Recent Posts

1

Other Equipment & Products / Re: The COMPLETE Octopus (We all need a chuckle these days)

« Last post by coppercone2 on Today at 08:05:29 pm »

If you've ever seen a DJI quad, you already know not to underestimate the Chinese. 

Everything we hear about China was once said about Japan.... and I mean everything.

keysight should lower prices a bit

2

Repair / Re: TSI361R - Identify obscure/old blown transistors

« Last post by floobydust on Today at 08:03:23 pm »

They zap the junctions to blow out tin whiskers, the germanium worshipers working on guitar effects pedals. Even pin-to-case.
For OP, I'd just evaluate the circuit if it must be Ge or not, and prefer to put in Si replacements which beat them in most regards.
Unless they want it all original.

3

Projects, Designs, and Technical Stuff / Re: TDR function in Cisco routers.

« Last post by madires on Today at 08:01:57 pm »

Isn't cable measurement a standard part of the echo cancelling function for gigabit ethernet and above?

Each side sends training sequences to learn how the echo looks like, to determine what to expect as echo when sending data. If the echo is different then the other side is also sending data. The other's side data is the difference between the expected echo and the received echo.

4

Test Equipment / Re: Test Equipment Anonymous (TEA) group therapy thread

« Last post by Robert763 on Today at 08:01:48 pm »

Why not just use the nearest size metric screws? Is there something critical about it?

Robert

5

Beginners / Re: 5V buck converter debugging

« Last post by DimitriP on Today at 07:58:50 pm »

Something has gone haywire with "something".
max current is too low (0.7A),
the Fsw is wrong, since the 5V fixed part doesn't have adjustable Fsw

Here is what mine looks like:
https://webench.ti.com/appinfo/webench/scripts/SDP.cgi?ID=5139B2DC7011C355
Fsw 2.1MHz, max current 6A @ 5V




 

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Repair / Re: TSI361R - Identify obscure/old blown transistors

« Last post by coppercone2 on Today at 07:58:50 pm »

can you like treat those ge transistors somehow to cure them, maybe temperature ?

7

Projects, Designs, and Technical Stuff / Re: Soldering in a life circuit

« Last post by floobydust on Today at 07:58:25 pm »

Don't solder live circuits, lest it become a bad habit.
I soldered a 12V live circuit and saw a spark come off the soldering iron tip coated in molten solder, when it touched the board. There was a ground-fault between the PE grounded tip and the circuit's ground, it shorted out the power supply and did no damage but...

8

Beginners / Re: On ground loop while connecting a Logic Analyzer

« Last post by mindentropy on Today at 07:53:51 pm »

Energy through a brushed connection is many times pretty low.
It can usually damage only the source of that 5V.
If wire is very thin it can only damage its self.

If it is powered by an external source with Over Current Protection, wouldn't that be much better safety?

9

Test Equipment / Re: Siglent SDS800X HD Review & Demonstration Thread

« Last post by Martin72 on Today at 07:51:08 pm »

0 dBm 1 MHz carrier, AM modulated with sine wave 10Khz / 100%, sourced by SDG2042x

In addition, you have changed the window to "Blackman" and manually reduced the sample rate to 10MSa/s,  to complete the settings...
Then I get the same result.
I don't know if these are the right settings.
In any case, anything below -72dBm can be doubted as to whether it actually exists.
Possibly these "artifacts" below this threshold are faded out in the DHO, unfortunately I don't have any more to investigate this.

10

Projects, Designs, and Technical Stuff / Re: Soldering in a life circuit

« Last post by coppercone2 on Today at 07:47:49 pm »

this is a job for batteries or butane

you might actually get a good solder joint that way. trying to overload the iron is not the proper technique