12 January 2023

Battery Angst

 Aaaarrrgggghhh! The battery on my Surface Pro 7 is giving up the ghost. Yesterday during a conference the screen started to flicker slightly and I noticed the battery level was dropping at a rate faster than I'd seen before. I knew it was inevitable, and I've been seeing indications of declining battery capacity for a few months now.

This is a work tablet, so I didn't pay for it. It's served as my office laptop for several years and I've come to really appreciate the Surface tablet form factor. I retire in less than a year, so I'm likely stuck with finding a replacement on my own (nothing provided by employer largesse). I've got several personal laptops that can fill the gap, but what I really like about the Surface line is the ability to outboard video to a dual monitor setup using the Surface docking station. My question now is, do I invest in a closed hardware solution? Surface Pros can not be opened up for a battery replacement. Microsoft wants you to toss it and buy a new one. Planned obsolescence. I'm thinking that any new laptops or tablets I buy for field use in Amateur Radio will have replaceable batteries.

I've got a very good Dell 5414 rugged laptop that I bought used about 4 years ago. It's my ham radio field laptop. It's got an i5 processor, 16 gb of RAM and a 128 gb SSD. It's a workhorse, and even four years on is still a very viable computer. It's only real drawback is that it'll eat a battery in about a year. But that's OK, because the design of this laptop means I can open the battery bay door and slide in a new battery. No dying battery angst. 

My experience is that the ability to easily replace batteries extends the service life of a laptop or tablet for at least a year. After three years most mobile device batteries start to show a serious decline in capacity; it's just the nature of the technology. Users find themselves plugging in their laptop or tablet more frequently to 'top it off', and very quickly the device turns into a small format desktop computer, permanently tethered to a power supply. A replaceable battery restores the functionality of the device - it gives your laptop or tablet a new lease on life. The vast majority of laptops and tablets, particularly laptops, are still very viable computing devices when they get tossed into the electronics recycling bin. The only reason they are there is because the batteries died.

Replaceable batteries also makes the concept of the fully off-grid computer possible. My expectation for a field computer is that I get at least 6 hours of laptop use with a 10% reserve. If that means I've got to swap out batteries in that 6 hour period, so be it. The design of laptops like the Dell 5412 (and its successors) means this 6 hour requirement is easy to achieve, and even exceed.

Of course all computers and tablets have limited lifespans. At some point my Dell will be orphaned by Microsoft (I already know I can't install Windows 11 on it), replacement batteries will become impossible to find, or I'll have a hardware failure. But considering that this is a 4 year old laptop that still has more than adequate processing power for today's routine tasks, and that I've been able to do two battery replacements on it for a small fraction of the cost of a new laptop, I'd say my plan to buy future devices only if they take replaceable batteries is a sound one.

W8BYH out

04 January 2023


I giggle when I read things like this: 

For those who have trouble reading the screen capture, it goes like this:

"I forwarded a few questions from HF Pack list members to a Special Forces commander whose unit has been using KX2s in the field for three years. He passed along the following additional comments:

"We prefer to use Off Center Fed Dipoles (OCF). They work for us because they present a consistent, predictable mismatch on the frequencies we use. I made a few small baluns out of binocular cores that are 4:1, which handle the output of the KX2 on Voice, CW and digital all day long. Typically the dipoles area strung up arms-reach-high in the field, which gives us easy 300 - 400 mile range in our KX2 nets. If we're fortunate enough to have a tree, that OCFD with a center height of 10 to 15 feet or so works perfect for NVIS, at least for us.

"You'd be proud to know my KX2 has survived remote jungles, 14-er peaks in Colorado, -30 degree F temps, a helicopter crash, and gunfights / IED blasts... I think the radio has held up better than I have."

Wayne, N6KR, is one of the co-founders of Elecraft and is the main designer of the KX2. He posted this on the HFPack Groups.io site back in 2020 in response to some folks who were looking for more information on the US Army Special Forces use of the KX2 as a back-up radio. The topic recently re-surfaced on the Elecraft KX Groups.io site.

I find it funny (the giggle part) that today, folks who use the Icom IC-705, the Lab599 TX500, the Yaesu FT-818 and other QRP rigs struggle to put together a deployable package that includes the radio, tuner, battery, cables, connectors, etc. and end up with a pile of stuff the size of a desktop printer, while all of that fits inside of the KX2, a radio you can hold in the palm of one hand.

This is one of the reasons why in today's era of IC-705 SDR do-everything QRP market dominance, the KX2 - a 7 year old design - is perpetually on back-order.

Also note the use of an OCF dipole. No sooper-dooper sneaky-pete million dollar Special Forces antenna solution. Just a plain-jane dipole. The US Army is actually very pragmatic about antenna designs for their radios - you just can't cheat physics. If an antenna's gotta' be a quarter wavelength, it'll be a quarter wavelength.

W8BYH out