Category Archives: Product Announcements

QRPer Notes: Simon’s World Map Update, RG-316 Assemblies, My-Key-Mouse (USB), and Canary Islands VCAN

Because I receive so many tips from readers here on QRPer, I wanted way to share them in a concise newsletter format.  To that end, welcome to QRPer Notes, a collection of links to interesting stories and tips making waves in the world of radio!


Simon’s World Map

Many thanks to reader, Mike Bott, who notes that Simon’s World Map has been updated to V1.2.3.

Click here to download Simon’s World Map.


RG-316 BNC to BNC assemblies

Don (W7SSB) shares two announcements.

First, he notes that Chameleon Antenna is now selling RG-316 assemblies with in-line RF Choke options and BNC fittings . They have a number of lengths available:

https://chameleonantenna.com/shop-here/ols/products/cha-50-coax-with-integrated-rfi-choke-cha-50-cx-wth


My Key Mouse

Don also notes that CW Morse is now offering a USB-CW keyer/ device interface called the My Key Mouse. Check out the product description:

New for 2022! Morse Code Key to USB Adapter!

Did you know that there is an ever growing list of Software and Apps that allow you to practice and/or learn Morse Code using Computers, Laptops, Tablets, Android and other devices? Truly a great idea, but, if you’ve ever tried using a mouse to send Morse Code, I am sure you’ll agree that it is makeshift at best. But why?

Because It takes the right tools for the job!
To Send Morse Code it takes a Proper Built Key Or Paddle.

Now You can practice with a host of software and apps using your own device!

Click here to read more.


Many thanks to Jesus Alberto de Lorenzo who shares a link to a fascinating field activity based in the Canaries: VCAN — a Volcano program!

Click here for full details.

Thanks to everyone for the tips!

POTA Field Report: Activating South Mountains with the new N6ARA TinyPaddle!

On Sunday, November 28, 2021, my family needed a little time outdoors after a Saturday full of home projects.

I packed my field radio kit in the GoRuck Bullet Ruck, then we jumped in the car and drove to the Clear Creek Access of South Mountains State Park (the same site in my previous POTA field report).

South Mountains State Park (K-2753)

It was a gorgeous day and we had the park to ourselves. First thing we did was hike the short Lakeview Trail loop.

This trail is only 1.3 miles long, but offers up some beautiful views.

Hazel also came along and enjoyed the sights, smells, and even got her feet wet in a stream!

Fortunately, no one was using the one solitary picnic table at the Clear Creek access, so we claimed it!

First thing I did was launch a line and deploy my 28.5′ speaker wire antenna.

I knew it would pair perfectly with the Elecraft KX2!

I love this compact Weaver throw line bag!

The new N6ARA TinyPaddle

This activation also gave me an excuse to check out a paddle my buddy Ara (N6ARA) recently designed.

He calls it the TinyPaddle:

An appropriate name, because this key is wee! Ara notes:

As someone who likes bring experimental gear to summits, I have had paddles break on me multiple times. […] I don’t like carrying the extra weight/volume of a second set of paddles, so I designed my own “TinyPaddle” for backup as a middle ground option. It weighs roughly 3.7g and is 1.2cm x 1.2cm x 5.0cm in size.

He’s right, the TinyPaddle could tuck away even in the most compact of field kits. You’d never know it was there.

Here’s the TinyPaddle connected to the side of my Elecraft KX2:

Ara sent this key to me for frank feedback (prior to doing a small production run of them) knowing I’d not only check it out in the shack, but (of course!) take it to the field.

I decided to do my activation at South Mountains State Park using only the TinyPaddle.

Gear:

Before taking it to the field, I had some concerns that the TinyPaddle might turn in the 3.5mm key port on the side of the KX2 as I used it. Once plugging it in, though, I could tell that it would not be a problem at all. The paddle is so lightweight and so sensitive, it’s simply not an issue. In fact, it would be rather difficult to use it in such a way that it would shift in the 3.5mm port.

On The Air

Knowing in advance that it was a contest weekend (the CQWW), I decided I would stick with the WARC bands during this activation.

I tuned the speaker wire antenna to 10.112 MHz on the 30 meter band.

Hazel asks, “Got any doggy treats in that pack, daddy?”

The 30 meter band was more crowded than usual as many other POTA/SOTA/WWFF and casual operators sought refuge from the signal density on 40 and 20 meters.

Since I had the family with me and since we’d spent most of our time at the park eating a late picnic lunch and doing a casual hike, I allotted only 20 minutes of air time for this activation. I was hoping I could validate the activation with 10 contacts in that amount of time.

I started calling CQ with the N6ARA paddles. First thing I noticed was how sensitive and precise they were. Although the TinyPaddle is a mechanical paddle (with spaced contacts), they feel more like a capacitive touch paddle they’re so sensitive.

I started calling CQ POTA and soon logged KE4Q.

A few minutes later, I worked AI8Z, followed by W5WIL, WO0S,  WA2JMG, AA0Z, WA2FBN, N0VRP, KA3OMQ, W9SAU, and K1MZM.

With a total of 12 stations logged in 21 minutes, I went QRT.

QSO Map

Here’s what 5 watts into a 28.5′ speaker wire did on 30 meters that fine day (click map to enlarge):

Video

Here’s a video of my full activation. Hazel was being very camera shy; for some reason, she doesn’t like the OSMO Action camera. My wife and I think it must resemble something she’s seen at the vet’s office? We may never know!

Click here to view on YouTube.

And the TinyPaddle?

In short? I love the TinyPaddle!

Ara is obviously a talented engineer. I’m always impressed with devices like this that are so simple, yet so effective.

The TinyPaddle is going to live in my KX2 field pack as a backup to the KXPD2 paddles which have actually failed me in the field before.

That time the KXPD2 failed me…

I mention in the video that I once needed to use my Elecraft KXPD2 paddles to communicate with my buddy Mike (K8RAT) to share my SSB frequency for a very rare park activation I activated in the spring of 2020. After plugging the KXPD2 paddles into the KX2, I found that I could only send “dits.” I couldn’t even set it up to send as a straight key from one side of the paddle.

This forced me to drive 25 minutes to a spot where I had cell phone reception to contact Mike with info for a spot, then drive back to the site. That effectively shortened my activation of this ATNO park by 50 minutes!

KXPD2 missing one of the two center posts.

I sent Elecraft the photo above and they quickly identified the problem: turns out, one of the center posts had loosened and fallen out.  They immediately sent me a replacement post free of charge (typical Elecraft customer service).

I use the KXPD2 paddles quite a lot because they mount directly to the front of the KX2 making it possible to use my kneeboard during SOTA activations.
Since that mishap in the field, I tighten the KXPD2 posts at least once a month and also carry a precision screwdriver with me in my field kit.

A proper backup!

But having the TinyPaddle now is even extra insurance that a paddle failure won’t stop me from completing my activation!

When I made the video, I wasn’t certain if Ara was planning to do a production run of these or not. I’m very pleased to see that he has!

He’s made a storefront on his website N6ARA.com and is now selling the TinyPaddle as a kit for $15 or fully assembled for $20 US.

I’m certain he could actually fetch much more for these paddles, but he wants them to be an affordable, accessible backup paddle for anyone doing CW field activations.

He even includes a link to his Thingiverse page where you can download and 3D print accessories (including a TinyPaddle holder) and replacement parts at home free of charge.

Ara, thanks for making your project so available and accessible to everyone!

Click here to check out the TinyPaddle at N6ARA.com. Note that he’s doing these production runs in batches, but you can pre-order them.

Thank you!

I hope you enjoyed this field report and activation.

I’d like to send a special thanks to those of you who are supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement as my content will always be free–I really appreciate the support.

Thank you!

73,

Thomas (K4SWL)

Bonus photos!

My daughter Geneva (K4TLI) took a few extra photos at the park that day. Enjoy!

She took this candid photo of me as I packed up the KX2. Check out my KSKO (McGrath, AK) tee shirt! Thanks for that, Paul Walker!

The new Xiegu X6100 portable HF transceiver: Yes, it’s real and no it’s not vaporware

It seems folks are now finding out about the new Xiegu X6100 HF & 6 meter portable transceiver.

There have been a few rumors about it, so I thought I’d share some of the few details that have been confirmed.

What is the X6100?

If the Xiegu X5105 and Xiegu GSOC had a baby, it would look like the X6100.

The X6100 is a completely self-contained SDR QRP transceiver much like the X5105. The X6100 sports a 4″ high-resolution color capacitive touch screen and is built on on a quad-core processor, 4G ROM, and 512MB RAM. I assume this will run on a similar Linux version/distro as the GSOC.

The X6100 will include an internal automatic antenna tuner (ATU) and a 3500 mAh internal rechargeable Lithium Ion battery pack.

Power output will be 5 watts when using the internal battery pack and 10 watts when connected to an external power source.

Key features:

  • Modes: USB/LSB (J3E), CW (A1A), FM (F3E), RTTY (F1B), AM (A3E)
  • Receiving: 0.5MHz~30MHz, 50MHz~54MHz
  • Transmitting: 1.8~2.0MHz, 3.5~3.9MHz
    5.3515~5.3665MHz 7.0~7.2MHz 10.1~10.15MHz 14.0~14.35MHz 18.068~18.168MHz 21.0~21.45MHz 24.89~24.99MHz 28.0~29.7MHz 50~54MHz
  • External voltage range : 9.0~15.0VDC
  • Integrated SWR meter
  • Voice and CW memory keying
  • Integrated modem
  • Native Bluetooth and WiFi functionality (easy keyboard and mouse connectivity)
  • Two USB interfaces supporting HOST and DEVICE
  • Standard high stability TCXO
  • 24bit sampling rate and “large dynamic RF front-end unit”
  • Ruggedized chassis and backlit buttons
  • Maximum current consumption in receive: 550mA

Early Product Sheet

I’ve also been sent a pre-production product brochure. This has a number of details and, as you’ll see, it even hasn’t been through a final edit.

Click here to download the preliminary Xiegu X6100 product brochure (PDF).

Pricing and availability

Pricing and availability have not been determined at time of posting. I will post an update when that information can be confirmed.

I can only assume bringing this new radio to fruition will take time. Most radio manufacturers are struggling to keep up inventory levels as we work our way out of the C-19 pandemic supply chain issues. Parts availability has become a real issue.

Craig’s free solar/propagation apps for the iPhone and iWatch

 

Many thanks to Craig (VK3NCR) who writes:

Hi Tom

I have upload two apps to the apple App Store recently
https://apps.apple.com/au/app/ham-solar-watch/id1558970244

and

https://apps.apple.com/au/app/ham-solar/id1557970640

Hope you enjoy my simple apps!

Cheers

Craig
VK3NCR

Thank you for designing these apps and sharing them, Craig. I love the simple design–I’m loading this on my iPhone. It’ll make for an easy check before I head to the field for a summit or park activation.

In the case of the iWatch app, I see this being a very “handy” tool! (See what I did there–? Yeah, sorry for that.)

Thanks again, Craig!

Testing the new Chameleon Tactical Delta Loop (CHA TDL) antenna

Chameleon Antenna has sent me a number of their antenna systems to evaluate in the field over the past few months at no cost to me. I appreciate not only the opportunity to test these antennas, but to provide the company with my frank feedback.

As I’ve mentioned previously, Chameleon antennas are military grade and build here in the US (check out Josh’s tour of their factory).  You pay a premium price–compared to imported options–but their gear is built for performance, easy deployment, and longevity.

What has impressed me most about Chameleon gear is how flexible and modular it is. Their antenna systems are adaptable to almost any situation and always built around the idea of emergency communications.

Recently, Chameleon sent me their new CHA TDL or Tactical Delta Loop antenna. This vertical loop antenna has been designed to be portable, and tunable from 3.5 to 54.0 MHz (80-6M), but, as Chameleon points out,  “is most effective on the bands from 10.1 to 54.0 MHz (30-6M). ”

TDL deployment

If I’m being perfectly honest, I wasn’t sure what to expect this antenna to look like–in terms of size–once deployed, so I set it up in the front yard prior to taking it to the field.

Set up couldn’t have been more simple: attach the 17′ telescoping whips to the stainless steel spike (with one whip attached to the Hybrid Micro), extend the whip sections, then attach the loop wire to connect the tips of both whips.

It might have taken me four minutes to set up the TDL on the first go.

This antenna needs a little space  for sure: this isn’t one you could easily deploy in a dense forest, but it has a very flat profile vertically. I can’t think of a single park I’ve activated that couldn’t accommodate the CHA TDL.

I like to try to give gear a fair chance when I do evaluations and thought I’d wait until propagation was at least stable before taking the TDL to the field and making a real-time, real-life video (as I used it for the first time). But, frankly, I’m way to impatient to wait for the sun to play fair! Trial by fire…

Lake Norman State Park (K-2740)

On Monday (March 15, 2021) I packed up the CHA TDL and headed to Lake Norman; one of my favorite parks to play radio.

Gear:

Propagation left much to be desired that afternoon, but the weather was perfect.

I decided to pair the CHA TDL with my Icom IC-705. Since the CHA TDL requires an ATU, I connected the mAT-705 Plus.

NVIS on the low bands

I had no idea what to expect from the CHA TDL in terms of performance, but Chameleon notes that it provides Near-Vertical Incidence Skywave (NVIS) propagation on 40 and 80 meters. NVIS antennas are very popular for the military and for emergency communications since the propagation footprint is much closer to home than it might normally be.

NVIS is also a brilliant option for park and summit activators, especially if they’re activating in an area with a high density of park/summit chasers. For example, if you live and activate sites in the state of Maryland, employing a NVIS antenna might make your site more accessible to the DC metro area, Pennsylvania, Virginia, New York, Delaware, and New Jersey–regions that might otherwise be in the skip zone of your 40 meter signal.

On the air

Operating five watts CW, I started calling CQ POTA on 20 meters and snagged four stations in about seven minutes.

I was very pleased to work a station in California and one in Montana with five watts. (Though I need to check, this might have been my first MT station logged from a park.)

Next, I moved to 40 meters and was very curious if the TDL would provide me with proper NVIS propagation.

It did! One litmus test for me is when I work stations in Tennessee on 40 meters. Typically, I only log TN stations when on 80 meters or when I’ve configured one of my wire antennas for NVIS coverage.

Here are my logs from this 28 minute activation:

Here’s a QSOmap of the activation–the delineation between my four 20 meter contacts and eight 40 meter contacts is pretty evident:

Video

Here’s my real-time, real-life video of the entire activation which also shows how the CHA TDL easily fit in among trees:

In a future video, I’ll show how I deploy the CHA TDL.

Unfortunately, I left my tripod at home, so apologies for the viewing angle as I operated the IC-705.

Summary

This first test of the CHA TDL really couldn’t have gone better.

I was able to easily deploy it on sloping ground, among trees, in a state park, and snag both locals and QRP DX within a brief window of time on the air.  All this, while our local star tried its best to interfere.

In terms of construction, the TDL is what I would expect from Chameleon: military grade.

For park activators and Emcomm purposes, the CHA TDL makes for a convenient, portable NVIS antenna on 40 and 80 meters.

While I have lighter, smaller footprint antenna options for SOTA, I must admit I’m very curious how it might perform on 20 and 17 meters from the summit of a mountain. The idea of being able to rotate the antenna and change the propagation footprint is very appealing. I’ll save this experiment for a summit that doesn’t require hours of hiking, though, and one where I know I can jab the stainless steel spike in the ground (i.e. not on top of a rocky mountain).

Any negatives? When I first deployed the TDL at home, we were having 30+ MPH wind gusts. When the gusts shifted, it did move the antenna. This could be remedied pretty easily by using a bit of fishing line filament to tie off one side of the loop. With that said, I’m not sure I’d configure the TDL as a loop if I expected strong winds. Also, as I mentioned earlier, this might not be the best antenna to pack if you plan to include a multi-hour hike in your activation.

And herein lies the brilliant thing about Chameleon Antennas: If I packed in the CHA TDL and found that winds were strong on site, I would simply configure it as a vertical instead of a loop!

The CHA MPAS Lite vertical

The CHA TDL can easily be configured as a CHA MPAS Lite portable vertical: all it’s missing is a counterpoise wire which you can buy separately from Chameleon or, better yet,  just use some spare wire you have on hand!

Or, you could configure it as a random wire antenna by directly connecting a length of wire to the Hybrid Micro transformer.

That’s the thing about Chameleon HF Antennas: they can be configured so many different ways.

If you’re interested in the CHA TDL, I’d strongly encourage you to read though the user manual: it’s chock full of info and ideas. Click here to download as a PDF.

Next time I take the CHA TDL out, I think it’ll be to a summit where I’d like to see how it might perform on the higher bands with the ground sloping away from the antenna site.

Click here to check out the CHA TDL at Chameleon Antenna ($355 US shipped). 

Icom publishes AH-705 antenna tuner details

Many thanks to Rob Sherwood (NC0B) who notes that Icom has published details regarding their new AH-705 antenna tuner which is designed to pair directly with the Icom IC-705 QRP transceiver.

Many Icom IC-705 owners have been waiting to learn more about the AH-705 before purchasing a dedicated portable ATU for their IC-705. Some of these details may help potential customers make a purchase decision.

Key specifications and features per Icom:

 

  • Covers the 1.8 MHz to 50 MHz bands

30 m, 98.4 ft or longer antenna: 1.8 – 54 MHz, 7 m, 23 ft or longer antenna: 3.5 – 54 MHz
* Depending on operating conditions or environments, the tuner may not be able to tune the antenna.

  • SO-239 antenna connector for 50 Ω antenna such as dipole or Yagi
  • “Terminal connector”, binding post socket adapter supplied for a long wire antenna

  • 2-way power sources using alkaline batteries (2 x AA cells) or external 13.8 V DC*
    * 13.8 V DC should be taken directly from an external power supply, not through the IC-705.
  • IP54 dust-protection and water resistance construction*
    * The connectors should be covered with an adhesive tape or a jack cover to prevent water seeping into the connection.
  • Full automatic tuning, just push the [TUNER] button on the IC-705
  • Latching relays used for saving power consumption
  • 190 × 105 × 40 mm; 7.5 × 4.1 × 1.6 in, 450 g; 15.8 oz* compact design
    * Battery cells are not included.
  • 45 tuner memories

Of course, I don’t have an AH-705 in hand to test yet, so there’s no way I can comment on performance.

Still, I can’t turn of the reviewer inside so I feel I can make some superficial comments assuming the specs don’t change.

Potential positives?

  • Complete integration with the IC-705
  • Could (potentially–?) be permanently mounted outdoors at the antenna feed point as a dedicated remote tuner
  • IP54 dust and water resistant
  • Power from internal batteries and an external DC source
  • It’s an Icom product, so I would expect excellent overall quality

Potential negatives?

  • Maximum wattage is only 10W, which I suppose is okay if you never put an amplifier between the IC-705 and the AH-705
  • Based on Icom specs, the AH-705 is larger than other portable ATUs at 7.5 × 4.1 × 1.6 inches. For example:
  • Some have noted pricing around $350 US price–that’s a premium for a portable ATU considering the Elecraft T1 is $180 assembled and many LDG models are less than $200. Of course, none of those ATUs have an IP54 rating, either.
  • Speculation here, but the AH-705 might only work with the IC-705 or Icom radios with similar ATU commands. One original pre-production prototype image of the AH-705 shows a power switch; the latest images do not. Like the mAT-705Plus, I’m not sure if the AH-705 can be turned on in order to tune only via RF sensing without essentially modifying a control cable to trick the ATU into powering up.

I was a little surprised to see that the AH-705 “only” has 45 tuner memories. In truth, I never really pay attention to this spec because I’m primarily a field operator. My radio sessions are only an hour or two long and I routinely pair my transceivers with a wide variety of antennas, so a portable ATU never has a chance to develop a complex tuner memory map for any given antenna. But as a reviewer, I try to step in other operators’ shoes so I see where this could be a slight negative for those who plan to use the AH-705 at home and connected to only one antenna. As a point of comparison, the mAT-705Plus has 16,000 tuner memories. Still, memories only help shave off a bit of the auto-tuning time. This would never have an impact on my purchase decision.

Biggest positive for me? IP54 rating

Since the AH-705 is designed to be dust and weather resistant,  it could be mounted at the antenna feed point. At home, perhaps it could act like an externally-mounted, remotely-controlled antenna tuner. I’m not sure what the maximum length of the control cable could be, but Icom Japan even lists a 16 foot control cable as an accessory. Of course, you would still need to follow Icom’s guidance about protecting the antenna, transmitter and control cable connection points.

Biggest negative for me? The size.

If the AH-705 specs are correct, it’s a little surprising Icom designed a portable ATU that’s this large. As you can see in the image above, it easily fits in the LC-192, but frankly since I’ve been an Elecraft T1 tuner user, I’ll notice that the AH-705 is 3.1″ longer, 1.6″ wider, and .7″ taller than the T1. It will certainly take up more backpack space.

Of course, unless I build an IC-705 control interface for the Elecraft T1, I can’t directly pair it with the IC-705 like I could with the AH-705. That said? I personally prefer pressing a tune button on the T1 and sending “QRL?” instead of hitting the PTT or CW key and allowing the IC-705 to kick in a continuous tune cycle for a few seconds. You might have noticed in some of my videos that when I tune to a new CW frequency, I’ll listen for activity, then tap the TUNE button on the T1 and send “QRL?” or “QRL de K4SWL”. By the time I’ve sent that string, the T1 has typically already found a match.

How will it perform?

I’ve got to assume the AH-705 will perform well. Icom tends to give their products thorough QC before shipping them to customers. I don’t anticipate any issues with the AH-705 as I did with the original maT-705, for example.

I’ll plan to test the AH-705 after it’s available.

For more information about the AH-705, check out the product page on Icom Japan’s website.

QRP Labs projects QCX-Mini CW Transceiver Kit availability in December 2020

I’m not quite sure how Hans Summers at QRP Labs has the time to innovate at the pace he does–especially during a global pandemic–but he believes he will have the new QCX-Mini CW QRP transceiver available for purchase in December 2020.

Hans shared the following message via the QRP Labs Groups.io page (click here for the full message):

Hi all

Quite a lot of people have been asking about QCX-mini.

QCX-mini manufacturing has slipped a couple of weeks longer than my estimated “4 weeks”. But all is going well now…

[…]Latest problem is apparently my 5-in-1 top PCB design… normally PCBs are panelized and SMD’d in a set of 6 (or more) like that, then separated later. But the top PCB design is such that the amount of cut away material is too much to be able to break apart the boards without damage. So the factory had to come up with a different method for manufacturing it. I tried to understand what they are doing but I gave up, anyway in reliably assured all is well.

The 1000 enclosures are all finished, cut, CNC’ed, drilled, laser etch printed, packed.

Current estimate is that the PCB assembly (SMD soldering) will be completed on 17-Nov-2020. It’s the last step in the manufacturing process, everything else is done… then the boards will ship to me.

So, still on track for 1,000 Christmas stocking goodies.

73 Hans G0UPL
http://qrp-labs.com

Although I look at this kit and think, “yeah, like I need another portable QRP transceiver!” I’m nearly 100% certain I’ll buy it.

For one thing, I love building kits and am very happy to see that the surface mount components will be pre-populated.

I purchased the QCX+ and, indeed, plan to review the build and transceiver for RadCom. I’ve almost been “savoring” this build for a nice stretch of cold winter evenings.

Frankly I’ll buy and build the QCX-Mini because I love supporting mom and pop innovators here in our ham radio world.

Click here to check out QCX-Mini updates at QRP Labs. Of course, we’ll post an update when the QCX-Mini is available to order.

Begali is making an Adventure Key stand and mounting bracket for the Icom IC-705

Many thanks to Ray Novak (N9JA) at Icom America who shares photos of the Begali-05 bracket prototype that is being developed for the Icom IC-705 transceiver.

Those who already own a Begali Adventure key will soon be able to mount it on the IC-705 with the Begali-05 bracket.

Ray notes that this is still an early prototype, so the finished product might look quite a bit different.

He also noted, “The plan is for the Begali-05 to be available at Authorized Icom Amateur Dealers.”

I’m a massive fan of Begali keys. Not only do they make some of the best, highest precision keys in the world, but the Begali family are proper ham radio ambassadors. I love supporting them!

Pietro Begali (I2RTF) winner of the 2019 Hamvention Technical Achievement Award.

I’ll attempt to acquire a Belagi-05 bracket and Adventure Key for review with my IC-705. In truth, though, I’m sure it’ll work beautifully. It’ll be a Begali!

An Introduction to the uSDX transceiver kit

Many thanks to Pete (WB9FLW) who shares the following article by Bob (KD8CGH) regarding the uSDX transceiver kit.

I reached out to Bob who has kindly given me permission to share his article on QRPer:


An Introduction to the uSDX

by Bob Benedict (KD8CGH)

There is a new open source, home brew multi band, multi mode QRP transceiver that grew out of the QRP Labs QCX. Through some serious wizardry  it retains an efficient class E RF amplifier for SSB and digital modes. It crams impressive SDR capabilities into an Arduino.

This has an interesting international development process conducted on  https://groups.io/g/ucx/topics with contributions by many, including the usual gang of suspects: Hans Summers G0UPL, Guido Ten Dolle PE1NN, Barbaros Asuroglu WB2CBA , Manuel Klaerig DL2MAN, Kees Talen K5BCQ, Allison Parent KB1GMX, Jean-Marie T’Jaeckx ON7EN, Ashhar Farhan VU2ESE,  and Miguel Angelo Bartie PY2OHH. I apologize to the many others whose names I didn’t list. A summary is in the WIKI https://groups.io/g/ucx/wiki.

The basic work uSDX appears to have been accomplished by Guido Ten Dolle PE1NNZ. It uses pulse width modulation of the PA supply voltage to transmit  modes other than CW while retaining class E efficiency and uses a direct conversion SDR receiver.

The basic idea behind Class E nonlinear amplifiers is that transistors have little loss when they are switched fully on or off. The losses occur when devices are limiting power flow in linear amplifiers. The idea behind a Class E amplifier is to use transistors in a switching mode to generate a square wave to drive a resonant circuit to generate RF power.

This method is used in the popular QCX QRP CW transceiver kit line developed by Hans Summers and sold through QRP Labs  https://qrp-labs.com/.  More than 10,000 of these great transceiver kits have been sold (I built one). There is a good discussion of the circuit and particularly of the class E amplifier in the excellent QCX documentation https://www.qrp-labs.com/images/qcx/assembly_A4-Rev-5e.pdf.

The QCX was the base for the QCX-SSB which starts with a QCX and modified the circuit and software to add SSB capabilities. The wizardry that  Guido accomplished uses pulse width modulation of the PA supply voltage to control the amplifier in an Envelope Elimination and Restoration (EER) technique  https://core.ac.uk/download/pdf/148657773.pdf. To generate SSB a DSP algorithm samples the  audio input and performs a Hilbert transformation to determine the phase and amplitude of the complex signal.  The phase changes are transformed into temporary frequency changes which are sent  to the  clock generator. This result in phase changes on the SSB carrier signal and delivers a SSB-signal with the opposite side-band components is attenuated.

On the receive side a direct conversion SDR receiver is used with the I and Q signal digitized and all further processing carrying out digitally. Attenuators are included to help not overload the ADC range.  Documentation is at  https://github.com/threeme3/QCX-SSB .  In addition to a good description of the theory and hardware mod there is also a good description of the software command menu.

From there development took off in several directions. One is by Barbaros Asuroglu WB2CBA  and Antrak that uses through hole components (mostly) and replaceable band boards that  hold the low pass filter and band dependent class E amplifier components (an inductor and capacitor). Barb also includes boards designed to be a case top and bottom, battery pack and a PA.

Another development track by Manuel Klaerig DL2MAN uses SMT components in a stacked board layout and has a relay switched band pass board https://groups.io/g/ucx/message/1596  and  https://groups.io/g/ucx/files/DL2MAN uSDX-Sandwich Files. A new revision has been released that uses serial resonance class E amp design and easier to obtain relays, https://groups.io/g/ucx/files/DL2MAN uSDX-Sandwich Files with new Serial Resonance Class E Multiband Circuit .

Other development streams include one by Kees Talen K5BCQ https://groups.io/g/ucx/files/K5BCQ uSDX Board Schematics and Jean-Marie T’Jaeckx ON7EN https://groups.io/g/ucx/files/QCXV4.zip.

I built the variant designed by Barbaros Asuroglu WB2CBA   and I’m pleased with it’s performance. I ordered 10 main boards and 40 LP filter band boards PCBs from PCBWAY, but now you can also purchase single boards sets from https://shop.offline.systems/.

I also designed and 3D printed a case for the transceiver and a small box to carry band boards. Info at https://www.thingiverse.com/thing:4582865 and at https://www.thingiverse.com/thing:4587868 and also in the files section https://groups.io/g/ucx/files/3D printed case for Barb WB2CBA V1.02.

In an example of hams collaborating at its finest, Hans Summers  announced on 9/11/2020 that his new QCX mini product, a QCX in a smaller package,  will include a daughter board that can be used to give the QCX mini a uSDX like SSB capability. The QCX mini has the same circuit as the QCX but uses SMD components packaged it into a two board stack that is less than half the volume of the original QCX. The mod is unsupported by QRP-LABS but may be supported by the uSDX group.

http://qrp-labs.com/qcxmini.html 

More information at https://groups.io/g/ucx/topics and don’t forget the WIKI https://groups.io/g/ucx/wiki.

73

Bob,  KD8CGH


Many thanks again, Bob, for sharing this excellent uSDX introduction. Thanks again for the tip, Pete!

Pete also notes that there is a very active uSDX experimenters discussion group on Groups.io with over 100 members: https://groups.io/g/ucx

CHA MPAS Lite: Chameleon designs a new QRP compact portable antenna system

Many thanks to, Don (W7SSB), who notes that Chameleon Antenna has just introduced the CHA MPAS Lite: a modular portable antennas system covering from 6M – 160 meters.

I know a number of participants in the Parks On The Air program who use the CHA MPAS antenna system–the MPAS Lite is the “little brother” of that antenna, according to Chameleon.

Although designed with the new Icom IC-705 and other QRP transceivers in mind, the CHA MPAS Lite can handle up to 100 watts in SSB or 50 watts in CW.

They plan to start shipping the antenna in early November 2020 and the price for the system is $340.00. That may sound like a lot of money for an antenna (it is, let’s face it!) but if you speak with pretty much anyone who owns a Chameleon antenna they’ll tell you it’s worth it. The quality is second to none. I’ve been testing their Emcomm III wire antenna recently and it must be one of the most robust portable wire antenna systems I’ve ever evaluated.

Also, all of their products are designed and manufactured in the USA.

Click here to check out the CHA MPAS Lite product page.

We recently added Chameleon Antenna to our list of sponsors here at QRPer.com. I’m very proud to include them because one of my personal missions is to promote mom-and-pop companies that push innovation here in our radio world! It’s humbling that they support us too.