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Short Takes #18: Tiny Time -- Shrinking the Kit!

By Dave Jensen, W7DGJ

One of the things I love about this radio interest of ours is that it comes in all shapes and sizes. We might begin our hobby with the purchase of a little handheld transceiver -- something tiny, but ultimately not very satisfying for "getting out there." Then, after fully getting the bug, the collection begins. This includes radios large and small, amplifiers, antennas, and more cables and connectors and gadgets than you've got room for in your living space. 

When you reach that point (gear spread across a room or multiple rooms) you might ask, weren't those early QSO's truly special, before the latest linear amplifier? I have a feeling that today's interest in all things QRP comes from operators like me who have nice stations with big radios and amps, but who enjoy getting back to basics from time to time. As I looked at my collection of gear the other day, clearing a spot for another amplifier on its way for review, I thought to myself that it would be fun to shrink my portable station down to a minimal size and see where I could go with it. This issue of Short Takes will review several products that fit into the "tiniest of the tiny" category to see just what kind of fun-factor that little station might generate.

Of course, there's another element in the consideration of a "tiny station," and that is price. I say that because it's possible to take the "who cares about the cost" approach and buy an ICOM IC-705 -- still considered QRP by some. That's not the approach I took here, as I did not want to walk away with $1500+ USD to get outfitted. My goal was to work with a budget the size of a bag of peanuts and still put out a signal that brings me pleasure. I don't have to rack up a zillion contacts, but I want to get out there and have fun.

A Portable Station Setting Me Back $350

The radio of choice for my tiny kit was the Venus SW3B, a CW-only QRP transceiver operating on 3 bands (40M, 30M, and 20M).  I was immediately impressed by this radio, but must admit to having very low expectations as it is produced in China. I was hoping that I hadn't just purchased something akin to a Baofeng HT, and was so incredibly happy when I opened up the box. It's clearly a well-made and highly useable QRP radio.

The SW3B retails for $188 USD plus shipping (China post to USA about $16, other countries will vary). It took about 3 weeks for the radio to arrive. It was packaged well and included a power cable and well-written instruction manual. Since my purchase, I have encountered the owner of the company a number of times via email and he's a champ at getting back to you with answers. The radio has also had some great user support with additional documents on its performance and design/build, most notably from user Don Koehler (KL7KN). See the document noted in the discussion forum linked at the bottom for Don's PDF.

I reviewed the Mountain Topper radio about six months ago, and there's some resemblance here (but not inside). The Mountain Topper is still a great radio and I use it often. The SW3B has a few things to like about it, however, and as this column began with making the go-kit smaller, the fact that this radio is about 25-30% smaller than the Mountain Topper is a serious benefit. 

There's no strain on my ears with this radio, as there are separate RF and AF gain controls, and as you can see, I opted for a simple pair of iPhone wired earphones, which worked great. Another nice aspect of this radio is that voltage input is very wide (8 VDC to 14.8 VDC) which is sure convenient when you are out on the trail with a declining battery pack. I'm sure a little 9V smoke detector battery would work as well, at least as a backup for a couple of hours of radio time. The SW3B uses a very robust IRF-510 power MOS-FET device for the final, which in comparison to other finals is essentially "bombproof." When playing with antennas in the field and questionable SWR, that's a strong plus as well.

The Antenna

I decided to pack the smallest antenna I had for such a purpose, and that is the N9SAB OCF Dipole, a nice little 40M-6M multibander. I've reviewed that antenna here previously, but I was perplexed by the fact that a YouTuber ham reviewer just published a video rave about the same antenna. He says he's getting 9 different bands out of it in a field application, and personally that isn't my experience. It's a good antenna and I use it regularly, and its maker is a great guy (Tim Ortiz, N9SAB). I like the rugged construction of the antenna (narrow gauge wire but very "rubberized" for great all-weather use) and here I'll show you how it does on 40M and 20M, my two bands of interest.

The Tuner and Key to Round It Out

In keeping with the country origin (China) of the Venus SW3B, I ordered what looked like a matching tuner (5W QRP) from the AliExpress website. The tuner was a real disappointment. It disappointed on every level and almost sabotaged my outing. While I've been surprised on the rare occasion, AliExpress disappointed once again as the makers of the Z-Match QRP Antenna Tuner have built something that doesn't fulfill its promise. On only one occasion have I been able to reduce the glowing Red LED by fiddling with the Load and Tune controls. The price attracted me on this one . . . $35 down the drain.

Finally, for my battery pack I used the terrific little Bioenno 0903W, which fully charged gave me 10V DC to work with, more than enough to put out 4-5 watts of CW from my new SW3B. And, the size (tiny!) is perfect for this kit.

For my key, I pulled a Magic Rabbit QU-210 out of a drawer, only because of its size. I wouldn't recommend this key, as it's so tiny that it's almost impossible to handle. A very small key with a super magnet would be fine, but when you take a tiny key and combine it with a nearly-worthless magnet, you're stuck holding the thing while you send code, which as you know is NOT a pleasure. 

The Setup In Action

There's something fun about putting everything you need into a tiny case and heading out. Literally, the radio, tuner, antenna, key and battery fit into the smallest protective cases that Harbor Freight offers, smaller than the size of a child's lunch box.  I wandered the desert park that I was in, found a picnic table and a nearby tree that could be the center point of my OCF dipole. This is where I remembered how much I hate putting up dipoles in a park environment!

It must have taken me 20 throws before I was able to get my rock over the top of the tree and hoist up the OCF. First off, let me note (and this may be the difference between my results and the YouTuber I mentioned) that trees out this way are very short, as I've said often. This one was perhaps 20-22 ft. in height. It was a Palo Verde tree, a beautiful desert resident that loves the heat and which stays green all year long (even the bark), but WOW is it hard to work with. Imagine hanging an antenna on a 20+ foot tall Rose Bush . . . there's nothing you can do in Arizona to reduce the threat of being prickled-to-death. I just went ahead with it and still bear the scars three days later. 

Ideally, an OCF dipole needs about 30 feet at the connection point with sides dropping to 8-10 ft. In order to get the angle right, I had to bring the ends down lower than that, but it still resembled an inverted V. And you'll see by the photo of the Comet Analyzer, the SWR on 40 was just GREAT. From there, it went up, with sweet spots in the 20 M SSB zone and the 10 and 6 meter bands with relatively decent SWR. But I couldn't get that tuner to do much of anything about the 2.5:1 SWR on 20M CW, which is where I wanted to work. As a result, I took the tuner out of the equation and went only to the 40M CW portion of the band where I enjoyed getting to know my new SW3B. 

Memory was a nice feature to find on a less-than-$200 radio, and I set it up to send CQ, easing my wrist from dealing with the micro-miniature key. I was pleased to make a number of contacts over two hours in the field. As evening approached, I loved the SW3B's lit up and super-clear screen, which shows you the battery power, frequency and more. The only complicating factor on this radio was the ease of changing CW speeds. Unfortunately, its not a one step process -- sometimes you want to slow down or speed up depending upon the preferences of your QSO partner. Once you have it set, it requires a bit of fussing to change the keying speed. But, it does accept both iambic paddles AND straight keys. The SW3B will select whatever type you have plugged in when you turn it on, and it sends a morse signal back to you to confirm. A very impressive little radio, which I rate a solid A in build quality and an A- for user experience, based solely on that one matter of changing CW speeds.

Dale (BA4TB) from Venus is extremely easy to talk to and I wish he and his young team all the best. The future is bright for this sector in China if Dale and others are producing equipment this good and representing this kind of value equation.

73 for now,



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Dave Jensen, W7DGJ

Dave Jensen, W7DGJ, was first licensed in 1966. Originally WN7VDY (and later WA7VDY), Dave operated on 40 and 80 meter CW with a shack that consisted primarily of Heathkit equipment. Dave loved radio so much he went off to college to study broadcasting and came out with a BS in Communications from Ohio University (Athens, OH). He worked his way through a number of audio electronics companies after graduation, including the professional microphone business for Audio-Technica.  He was later licensed as W7DGJ out of Scottsdale, Arizona, where he ran an executive recruitment practice (CareerTrax Inc.) for several decades. Jensen has published articles in magazines dealing with science and engineering. His column “Tooling Up” ran for 20 years in the website of the leading science journal, SCIENCE, and his column called “Managing Your Career” continues to be a popular read each month for the Pharmaceutical and Household Products industries in two journals published by Rodman Publishing.

Articles Written by Dave Jensen, W7DGJ

This page was last updated September 14, 2023 23:13