Recent Posts

1

Repair / Re: Help Repairing Weller WR3M Soldering Station

« Last post by Brycharlie on Today at 09:34:24 pm »

Would it be possible for me to get those images? I'm currently working on one of these. I'd also appreciate photos of the internals of the unit in general. Thank you!

B.C.

2

Test Equipment / Re: Rigol's New Function Generator and DMM: DG800Pro / 900Pro / DM858

« Last post by ZhuraYuk on Today at 09:32:02 pm »

So what about simple instruction about how to do the calibration with oscilloscope? Se most unclear part is how to edit the calibration file based on oscilloscope readings.

3

General Technical Chat / Re: Engineers poorly referenced by their ex-employers.

« Last post by tggzzz on Today at 09:31:15 pm »

What’s hilarious/ridiculous is the practice that developed in the German speaking world of “coded” letters of “recommendation”.

Do you mean something like, "You'd be lucky to get this person to work for you?"

IIRC that was another one

4

Test Equipment / Re: LCR meter questions and maybe recommendation.

« Last post by Martin72 on Today at 09:30:13 pm »

2 decades ago I was also looking at LCR meters and also getting into SMD.
I selected smart tweezers as a universal solution for both which quickly became an indispensable tool.

Much has changed and now many bench LCR devices exist yet SMD tweezers remain my tool of choice.
I highly recommend you look hard at ST42 and its record of development here:
https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/

For more detailed info, Shannon's website might be useful also:
https://shannontweezers.github.io/docs/introduction/

For the applications he has outlined, the tweezers can only be considered as a supplement.
Or I would only get them as a supplement, not for everything, the maximum frequency alone is too low for that.

5

Projects, Designs, and Technical Stuff / Re: Increasing DESAT diode voltage rating

« Last post by David Hess on Today at 09:29:18 pm »

How about collector voltage in it's stable state and higher than the rating of a single diode in the network? Since it's basically a charged capacitor can't it still exceed the breakdown voltage?

Sure, the leakage of the diodes will not match exactly, so some diodes will reach their breakdown voltage and their leakage will increase, but this will not damage them.

6

Test Equipment / Re: RS232 decoding vs UART decoding - Rigol ds1054z seems confused (or maybe I am)

« Last post by 2N3055 on Today at 09:26:00 pm »

Inverting hex values could be about MSB/LSB (Bit order) setting.

7

Test Equipment / Re: LCR meter questions and maybe recommendation.

« Last post by shabaz on Today at 09:24:11 pm »

From what you mention, probably a VNA is way more useful. Agree it's not as convenient as a couple of of alligator clips to perform a measurement, but you'll get way more satisfactory results since you're measuring at the frequency you'll actually be using it.

I have a couple of LCR meters, plus other tools that perform similar-ish operations, but I probably use the VNA more often, especially if as you say, the frequency of operation is going to be much higher.

For toroid and air core, calculations can be fairly accurate, so unless even more accuracy is needed, I might not measure and just tune in the circuit.

Sometimes I might use ready-made inductors, e.g. CoilCraft kits can be handy, they come in tolerances like 2.5%. I have no issue constructing DIY inductors, and keep various ferrites and iron cores handy. For typical HF/VHF work, software like Coil64 is as accurate as is practically possible without electromagnetic simulation tools I think - I've had a good experience with that software.

8

General Technical Chat / Re: Engineers poorly referenced by their ex-employers.

« Last post by RJSV on Today at 09:24:01 pm »

   Going by your title,  I know the feeling, as a person does not usually have any way to directly demand fair reference.
   I got lucky, when people noticed what I had going, and was actually just asked to work for them.   More than once, somebody noticed my liver of the work, and this last time I could 'name my price'!

That's for Live Animal daycare (puppies). Some even fought over me, flattering.  Current gig going on more than 2 years!  That's so nice, after 40 years in the Silicon Valley bs.

   You need to be good, in whatever field, and consider the customer.  Service attitude is very important, as customers talk to each other.

   Be good, very good, and get them fighting over your services.
   Customer payz,   don't get laze.

9

Repair / Re: help about multimeter UNI-T UT58C

« Last post by BENAMORMED on Today at 09:20:24 pm »

Hello
Im not sure but may be yes
The buzzer work perfectly in beep mode when i connect the probe

But it beep constantly in the rest of range except the capacity
Any idea!
Thanks

10

Test Equipment / Re: Siglent SDS3000X HD and upgraded SDS1000X HD

« Last post by tautech on Today at 09:20:06 pm »

That's a pretty busy PCB ! 
Especially when you consider it's in the same small box as SDS1000X HD and 2000X HD.

Note the power connection, 8-pin instead of 4-pin.
There is probably a bit more current going through than with the 2000X HD.

I had.

4+ are need to pass Line frequency to the Trigger engine.
8 pin is used on X-E DSO's and a # of other products including the SSA/SVA range.