Tag Archives: KX1

KH6 – Hawaii Bound

My current assignment at Fort Leavenworth has me traveling quite a bit. My intent has been to bring a rig with me and have some casual QSOs while on the road. My success has been mixed. I would mostly attribute this to either a lack of planning on my part or being in a stuck in a hotel room with zero antenna opportunities.

One of the most inspiring ham radio blogs I ever ran across was the 100 Pound Dxpedition. I enjoyed how Scott, NE1RD, covered his adventures of conducting portable operations… documenting what worked and what did not. His last post on that paticular blog was back in 2007, but I still use the site as a reference. Scott’s praise for the Buddipole led me in using the Buddipole during my recent tour in Korea. Another tip from Scott I am going to try out is using a hardside golf bag case to transport my Buddipole to Hawaii.

Now for a rig… I think the Elecraft KX3 would be ideal for a Hawaii trip. With 10 watts output and an internal battery, I can’t think of better rig to take to the beach. But the wait time for the KX3 is still quite a while. I have both an Elecraft KX1 and a Yaesu FT-817ND. The KX1 would be great due to its small size and ease of use. But it is limited to only CW and I would like to do some PSK in addition to CW.

I pulled out my FT-817 and conducted an inventory:

    - West Mountain Radio RIGblaster Plug n Play connects directly to the DIN socket on the back of the rig.
    - CAT cable that connects from the RIGblaster to the rig’s ACC socket which enables rig control.
    - PowerPole 12v adapter.
    - Palm Paddle.
    - Elecraft T1 Auto-tuner.
    - Nifty manual for the FT-817.



My FT-817 has quite a few of the optional bells and whistles from W4RT:

I also splurged on two recent upgrades:

    - Peg Leg tilt stand – I think this will be helpful as one of my significant dislikes of the FT-817 is the small display which is hard to see.
    - Magnets for the Palm Paddle – this is critically important as the Palm Paddle by itself is not heavy enough. The magnets allow the Palm Paddles to firmly stick to the top of the FT-817.

For PSK, rig control, and logging I have my Dell Mini netbook. I had not used the netbook in a while, so I started it up to see how it was working. I initally purchased it back in 2009 baselined with Ubuntu and have kept Ubuntu installed on it since then. After booting it up. I updated the distribution to 10.04 LTS and installed fldigi. The RIGblaster easily interfaced with the netbook via a USB connection and the headphone/microphone jacks.

I configured fldigi to work with the RIGblaster to include rig control using Hamlib:

    - Audio: PortAudio using the netbook’s hardware soundcard for both Capture and Playback
    - Rig: Hamlib; Device /dev/ttyUSB0; Baud rate 38400; Stopbits 2; PTT via Hamlib command checked

… clicked on the Initialize button and I was good to go.

Setting up the macros on flidigi is pretty straightforward with the default macros only needing slight tweaking for my personal preferemces.

Once I fired everything up all I had to do was switch to 14.070 MHz, switch the mode to DIG, and drop the input level a bit. With the narrow yellow PSK streams cascading down the waterfall, I picked one that was calling CQ and answered. Transmit worked and my home antenna provided a nice low SWR, no need for the tuner. My macros worked and the QSO was concluded successfully. All with 5 watts.

I plugged in the Palm Paddle, switched to 7.115 MHz, listened and heard nothing, then used the paddles to send QRL? a few times. SWR still looked decent. After a few CQ calls, I got an answer followed by a short QSO. Great – both PSK and CW were working FB.

Now the question is: do I want to bring my small Tokyo Hy-Power HL-100B amplifier that will raise the output to 100 watts? If I bring the amp, I will have to bring a power supply and a different tuner. I am thinking I need to be able to use two different configurations:

    (A) Beach and Buddipole: using the barefoot FT-817, running everything on batteries.
    (B) Lanai Portable: used from the hotel room, with amp and assoicated power supply.

Now it is time to go through my Buddipole bags and figure out what I need to pack.

Looks like I will be there during the Hawaii QSO Party!

Autumn = amateur radio time

Out here in Kansas, on the eastern edge of the prarie, the leaves are turning and the first frost is upon us. The time is NOW to get the hamshack in order.

(1) My VHF/UHF antenna and Davis weather station NEEDS to get mounted up on the chimney. I have the mounting brackets – thin aluminium straps that circumnavigate the chiminey. However, the roof at the new QTH is basically three stories high and the roof itself is pretty steep. Too steep for me. The solution? I am trying to get a local roofing company to give me an estimate for the job.

(2) The HF antenna. In the course of sorting through all the hamshack flotsam, I’ve started to identify “stuff” I can part with. Already I’ve said goodbye to some old MFJ TNCs, the Kenwood TS-930S, and my old TinyTrak (thank you Craigslist!). There’s more to part with and I’m still in the process of identfying them (… like an ICOM PCR-1000, TenTec RX-320, and a D-STAR DV Dongle for starters). More importantly (and back on topic), I unearthed two in-the-package wire antennas. The first is an 80M OCF dipole from RadioWavz and the second is a G5RV+ from RadioWorks. Now I need to dust off the CSV19 Pneumatic Antenna Launcher and let the tennis balls fly.

(3) Once I have my antenna situation under control, I can take the hamshack innards to the next level.

Questions to ponder:

Do I retain the hardcopy collection of QST magazines I’ve been carting around since 2005ish? Starting for the late 40′s, it is a solid collection up to 2000. It takes up a great deal of space and I have the same issues on CD. I’d like to find the collection a new (local) home, if possible.

My new job has me on the road – it would be great to take some gear on the road with me. What to take? Needs to have a small footprint. Sounds like a job for the KX1. What to use for an antenna?

4th of July

I have been here in Korea for just over two weeks and am settling in at Camp Red Cloud, located north of Seoul. I think I’ve done a poor job in the blog of laying out the last month and half in which there has obviously been some significant changes in what I am doing.

On May 20th, I graduated from the School of Advanced Military Studies, culminating my two years at Fort Leavenworth, Kansas, knee deep in graduate-level text books and Army field manuals. One of the requirements for graduation was to write a monograph on a military subject. I choose to write on the early history of MARS prior to World War II, when it was known as the Army Amateur Radio System (AARS). During this years Hamvention at Dayton, I had the opportunity to present the paper and I am pretty happy on how it all came together. No significant research had ever been done on early MARS history so I spent the majority of my research combing through primary sources and even conducting a few interviews with the few remaining former members of the AARS. If you have an interest in MARS, the history of radio in the Army, or the origins and organization of radio emergency communications, the paper is available here at no cost. One facet to the history of the AARS that I found intriguing was the relationship that grew between the AARS and the Civilian Conservation Corps during the Great Depression. The ARRL recently posted a short article I wrote on the subject and you can see it here if you are interested.

My assignment following school was to Korea with the 2nd Infantry Division. To actually get there, I elected to take a less typical means of transportation for part of the journey. I decided to take Amtrak from Kansas City to Seattle, where I would board a government contract flight to Seoul. I had ridden trains quite a bit in Europe, but never had taken a train for more than a short distance in the United States. I had also recently read Waiting on a Train: The Embattled Future of Passenger Rail Service, A Year Spent Riding Across America by James McCommons. If you are interested in passenger rail travel, enjoy a good road trip, or would like to know why train travel fell victim to the car culture, you will enjoy this book. The author, James McCommons, travels all the primary Amtrak routes (with mixed experiences) and talks with US rail movers and shakers around the country. Overall, he said Amtrak was good and getting better. I decided to see for myself.

One of the countries more historic and picturesque routes is that travelled by the California Zephyr. Originating in Chicago, the train traces its way west, climbing through the Rockies west of Denver and on to the Sierra Nevada’s an into California, terminating near San Francisco. My folks still live where I grew up near San Jose, so California was great for a stop over. I could then take Amtrak’s Coast Starlight from San Jose through Northern California, central Oregon through Eugene and Portland, then on to Seattle.

The train ride west was wonderful and I did write a post about it. The stop over in California was a lot of fun. Arriving during the early evening of Thursday, June 10th, I was able to get some sleep and meet my dad for some QRP portable field operations. We headed up to the Santa Cruz Mountains, above Saratoga, strung up a 40m dipole and had fun playing with my FT-817 and KX1. Although we didn’t achieve any great DX contacts, it was a great time. Saturday morning we headed over to a local monthly hamfest known as the Electronics Flea Market @ De Anza College. De Anza College is a little known junior college which has overseen the growth of Silicon Valley. Although I did not find anything I couldn’t live without, I enjoyed roaming around and seeing what the vendors had.

Before lunch, we headed over to the Computer History Museum in Mountain View. Founded in 1999, the museum opened long after I had left the Bay Area. Very cool museum!

Then it was back to the train station in San Jose and I hopped on the Coast Starlight and headed north. The train ride was relaxing with some amazing scenery.

I spent Sunday night in Seattle and caught a shuttle bus on Monday to SEATAC. Flying with AMC can be an experience and differs from a commercial flight. The AMC counter was located at the far end of the international terminal and I joined a long line of guys with short haircuts and heavy, canvas green bags. Although I had to check in at 7:00pm, the flight wasn’t scheduled to board until 1am. They didn’t pack the flight, so there was a little elbow room. Instead of flying directly to Korea, our route would take us to Anchorage, followed by Yakota (near Tokyo) and then Osan Airbase in Korea. We got to Anchorage, deplaned for fueling, reboarded and then sat for three hours. Apparently the weather was bad over Japan, so we were held over for about 24 hours in Anchorage. I had been stationed in Alaska during 1993-1994 and it was nice to see that midnight sun again (sunset at 11:30pm with sunrise at 4:30am).

From Anchorage to Japan with a short layover and then on to Korea. The rest of the story is here.

And on the amateur radio side of things… My equipment is here. I shipped over my Icom IC-7000 for HF and a Kenwood TM-D710A to use with my EchoIRLP node. Also on the way is a Davis Vantage Vue weather station that I hope to get on line and on APRS. I need to get my Korean license and have all the necessary paperwork. Just need to get it turned in now. There is a monthly hamfest in Seoul next Sunday that I am going to try an attend – that should be an experience and I will have to bring my camera.

Have you been enjoying Jeff’s new podcast at KE9V.net? Cornbread Road is a Jeff at his best, weaving a tale of mystery and amateur radio in the heartland.

I will endeavor to keep my blog up to date with posts about my experiences here in Korea.

Enjoying the Sunshine

My intent this morning was to shake-out my portable operations gear. I am travelling out to California next week, enroute to Seattle and then Korea. For the flight to Korea I am allowed to take two duffel bags (<70 lbs each) and a carry-on. I get to ship a small amount of gear (aka “household goods”) from here in Kansas to Korea, but I likely will not see that stuff again for a few weeks. So along with all the stuff I will need to function for a few weeks, I also want to bring some radio gear.

The current plan is to use the Elecraft KX1. The rig has a tiny footprint and includes its own tuner and tiny set of paddles. For an antenna, I’m going to use my Buddistick. All the components fit into a small case. I decided to take the KX1 and Buddistick out for a test drive and see how everything worked together.

I set up in a small park in Leavenworth on a bluff overlooking the the Missouri River. My dad had given me a heavy duty tripod from High Sierra that served as a great base for the Buddistick. The tripod is too big pack with my luggage, but I am definitely going to ship it with the rest of my household goods. I also brought along MFJ-259B to help tune the Buddistick. The Buddistick comes with a 31′ radial. I found the challenge with the Buddistick is keeping the radial off the ground (as recommended). Instead of the 5.5′ whip that comes with the Buddistick, I have the MFJ-1956, a 12′ telescoping whip.

40M tuned up quick. I had the radial extended out all the way to 31′. Due to where I was at, there was no nearby tree that allowed me to get the radial up off the ground. The tripod let me raise up the Buddistick about 6′. It was interesting to see the SWR change as I adjusted the height. After connecting up the KX1, I found W5VYH, Bru, calling CQ around the old 40M Novice band. Bru was down in Arkansas and gave me a 559. Next up was 30M. After playing with the coil clip, I got the SWR down. Not much heard there. 20M was a bit harder to tune up. After playing with the coil clip and rolling in the radial, I was able to get the SWR down to 1:1.7. 20M was very busy with a bunch of station around 14.150 MHz. I responded to one or two stations calling CQ, but I imagine my small sized signal was hard to pull out of the mix.

I’m going to try a few more trial runs. Also need to try out the adjustable clamp that comes with the Buddistick as a mount.

We’re Going To Disney World!

It has been a tough few weeks with multiple papers and writing assignments falling within a very small period of time. I kept my nose to the grind stone and with the hep of the XYL running interference to keep me away from distractions (amateur radio being one), I successfully finished all my work!
Yahoo!
Now we’re off to Disney World. The kids and I have never been before, so we are all really looking forward to the trip. We’ll be staying at one of the Disney World resorts and intend to have a complete blast. The XYL and I will have our HTs to stay in contact (I believe there is actually a 2M repeater at Disney) and I may even throw my Elecraft KX1 to see if I can scare up some HF QSOs.

Achieved the vision…

It has been a long time goal to be able to sit in a comfy deck chair out in the backyard and have CW QSOs using my Elecraft KX1. Tonight it happen!
Last weekend I routed a feedline from an antenna switch down in the ham shack up to the deck in the backyard. I played around with it a bit, using the internal tuner to get a nice SWR on 80M, 40M, 30M and 20M. I listened around and tossed out my callsign a few times but didn’t have any takers.
I found myself back out in the backyard after dinner tonight, enjoying a wonderful evening. I broke out the KX1 (when I should of been doing my homework) and was listening around on the former 40M novice CW band…. I heard WA0TYS ably using a straight key and a Heathkit rig, calling CQ at a speed I could comfortably handle. I answered and Craig picked me up after a few tries. It was a short QSO, but I was elated. I hope to repeat this performance on a regular basis – it goes along way in maintaining my sanity.

a brasspounder’s cafe


Check out the wonderful blog of JJ8KGZ. Leo is in the process of assembling an Elecraft KX1 and has also started to share the joy of kit building with his son. Although I am sure there are many non-Western hamblogs out there, this is probably one of the first I’ve really explored and quite enjoy. I’ll be looking forward to Leo’s next post.

The Evolution of the Elecraft KX1 Transceiver

ANYWHERE, ANYTIME HF: The Evolution of the Elecraft KX1 Transceiver

By Wayne Burdick, N6KR
Special to the ARS Sojourner

If there is a place, and you can get to it, you must operate from there.
—Ade Weiss, WØRSP, Joy of QRP
Some years ago at the Dayton Hamvention I did a presentation entitled Ergonomics and Amateur Radio. It was not lost on either me or the audience that the title was an oxymoron. I spent an hour suggesting ways to improve the situation.

While discussing field operation, I alluded to something called a “trail friendly radio” (TFR), and speculated on what form it might take. Ergonomically, it’s an interesting assignment. Suppose you have no table? No chair? No room to string up a dipole? Suppose like Ade Weiss, you wanted to operate from anywhere?

Though the need for a trail-friendly radio has been evident for years, we can thank Richard Fisher, KI6SN, for giving the genre a name. He and Russ Carpenter, AA7QU, popularized it here on the ARS web site in the form of the TFR Challenge, and many interesting designs have resulted. Cam Hartford, N6GA, and I talked about it at length at the Zuni Loop field day site one year, when Cam showed me his own beautifully-designed TFR.

I’ve always wanted to explore TFRs myself, with the goal of optimizing them for small size, ease of use and maximum integration. But the idea had to simmer and morph in my mind for about a decade before all pieces of the puzzle came together – in my case, as the KX1.

Early Attempts

The story of the KX1 really begins in the 1970s. Like many hams who grew up in the era when transistors and ICs had just become affordable, I had the great fortune to acquire a copy of Solid State Design for the Radio Amateur by Wes Hayward, W7ZOI, and Doug DeMaw, W1FB (silent key, 1997). Armed with a Radio Shack etch-resist pen and ferric chloride, I home-rolled Wes’s Mountaineer, a crystal-controlled, direct-conversion, 40-meter transceiver. From then on I was hooked on both homebrew and QRP.

But it was the small, grainy photo of Wes operating the Mountaineer with gloved hands and wool cap – while while standing – that fired my imagination. Wes listed the many difficult constraints he had to satisfy in this design. The rig had to be small and lightweight to be suitable for backpacking, which dictated the use of QRP and a small battery pack. The antenna system had to be similarly light, so he opted for a simple dipole and RG-174 miniature coax cable. It had to be usable in cold temperatures, which suggested crystal control. Finally, it had to be usable in many different operating situations, including sitting on the ground, lying in a sleeping bag, or standing beside a trail. These constraints would inspire my own explorations in the TFR design space.

In 1989, I designed something I called the Safari-4 (QEX magazine, Oct. / Nov. / Dec. 1990). While not exactly a TFR, this 5 x 7 x 3″, 4-band, 1-watt transceiver did push the envelope on integration. It included an internal 0.8 amp-hour gel-cell, manual antenna tuner, SWR bridge, and keyer, and had a stack of four transverter boards covering 40, 20, 15, and 10 meters. Like the KX1, it had keyer paddle mounted on the front. Unfortunately it was actuated by skin resistance, and despite the gold-plated comb pattern on either paddle, it suffered when humidity was low. It also could not be used with gloves on.

Still, a rig like this had been my dream for many years. All you needed to set up a station was a random-length wire and a pair of headphones. I used the Safari-4 at every opportunity, and once managed to work Angola from Arizona on 15 meters with 200 milliwatts and a 16′ wire strung horizontally just 8′ off the ground. All of the credit goes to the operator in Africa, of course, and to extremely quiet band conditions.

I built my first truly back-packable, hand-held HF transceiver in 1991 while living in Massachusetts. It was 2 x 4 x 1″, operated on 15 meters only with a VXO and superhet receiver, and had a push-button CW key on the top. With two internal, paralleled 9-volt alkaline batteries, it eked out just one-half watt. This level was significant. According to Solid State Design, a half watt represented a good tradeoff between communications efficiency and battery weight. Taking this wisdom from my QRP heroes for granted, I took the little rig out on many occasions and made several interesting QSOs. The most memorable happened when I was operating mobile, driving north on I-495 outside of Boston one winter day. Using a three-foot-long whip on the roof – a Radio Shack CB antenna re-resonated at 21 MHz – I had a solid, 10-minute QSO with a station in St. Louis.

A PIC in the Pocket

Several years later, after designing a few PIC microcontroller projects at work, I decided to see what a PIC might do for the cause of further transceiver integration. The result was another hand-held, which I dubbed the Koala. This was a 2 x 4 x 1″, half-watt, 40-meter superhet that ran from a single 9-volt battery. The Koala had a keyer, dot and dash buttons on the top cover, frequency counter, battery voltage monitoring, and most significantly, audio-Morse-code frequency readout of all parameters including the VFO. This allowed operation with no display.

I should also briefly mention my club project phase, which led to the NorCal 40, Sierra, and SST transceiver kits. Again, these were not TFRs, but each furthered my goal of optimizing transceivers for portable use. All three were also enhanced by the addition of microcontrollers.

The NorCal 40 was the first NorCal club project. Doug Hendricks, KI6DS, Jim Cates, WA6GER, and others helped me specify the NC40′s features, which included small size, very low current drain, “wireless” construction, and the now-ubiquitous BNC antenna jack – I liked the small size, and I couldn’t find a PCB-mount SO239 anyway. I can’t thank Doug and Jim enough for their efforts, which made this rig and other NorCal projects a success.

The KC-1 keyer / counter option was added when another NorCal member, Bob Dyer, K6KK, started Wilderness Radio to sell the NorCal 40A commercially. The KC-1 used a PIC as a keyer and audio-Morse frequency readout – features now widely found in small transceivers. But I added one other unique firmware feature: the operator could use the keyer paddle to enter a target VFO frequency in kHz, then rotate the VFO knob until they heard an acknowledgement from the KC-1.

To minimize complexity while preserving low current drain, I used plug-in band modules in the Sierra, NorCal’s second transceiver project. Having tried a band switch in the Safari-4 and modules in the Sierra, I am now a firm believer in a third solution—latching relays—which I’ve used in every multi-band rig since, including the KX1. I later designed the KC-2 keyer / counter for the Sierra – yet another PIC-based unit. By running the KC-2′s MCU at just 100 kHz, and using a non-multiplexed LCD display, I was able to keep RFI to an absolute minimum. The Sierra construction article, sans KC-2, can be found in any ARRL Handbook from 1996 through 2003.

In the case of the SST, or Simple Superhet Transceiver, I tried to cut the size, parts count – 85 or so – and current drain to absolute minimums while preserving ease of construction and decent performance. The receiver still included AGC, the transmitter put out 2 to 3 watts, and there was room inside the box for a 9-volt battery and a KC-1. The combination of these features has made the SST popular as a Spartan Sprint rig. I suppose it could even qualify as a sorta-TFR if the KC-1 controls and dot / dash buttons were installed on top.

The NC40A, Sierra, and SST are all still available from Wilderness Radio.

Five Field Days

Before I could turn my attention to a serious TFR, a most amazing thing happened: I quit my day job. I did this even though my wife and I were only a few months away from having our first child. What inspired this irrational behavior was my teaming up with Eric Swartz, WA6HHQ, to start Elecraft.

Eric and I had met quite a bit earlier, through NorCal. He was recruited as a technical advisor to the club, and helped me with some last-minute Sierra design issues. He also proved he was serious about QRP by racking up over 100 countries on his NorCal 40.

But it was doing Field Day together for five straight years that laid the foundation for Elecraft and for our transceiver designs. At FD 1995 and 1996 we used a hodge-podge of radios, batteries, antenna tuners and antenna switching schemes, often doing more QRP experimentation than operating. Finally, in 1997, we looked at that year’s pile of gear and concluded that there just had to be a better way. By early evening we had abandoned operating and were sketching out the K2 on the backs of FD log sheets.

The K2 was our notion of the ultimate Field Day rig, with all-band coverage, wide receiver dynamic range, current drain of about 200 mA, and internal accessories – battery, ATU, antenna switch, power meter, and contest keyer. But it was not really a backpacking transceiver. So in 2000 we introduced the K2′s baby brother, the K1. Now we were getting close!

The K1 is just a bit larger than a NorCal 40, draws 55 mA or so on receive, covers up to 4 bands without modules and includes an integral battery and ATU. We wanted the K1 to function like a TFR, so we designed a special tilt stand (KTS1) that would allow the rig to be aimed up, even when it was resting on the ground. The tilt stand is fully collapsible for transport, keeps the connectors up off the ground, and provides a place to mount a keyer paddle such as the Paddlette Backpacker.

But the K1 still doesn’t meet all of the design constraints for a TFR. It’s too heavy for many backpacking expeditions, and can’t be used conveniently in difficult operating situations, such as when sitting in a camp chair, lying in a sleeping bag, or standing up. So for two years the idea continued to simmer. And then, finally, something bubbled over.

Inspiration, Perspiration

One morning in March, 2003, I woke up suddenly with the design for a plug-in, physically-reversible keyer paddle in mind. This was the all-important missing link. The trick was to mount the paddle at a 45-degree angle for ease of use. I could thread a metal-bushing eighth-inch stereo plug into the custom mounting bracket and use a captive thumb screw to hold the paddle firmly to the panel. I quickly sketched out a TFR-style radio around this paddle: controls facing up, paddle facing forward, and batteries accessible via a removable bottom cover.

A few days later Eric and I fleshed out a set of performance and feature requirements. Like usual, Eric pushed performance and features, while I aimed for low current drain and ease of construction. Then, at the expense of other projects that I had been pursuing, I spent the next month doing the design.

This is where, for me, all of the constraints and possibilities of the CW TFR finally converged. I now felt that it was possible to satisfy all of the requirements Wes Hayward had laid out for us in the Mountaineer, while providing much better performance, enhanced usability, multiple bands and more operating features.

The most important design decision was to use a DDS VFO. This would eliminate a number of parts, including the transmit mixer and its crystal oscillator. While it wouldn’t provide the high spurious-free dynamic range of an L-C VFO, it would be very stable over a wide temperature range, and also frequency-agile, allowing full coverage of 40, 30, and 20 meters as well as nearby SWL bands. Other designers had used DDS VFOs in QRP rigs with success, notably Dave Benson (NN1G) in his DSW series. But I’d been holding out for a DDS chip with much lower current drain. Luckily, one appeared: the Analog Devices AD9834, which draws just 5 to 8 mA.

Another critical question was whether to use an LCD or LED for the 3-digit display. An LCD would have required a backlight, complicating packaging given the small area available for the display. It would also have required a separate display driver, since the KX1 had to get by with only a 28-pin MCU. So we opted for a rugged, incredibly efficient red / orange LED. The unit we selected can be driven directly by the MCU (multiplexed), and requires less than 100 microamps average per segment in typical room lighting. For outdoor use, the current requirement increases to as high as 0.8 mA per segment, meaning the LED contributes up to about 10 mA average (12 segments lit) at its brightest setting. However, we included two refinements to make this a non-issue: a programmable display-off timer, and a 100 percent audio Morse-code interface, even including menu text.

The Morse-audio feature allows the KX1 to be used without looking at the display, which is great for bicycle mobile operators, too-sleepy-to-keep-your-eyes-open Field Day operation, and operation in extremely bright sunlight. But we’ve also discovered that blind hams appreciate the KX1′s Morse-audio interface, and that alone was worth its inclusion.

Revisiting the Power-to-Weight Issue

In order to allow room for the automatic antenna tuner option (KXAT1), we decided to use just six AA cells for the rig’s internal battery pack. We discovered we had to use two 3-cell sockets with a gap in the middle to accommodate the keyer paddle jack and the I.F. and BFO crystals.

Six 1.5-volt lithium cells work very well in this application, providing around 1.5 to 2 watts output. And they last forever, it seems, with a rating of nearly three amp-hours and a very long shelf life. I did six KX1 field-test outings from May through September on a single set of these batteries.

So let’s return to the issue of how much power output is required for a backpacking rig. As you recall, Wes Hayward suggested one-half watt to attain a good power / weight tradeoff. But he didn’t have access to lithium 1.5-volt AA cells, which were invented in 1992. Alkalines have a similar milliampere-hour rating, yet their voltage rapidly drops as they discharge, and the mA-hr rating is based on an end-of-charge voltage of 0.9 volts. In contrast, lithium cells have a nearly flat discharge curve, remaining at about 1.4 volts for some 90 percent of their charge life. They also weigh just over half as much as alkalines – a six-cell pack weighs just 3 ounces.

So the equation really has changed. Given lighter batteries with better performance, I think the optimal power level for backpacking rigs is around 1.5 to 2 watts. This will produce more QSOs and more reliable emergency communications.

Finishing Touches

There are a number of other subtleties in the KX1 design that contribute to its small size and moderate parts-count. For example, the transmit low-pass filter is a careful compromise, covering three bands yet using just one relay. Only three crystals are used in the varactor-tuned IF filter, rather than four (K1) or seven (K2). T-R switching of the receiver’s bandpass filter is handled using a series-tuned circuit and an NPN transistor clamp rather than PIN diodes. The BFO is fixed-frequency, optimized for a 600 Hz sidetone / TX offset. A contacting rather than optical encoder is used, the former being much smaller and still having a long predicted lifespan of more than 100,000 rotations. Four sidetone levels are provided by simply using two outputs on the MCU and two resistors (i.e., a 2-bit DAC). And finally, a simple AGC circuit is used in combination with limiting at the AF amp. The LM386 runs from just 6 volts, so it clamps leading-edge thumps pretty effectively.

Two other features provided the icing on the cake: the log lamp and SWL coverage.

The integrated white LED log lamp elicits a lot of smiles when we demonstrate the KX1. It’s really handy for nighttime operation, allowing you to shut off your larger lantern or flashlight, which might disturb someone sleeping nearby. The LED only requires about 6 mA when operated from internal batteries, and since it has its own on-off switch, it doubles as a book lamp, flashlight, or a visible signaling device. During field test someone suggested that we use a red rather than white LED, since white light attracts flying insects. You can easily swap LEDs if this is a concern.

The KX1′s SWL coverage allows you to get news, time beacons (including WWV at 5, 10, and 15 MHz), weather information, and a variety of perspectives on world events. This seemed like a useful addition to a backpacking rig, since it may be the only radio you carry, and it has proven popular with early builders. The crystal filter can be widened out to about 2 kHz to listen to AM and SSB stations. For flexibility, we also added 5 kHz tuning steps, three frequency memories per band, and USB / LSB capability.

The KX1 could be made much smaller if we had used surface-mount components and AAA batteries, left out the ATU, and had been willing to pack the controls together more tightly. While this might help someone win in the “skinny” division of the Sprint, it would also make the rig less rugged and a lot harder to build and use. Instead, we designed the rig from the ground up to be a reliable, easy to build, easy to use, fully-integrated station. Our chosen 3″H x 5″W front panel size allows quite a bit of room for controls and display, and the 1.2″ height allows for AA batteries and an automatic antenna tuner.

K-zero (Not!)

Initially we didn’t know what to call the rig. We tried and rejected K.5, KR5, K-zero, and other names that would complete the dubious mathematical series { K2, K1, … }. We also rejected “Elecraft Elf,” although we may use that for something else . . . someday. “KX1″ won in the end. “K” would keep the KX1 firmly planted in our line of transceivers. “X” was a reference to “eXtreme” operating conditions or “eXtremely small.” And “1″ seemed a reasonable choice, since the rig is just too small to be a “2″.

When I first envisioned the KX1, what came to mind right away was the Adventure Radio Society. Russ and I had had a meeting about his ARS proposal a few months before the launch, and it was clear that he really did have adventurous and innovative plans for the organization. Given the many serious backpacking trips taken by Russ and other ARS members, the KX1 just seemed to be a good fit. I’m hoping we’ll get a lot more feedback on the design as the rigs find their way into the field.

But I also had a more esoteric goal for the KX1: I wanted it to be the ultimate radio for couch potatoes. Imagine lying on the couch, working CW DX with a paperback-novel-sized lap-top transceiver. It’s an entirely new way to experience CW – anywhere, anytime!
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Wayne Burdick, N6KR, a founder of the Adventure Radio Society with membership No. 2, is one of amateur radio’s leading designer / innovators and co-owner of Elecraft, manufacturer of the KX1 trail-friendly transceiver.

Riding the shortwaves

I’ve enjoyed a little of my down time by tuning around with my Grundig YP300E. While not a feature rich radio, I’m surprised at how well it does. Two nights ago I enjoyed listening to a news program on Iranian radio. Reception was pretty solid and the propaganda reminded me of when I used to listen to Radio Moscow as a kid. Last night I tuned in to Radio Sweden for their half hour English language broadcast. I also briefly heard the Voice of Turkey, but was unable to get strong reception. It seems like I can always find the BBC.

The radio I’m looking at to give me the ability to receive LSB/USB as well as CW is the Elecraft KX1. What intrigues me most is it’s compact size. The radio has received excellent reviews on eHam.net. The radio’s small size will also allow me to take it on the road when I travel to Europe early next year.

An interesting website I stumbled across: ham-shack.com. It’s one stop shopping for a variety of information on amateur radio. I’m now reading the section
on the history of amateur radio called The Way Back Machine by Bill Continelli, W2XOY. Well written – great stuff.

New Elecraft Product

80/30m Module for Popular KX1 Portable Transceiver

from Wayne Burdick, N6KR

We’re pleased to announce that the KX1 is now a 4-band radio!

Many KX1 owners have asked for 80 meter coverage, notably Bruce Prior, N7RR, who pointed out that 80 meters is a great band for traffic handling at night (in both the CW and SSB segments). Up till now, Bruce has been taking his KX1 and a second rig that covers 80 meters on his extensive backpacking trips. Our new KXB3080 option will lighten his load a bit. 80 meters is also a popular field day and QRP band, and is especially active in the Eastern U.S. and in Europe. Band noise is lower in Winter, so this is the perfect time to give 80 meters a try.

The dual-band KXB3080 module installs in the same location as our 30-meter-only module, the KXB30. The KXB3080 is very easy to add to your KX1, since all but two components are surface-mount, pre-installed at the factory. (This was necessary in order to provide both bands in such a small amount of space.) Also supplied is a small PC board that mounts in place of the original low-pass filter inductors (L1 and L2). This board includes a relay that configures the low-pass filter for efficient operation on either 80 or 40/30/20 meters.

The KX1’s firmware has been updated in conjunction with the KXB3080. The new firmware adds:

* Full 80-meter band coverage on transmit and receive
* Additional receive-only coverage: 1000 kHz to 5000 kHz (reduced sensitivity outside the 80-m band)
* Programmable scanning (great for monitoring quiet bands, waiting for signals to show up)
* Variable-rate fast tuning: 1 kHz in ham bands in all RX modes, 5 kHz outside ham bands in USB/LSB modes

We have several beta testers lined up for the KXB3080, and will be supplying them kits in a couple of weeks. Meanwhile, I’ve been having great fun on 80 meters with the first 4-band KX1, even with a wimpy 40-foot random wire. In addition to 80 meter transceive operation, I can copy many AM stations from 1.0-1.6 MHz. This broadcast band coverage should prove useful feature for field operation.

If you have any technical questions about the KXB3080 option, feel free to send them to n6kr@elecraft.com. One question I’m sure to get is whether the KXAT1 ATU is usable on 80 meters. The answer? Yes, but the KXAT1 wasn’t designed to cover this band, so it will only help with specific end-fed wire antenna lengths to be determined. It will of course help with tweaking of nearly-resonant antennas, such as portable whips and ad-hoc dipoles.

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Please don’t call about the KXB3080 or new firmware just yet. We will announce the price of both in late January, and take orders then.

Elecraft Web Site