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Wireless Keyboards

Wireless keyboards come in two broad categories: Bluetooth and proprietary.

Bluetooth is generic and universal, and works with any computer with built in Bluetooth or a Bluetooth dongle.  Any Bluetooth keyboard will identify itself as such.

Proprietary is usually called “2.4Ghz” and uses a small USB device called a “dongle” to communicate with the computer. These cannot be used with mobile devices, because mobile devices generally don’t have USB ports. If a keyboard’s box doesn’t indicate that it’s “Bluetooth”, it’s probably using a proprietary dongle.

Avoid the Dongle

The problem with these dongles is when they’re lost.  Generally, you cannot get a new one, and you’re going to be unable to use the keyboard.

The exception to this rule are the Logitech devices that are compatible with the Logitech Unifying Receiver.

Multiple Logitech devices can communicate via their Unifying dongle, which is sold for around $8 to $15, separate from the keyboards and mice, so if you lose the dongle, you can replace it.

Funny Video Demonstrating the Nightmare of these Receivers

This video is the “reasonable case” scenario of a guy with a pre-Unify “nano, non-unifying receiver”, and a newer mouse with a Unifying receiver. Both mice will work with the newer Unifying receiver, but the old nano works only with the older mouse.

Like I said, this is a reasonable situation.

What about Non-Logitech Dongles?

When you get into other brands, things aren’t so easy.

Multiple HP devices can communicate via Link-5, which is much like Unify, but I haven’t found sources for Link-5 receivers. They were announced, but I don’t find them for sale.

Dell also had a Dell Universal Receiver, which also allowed six pairings to one receiver, and is also rare and difficult to find… but I did find some at Ebay. According to the FCC ID, it’s the Primax Electronics Ltd Melon 2.4G Nano Dongle D2EO01. According to the manual, it uses the “Nordic” technology, which is probably a reference to the nRF24LU1 by Nordic Semiconductor, which is the same chip used in the Logitech Unifying receiver – but these are not compatible devices.

That Melon dongle was also used for the Lenovo Wireless Mouse N3902.

Primax is an OEM for big-name computer companies, including Dell, Lenovo, HP, Huwawei, Sony, HTC, Sharp,    They also made products for the lesser known brands Dynex, Rocketfish, Icon7.

Compared to these others, the Logitech  Unifying Receiver seemed to do okay, and there are some (expensive) receivers for sale on line, and there are even two “clone” brands from Taiwan called Fornorm and Powstro.  These cost around $8 each. Check the FCC IDs. They may be genuine Logitech product, or they may be fake. One searched revealed an FCCID issued for Logitech Far East.

They all seem to use the nRF24LU1+ SoC chip, or something similar, but the firmware differs, and the older dongles support pairing only one device. Logitech also used the TI CC2544 SoC, which does the same thing.

The older “nano” receivers also use a related chipset, and the Linux Solaar application can pair the nano to a mouse.

This broad use of the nRF24LU1+ and Nordic’s good documentation has made it popular with hackers, and hacking the Logitech Unifying Receiver, specifically, has been the common hack, so it’s possible to buy clones of the Logitech Unifying Receiver, as well as generic modules that use the chip, on AliExpress.

Despite the fact that many companies are selling similar, virtually identical, devices, they are all mutually incompatible. The market is fragmented, and unpopular devices become garbage once a part fails.

It’s an environmental mess that could be averted if companies would, after sunsetting a product, release the firmware source code onto the web, and allow it to be integrated into some kind of universal firmware for a generic dongle.


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Computer Keyboards

Some people love their laptop keyboards, and want one for their desktop or mobile phone that feels exactly like their laptop. This type of keyboard is called a scissor switch keyboard. “Scissor” refers to a small plastic mechanism that distributes a keypress’ force, allowing for the construction of a very thin keyboard.

While most people aren’t sensitive to the differences between laptop keyboards and desktop keyboards, typists with a light touch will notice the difference in the way the keys resist pressure, and how the keys travel only 1mm to 2mm. When they switch from a laptop to a desktop, they find themselves pressing too lightly, and need to slow down to re-press.  A solution is to use scissor switch keyboards on all devices.

Unfortunately, it’s hard to find these keyboards, because “scissor switch” is not usually indicated. This website will attempt to find and list all the scissor switch keyboards, and link to purchasing websites.

External Bluetooth Keyboards

Bluetooth keyboards are usually designed to work with tablets and phones, and are light and portable, and usually use scissor switch mechanisms.

The most popular keyboard in this class is probably the Apple Wireless Keyboard.  The main company serving the laptop market with add-on keyboards is Adesso.

Scissor Switch Keyboards for Desktop Computers

These are exceedingly rare to find, but a few manufacturers still produce them, and a few brands still sell them. The most popular keyboard is probably the Apple Aluminum Wired Keyboard.

Gaming and Other Keyboards

These are keyboards for desktop computers, but are a lot more expensive, and broken out into a different category, because they tend to have some features which non-gamers may not want, like extra keys, clicking, and backlit keys.

Most gaming keyboards have full-travel, mechanical keys, so, as a category, this isn’t what typists are seeking.  However, the gaming keyboard companies are mostly re-branding products made by OEMs, so some may add a scissor switch keyboard to their product line.

Replacement Keyboards for Laptop Computers

If your laptop keyboard breaks, you can replace it.  The most common way to find a replacement is via Ebay. The cheapest way to replace the keyboard is to purchase a used keyboard.

Replacement Keycaps for Laptop Computers

It’s common to lose a key from a laptop keyboard.  You can replace it by purchasing a single key from vendors on Ebay.  They hoard keyboards from broken laptops, and resell the keys one at a time. Make sure that they include the plastic scissor mechanism.

Low Profile Keyboards without Scissor Switches

Desktop keyboards fit into three main classifications: low profile, regular height, and ergonomic. The low profile keyboards attempt to replicate the laptop typing experience, but at a much lower cost. The most popular brands are Logitech, Microsoft, and HP/Compaq.

Ultra-low Profile Rubber Button Keyboards

These are “roll up” rubber keyboards that are meant to give full size keys to mobile devices. In photographs, they may appear to be low-profile scissor switch keyboards, but they are not, so be careful.

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Hose Bibb Washers for Made in China Faucets, Smaller than #00

Buy on Ebay: Made in China Washers for the Garden

These washers measure 11mm diameter x 4mm thick height.

We recently had a hose bibb, the garden water faucet, replaced, and this new one has already started leaking.  I fixed it with a #00 (double aught) neoprene washer, but it wasn’t the right size. 

I ended up carving the edges off with a knife to fit, but it took a long time, and the fit wasn’t quite right, and it bulged in places, causing the washer to squish down when I shut the valve. It worked, but what a headache.

Eventually, I found the right item.

Once the #OO wore out – and prematurely because, after it got seated into the handle, there was less than 1 mm of rubber left to wear away – I replaced it with this washer. It was a 5-10 minute job. It worked perfectly, and was slightly thicker, so it should last longer.

These are not widely sold in the US. I was unable to find any of these at any of the regular hardware store websites, so I turned to China. There, I could only find them in bulk, so I decided to buy some, and resell them, shipped from the US, so you can get a set of them delivered in a week or less.

Most hose bibbs on the West Coast of the United States use the flat OO washer.  I think if the valve is made in the USA, it’s 00.  Now, 00 is a weird size, being around 1/2 inch, at a nominal 16/32″. The 00 washer is as common as pennies. You find them all over the place, and they were the standard for hose bibbs, water faucet handles, clothes washer inlet valves, and pretty much everything consumer-size.

(The weird thing is that the official designation is 1/4S, or 1/4 something, small. There are two other sizes 0, and 000, which correspond to 1/4 and 1/4L, which are 15/32″ and 17/32″ respectively. These are also hard to find, and I’ve only found them as part of “assorted washer” packs. If you need 0 or 000, you’re kind of stuck with that, but you’ll get a bunch of 00 and hose washers along with it.)

Back to the story.

I measured my worn washer with a regular metric ruler, and it was 11mm across, and 4mm thick. I didn’t use a caliper, so I can’t tell if that was an accurate measurement, but it seemed pretty close. (You can get better precision by using a thin plastic ruler.)

Searches for this dimension turned up a bunch of Asian options, so I assumed it was common over there.

If you find that the 00 doesn’t fit right, try out these washers.  $3 for six, delivered by mail.