After rumors surfaced about the demise of the Elecraft “K1” line, Wayne Burdick (N6KR) made the following announcement on the Elecraft email reflector, specifically mentioning the original K1:
We should have made a formal announcement here. Yes, we discontinued it because certain parts are hard to come by now, making it no longer cost effective for us to manufacture.
It was a great product for us, and I used mine for years, taking it on many trips. I thought of it as a “Sierra on Steroids” at the time (referring to an earlier design I did for the NorCal QRP Club). But we’ve moved on to more versatile field radios, including the KX2 and KX3.
I’ve owned both the K1 and KX1 and they performed amazingly well. I suppose that’s why I also invested in both the KX3 and KX2 transceivers. I suppose all good things must come to an end.
I still own a K2/100 and I certainly hope Elecraft continues to support this fine transceiver. It’s unique in that it’s about the only American-made transceiver kit on the market that’s easily serviceable by a non-technician. It’s also a rock-solid performer and, frankly, has a cult following of its own.
NOTE: I am embarrassed to admit that I made a significant error in my original measurement methodology and the numbers originally listed below were inaccurate. I’ve redone all the measurements and the text and tables below reflect the corrected measurements. *
Your host, K4SWL, asked me to share my experiences in trying to find a small, lightweight, battery pack for use with my field-portable QRP station. While I’m looking for a battery pack specifically for my Elecraft KX1, what I’m learning should be useful for users of any low-current QRP transceiver.
Currently, I’m experimenting with a pair of ten-cell AA battery-holders, one of unknown provenance (photo) and a new, more rugged one from Batteries America (p/n 10AAT, photo). When filled with ten AA NiMH cells, the resulting battery-packs provide about 14v at full-charge. At the 2012 Flight of the Bumblebees, my KX1 generated an indicated 2.6w on 20m and 4w on 40m while being powered by one of these packs; the nearly four hours of low-stress operating during this event did not discharge this pack of 2,000mAh cells very deeply. The use of two AA dummy-cells will also allow the use of eight lithium primary or alkaline cells in an emergency.
I became concerned about using this style of spring-contact battery-holder when I found an article (link) by Phil Salas, AD5X, in which he reported that this sort of battery-holder is likely to display significant voltage drop under load.
I tested my original battery-holder with ten 2,000mAh NiMH cells and my KX1 transmitting into a dummy load. In addition to measuring whole-pack voltage-drop, I measured the voltage-drop of each of the individual 2,000mAh cells as I transmitted into the dummy load on 20m.
Original Battery-Holder / 2,000mAh cells
The sum of these individual drops was 0.52v, so I’m losing 0.24v in the spring-contacts and/or battery-holder’s “transistor battery” output connector.
After replacing the original nylon connector with a pair of Anderson Powerpoles, I tested the same 2,000mAh NiMH cells in the new, more rugged battery-holder, this time only on 20m:
New Battery-Holder / 2,000mAh cells
I’m losing about 0.20v in the battery-holder’s spring-terminals, slightly less than with the older battery-holder.
The 0.20v ~ 0.24v drop from the spring-terminals doesn’t seem excessive to me and the difference in these measurements between the two battery-holders is probably not significant. I am more concerned by the 0.53v ~ 0.54v voltage-drop I measured in the individual cells. It is likely that these older 2,000mAh cells, which have been cycled many times, are exhibiting greater voltage-drop than new cells would. To test this theory, I purchased new 2,100mAh cells to measure.
I measured the new cells as above, again on 20m into a dummy load, and found that with each of the battery-holders, the sum of the individual cell voltage-drops was 0.22v, so my speculation appears to have been correct–the new cells do have lower voltage drop under load than the old cells do.
Orignal Battery-Holder, 2,100mAh cells
New Battery-Holder, 2,100mAh cells
The new 2,100mAh NiMH cells are marketed by Polaroid and cost $6 per four-pack at Big Lots; the least expensive AA NiMH cells available at Batteries America, 2,500mAh Sanyo cells, cost $3 each at the time of this experiment. I don’t know if the Polaroid cells will last for as many cycles as the probably-higher-quality Sanyo cells would but trying the significantly less expensive Polaroid cells seemed like a a good gamble.
As indicated above, the new battery-holder (Battery American p/n 10AAT) is more rugged than my original battery-holder; it holds the AA cells more securely and and doesn’t use a “transistor battery” connector to connect to the load. I replaced the original nylon connector with a pair of Anderson Powerpoles. This battery-holder will be my preferred battery-holder for field operations with the KX1.
In his article (link), Phil Salas, AD5X, recommends foregoing battery-holders in favor of soldered/welded battery packs but I will continue to experiment with battery-holders. I prefer to charge my NiMH cells individually, using an intelligent MAHA charger, rather than charging an entire pack. In addition, my KX1 draws significantly less current on transmit than Phil’s IC-703 does so the the IxR losses I’ll experience will be less significant than that which Phil experienced.
* What had I done wrong? I discovered when testing my new battery-holder that the previous measurements of the old and new NiMH cells in the original battery-holder had been made with the KX1 transmitting into a 50Ω dummy load with the KX1 autotuner configured in tune mode instead of in bypass mode; because the KXAT1 autotuner doesn’t sense a mismatch and automatically tune, this meant that transmitter current–and the measured IxR voltage losses–might be also be significantly different than with the KX1 transmitting into a matched load. Comparisons of my original numbers to measurements made later of the new battery-holder wouldn’t be meaningful, so I had to do all the measurements again.
I’ve been meaning to write a post about my Elecraft KX1, because, of all of the rigs I own, it’s the most-often-used, thus the clear favorite in my stable. But: this morning, I read John Harper’s (AE5X) excellent assessment of the Elecraft KX1 vs. the Ten-Tec HB1B. He provides some significant numbers to consider when comparing these two lightweight CW-only QRP rigs, and makes a great case for elevating the newcomer HB1B over the KX1–at least, for some readers.
I’ve had my Elecraft KX1 for over three years, and, in all honesty, absolutely love it. But, let’s face it: if I didn’t have one, if I had never touched nor used one, I would be seriously tempted by the HB1B–for its price, for the fact that Ten-Tec sells it (I’m a long-time Sevierville radio fan), and for the fact that it’s not a kit. Oh, yeah: and because it works very well.
However, having used the KX1 for so long, I know that the HB1B (at least in its current state) could not replace my KX1. But before I explain why, I would like to make some strong points in favor of the HB1B.
The Ten-Tec HB1B
At least on paper, the HB1B has better filtering, a better display, and generally speaking, more bells and whistles than the KX1. Best of all, it comes fully assembled.
Why is this last point an advantage–? For a number of talented QRPers reading this, building the kit is the best part! I know, I get it…And to tell the truth, I want to be like you kit-builders out there! But I am only now getting into kit building, and building my confidence in kit-building. I’m sure there are many others out there like me. For these QRPers, please note: the KX1 is not a beginner’s kit. I did not build mine. When I bought my KX1, I purchased it from a KX1 beta tester and professional engineer. The soldering and overall build quality are top-shelf.
Moreover, no matter how great an Elecraft radio is, it’s only as good as the person who built it. If the builder does sloppy work, your rig’s longevity and performance may suffer. Since you’ll likely be taking the KX1 with you everywhere, and it’ll experience a fair amount of movement (aka, hard knocks), this is especially important.
If, like me, you’re not prepared to take on building a KX1, fear not!–you should simply purchase from someone who knows their stuff: Elecraft can suggest some builders (including the amazing Don Wilhelm, W3FPR) or you can simply purchased a used KX1 fully-assembled. Or, you can simply purchase the fully-assembled HB1B.
So, why do I not find the HB1B enticing?
Yes, the Ten-Tec HB1B comes ready to roll. Still, could it replace my KX1? I don’t think so. Two HB1B deal-breakers for me:
As AE5X mentions, there is no internal antenna tuner option.
There is no way (at least, on this version) to attach paddles directly to the rig.
Portability + Simplicity = QRP Fun
Why are these features so important? Well, my KX1 has an ATU, four bands, and an attachable paddle. One of my favorite things to do with my KX1 is, while traveling, to pull it out of its Pelican case, toss a 28′ wire into a tree, and lay a ground wire. As I stand there, I can hold the KX1, tune the antenna (easily 40M and up, with the internal ATU) and work stations my favorite way: while standing up. I can also (if I like) sit for a moment, then jump up again, walk a bit, and generally move freely–just not possible with sit-on-a-table units.
Additionally, everything I need fits inside a Pelican 1060 case. The Kx1 itself is an all-in-one unit–nothing external to attach, unless I want to. Oh, and I can also operate the KX1 with gloves on in below-zero conditions.
Why would I want to operate standing up? Fact is, where I go, I’m only operating for thirty minutes or so, and in places where there’s no convenient spot to settle down or get too comfortable. In many cases, I’m operating on a whim–when I can grab a few minutes in a busy itinerary, or on a hike or day trip. With the Kx1, this is remarkably easy to do. I can have my KX1 on the air in four minutes or less, in most cases–and that includes the time to hang a wire–! Packing up is also quick. This kind of operation feels as free as flying a kite. Spontaneity at its best.
Part of that functional synergy comes from the fact that there are no additional components to hook up (i.e., no external tuner, external paddles). With the HB1B, I would be forced to either build a set-up, so that I could stand and hold the transceiver, tuner and paddles, or I’d have to…sit down.
Wayne’s inspiration for the KX1
Thinking back to a Dayton Hamvention several years ago, I seemed to remember that Wayne Burdick, N6KR (co-founder of Elecraft) was inspired by just this sort of off-the-cuff operation. To confirm this, I asked Wayne, just this morning, if I was on track with that. He offered this very thorough (and insightful) response:
I had been designing portable QRP gear for my own use for many years, including the “Safari 4″ (documented in three issues of QEX magazine in 1990). The Safari-4 was 3x5x7”, but it was fully self-contained, including an attached keyer paddle, internal 1-Ahr gel cell and manual antenna tuner, wattmeter, SWR bridge, and 4-band coverage. But it was too large for backpacking. Later, I designed some far smaller rigs with very good performance for NorCal and Wilderness Radio, including the SST, NC40A, and Sierra.
Then I started Elecraft with Eric, WA6HHQ. After we had success with the K2 and K1, I pitched the idea of a smaller version of the Safari-4 to Eric.
There were two inspirations for this. Back in the 70s, W7ZOI (Wes) created his “Mountaineer”, which was a crystal-controlled 40-m QRP rig that was very simple to use, very small, and self-contained, in that battery and paddles were built in. But it had no VFO, no ATU, a single band, and no frills. Taking what we’d learned in the K2 and K1 designs, I figured we could pack a great radio into this same size using updated technology. It had to cover at least 40 and 20 meters, and the idea was to use latching relays to minimize current drain and simplify band switching. We also used a DDS chip for the VFO–not quite as pure as crystal control, but just as stable, and totally adequate for a portable radio.
The other inspiration was my idea for an attached, but easily removable and mechanically reversible, keyer paddle. This became the KXPD1. I literally woke up at 5 AM with this idea. I realized immediately that this was the enabling technology for a hand-held radio, and I got busy with the design.
Having spent time camping and hiking with other rigs, I also knew that the ATU had to be built in. This allows the use of ad-hoc, wire-in-a-tree antennas, which is the secret to quick setup. It was a challenge creating an ATU that’s just 1 x 5″, but it worked. We spent weeks refining the rig and the ATU to work with typical field antennas, adjusting the component values to cover 40 and 20 meters. When we added the 30-m module, we found that it handled this well, too.
Most of my KX1 operation involves not even sitting down. I literally stop on the trail at a scenic overlook, pull the daypack around and extract the rig, toss a wire into one or two trees, and I’m on the air. I love this kind of operation. I’ve gone so far as to operate while sitting in a tree (an “inverted vertical”–a dangling wire–works amazingly well). Having to futz with add-ons can be fun, too, but it discourages “instant” operation. I like to quote Ade Weiss, W0RSP, from his book The Joy of QRP: “If there is a place, and you can get to it, you must operate from there.”
You can’t overlook performance and features, either. The KX1 is stable in all operating environments and draws only about 35 mA. It includes a variable-passband crystal filter that can be widened out to copy AM and SSB signals, and can even do cross-mode (transmitting in CW while receiving LSB or USB). It has a full set of frequency memories and CW message buffers. For blind hams (or when you’re too tired to keep your eyes open), the KX1 has a 100% Morse-audio-feedback system. I tested this firmware with my eyes closed, and the result was very well-received by the blind amateur community.
Thanks for the history, and your inspiration, Wayne. Love it!
When you hold and operate the KX1, this legacy is all too apparent. Thoroughly thought through–down to a built-in LED lamp for logging–and, without a doubt, the original inspiration for several radios that followed: the HB1B, the MFJ 92XX series, and the Hendricks PFR3.
My guess is that the next generation of HB1B will have some of these clever features.
In the meantime, if you’re in the market for an inexpensive, CW-only, very portable QRP rig, and you’ve no plans to embark upon impromptu operation, the HB1B could be your rig. Based on my experience with Ten-Tec, if they sell it, they’ll give you excellent customer service. That is the beauty of these two choices, both Elecraft and Ten-Tec are excellent companies to do business with.
I only think I’d give up my KX1 for…the new KX3, and I’m not even convinced I’d do that, yet. The KX1 has become my little travel buddy. Time will tell, though. Check back here–if I’m wooed by another QRP radio, I may eat my words.
By the way, as I mentioned at the beginning of this post, the inspiration to finally write down my thoughts on the KX1 came from John Harper (AE5X) who has an excellent QRP blog that you should certainly add to your favorites! And thanks, again, to Wayne, both for his response, and for his original ideas that continue to make QRP so liberating.