 Euro + VAT):
https://www.instrumex.de/en/8773

GUESS THE PRICE CONTEST!

I just sent an email to them, I want to turn in my immaculate 34661a and get a 34665a, how much will I pay?
The one who get closed to what they will ask me will win some Metcal sponges.

[Saskia]

question:
which self adhesive copper tape / foil /... do you use to repair traces ?

[bd139]

Usually avoid that and use copper wire. Much easier to work with and doesn't roll up when you heat it.

Before:



After (all carbonised areas ground out and epoxy filled):



Wire above was stripped out of 600 ohm ladder line offcuts.

[tonyalbus]

Neeeeeeeeeeeed: https://tinysa.org/wiki/pmwiki.php?n=Main.HomePage

Seems a nanoVNA with defferent software

[BU508A]

question:
which self adhesive copper tape / foil /... do you use to repair traces ?

I'm using usually 0.2 or 0.3mm enamelled copper wire to repair traces.
The one from reichelt is good imho.

[tonyalbus]

This seems to be hot in SA
https://www.rtl-sdr.com/satsagen-software-to-use-a-plutosdr-as-a-tracking-spectrum-analyzer/
https://www.hamdigitaal.nl/2020/03/satsagen-spectrum-analyzer-voor-de-adalm-pluto/

ADALM-Pluto with a AD chip

[bd139]

Fail of the day: never outsource a chunk of your software team to somewhere politically unstable where the government likes to pull the plug on the Internet 

I feel for them really.

Edit: LOL at end price.

[drussell]

crap.  unfortuately the specsheet says "caphat".  if it were a "snaphat" it would be a piece of cake.

my attempt to drill, file, or whittle down to the battery connections on a few of these bastards were unmitigated disasters.
...
edit  if you come up with novel fix for this predicament please post details.

Why don't you just buy another M48Z18-100 and copy the contents over? 
They're only $14.32 USD at Digikey and they have 443 in stock.

[Kosmic]

This seems to be hot in SA
https://www.rtl-sdr.com/satsagen-software-to-use-a-plutosdr-as-a-tracking-spectrum-analyzer/
https://www.hamdigitaal.nl/2020/03/satsagen-spectrum-analyzer-voor-de-adalm-pluto/

ADALM-Pluto with a AD chip

I posted about it couple of months ago. Really nice software.

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3020868/#msg3020868

https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3020888/#msg3020888

[mnementh]

This little BASTARD cap...      So I’m putting together my parts list for the 54645A, and I can’t find a schizzmatic or component level parts list to save my life.

Of COURSE, this is the side jammed up tight against the heat sink so I can’t tell what voltage, and parametric search on DigiKey returns bupkis for this value in the current P561 product line.

So I bite the bullet and remove the little stinkbomb; it’s a bit of a PITA due to silicone spooge entanglement, but not too bad. I keep telling myself.

I get my numbers, and I look for anything close available locally, but no. Gonna have to order. *sigh*

I go about cleaning up the pads on this and another bastard cap that was completely obfuscated with a heat-shrink wetsuit, and the ground pad is just a complete dicksore to get clear. Tried solder-wick multiple times, even dipped in flux, tried solder-sucker several times and finally got it by propping up the board on edge so I could get sucker on one side and big chisel iron on BOOST contacting the other side. That GND fill was just sucking away the heat like a vortex.

So now I want to put it all back together until parts arrive... and I realize I do NOT want to do that desoldering job ever again for fear of cooking the PCB to death.

Fuck me. With a shovel. Sideways.^* 

mnem
^*in the room. I may be a perv, but I’m not suicidal.

Okay... looking to find a sub for this little bastard; I was thinking of going to Y2 poly, and I've found a EPCOS MKP B3202 series that should just fit while having a lot more headroom. The manufacturer recommends this line for SMPS DC conversion applications, which is good, as this one is right across the gate/source of a big ol' IRFPC50 MOSFET in the first DC converter.

The only problem I see right now is that from experience these tend to have pretty low ESR, often similar to ceramic, so even for a 47nF I'd still expect ESR of 1Ω or less. The one I just took out measures 40Ω ESR. Can't tell from the datasheet if that's in the normal range or not. I know these can be used as drop-in replacements for the dread RIFAs in AC line applications; I've seen it oodles of times. But here I'm concerned about low ESR affecting the stability of the SMPS at these higher frequencies.

Opinions?

mnem
 

Sounds like it might be a snubber with built in resistance of intentionally high ESR. I'd be  very wary of replacing with anther type if you don't have full data. I've seen epoxy aed snubbers were you could see the resistor through the resin.
How about a pictue of the markings on the original?

EDIT
E.G. https://content.kemet.com/datasheets/KEM_F3024_PMR205.pdf

It’s not a specialist snubber. It’s PME261. https://kr.mouser.com/pdfdocs/KEM_F3294_PME261.pdf

Replace like with like lest you pick a fight with the SMPS gods. The only issue is it’s an old capacitor. New ones of the same type are fine.

47nF with a test frequency of around 100KHz turns up around 40 ohms reactance.

Yup; just the ubiquitous PME261. Which KEMET has superseded to their own P561 product line; I attached both datasheets to my original post.


   

The IRFPC50 has the usual integral clamping diode as well as a reverse p-n junction diode; this affects both the gate and the D-S path capacitively. This stuff is generations newer than anything I ever worked on; trying to wrap my brain around these interactions literally makes my brain hurt.   It feels like the same kind of voodoo as that 500MHz nuvistor oscillator we all know & love. 

I suspect you are both right; I think the PME261 was chosen BECAUSE of its high ESR in this circuit. I can see they had access to the same Y2 series polys; they're used elsewhere on the board. I was just looking for a better part since I'm already knee-deep in the hoopla.

*sigh*  This is going to be another case like that bastard NVRAM; just do your best and live with it until it dies. Even if I just put the same exact PME261 back in it, may very well still outlive ME. 

Under any circumstances, I've contrived a bodge that gets the old RIFA back in circuit mostly safely so I could put the scope back to standby duty instead of the repair queue; no, I'm not going to post pics of that crime.    Just know that I've admitted my guilt here and now; if Karma catches up with me, I can greet Murphy with a clear conscience. 

mnem
 

[Robert763]

You could put a 27R in series with a newer capactor.

[FransW]

Talking about service.... remember i was emailing around to get a manual for the Anritsu MF1603A
i received a phone call today from Anritsu Germany
from a very friendly older guy, saying its out of support but he went to his files, and it realy is not available. he was in de development team before.
he gave me some.. very nice conversation... he even asked if the 1603 was still works and was happy for me..
no manual, but a very nice call..
also prob means it will be very hard to find...
if it was there this guy would prob had found it..
he could have emailed, but decided to personaly tell me...

This really sounds ridiculous.
No Anritsu Company, workshop, calibration office without manual?
Not even for payment?

Can't believe it.
I think you have to construct with the aid of other owners.
Shouldn't be that difficult for the primary functions.
Frans

[bd139]

Not unusual. I worked for a company here and they shredded all the paperwork for discontinued products.

[tonyalbus]

Talking about service.... remember i was emailing around to get a manual for the Anritsu MF1603A
i received a phone call today from Anritsu Germany
from a very friendly older guy, saying its out of support but he went to his files, and it realy is not available. he was in de development team before.
he gave me some.. very nice conversation... he even asked if the 1603 was still works and was happy for me..
no manual, but a very nice call..
also prob means it will be very hard to find...
if it was there this guy would prob had found it..
he could have emailed, but decided to personaly tell me...

This really sounds ridiculous.
No Anritsu Company, workshop, calibration office without manual?
Not even for payment?

Can't believe it.
I think you have to construct with the aid of other owners.
Shouldn't be that difficult for the primary functions.
Frans

Still waiting for Japan and US to respond..
Service companys stopped serviceing in 2008 production stopped +/- 2000 as i understood from the nice man.

[edit] wait... one of my stickers said 2014.. 

[med6753]

Under any circumstances, I've contrived a bodge that gets the old RIFA back in circuit mostly safely so I could put the scope back to standby duty instead of the repair queue; no, I'm not going to post pics of that crime.    Just know that I've admitted my guilt here and now; if Karma catches up with me, I can greet Murphy with a clear conscience. 

mnem
 

  I share my bodges for the entire group to criticize and laugh at. What makes you special? 

[FransW]

Tony, when you professionally dis-assembled the counter to clean it, did you take some high resultion pictures of the different PCB's?

Were the IC's and processors (if any) identifiable?

Toyocom OCXO type?

[FransW]

Med,

An AI is driving developments.

[Mr. Scram]

Regarding these thermal wire strippers:

I've found this one in the bay and bought it for 5 Euro plus 4 for shipping:



It is called a "Mentor-Strip", no idea if it is any good.

Hot strippers are the best.

[Mr. Scram]

I share my bodges for the entire group to criticize and laugh at. What makes you special? 

How much time do you have?

[tggzzz]

Does anyone have opinions about the relative merits and problems of an Agilent 34410a vs an HP or Agilent 34401a?

[bd139]

34410A has a fan if that bothers you.

[Mr. Scram]

Does anyone have opinions about the relative merits and problems of an Agilent 34410a vs an HP or Agilent 34401a?

The 34410A has a fan and the 34401A doesn't. While I understand compromises sometimes have to be made for the sake of performance I feel that they're too close for a fan to be worth the trouble.

Damn you bd, again! 

[Connecteur]

Does anyone else use one of these? https://www.canadiantire.ca/en/pdp/mastercraft-smart-meter-0520726p.html
It's a multimeter with only one button on it.  Just hook it up to a circuit and it will figure out how to measure it.
I keep one handy in my shirt pocket.

[mnementh]

Under any circumstances, I've contrived a bodge that gets the old RIFA back in circuit mostly safely so I could put the scope back to standby duty instead of the repair queue; no, I'm not going to post pics of that crime.    Just know that I've admitted my guilt here and now; if Karma catches up with me, I can greet Murphy with a clear conscience. 

mnem
 

  I share my bodges for the entire group to criticize and laugh at. What makes you special? 

Because it's WORSE than this one, which, thankfully, did NOT fit in place. 

mnem
 

[Mr. Scram]

Does anyone else use one of these? https://www.canadiantire.ca/en/pdp/mastercraft-smart-meter-0520726p.html
It's a multimeter with only one button on it.  Just hook it up to a circuit and it will figure out how to measure it.
I keep one handy in my shirt pocket.

At $70 I'd rather have a Fluke 101 or full fat Brymen BM235 if I'm honest.