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Has anyone considered or even actually built an integrated handheld QMX rig? I am thinking something like the KH1. I can envision a 3D printed case that includes the QMX, small battery pack, and a manual Z-match or even automatic tuner that could be used with a whip or random wire antenna. Could include integrated touch paddles or paddles jack…
Seems like something like this could be in high demand.
Steve AK0M
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Its been mentioned and can be done...save for that pesky antenna.
At 10M a moderately decent antenna is 8ft long.? However at 40M
anything that's under about 16ft long is about as efficient as a
dummy load due to the loading coils needed to shorten it.
?
So if you mean hand held its nearly there as is (QMX+) but it needs
power, antenna, Key (for CW), MIC for SSB (future), or computer
for digital modes.? Antenna for QRP is not small unless highly
inefficient.
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Obviously you have missed all of the QMX ABS (antenna tuner, battery, speaker).
?
--
Allison
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Post online only,?
direct email will go to a bit bucket.
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It's all here including common mode choke - except the whip which is inefficient. Since the radiation with a whip is mostly from the counterpoise, I am using an EFRW of 10m or more (no counterpoise, the coax is sufficient)
73, Peter
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See also this post from a few weeks ago.
?
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Somehow, handheld HF is an under-served market segment. I have seen some very nice modifications in this group and I tried myself but failed, I end up brought a KH1.
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If you have a full-time job and you want to chance SOTA, KH1 is your only choice for now. I buy KH1 not for this performance, but for its quick-deployment. Its 1.3m whip antenna performed very well, especially when you're on the roof of a parking structure.
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But KH1 doesn't support 10/12m(while having an over-kill battery runs for weeks). If Hans can add a small battery, a small ATU to QMX(10-40m)and turn it to vertical, it will generate some momentum. Let's call it QMX# since M stands for multi-mode/band.
?
73
Wei AG6AQ
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On Fri, Feb 21, 2025 at 06:11 PM, Wei AG6AQ wrote:
Somehow, handheld HF is an under-served market segment.
?
?
Try putting a simple 50-150cm whip antenna on an HF TX and then
measure the performance / narrow bandwidths / low effiency / variable
impedance due to numerous external factors whilst actually operating.
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Interesting and educational , but you'll soon move on ;-)
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[Same practical issues for 27/28Mhz/50Mhz HT's, and why barely
anyone bothers with their EDC operations].
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Just stick to throwing a wire up a tree / convenient sky hook with a
mini rig.
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- Andy -
?
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It seems any photos attached to a thread are gone after a couple of weeks? So instead of posting my handheld QMX photos here again, I recommend you to visit my QRZ page to see how I'm operating QMX as HT -
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I have integrated it with the battery (3s1p 14500 li-ion cells with BMS), the internal speaker (though not much useful for noisy outdoor), and the plugin single lever cw paddle. For the whip antenna and the reel counterpoise wire combined with the QMX's built-in SWR bridge, I don't need an ATU.
?
73,
Yoon KM6KJI
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Hi Yoon,
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I was inspired by your post and tried myself with MFJ1720, the major problem is RFI. Have you seen RFI problem in your handheld setting?
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I can put battery in my pocket to reduce weight/volume and I agree ATU is not needed if you tune the antenna first.
?
73,
Wei AG6AQ
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On Fri, Feb 21, 2025 at 11:49 AM, Wei AG6AQ wrote:
I was inspired by your post and tried myself with MFJ1720, the major problem is RFI. Have you seen RFI problem in your handheld setting?
Wei, what was the symptom of the RFI problem? Maybe some erratic behaviors of QMX like turning off itself or the keyer suddenly not working, etc.?
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I do remember having that kind of problems when trying handheld operation with different whip antennas and certain lengths of counterpoise wire. I think the problem can be generally minimized with the lowest SWR you can achieve, although there are many other factors affecting the antenna match with HT operation - your hand, head, body and your posture, also the dry or wet ground where you stand on, etc.
?
Then I found it very handy to use the reel wire as the counterpoise, with which you can easily find the best match in any circumstances, which will surely minimize the RFI problem. I haven't had the problem with my whip antenna and the reel counterpoise wire.
?
73,
Yoon KM6KJI
?
?
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Hi Yoon,
?
Yes, besides erratic behaviors you described, the side tone also sounds funny.
Looks like to use reel wire to lower the SWR is the key. I could only get 1.8:1 from MFJ1720 as I remembered.?
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I will try on 10/12m again. If it works, it will be a good supplement to KH1.
?
73
Wei AG6AQ
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Many years ago W7ZOI is pictured with a handheld cw rig. Key is attached, maybe battery in his pocket and a wire antenna is deployed into a tree. Certainly qmx can do this with a suitable key. I may have seen something pictured here recently.?
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Curt
?
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Go down 7 photos here, Wes working his Micro-mountaineer is the small black and white photo to the right:
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His QST article describing the Micro-mountaineer starts on page 11:
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Built it shortly after that was published in 1973.
Laid out and etched my own board with ferric cloride.
A step up from them Pixie thingies on ebay today.
Lots of plans for it, but made perhaps 2 contacts.
Climbed Mt Hood, but didn't bother taking the Micro-mountaineer.
It's in a box somewhere down in the basement.
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Also in that issue:? the WB4VVF Accu-Keyer.
Built that too, I think it's down there in the same box.
After 40 years as a digital design engineer I took another look
at the schematic, still can't figure out how all of it works.
A very elegant design, but uses some nasty tricks.
Set the standard for decades to come on how a keyer should behave.
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Another article in that issue was the third installment of W2DU's
"Another Look at Reflections".? That I did figure out a few years ago
but it was some very tough sledding.? He had some nice insights?
into how transmission lines work, but no idea how to write.
?
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I just bought some AT42QT1011's so I can add M0UKD's touch keyer to my QMX
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Jerry, KE7ER
?
?
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On Fri, Feb 21, 2025 at 07:04 PM, Curt wb8yyy wrote:
Many years ago W7ZOI is pictured with a handheld cw rig. Key is attached, maybe battery in his pocket and a wire antenna is deployed into a tree. Certainly qmx can do this with a suitable key. I may have seen something pictured here recently.?
?
Curt
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Great stuff Jerry, and good to take a look back when building was the norm!
Just a word on the touch keyer. I built it, because touch is what I had in the old times. With the QCX I found it to be quite temperamental depending on the antenna (RF I guess), so moved on to the pressure paddle.
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73, Peter
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Wes Hayward was not the norm (and still isn't).
Check the station photos toward the back of that 52 yr old QST, all appliance gear.
Lots of Heathkits, though that's hardly building your own.?
You pretty much have to go back to before WWII to find a time when most hams built their own gear.
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I'll look out for issues with the touch paddle.
Seems a common mode choke in the transmission line should cure issues with RF in the shack.
Especially at 5 Watts.
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Jerry, KE7ER
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On Fri, Feb 21, 2025 at 09:27 PM, Peter HB9EBE wrote:
Great stuff Jerry, and good to take a look back when building was the norm!
Just a word on the touch keyer. I built it, because touch is what I had in the old times. With the QCX I found it to be quite temperamental depending on the antenna (RF I guess), so moved on to the pressure paddle.
?
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Yoon,
Where did you get that neat key in this photo?
A friend of mine gave me one just like it yesterday at breakfast. He thought it was a prototype as it was included as a freebie when he ordered a cap/resistance measuring device from Denmark. He uses big manly keys so had no use for it. Ha! ?I am finding that it has a nice feel and will no doubt use it with some of my QRP rigs.?
Dave (Djwilcox01 at gmail)
Dave K8WPE
PS ?Now I understand…… He who dies with the most toys has probably forgotten much what he has and why……. So true!
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On Feb 21, 2025, at 2:32?PM, Yoon KM6KJI via groups.io <yoonh.choi@...> wrote:
? It seems any photos attached to a thread are gone after a couple of weeks? So instead of posting my handheld QMX photos here again, I recommend you to visit my QRZ page to see how I'm operating QMX as HT -
?
I have integrated it with the battery (3s1p 14500 li-ion cells with BMS), the internal speaker (though not much useful for noisy outdoor), and the plugin single lever cw paddle. For the whip antenna and the reel counterpoise wire combined with the QMX's built-in SWR bridge, I don't need an ATU.
?
73,
Yoon KM6KJI
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Yoon, I have had some RF feedback using my KH1 at times in certain circumstances. ?It was usually on my deck in a stucco sided 3rd floor condo here in Florida. ?I was using my SuperAntenna MP-1 fastened to the deck railing. ?I then put a CMC out 10’ in the feedline and that solved the problem.? Dave K8WPE
PS ?Now I understand…… He who dies with the most toys has probably forgotten much what he has and why……. So true!
toggle quoted message
Show quoted text
On Feb 21, 2025, at 4:08?PM, Yoon KM6KJI via groups.io <yoonh.choi@...> wrote:
? On Fri, Feb 21, 2025 at 11:49 AM, Wei AG6AQ wrote:
I was inspired by your post and tried myself with MFJ1720, the major problem is RFI. Have you seen RFI problem in your handheld setting?
Wei, what was the symptom of the RFI problem? Maybe some erratic behaviors of QMX like turning off itself or the keyer suddenly not working, etc.?
?
I do remember having that kind of problems when trying handheld operation with different whip antennas and certain lengths of counterpoise wire. I think the problem can be generally minimized with the lowest SWR you can achieve, although there are many other factors affecting the antenna match with HT operation - your hand, head, body and your posture, also the dry or wet ground where you stand on, etc.
?
Then I found it very handy to use the reel wire as the counterpoise, with which you can easily find the best match in any circumstances, which will surely minimize the RFI problem. I haven't had the problem with my whip antenna and the reel counterpoise wire.
?
73,
Yoon KM6KJI
?
?
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N6ARA is working on a tiny-tunable-antenna (based on the "" design antenna that seems popular in...Asia) that can go directly on small QRP rigs. https://www.instagram.com/p/DD5xJzuPVHj/?img_index=1
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This may be a winner for super fast and light field use with the QMX - frankly, any QRP radio.
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Also note tiny paddle at bottom plugged right into key port - he’s built a poor-man’s KH1.
?
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I don’t know, Jerry, maybe not the norm, but a significant proportion of hams built their own gear back then. “Solid state design for the radio amateur” sold more than 50,000 copies, the ARRL handbook was filled with practical projects and a reasonable amount of electronic and RF theory, and there were still lots of local places to buy parts. I was a digital design engineer in those days, and did RF stuff when I got tired of zeros and ones.
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Or maybe my nostalgia for the golden years of DIY PCBs, ECL and 40763s, leaded components, and deadbugging continue to get the better of me. :)
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bill K7WXW
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And here I always thought those dual gate FETs were 40673’s. ?Ahh, the good old days when parts were visible and the part numbers could be read by the unaided eye.
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On Feb 22, 2025, at 10:38, bill K7WXW via groups.io <K7WXW@...> wrote:
? I don’t know, Jerry, maybe not the norm, but a significant proportion of hams built their own gear back then. “Solid state design for the radio amateur” sold more than 50,000 copies, the ARRL handbook was filled with practical projects and a reasonable amount of electronic and RF theory, and there were still lots of local places to buy parts. I was a digital design engineer in those days, and did RF stuff when I got tired of zeros and ones.
?
Or maybe my nostalgia for the golden years of DIY PCBs, ECL and 40763s, leaded components, and deadbugging continue to get the better of me. :)
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bill K7WXW
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On Sat, Feb 22, 2025 at 03:26 AM, David Wilcox K8WPE wrote:
Where did you get that neat key in this photo?
You can search QU-7025 to find it. It's cheap and not any fancy, but works. I added the guardrail to prevent the levers from being derailed accidentally.
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73,
Yoon KM6KJI
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Peter HB9EBE
David Wilcox K8WPE
bill K7WXW