30 April 2023

Building The Bomb

No, not that bomb. I've set out to build what I consider the ideal field computer for Amateur Radio use. I guess in this case I shouldn't use the term 'the bomb', but instead, 'da. bomb', as in 'this computer is gonna' be da' bomb!' When the grid goes down, this bomb needs to keep on ticking.

This little project is an extension of my experience with tablet computers (discussed here), and my frustration with any ham radio manufacturer's inability or unwillingness to deliver a ruggedized full featured field radio that doesn't cost more than my camper (which, if you're curious, set me back $22,000). Any rugged field computer would need to be accompanied by an equally rugged computer to run digital modes, CAT control software, etc. While Icom or Yaesu still can't get the radio side done, at least Dell can get the computer side done.

I've come to really like the Dell Latitude line of ruggedized computers, particularly their tablets - the 7212 and 7220 line. The 7212 went out of production last year, and the 7220 is about to be replaced in Dell's lineup with the 7230, but good used examples of both tablets - the 7212 and 7220 - are available on eBay and from on-line resellers like Bob Johnson's Computer Stuff out of Delaware. (Side note - I've bought from Bob Johnson's in the past and can highly recommend them.)

Dell Latitude 7220 in all its naked glory

I was fortunate enough to have evaluated the 7212 at work, and of all the tablets I tested I found it to be the best in overall performance and design. There's nothing unique or spectacular about the guts of these Dell tablets - they are run-of-the-mill i3, i5 or i7 processor units with on-board graphics, 8 or 16 gigabytes or RAM and up to 1 TB of storage. There are dozens of tablet manufacturers that can deliver the exact same specs and performance. The big difference with the Dell units is how those specs are delivered - the design and manufacturing of the overall tablet. This is where Dell excels. From the port covers to the battery design to the folding stand and how the removable keyboard integrates, Dell just does it better. The best example is the detachable folding stand. For most rugged tablet manufacturers, a folding stand (if they even offer one) is a kludgy after-thought. Yet everyone I know who uses a tablet wants one. Dell thought about this from the start, and designed the rear of the tablet around the folding stand. It's an extremely simple yet very well executed design. 

And of course, the 7212 & 7220 are IP65 and MIL-STD 810G rated, so they can withstand some rough handling and wet weather. Take the hint, Icom & Yaesu...

A bit of sniping on eBay got me a like new condition 7220 at a great price. That was just the tablet, and I needed a detachable keyboard, folding stand (as discussed above) and a carrying handle, all Dell accessories. Once again, eBay helped a here. A few non-Dell accessories like a screen protector, USB port extender and microSD card for additional storage came from Amazon. 

The next step was to test it in the real world. That started with loading common productivity apps like Microsoft Office and LibreOffice, followed by ham radio apps. The list of ham radio apps I wanted to have available on the 7220 was extensive:
  • Fldigi
  • Ham Radio Deluxe
  • Winlink
  • Vara
  • JS8Call
  • VarAC
  • Log4OM
  • Ion2G ALE
  • RTSystems programming apps for the IC-7300, IC-705 and the ID-52 and the Yaesu FT-3DR
  • Black Cat WEFAX and SSTV apps
  • VSPE - virtual serial port emulator
  • NetLogger
  • uBlox GPS management software
  • SCSChat 
  • SDRSharp
Little of this software gets used regularly. Most of it is loaded (and regularly updated) for just-in-case situations. In the field it's mostly Winlink, VarAC, Vara, Fldigi and occasionally Log4OM. While I pay an annual subscription for Microsoft Office (the family plan), my experience is that LibreOffice does better in the fully disconnected mode. Even without internet, Microsoft Office keeps trying to 'phone home' and sync with OneDrive. It can be a PITA, and consume computer resources you might need for something else. LibreOffice is mature, stable, compatible with Microsoft Office file formats, free, and has no internet dependencies. 

This grid down setup still needs some hardware add-ons. The Dell detachable water resistant keyboard is one of the best of its genre for typing, but the trackpad leaves something to be desired. A good Bluetooth mouse is in order. The attached stylus that Dell provides (it stores in the carrying handle) is quite good, but it's a bit cramped for regular use. A larger stylus helps for pointing duties when you are not using the mouse. Like most tablets, the 7220 is 'port challenged', so you'll need a USB-C based port extender. For headphones I toss in a set of C.Crane's excellent earbuds. I also bring along my ZumSpot USB DSTAR dongle, a USB isolation dongle, a u-Blox GPS/GLONASS dongle and a small handful of  USB thumb drives for data exchange with other operators. And don't forget spare batteries for your mouse, pen and any other battery powered devices. And then you've got to schlepp all this stuff around. A good quality, rugged computer bag is an absolute necessity. 

So how does it all work in the field? Pretty darned good. Battery life is excellent. I routinely get five hours of continuous use with two batteries installed. This is with screen brightness turned up for use in full sunlight, and using the detachable keyboard (which draws power from the tablet). Replacement batteries can be hot swapped, so I can snap in a spare fully charged unit and keep running almost indefinitely. Another great feature of the 7220 is that can charge via the USB-C port. This goes a long way in helping to move as much of my field gear as possible to USB-C connectivity and charging. One high capacity 3 amp USB-C charger can keep a lot of gear running in the field - my phones, iPads, Android tablet, this Dell tablet, my Surface Pro and Go, and more. Sadly, the only equipment manufacturers that haven't caught on yet are the ham radio manufacturers. They are still stuck on micro and mini(!) USB ports. C'mon guys, get with the program. But I digress.

I've used this tablet as a daily driver computer for a few months now. Not just for ham radio use, but as a home and work computer. It's a great all-around unit and really shines when out in the field. With all the ports buttoned up I don't have to worry about dust, pollen, heavy humidity or a light rain shower, and when the sun comes out I can bump up the screen brightness and not have to worry about finding shade. If I bang it into something (which I have) I'm not worrying about screen damage. It's a high performance, worry free device. Is it as good as a dedicated business laptop? No. I'm not going to try to fool anyone - there are plenty of cheaper computers that make better home and office units. My Surface Pro 7 is a better all-around business machine. Except when I drop it. Or leave it out in the rain. Or the battery dies. Or the sun comes overhead. That's when the Dell 7220 chuckles and says "hold my beer".

W8BYH out.

16 April 2023

Behold The Lowly Tuner

Antenna tuners* get little love. Every ham needs one, most have at least one, but they rarely get talked about in glowing terms, like a good radio, or great antenna design, or a fine cigar. Instead they are viewed mostly as lumps - lumps of metal or plastic that sit nearby and make sure the finals on your precious $2,000 radio don't burn up because you keep trying to put a 100 watt full duty cycle signal into an antenna that's a 10:1 mis-match.

The tuners built into most radios designed for Amateur Radio use are pretty anemic - handling (at best) a 4:1 mis-match. About all they'll do is lightly tweak a nearly resonant antenna. There are exceptions, like the internal tuners Elecraft builds for it's KX line of QRP radios. These remarkable units can tune the bumper on my wife's Hyundai. And I have to admit, Chinese manufacturers like Xeigu have put very good tuners in their radios almost from the beginning. This begs the question - if the Americans and Chinese are building really good internal tuners for their radios, why can't the Japanese? Has advanced tuner technology not made it across to that part of the Pacific rim yet? Geeze.

There is a single tuner that keeps popping up whenever I need to run a portable HF radio at 100 watts with a sub-optimal antenna. I've had it for several years, and bought it when I owned a Yaesu FT-891. I wanted something that could run off of batteries and handle just about any antenna I hooked up to it. This tuner worked great with the FT-891, and when I needed a tuner for an FT-991A it worked great for that, too. Then I got my hands on an Icom IC-7200, followed by an IC-7100, and guess what? It worked great with those radios. When I got my IC-705 and didn't want to pay Icom's outlandish price for the AH-705, I saw Ham Radio Outlet (HRO) was offering my tuner in a 'special IC-705 configuration'. I emailed the manufacturer and asked what made the tuner 'special'? In about an hour I got an answer back - all HRO was doing was bundling the tuner with a 3.5mm audio jack cable, to serve as the control connection between the radio and tuner. Like most hams, I had a several 3.5mm audio jack cables laying around. I hooked the tuner to the 705 and, sure enough, it worked! Seems the tuner was '705 ready' before the 705 was even a glimmer in Icom's eye. 

Most recently, I've begun testing the Icom IC-7300 for use as a field radio and needed a tuner that could handle antenna mis-matches greater than 4:1 (about the limit of the 7300's internal tuner). Once again, I grabbed this tuner and it worked great.

Recognize the tuner? It's the LDG Z-100 Plus. It's an unlovely lump - just a black metal box with some LEDs and a tune button. But what it lacks in aesthetics it makes up for in performance and versatility. It's relatively compact, runs on internal power (via a AA battery tray mounted inside), is rugged, reliable, fairly priced, and has tuned just about everything I've hooked up to it. 

The Z-100 Plus with an ID-52 for size comparison. Sorry for the goofy color balance - I
shot the tuner on a green tray, underneath a red umbrella. The sensor in my camera
must have gone nuts trying to get it all balanced out

LDG offers Icom and Yaesu specific cables for this tuner so they'll interface with your rig - hit the tune button on your radio and the Z-100 Plus wakes up and runs a tune cycle. The tuner will also work with just about any other radio by putting out a low power CW carrier and tapping the Tune button on the tuner. If there's any weakness in the system it's in the Icom control cable (which works with any tuner in the LDG line). I've gone through three due to broken or poorly crimped pins on the Molex connector that mates with the radio. Thank goodness the cables are reasonably priced. My advice is, if you are going to use this with an Icom rig, have a spare cable (or two) on hand.

Operating off grid? No problem. Just stuff a handful of AA batteries into the internal tray

If you are looking for a compact, internally powered 100 watt tuner with a proven track record that will interface neatly with Icom and Yaesu radios, check out the Z-100 Plus. LDG as a company has been around for a long time and they make quality products. This tuner may not be much to look at, but it performs great and is as reliable as a hammer. Almost as heavy as one, too.

*Ok, ok, ok, antenna tuners don't tune antennas. They just make the antenna look like a 50 ohm match to the transceiver. But 'tuner' is the commonly used descriptor for what we're talking about here, so we'll use it.

W8BYH out

09 April 2023

A View From The Bench - 09 April 2023

Happy Easter!

The way things are going, I'll be dead before I get all my ham radio projects out of the way. I'm guessing that's a that's a good thing? It means I'll be busy right up until the end.

The view from the bench is... messy

I've already told my employer that I intend to retire around Christmas 2023. The retirement finances are lining up (as long as the current administration doesn't screw things up even more) and my wife and I have decided it's just the right time.  There's so much stuff we want to do while we are physically able to do it.

That includes more radio projects. The way these projects are stacking up, I'm beginning to think I should have retired a few years ago.

  • I've built a HobbyPCB HardRock50 amplifier for use with my Yaesu FT-818, KX2 and IC-705. The kit I bought from a seller on QRZ.com was new-in-the-box. It seems to work fine with the FT-818, but now I need to finish putting together the tuner. It's a project I've been putting off, and off. Time to finally get it done so I can test it with the Icom IC-705. That's a radio badly in need of a good 50 watt amplifier/tuner.
  • How about a TNC for the IC-705? I'm still trying to figure out how to get my Mobilinkd TNC3 working with the IC-705, so I can do VHF packet (and maybe APRS?) on it. Any ideas?
  • As for APRS, there's more to do be done. I'm increasingly curious about APRS and its potential use for emergency communications. Sadly, there are few good out-of-the-box solutions. The biggest issue is the difficulty of composing and managing messages. This is where the Yaesu FT-3DR (and, I suspect, the FT-5DR) fails. Spectacularly. To be fair, offerings from other manufacturers like the otherwise great Kenwood TH-72D and 74 had the same issue: lousy messaging interfaces. The best solutions I've seen so far are third party apps like APRSDroid for Android and APRS.fi for iOS, linked by Bluetooth to a TNC like a Mobilinkd TNC4
  • Speaking of Yaesu, Kenwood & Icom, things have been very quiet on the new announcement front. While not normally a bad thing, these are not normal times. Yaesu has done a good job of keeping interest going in their radio lineup with some new releases like the FT-5DR, the FT-DX10 and the FT-710, but there's been almost nothing out of Icom, and Kenwood has been silent on new releases since before the pandemic. With the announced demise of the IC-7100, Icom has a huge hole in their HF/VHF offerings. Specifically, Icom has no high power HF DSTAR offering, a significant market gap for a company that has hitched it's ham radio star to DSTAR (pun intended). All eyes are on Hamvention!
  • Web map development. The ARES Southeastern US Situational Awareness Map is slated to receive a major clean-up, where I'll be pulling selected data layers from the map to improve performance. Many of the more esoteric layers that get little, if any, use will be dropped in an attempt to improve map load and refresh times
  • I've about finished my hunt for the perfect laptop for use during outdoor activations, and I've got an upcoming post on the topic. After spending over a year testing and evaluating I've found my ideal. And it's not just good - as Tony the Tiger says, "It's great!"
  • I'm getting back to an earlier interest in HF-based off-grid emergency communications. I covered the topic in some depth a few years back, but the new player on the scene - VarAC (Vara Chat) - looks like it's lapped the previous HF chat application leader, JS8CALL. Back in October I did a short post on it, but since then the pace of development on VarAC has been almost frantic, as the author and his supporting developers rush to incorporate new features. As a result the application interface has gotten a bit messy. My feeling is that the developers now need to take a pause and work on the interface and do an overall look and feel improvement
  • And last, sometimes the simplest works just fine. Yesterday I had a limited window of opportunity to 'play radio' in my back yard before a cold front with rain pushed through. I wanted to do some Winlink and if possible a few VarAC sessions, but I got caught up in some antenna issues. After fumbling with various configurations I just said 'screw it' and stuck a 17' Chameleon collapsible whip on a tripod with one counterpoise. I was surprised to find that combination worked just great on 10 - 40 meters (using a tuner, of course). I was hitting Winlink RMS nodes up to 400 miles away on 10 watts. I'll take that!
Chameleon 'mini' base with a 17' collapsible whip
and one counterpoise

The battery powered Ryobi fan does a great job of
keeping the little biting buggers away and the
operator cool. Runs almost all day on a
4 ah battery

Have a great day! W8BYH out.