Recent Posts

1

Test Equipment / Re: My poor mans SMU - The Agilent 66311B

« Last post by Hydron on Today at 06:16:51 pm »

My 66309D does not, hence my comment that it's just some of them without it. The control PCB has the connector and transceiver de-popped, dunno why they removed it, it's certainly annoying.

2

Test Equipment / Re: Handheld meter robustness testing

« Last post by ploxiln on Today at 06:16:42 pm »

I purchased a 121gw from Dave's online store back in September 2023, I think that's probably recent enough.

I struggled to get the range switch shaft clips off to get the board out ... damaged the plastic clips around the range switch shaft a tiny bit, not too bad, it'll be fine. There is no shim, as expected. The PCB is about 1.6 mm thick. Clamps are the latest version (I think there was a tiny daughter board on some older revisions).

3

General Technical Chat / Re: Watches lovers

« Last post by helius on Today at 06:15:38 pm »

I've found the rubber rings used for opening camera lenses can also open some watch backs, depending on how tight the back is screwed in.

4

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

« Last post by temperance on Today at 06:15:08 pm »

I just updated the forum rules. When new equipment is shown, the forum doesn't accept new posts from that user unless a teardown is shown.

@Martin  I can send you screwdrivers for free if you don't have any to perform the requested action.

5

Beginners / Re: Help identifying these possibly RF/Microwave components?

« Last post by cincin on Today at 06:14:43 pm »

Well, I put the unsealed TriQuint pack under the microscope, and it looks like tiny PCBs with antennas? Custom dies? ChatGPT tells me they are likely Microwave Planar Resistors, 240.0 would be 240 Ohms.

Are these likely to be of any use to anyone today?

Cheers!

6

Projects, Designs, and Technical Stuff / Re: How to shorten the signal to my doorbell

« Last post by ajb on Today at 06:14:43 pm »

There's an easy off-the-shelf solution: a timer relay.  These are standard automation components, and can often be configured for multiple operating modes with a wide timing range.  The mode you'd want is usually called "one shot". 

There are cheaper options than these, but AutomationDirect has a lot of options with very good documentation (not sure if they ship to Canada): https://www.automationdirect.com/adc/shopping/catalog/relays_-z-_timers/timer_relays

These instructions in particular have a nice description of the various configurations, but many/most multifunction timer relays will have similar options: https://cdn.automationdirect.com/static/manuals/fujitimersm/trm10installation.pdf

7

Projects, Designs, and Technical Stuff / Re: Passing 2 wires into a hot water cylinder

« Last post by tmd63 on Today at 06:12:43 pm »

My HW Tank has one sensor strapped to the outside of the tank! Copper is a very good conductor of heat so the sensor is directly on the tank under the insulation jacket.

8

General Technical Chat / Re: Do you think an LED is a resistor?

« Last post by Sredni on Today at 06:12:23 pm »

A bald man is a man.
A one-legged man is still a man, even if in all medicine books the body of a man is shown with two legs.

How about a fictional man?  Or a robotic man?  An AI man?  A virtual man? 

Seriously?
Is a non-car a car?
Is a carrot a car?

We are at this point?
If you had read anyone of the circuit theory or general engineering books I have given you would know that in order to be part of the set --- let's call "all resistor" the elements need to share a common trait. Like when in that video for kids you have all vegetables in one set and all fruits in another set (and do t bring out the tomato!).

So, what is the common trait shared by the elements of the set "all resistors"? It's that they are fully characterized by a relationship between voltage and current. Only between V and I. Not q and V (those are capacitors) and not phi and I (those are inductors).

So, "all resistors" have a characteristic implicitly defined by  f(v, I)=0, that is a curve in the vi plane.

Now, among all these resistors, some have a curve that is a straight line, that is a v + b I = 0, which you can rewrite as v = R I. This is the subset "linear resistors" of the set "all resistors". It is a very important set because it has all the easy to understand properties of linear function, including superposition. That is why we strive to make our.components the more linear possible (yes, the five striped thingies called "resistors" you can buy are actually nonlinear and can only be considered linear within specified limits). Since they are so easy to understand, we teach a out them in high school and we simply call them "resistors" not to overload feeble.minds with unnecessary complications
 
But the set "(linear) resistors" is not the entire set "all resistors". We are left with all those components that are described by a VI characteristic that is NOT linear, like diodes, scrs, mov, incandescent lamps, neon bulbs... These form the huge subset "nonlinear resistors" of the larger set "all resistors". So, they are resistors with f(v,I) nonlinear.

And no, a carrot is not a car.

9

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by KungFuJosh on Today at 06:10:00 pm »

Not on Siglent. Once a feature is unlocked, it stays that way.

"unlocked" features stay unlocked on Rigols, too.

We're talking about modifications

At least part of what you're talking about are modifications that bring some of the features that can simply be unlocked on the relevant Siglent being discussed in this thread.

The other part would be customizations to the UI.

10

Programming / Re: Linux Dependency Black Hole

« Last post by mag_therm on Today at 06:09:35 pm »

It depends on what you are installing. Most libraries and software in the distribution repositories are usually well matched, since package maintainers do that work.

If you are installing some random software you download in *.tar.gz, then you are on your own. If you are installing some proprietary software, you need to make sure your system matches the requirements.  Usually those things target recent version of mainstream distributions.

I would not say it is getting worse, if anything, it is getting better. But for things to get better, incompatibilities are introduced, so all the old software that was not updated in decades is less compatible. The new software benefits from improvements though.

Having things improve while staying the same is the perfect example of incompatible requirements.

My experience over 18 years is that the Fedora dependency problem has become not better, a lot worse since about 2020, but that could be partly  in my usage changing from day job to ham radio
And yes,the packages installed from repositories by dnf usually had commendably few or no dependency problems