How to Really Make the QMX Ready for the Big Blue Sky Shack

The QRP Labs QMX is a wonder of modern technology. By employing an SDR hardware platform a whole plethora of features can be made available by simply installing new firmware. I absolutely love my QMX. It has become my most used radio for field operations. I grumbled into my beer glass about the long wait for my factory assembled unit to arrive, but when it finally got here I held it in one hand and marveled at its miniaturization.

So what’s wrong with it? Why would I even entertain the thought of making it better? I’ll tell you what the problem is – it’s too darn small! What???

Way back in the dawn of time, in the land of far, far away, my introduction to amateur radio came in the form of the venerable Wireless Set No. 19. Developed by British radio engineers and subsequently improved upon in Canada (according to Wikipedia). It was widely deployed by Commonwealth Allied forces during the Second World War. When the war ended lots of these wireless sets were acquired by hams who modified them for amateur use.

The #19 set was a hefty beast quite unsuitable for hauling up a mountain or carrying down a trail. And now I have come to the same conclusion about the QMX. Oh, sure, if you operate from inside your vehicle, or on a picnic table adjacent to your vehicle while the sun is shining and the bluebirds are singing you are probably going to dispute my statement. But would you feel the same way if you had to hike through deep snow in the dead of winter to set up in a clearing in the woods?

Drop a #19 set in the snow and nearby seismometers will detect exactly where it fell. Drop a QMX in the snow and it’s sayonara baby radio, nice to have known ya. Even if you manage to dig through a foot of snow and find the miniature marvel, chances are all the little jacks for connecting power, paddles, earphones and all will have filled with the icy wonders of winter and the outdoor operating session you just expended thousands of calories to get to will have to be aborted.

In a previous post on Ham Radio Outside the Box we dealt with the issue of all those pesky, vulnerable holes in the QMX case. All those little 3.5mm jacks are commercial grade connectors designed for devices such as cellphones which are typically discarded and replaced every two years. One of the jacks on my QMX has a “lumpy” feel as a plug is inserted; I am sure it’s going to fail at some point in the future. I can’t fault QRP Labs for this; other radio manufacturers use the same, or lower, quality connectors. I have had particularly bad luck with 3.5mm connectors on a leading Japanese brand of handheld radios.

I guess you just can’t build ’em real small and use mil-spec connectors. Was the QMX designed to be deployed in the field? Yes probably, in which case it is really only suitable for light duty – you know, sunshine and bluebirds operations.

What’s to be done to make it better?

Ever since my QMX crawled off the slow boat from Turkey almost a year ago I have experimented with different ways to ruggedize the little fella. It isn’t often that She-Who-Must-Be-Obeyed (a moniker my lovely wife adores) grants permission to buy a new radio so I need to make the Tiny Turk last as long as possible. But how?

Bigger is Better

Frankly I should have bought the QMX+. When SWMBO gave the green light for a new radio I rushed to place an order before she changed her mind. The QMX+ is basically a multiband QMX inside a cavernous housing into which basic essentials like a battery and maybe even an amplified speaker or an antenna matching unit can be mounted. I could still order a QMX+ I guess but, if I did, I would never use my QMX again. I couldn’t even order a QMX+ case and build my QMX into it. QRP Labs’ aluminum cases are top quality but the QMX+ faceplate layout is completely different to the QMX. But, I think I have found a solution.

Now here’s the thing …

The QMX is not a complete transceiver. It still needs an external speaker or headphones and, of course, a battery. Curiously, it has a built-in microphone but no means of easily connecting paddles directly to the case. Curious because the QMX is primarily a CW radio – SSB remains a future feature which, at the time of writing, is still under development. Other radios, albeit mostly with slightly larger form factors, can accommodate directly connected paddles. Even my ancient steam-powered Hendricks PFR-3 has this feature (as well as an internal battery and tuner). So, even though it is packed with so many advanced features, the QMX needs external paraphernalia to make it all work. Why? Because it is too small!

Here is my solution (for now)

The only constant at Ham Radio Outside the Box is change. Every time I complete a new build of field equipment I think of a better way. My shack is strewn with the carcasses of discarded equipment that were the best idea ever – until they weren’t. And so, with that confession, here is the latest build of my QMX field wireless set.

All those fragile, made to fail connectors have been given extended life by leaving paddles, battery and earphones permanently connected. I have not used any mil-spec connectors to protect against the ingress of sand, snow and mosquitoes, but I have used easily replaceable external cables and adapters.

The QMX, which is literally a very small component of my field radio set, has been modularized. It has been integrated into a skeletal frame, roughly the shape of a QMX+, that also houses a battery and has room for an antenna matching unit (“tuner”) should I feel the need.

The skeletal frame isn’t rugged enough for field deployment when the sun isn’t shining and the bluebirds aren’t singing, so it is mounted inside a steel ammo case. If I drop the steel ammo case in the snow it will survive the fall and may not even register on seismometers. And, for an added bonus, I can attach my paddles to the steel case with magnets.

Sounds heavy doesn’t it? Maybe, but at only a tiny fraction of the weight of Wireless Set No. 19, it is very portable. The ammo case is actually quite light. It is designed for hunters who need a box to safely store their 30-caliber ammunition and is constructed of lighter gauge steel than its military equivalent. The ammo case slips easily into my backpack so I can hike in comfort to my favorite operating site on the edge of a cliff overlooking the waters of one of the Great Lakes hundreds of feet below.

So why is my backpack so darned heavy?

I can drop the ammo case down on the ground, remove the bullet-proof lid, hit the go-switch and be ready to operate. But what about all the other things needed for a field station out in the Big Blue Sky Shack? A chair, a table, tarp, choice of antennas, emergency repair tools, water, food, bothy bag, spare cables, connectors, go-away-nasty-bear stuff? That’s a topic for another post!

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