Like many of us, [Gabe] has things he just can’t stop buying. In his case, it is portable satellite dishes. You’ve seen these. They look like a dome or maybe a hard hat on some kind of motorized base. What’s in them? What can you do with them? Watch the video below and find out.
As [Gabe] points out, you can often find these on the surplus market for very little money. You can sometimes find them on the side of the road for free, too. Although we’ve never been that lucky.
The video shows three generations of Winegard antennas. It shows what’s inside and how to command them. Of course, the obvious use for these is as an antenna. But we also were thinking they’d make a fair motion base for something, too.
Some of the antennas lack any limit switches. On startup, the system spins until it grinds the plastic gears to find its travel limits. We expect that’s not good for the gears, but it does work. [Gabe] mentions it might be a bit of planned obsolescence, but we imagine it is more of a cost-saving measure.
Machines that automate the various tedious tasks that come with being a servant in a cat’s household — like feeding and cleaning Mr. Fluffles’ litter box — are generally a godsend, as they ensure a happy cat and a happy human. That is, unless said litter box-cleaning robot kills said cat. That’s the gruesome topic that [Philip Bloom], also known as the bloke of the One Man Five Cats channel on YouTube, decided to investigate after coming across a report about a certain Amazon-bought unit.
The theory of a self-cleaning litter box: a happy Mr. Fluffles.
Although he was unable to get the (generic & often rebranded) unit off Amazon UK, he did get it via AliExpress for £165 + £80 shipping. Although this version lacks the cute ears of other variants, it’s still effectively the same unit, with the same moving components and mechanism. An initial test with a cat plushie gave the result that can be observed in the above image, where the inner part with the opening will move upwards, regardless of whether a cat is currently poking through said opening. Once the victim is stuck, there is no obvious way to free the trapped critter, which has already led to the death of a number of cats.
The other self-cleaning litter boxes which [Philip] owns have a number of safety features, including a weight sensor, an infrared sensor above the opening to detect nearby critters, a top that will pop off rather than trap a critter, as well as a pinch sensor. During a test with his own hand, [Philip] managed to get injured, and following a banana test, he had a nice banana smoothie.
What takes the cake here is that after [Philip] connected the mobile app for the litter box, he found that there was a firmware update that seems to actually change the machine to use the pinch and infrared sensors that do exist in the litter box, but which clearly were not used properly or at all with the shipped firmware. This means that anyone who buys any of these self-cleaning litter boxes and does not update the firmware runs the significant risk of losing their pet(s) in a gruesome incident. In the video a number of such tragic deaths are covered, which can be rather distressing for any cat lover.
Of note here is that even with the improved firmware, any issue with the sensors will still inevitably lead to the tragic death of Mr. Fluffles. If you do want to obtain a self-cleaning litter box, make sure to for example get one of [Philip]’s recommendations which come with a paw stamp of approval from his own precious fluff balls, rather than a random unit off Amazon or AliExpress.
[MIKROWAVE1] claims he’s not a radio repair guy, but he agreed to look at a malfunctioning Hallicrafters S-120 shortwave receiver. He lets us watch as he tries to get it in shape in the video below. You’ll see that one of his subscribers had done a great job restoring the radio, but it just didn’t work well.
Everything looked great including the restored parts, so it was a mystery why things wouldn’t work. However, every voltage measured was about 20V too low. Turns out that the series fuse resistor had changed value and was dropping too much voltage.
It is common these days to have a soldering iron where you can set the temperature using some sort of digital control. But how accurate is it? Probably pretty accurate, but [TheHWCave] picked up a vintage instrument on eBay that was made to read soldering iron temperature. You can see the video below, which includes an underwhelming teardown.
The device is a J thermocouple and a decidedly vintage analog meter. What’s inside? Nearly nothing. So why did the meter not read correctly? And where is the cold junction compensation?
Over at EDN, [Brian Dipert] has been tearing down web cameras. A few months ago, he broke into a bargain basement camera. This time, he’s looking into a premium unit. Although we have to admit from some of what he reports, we are a little surprised at some of the corners cut. For example, it’s a 4K camera that doesn’t quite provide a 4K image. Despite a Sony CMOS sensor, [Brian] found the low-light performance to be poor. However, it does carry a much larger price tag than the previous camera examined.
The interesting part is about half way down the page when he tries to open the unit up. It seems like it is getting harder and harder to get into things and this camera was no exception. The device finally gives up. Inside is a relatively unremarkable board with a host of unknown ICs. One interesting item is a gyro chip that determines if the camera is upside down.
[Brian] managed to get the camera back together with no harm. It is interesting to compare it to the $15 camera he took apart earlier.
Canadian consumer goods testing site RTINGS has been subjecting 100 TVs to an accelerated TV longevity test, subjecting them so far to over 10,000 hours of on-time, equaling about six years of regular use in a US household. This test has shown a range of interesting issues and defects already, including for the OLED-based TVs. But the most recent issue which they covered is that of uniformity issues with edge-lit TVs. This translates to uneven backlighting including striping and very bright spots, which teardowns revealed to be due to warped reflector sheets, cracked light guides, and burned-out LEDs.
Excluding the 18 OLED TVs, which are now badly burnt in, over a quarter of the remaining TVs in the test suffer from uniformity issues. But things get interesting when contrasting between full-array local dimming (FALD), direct-lit (DL) and edge-lit (EL) LCD TVs. Of the EL types, 7 out of 11 (64%) have uniformity issues, with one having outright failed and others in the process of doing so. Among the FALD and DL types the issue rate here is 14 out of 71 (20%), which is still not ideal after a simulated 6 years of use but far less dramatic.
Cracks in the Samsung AU8000’s Light Guide Plate (Credit: RTINGS)
As part of the RTINGS longevity test, failures and issues are investigated and a teardown for analysis, and fixing, is performed when necessary. For these uniformity issues, the EL LCD teardowns revealed burned-out LEDs in the EL LED strips, with cracks in the light-guide plate (LGP) that distributes the light, as well as warped reflector sheets. The LGPs are offset slightly with plastic standoffs to not touch the very hot LEDs, but these standoffs can melt, followed by the LGP touching the hot LEDs. With the damaged LGP, obviously the LCD backlighting will be horribly uneven.
In the LG QNED80 (2022) TV, its edge lighting LEDs were measured with a thermocouple to be running at a searing 123 °C at the maximum brightness setting. As especially HDR (high-dynamic range) content requires high brightness levels, this would thus be a more common scenario in EL TVs than one might think. As for why EL LCDs still exist since they seem to require extreme heatsinking to keep the LEDs from melting straight through the LCD? RTINGS figures it’s because EL allows for LCD TVs to be thinner, allowing them to compete with OLEDs while selling at a premium compared to even FALD LCDs.
AVO meters — literally amp, volt, ohm meters — are not very common in North America but were staples in the UK. [TheHWcave] found an AVO 8 that is probably from the 1950s or 1960s and wanted to get it working. You can see the project in the video below.
These are very different from the standard analog meters many of us grew up with. [TheHWcave] shows how the dual range knobs work together to set the measurement. There are three separate ohm settings, and each one has its own zero pot. We were surprised that the meter didn’t have a parallax-correcting mirror.
Other than dirty switch contacts, the voltage measurements still worked. After cleaning the contacts, most of the ranges worked well, although there were still some issues. Some of the resistor ranges were not working, either. Inside the case were an old D cell and a square battery, a B121 15 V battery. Replacing the 15 V battery with a bench supply made things better.
Some plugins are available to allow the meter to read low resistance or high currents. We thought using the soldering gun as a current source was clever. Once he gets it working, he opens the box around the 14:30 mark.
The inside was all hand-wiring and power resistors. Of course, there are also a ton of contacts for the switches. So it isn’t just an electrical design, but a mechanical one, too. The electrical design is also interesting, and an analysis of it winds the video down.
