Recent Posts

1

Repair / Re: Rigol DP712 Output Shorted; Fuse? / I Screwed Up

« Last post by macboy on Today at 07:38:43 pm »

The Thyristor (SCR) is part of the over-voltage protection circuitry. It is designed to protect the device connected to the supply from excessive voltage. Various things could cause over-voltage including failure of the power supply's regulation, but the protection works the same in all cases: when excess voltage (over the user-programmed limit) is detected, the SCR is triggered, which essentially shorts the output. Usually, when the power supply itself is the only source of energy at the output terminals, this is OK. When a high energy battery is connected, this is not OK!

2

Test Equipment / Re: Siglent SSA 3021X... Ooops

« Last post by tautech on Today at 07:37:17 pm »

Something very strange happened.

When I did the sweep, the SA barked at me with an overload.

I need to look at this more and make sure I'm not chasing bad data.

Good.
After a Preset all previous settings are set to factory and the analyzer attempts to protect itself.

Some wrongly use Manual attenuation to correct for external attenuation when instead they should shift the Ref Offset for Markers to display the correct level.
When set to Manual the analyzer is locked out from automatically managing its internal attenuation that varies with settings used.

3

General Technical Chat / Re: Is LinkedIn worth keeping?

« Last post by coppice on Today at 07:36:56 pm »

I had one headhunter phone my present day employer for a reference  The boss was freaked out of course. That was awkward - I phoned the recruiting company and flamed the manager, for hiring total bimbos. Headhunters are generally stupid and sharks that are only after the placement dollars and collecting candidates. I have a friend in that business and she tells me the stories. It's basically desperation to pimp you out, by people who have no idea about the technical skills names, meanings etc.
Within a headhunting company, they routinely backstab each other and steal candidates.

When you find an ex-engineer working in recruitment its such a wonderful experience. Most recruiters aren't just limited by their own understanding, they aren't even trying.

4

Beginners / Re: Fast PWM IC

« Last post by langwadt on Today at 07:36:26 pm »

Frequency.

and how many bits of resolution?

5

RF, Microwave, Ham Radio / Re: NanoVNA Custom Software

« Last post by joeqsmith on Today at 07:34:35 pm »

Prompted by a viewer, finally compared the lastest LiteVNA 64 hardware with the previous version.  Looks like they made a few hardware changes.

6

Beginners / Re: Need a (slightly) random signal ? Hers an idea, using CDS light sensor.

« Last post by RJSV on Today at 07:31:38 pm »

Here is a daytime view, of the solar garden lamp, with simulated yellow 'candle flicker'.

7

Test Equipment / Re: RIGOL DS1102Z-E

« Last post by trmntr on Today at 07:29:54 pm »

As a result, I installed this encoder from the link below.  Fits very well.  Both in height and in work.

https://aliexpress.ru/item/4000914884857.html

8

General Technical Chat / Re: Is LinkedIn worth keeping?

« Last post by floobydust on Today at 07:28:19 pm »

I had one headhunter phone my present day employer for a reference  The boss was freaked out of course. That was awkward - I phoned the recruiting company and flamed the manager, for hiring total bimbos. Headhunters are generally stupid and sharks that are only after the placement dollars and collecting candidates. I have a friend in that business and she tells me the stories. It's basically desperation to pimp you out, by people who have no idea about the technical skills names, meanings etc.
Within a headhunting company, they routinely backstab each other and steal candidates.

9

Beginners / Re: Fast PWM IC

« Last post by elki on Today at 07:25:22 pm »

Frequency.

Is there any IC that could provide a PWM at 100 MHz or so? I would love to use atmega ICs but these go up to 20 MHz, if I am not mistaken. The idea is to use it for a voltage control in sample-and-hold circuit for short input pulses. Thanks!

100MHz pwm frequency or 100MHz time resolution?

10

Test Equipment / Re: TinySA Ultra launched

« Last post by shapirus on Today at 07:21:58 pm »

If you need that, you should buy a SG that does a true continuous sweep.

I never argued with this. I just said that if it could be fixed without compromising anything, then it would be nice and would benefit everyone. If it's not possible, then it's not really an issue.