Category Archives: QRP

Parks On The Air 101: Some real-time, real-life videos of a typical POTA activation using the Icom IC-705

On Monday (October 19, 2020) I received an inquiry from Dale (KI5ARH) only an hour or so before packing up my radio gear to activate Lake Norman State Park (K-2740).

Dale is interested in using his recently acquired Icom IC-705 to get involved with Parks On The Air (POTA) and play radio in the field.

What’s in my field kit

Dale was curious about all of the components of the field kit I use with the IC-705, so I made this video:

Equipment links:

Since I had already set up my phone to record the video above, I decided to make a couple more.

I thought there might be some value in making real-time videos showing what it’s like operating CW and SSB during a POTA activation.  The videos have no edits and haven’t been trimmed.  It’s as if the viewer were there at the activation sitting next to me at the picnic table.

Operating CW with the IC-705

After setting up my station, I first started on the 40M band in CW. I meant to start the camera rolling during tune-up, but forgot to hit record. The video begins after I’d made a few CW contacts, but shows what it’s like changing bands and relying on the Reverse Beacon Network (RBN) to pick me up then the POTA website to auto spot me.

Note: to be automatically spotted by the RBN, you must schedule your activation via the POTA website in advance, or have been already spotted by yourself or someone else, so the system will know to look for you.

My video cut off abruptly due to a low battery message. I had to give my iPhone a quick power charge to make the next video.

Operating SSB with the IC-705

After operating CW for a while, I plugged in the hand mic that ships with the IC-705 for a little SSB action. My main goal with this video was to show how I call CQ and use the voice keyer memories in order to manage the field “work flow” process.  I also speak to how important it is to either self-spot or have a friend spot you to the POTA network while operating phone.

I spent so much time setting up and running the camera, I wasn’t actually on the air for very long, but I easily managed to achieve a valid activation and had a lot of fun in the process.

I’m not a pro “YouTuber” as I say in one of my videos. I much prefer blogging my experiences rather than “vlogging,” I suppose.

Still, I think I’ll do a few more “real-time” videos of POTA activations and speak to the various techniques I use to activate parks. Since these videos aren’t edited for time, they may not appeal to the seasoned POTA activator or QRPer–that’s okay, though. My goal is primarily to assist first-time POTA activators.

Have you been activating Parks or Summits lately?  Do you have any advice or suggestions I failed to mention? Or do you have suggestions for future topics? Please comment!

MAT-TUNER mAT-705 woes

Last week, I posted a review of the Mat-Tuner mAT-705 antenna tuner that is designed to pair with the new Icom IC-705 transceiver.

My initial assessment was very positive, but since then the shine has worn off. I’ll explain…

On Monday, I took the IC-705 and mAT-705 to the field for a little Parks On The Air (POTA) fun.

The Par EndFedz EFT-MTR triband (40/30/20M) antenna

Enroute to the site, I thought it would be a good test for the mAT-705 to attempt to tune the excellent EFT-MTR antenna (which is resonant on 40, 30, and 20 meters) on all bands above 40 meters.

After arriving on site, I very quickly deployed the EFT-MTR antenna using my throw line. I then hooked the EFT-MTR up to the mAT-705 ATU and connected the ATU to the IC-705.

After turning on the IC-705, I opened the menu screen and tried to engage the mAT-705 ATU. Unfortunately, the ‘705 didn’t recognize the tuner. I double-checked to make sure the control cable to the mAT-705 was secure–it was. After some head-scratching, I realized I must have left the ATU’s mechanical power switch in the “on” position while using it a few days prior.

This evidently depleted the mAT-705’s internal 9V battery. What a bummer!

I bragged about the mAT-705 in a previous post because, frankly, it is a very capable ATU–quickly finding matches from 160 to 6 meters on my random wire field antenna and horizontal loop antenna at home. It also has an incredibly sturdy aluminum enclosure.  It’s a very capable ATU in terms of quickly and efficiently finding matches and, superficially smacks of superb build quality.

Issues

But if I’m being honest, my love affaire with the mAT-705 ended Monday due to a number of discoveries.

9 volt batteries

The mAT-705 next to the IC-705

According to Mat-Tuner’s product description, the mAT-705:

“[I]s powered by an internal standard 9 volt alkaline battery. Power saving technology inside the tuner allows the use of the unit for months without replacement. No battery power is consumed by the unit when powered off.”

Turns out, they mean it saves power only with the mechanical power switch turned “off.”

This, in turn, means that the user must remember each time they use the mAT-705 to flip the mAT-705 mechanical switch off.  If left in the “on” position by accident, even with no connection to the IC-705 and while not in use, it will deplete a 9V cell in a matter of a few days.

This is a significant issue, in my opinion, and is compounded by a few other design choices:

Complicated battery removal

There is no “easy access” to the mAT-705 battery. The user must use a supplied (standard) Allen wrench and unscrew the rear panel from the chassis.

As we mentioned in our previous post, Mat-Tuner actually has a procedure for opening the case and replacing the 9V battery in order to prevent the LED illuminators from falling out. I followed this procedure to the letter, yet the illuminators still fell out. They simply aren’t secured properly and would be very easy to lose if replacing a battery in the field.

The LED illuminators

Once open, you discover that the 9V battery’s holder is a piece of double-sided tape. Seriously:

The mAT-705’s 9V “battery holder”

In addition, the ATU board essentially “floats” in the chassis secured in slide-in slots. The problem is the back panel–which you pull to remove the board–is only secured to the ATU board with three wired solder points.

Even when I lay the board down carefully, gravity will bend those BNC connections.

I can’t imagine this holding up with multiple battery replacements.

No external power port

Given that battery removal will take a user at least 5 minutes, I find it a little surprising that there’s no external power port.

It would be no problem at all for me, if the 9V battery died, to simply hook the mAT-705 up to my portable DC distribution panel like I can do with other external ATUs. But since this isn’t an option, you’re simply out of luck in the field. Better carry spare 9V batteries!

Where the lack of an external power port is really an issue, though, is for mAT-705 users in the shack. If the IC-705 becomes one of your main radios, you’ll have to be very disciplined to turn it on and off each time you use it, else you’re going to be replacing a lot of 9V cells.

Command connection to the IC-705 is basic

It seems to me that if you build an antenna tuner specifically to pair with a radio via a dedicated control cable, the tuner could potentially:

  • derive power from the transceiver
  • or at least be told by the transceiver to turn completely off when not actively in use. Especially since once a match is found, it’s locked into position even if the mAT-705 has no power.

The mAT-705 can’t do either.

Is it a good ATU? Yes, but mostly no.

As I said above, my original review stands in terms of the mAT-705’s ability to match antennas, I think it’s brilliant.

But I can no longer recommend the mAT-705 until some of these design shortcomings are addressed.

I’ve never owned a portable ATU that required so much discipline from the user in order to preserve the battery. I’ve also never owned one that was so fragile internally. Most portable ATUs *only* turn on when finding a match and then either “sleep” or turn off when not in use.

And portable ATUs like the Elecraft T1, for example? Even have a convenient battery compartment for easy removal. (And, oh yeah, the T1 will run ages on a 9V!)

The Elecraft T1 ATU 9V battery compartment

To add insult to injury, it’s one thing to discover that your mAT-705 ATU eats 9V batteries if left on but not in use, but it’s quite something else to discover your $220 ATU’s 9V battery is held in with a piece of double-sided sticky tape.

Seriously?

How long could this possibly function if you’re replacing batteries frequently in the field?

My hope is that Mat-Tuner will sort out this design and re-introduce the mAT-705 to the market. I’ve heard so many positive things about other Mat-Tuner models which is why I wanted to try one out with the IC-705.

Mat-Tuner ATUs are sold by respected retailers in the ham radio world (like Vibroplex, who loaned this model for review) so I expect they’ll address these concerns in the coming months. I’ll certainly post all updates here on QRPer.

Until then, I have to recommend skipping the $220 mAT-705 and instead purchasing the excellent ($160 kit/$190 assembled) Elecraft T1.

Guest Post: Steve builds a DC30B QRP Transceiver

DC30B QRP Transceiver ProjectMany thanks to Steve (KZ4TN) who shares the following guest post:


DC30B QRP Transceiver Project

by Steve Allen, KZ4TN

I wanted to build a lightweight backpackable transceiver I could take hiking and camping. I chose the 30 meter band as it is specific to CW and the digital modes. I am also in the process of building Dave Benson’s (K1SWL) Phaser Digital Mode QRP Transceiver kit for the 30 meter band. Also, a 30 meter antenna is a bit smaller than one for 40 meters and the band is open most anytime of the day.

I sourced the DC30B transceiver kit, designed by Steve Weber KD1JV, from Pacific Antennas, http://www.qrpkits.com. It appears that they are now (10-11-20) only offering the kit for the 40 meter band. The following information can be used for the assembly of most any kit that lacks an enclosure.

Lately I have been finding extruded aluminum enclosures on Amazon.com and eBay.com. They come in many sizes and configurations. I like to use the versions with the split case which allows you to access the internal enclosure with the front and rear panels attached to the lower half of the enclosure. Most of these enclosures have a slot cut into the sides that allow a PCB to slide into the slots keeping it above the bottom of the enclosure without having to use standoffs. The one requirement for assembly is that the PCB needs to be attached to either the front or rear panel to hold it in place.

DC30B QRP Transceiver Project

As the enclosure is anodized, I didn’t want to rely on the enclosure for common ground. I used a piece of copper clad board that I cut to fit the slot width of the enclosure and attached it to the back panel. I was then able to mount the transceiver PCB to the copper clad board with standoffs. This basic platform of the enclosure with the copper clad PCB provides a good foundation for any number of projects. All you have to do is mount the wired PCB on the board, install the components on the front and rear panel, then wire it up.

DC30B QRP Transceiver Project

I wanted to have the choice of a few frequencies to operate on so I searched eBay for 30 meter crystals and found a source for 4 different popular frequencies. I installed a rotary switch on the front panel and added a small auxiliary PCB with two, 4 pin machined IC sockets. This allowed me to plug the crystals into the sockets. I wired the bottom of the socket PCB first using wire pairs stripped from computer ribbon cable leaving extra length. I marked the wires with dots to indicate which sockets each wire pair went to so I could solder them onto the rotary switch in the correct order. It was tight but I always work with optical magnification so I can see exactly what I’m doing. I have used this crystal switching method in the past with good success.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe rest of the assembly was straight forward. I find that most kits are well designed and documented, and if you take your time and follow the directions carefully all should go well. The two most common speed bumps seem to be soldering in the wrong component or bad soldering technique. I double check all component values and placements prior to soldering, and I always use optical magnification while working. I inspect each solder joint and look for good flow through in the plated through holes, and make sure there are no solder bridges.

DC30B QRP Transceiver Project

DC30B QRP Transceiver ProjectThe finished product. I bought a Dymo label maker and it works very well for projects like this. I love using these enclosures and they are a leap forward from the old folded aluminum clam shells I used in the past. I could stand on this without causing any damage. Power out is 1-3 watts depending on the DC power in. The receiver is sensitive and the ability to choose from four frequencies is a real plus.

73 de KZ4TN

Steve Allen
Elizabethton, TN


Wow, Steve! What a top-shelf job on this build! I’ll have to look for those aluminum enclosures as well. Beautiful little rig you’ve made there and I think it’s fantastic you’ve a few crystal frequency options! Thank you for sharing!

Eric’s DIY Cootie: “Levon”

Many thanks to Eric (WD8RIF) who writes:

Well, if K8RAT is going to tout Hermione, I guess I need to tout Levon.

My cootie/sideswiper was inspired by an article (http://sideswipernet.org/articles/w9ok-modernization.php) by W9LA about how hams in the 1930s might have constructed a cootie/sideswiper using a ceramic DPST knife switch. I didn’t have a ceramic DPST knife switch, but I did have a nice Leviton ceramic DPDT knife switch which I used as the basis for my cootie/sideswiper. Instead of using tape for the fingerpieces as described in the article, I used Fender guitar picks.

This cootie is the key I use most often for home-based operations.

While operating in the field, I usually use an inexpensive and lightweight Whiterook MK-33 single-lever paddle as a cootie key.

Levon is a handsome sideswiper, Eric! Thanks for sharing his story and your photo!

Thanks to both of you, I feel inspired to make my own “cootie” this winter. Perhaps I’ll try to find some historic context/inspiration as well!

Any other homebrew sideswipers, straight keys, or paddles you’d like to share? Please contact me and we’ll feature your creations!

I’ve got a very special one that’ll be featured later this week. Stay tuned!

Operating the Icom IC-705 QRP transceiver in CW with full break-in QSK

Readers have been asking me about operating the new Icom IC-705 in CW; specifically if the T/R relay is noisy and how full break-in QSK sounds.

Here’s a quick video that should answer a few of those questions:

I made this video yesterday while testing the new mAT-705 ATU.

Please comment if you have other IC-705 questions.

Icom IC-705: Reviewing the Mat-Tuner mAT-705 in the field

UPDATE: My review of the mAT-705 ATU below is accurate as of its original posting. Since this review, however, I’ve discovered some design issues that prevent me from continuing to recommend it. Click here for details.

Last week, Vibroplex sent me their new Mat-Tuner mAT-705 external ATU on loan to evaluate with my recently acquired Icom IC-705.

Here’s some info about the mAT-705 from Vibroplex’s product page:

The new mAT-705 antenna tuner is designed specifically for use with the new Icom IC-705 QRP transceiver. Connect the mAT-705 directly to the TUNER jack on the IC-705 with the included cable and control the antenna tuner directly from the front panel of the radio or use RF-sensing to actuate the tuner when changing bands. 1.8-54 MHz, 5-1500 ohms matching range, 16000 user memories recalling previous used settings internal to the tuner when returning to an earlier used frequency.

The tuner is powered by an internal standard 9 volt alkaline battery. Power saving technology inside the tuner allows the use of the unit for months without replacement. No battery power is consumed by the unit when powered off.

Yesterday, I stopped by South Mountains State Game Land (K-6952) to give the mAT-705 some field time. Up to this point, I had not used the tuner other than tuning to the 80 and 40 meter bands from home (mainly to make sure it worked before hitting the field).

To really give the mAT-705 a workout, I deployed my CHA Emcomm III Portable random wire antenna. The Emcomm III is the only field antenna in my arsenal that covers 160 meters – 6 meters–an exceptionally wide frequency range.

What I like about this particular POTA site is the open parking area which allows me to configure the Emcomm III a number of ways.

The Emcomm III, being a wire antenna, is incredibly stealthy. Since you can’t see it in the photo above, I’ve marked up the configuration below (click to enlarge):

I’m guessing the apex of the antenna was easily 45′ high.

Activating

I started my activation on the 80 meter band.

After working a few stations on 80 meters, I decided to test the mAT-Tuner over a fairly wide frequency range before calling CQ on the 40 meter band.

Here’s a short video:

POTA Hunters: look for me on the 160 meter band this fall and winter! I’m so impressed how well it matched the Emcomm III on 160.

 

Indeed, I am very pleased with how quickly and efficiently the mAT-705 found matches on every band I tested.

In terms of form factor, the mAT-705 is quite compact, but a little longer in length than I had anticipated. Honestly, though, there’s nothing here to complain about.

The enclosure/chassis is incredibly strong. I’m willing to bet you could accidentally drive over it with your car and it would survive in tact.

The mAT is powered by an alkaline 9V battery. Vibroplex expects that this battery will last for months under normal use.

Note that there is a specific procedure for replacing the battery in order to protect the LED “illuminators” that are press-fit to the board.:

  1. Remove the case by removing the 4 rear 2mm allen screws.
  2. Turn the tuner upside down and shake it a little to get the PCB to slide out of the case enough to grab.
  3. Carefully grasp the PCB sides and slide the board out slowly.

Update: I’ve followed the procedure above and still had an issue with the illuminators falling out. They really need to be secured better. I was able to re-insert them and close the ATU, but when you open the mAT-705 to change the battery, be in a space where you can capture both of them if they fall out.

Any mAT-705 negatives?

Not really, but I do feel the price is a little steep at $219.95–but then again the mAT-705 seems to do the job and do it well. I have to assume the TBA Icom AH-705 ATU will cost at least as much. I’m okay with paying at the top end of the market if I’m getting a quality product and this certainly seems like one.

I like the fact that the mAT-705 integrates perfectly with the IC-705 via the control cable and that I don’t have to worry about protecting it at all in my backpack. It’ll also take the IC-705 through the entire HF spectrum and even up to 6 meters.

 

I plan to continue using the mAT-705 for a while and even test it on severely non-resonant antennas just to see how far I can push it for a match.

Stay tuned! (See what I did there–?)

Many thanks to Vibroplex, again, for lending me this mAT-705 for review and evaluation.

Click here to check out the mAT-705 at Vibroplex.

Hiking to a POTA “two-fer” site from home

I feel pretty lucky that my QTH borders tens of thousands of acres of protected lands: a watershed, Pisgah National Forest, and Pisgah Game Land WRC. Our family enjoys hiking, so we often venture into the forest around our house  and explore the ridge lines, peaks, and views.

This year, while exploring all of the public lands available to activate in the Parks On The Air (POTA) program, I realized there were no less than two sites within a 30-35 minute hike of my home! Quite literally, in my back yard.

In fact, there’s a large area where two POTA entities overlap–Pisgah National Forest and Pisgah Game Land–giving me the opportunity to activate both sites simultaneously as a “two-fer.”

If it’s so close, you may wonder why I haven’t activated it yet–? Well, by the time I realized the park boundary overlap was within hiking distance of the house, we were well into spring, thus the forest was lush with vegetation and the hike to the site requires proper trail-blazing with an elevation change of 600′ (183M). It’s a much easier hike in fall and winter when you can actually see where you’re going through the trees.

Still: Saturday morning, the weather was so perfect for hiking I floated the idea by my teenage daughter, Geneva: “I’ve got a hankering to hike up the mountain today and do a POTA activation.” She replied, “I’ll need to pack my daypack and take the HT.” She was eager to see if she could communicate back to the house simplex with her mom and sis with her new FT-60R handheld.

My wife gave me her blessing, so I packed my trusty Red Oxx C-Ruck with my Elecraft KX2 kit, CHA Emcomm III Portable antenna, water, snacks, logbook and tablet, and used the ruck top flap to secure my three leg folding stool.

Pisgah Game Land WRC (K-6937) & Pisgah National Forest (K-4510)

We arrived at a suitable site about 40 minutes after leaving the QTH. My Garmin GPS and topo maps confirmed we were well within park boundaries. I found a rock outcropping and set up my station.

Even though the area was pretty dense with trees, Rhododendrons, and Mountain Laurel, I had no difficulty deploying the Emcomm III Portable antenna using my throw line.

That’s not a flying squirrel, it’s the winder/balun of the Emcomm III.

The Elecraft KX2 had no trouble at all matching the Emcomm III on all bands.

Even though Geneva was busy communicating with her sister (back at “Mission Control” via simplex) on the FT-60R, she actively logged all of my contact on the Surface Go tablet using N3FJP’s excellent contact log.

I quickly logged eleven contacts on 80 and 40 meters and my daughter suggested we cut the activation a bit short to take in more hiking.

We both wanted to follow a trail we found and see if it lead to the Blue Ridge Parkway.

Hazel has that “Seriously? You want to continue hiking?” look.

I packed up the station and hit the trail!

It turned out to be a good 45 minute trek along a ridge line increasing our elevation about 1,000′ (305M) ASL compared with home. The trail to the BRP was what I would call a moderately difficult trail (much easier than trail-blazing up the mountain!).

In the end, we found the Blue Ridge Parkway and the trail head to ascend Lane Pinnacle which is an excellent SOTA site. We decided to save Lane for another day this fall/winter with a very early departure from home.

Neva also discovered she could easily chat with her sister back at the QTH via 2 meter simplex at the parkway. This means I can definitely chat with the family back home when I eventually make that Lane Pinnacle SOTA activation.

The hike back to the POTA site was mostly downhill so only took about 40 minutes. I then veered off the path to trail-blaze our way back to the house. I did get a little off course which added about 25 minutes (!!) to our descent and requiring us to mitigate the steepest part of the ridge. Next time, I’ll pay more attention to my GPS map (although, in the winter, it’ll be much easier).

Still, it was a very enjoyable hike and certainly one of the more challenging I’ve been on in ages mainly due to the steep part at the end.

All-in-all: I discovered that there are no less than three POTA sites and one SOTA site within hiking distance of the QTH. The best part, by far, was the father/daughter time. Geneva is always up for an adventure (including currently studying for her General class license!).

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

W9FKC’s suitcase portable

Many thanks to Pete (WB9FLW), who writes:

Found this link on the Soldersmoke Blog this morning.

Click to access W9FKC.pdf

Interesting to compare this 70 year old Rig with your KX2 or KX3!

We’ve come a long way since then.

Indeed we have, Pete! But, man oh man! What a gorgeous vintage portable–absolutely beautiful vintage example of form following function!

Click here to download the PDF.

Seven Park Activations in Six Days: A review of the adaptable Chameleon Emcomm III Portable antenna

Weather in North Carolina has been absolutely stunning over the past week, with the exception of two days where the remnants of Hurricane Sally dumped torrential rain. Two cold fronts provided us with gorgeous clear skies and dry conditions before and after Sally’s visit.

Of course, what better way to enjoy the outdoors than taking my radios to the field?

Last Wednesday, after several hours of knocking out home projects, my wife and I decided to enjoy the fall-like weather and get lost in Pisgah National Forest. My daughters were also keen for a little outdoor adventure, waterfalls, and hiking.

And our canine family member, Hazel? Always up for an outing!

“Let’s go, daddy!”

Of course, my wife was throwing me a bone as she knew I was chomping at the bit to try the new-to-me Chameleon Emcomm III antenna.

CHA Emcomm III antenna

Photo Source: Chameleon Antenna

I decided I’d pair the Emcomm III with the amazing Mission RGO One transceiver (a rig I’ll be reviewing in an upcoming issue of The Spectrum Monitor magazine).

Up to this point, I’d never used a Chameleon antenna in the field.

Chameleon Antenna kindly sent me both the CHA Emcomm III and CHA P-Loop a couple weeks ago for an honest field evaluation (and disclaimer: at no cost to me).

And being honest? The overall length of the Emcomm III wire antenna was intimidating.  I’m used to field-ready wire antennas that are perhaps 30-41 feet in total length. The Emcomm III has a 73 foot long radiator and 25′ counterpoise! Holy smokes!

In my head, I imagined the only places I’d be able to use the Emcomm III would be in an open park with large, widely-spaces trees.

Turns out, I was wrong.

Two things make deploying the Emcomm III a breeze–even in the middle of a forest:

1.) An arborist throw line: this piece of kit has revolutionized my  field antenna deployments. Not only does it give me the ability to suspend antennas much higher than I could before, but also to raise/lower antennas with ease compared with fishing line.

2.) The Emcomm III also has a floating dielectric ring on the radiator wire that allows you to create a suspension point. In fact, there are a number of ways you can deploy the Emcomm III which, I see now, makes it such a popular antenna among POTA operators.

To the field!

The first activation was actually a “two-fer”–meaning, two geographically-overlapping POTA park entities.

Wednesday, September 16: Pisgah National Forest (K-4510) & Pisgah Game Lands WRC (K-6937)

Propagation conditions on Wednesday were so crappy I found myself breaking with QRP to run 40 watts with the Mission RGO One into the Emcomm III. (The Emcomm III can actually handle up to 50 watts CW, 100 watts SSB.)

I first deployed the Emcomm III by pulling the radiator over a tree branch about 50′ high with the balun and winder near the ground. I then unrolled the counterpoise stretched out on the ground.

After only snagging about eight contacts in 50 minutes (a very meager amount for the typical park activation), I decided to re-configure the Emcomm III Portable so that it would act more like a NVIS antenna and perhaps grab a few regional hunters on 80 meters. There was no way I was leaving the forest without my 10 contacts to validate the activation!

I reeled in the radiator and re-attached my throw line to the floating loop and reconfigured the antenna to roughly match this “V” shape with a lower (roughly 25 ft) apex point:

NVIS “V” configuration (lifted from the CHA Emcomm III Portable product page)

I used the RGO One’s internal ATU to match the 80 meter band 1:1.

I started calling CQ on 80 meters CW and, evidently, the POTA site auto-spotted me via the Reverse Beacon Network (RBN) because within a minute, I found myself at the other side of a mini pile-up! I very rapidly worked 8 stations–most of them were in nearby Tennessee. These were callsigns I was not used to logging because typically they’d be under my skip zone–a little too local.

It was nice to get solid copy on 80 meters without the deep QSB on 40, 30 and 20 meters.

The thing that struck me about the Emcomm III at this first activation was how easy it was to reconfigure in the field despite the lengthy radiator. The wire is Copper Clad KEVLAR PTFE (Telflon-coated) and doesn’t easily tangle. It slides so easily through the trees–there’s no coil or bulky bits to get caught in the limbs.

When packing up, it wraps around its built-in winder very easily. Kudos to the designer.

Saturday, September 19: Pisgah National Forest (K-4510) & Pisgah Game Lands WRC (K-6937)

Last Saturday, I wanted to try the CHA Emcomm III in a different region of Pisgah National Forest and see how well it might pair with my Elecraft KX2.

We found an ideal spot to set up: a forest service road that had obviously been closed the entire season.

I deployed the Emcomm III Portable in the same “V” configuration as I did during the first activation, but this time raising the apex of the “V” up to 45 feet.

It’s important to note here that being a random wire antenna, the Emcomm III relies an an ATU to get good matches on each band. The Mission RGO One’s internal ATU did a brilliant job finding matches and, turns out, my KX2 did as well.

In fact, before I started calling CQ, I moved across the bands to see if I could get good matches with the KX2 ATU. From 80-20 meters, I think the highest SWR I had was 1.3:1. (The KX series ATU is truly a benchmark in my book!)

That day, even though the weather was gorgeous, propagation was terrible.  I read a few reports from experienced POTA and SOTA folks who couldn’t snag the needed 10 contacts for a valid activation earlier that day. There were contests and QSO parties on the bands so lots of signals–but more than once on the phone portion of the 40 meter band,  I could hear two stations calling CQ on the same frequency and trying to work the same stations totally unaware of each other. Not a good day to play radio in the field and was starting to wonder if I could even snag my needed ten contacts.

Turns out, I had nothing to fear.

Since I could, quite literally, pick any band the KX2 could transmit on, I was able to float across the HF spectrum, call CQ, and the RBN would make sure I was spotted properly to the POTA network.

Getting that first ten is a great feeling!

I pretty effortlessly snagged my ten, and then a number to boot.

When I seek a spot to set up in a national forest, I often look for forest service roads with locked gates. When I set up on an unused road, it typically means I’ll have a high branch to hang the antenna and also a little space to deploy it without touching other trees. Our spot on Saturday was ideal.

Again, hanging and deploying the Emcomm III was effortless. I did bring about 12 feet of paracord with me this time allowing me to tie off the end of the radiator if I chose the “V” shape.

Monday, September 21: Mitchell River Game Land (K-6926) & Stone Mountain State Park (K-2754)

Monday was another stunning weather day.

I decided I wanted to finally make a pilgrimage to an ATNO (All Time New One) POTA site I’d been eyeing for a few months: Mitchell River Game Land.

Because propagation was fickle and this site was a good 3 hour round trip from where I was staying with family, I planned to use the Mission RGO One and run 40-50 watts or so.

However, when I got to the site, I realized I’d left the RGO One’s power cable at home. Fortunately, I still had my Elecraft KX2, so 10 watts would have to do.

I found a large parking pull-off area surrounded by trees. There was a ton of room to deploy the Emcomm III.

I decided to extend the radiator in a sloping configuration and elevate the 25 foot counterpoise.

The configuration was Identical to the one above , but the balun/center winder and counterpoise were suspended about 4 feet off the ground.

I fired up the KX2  and started calling CQ on 80 meters. The RBN picked me up and the POTA site auto spotted me. In a couple of minutes, I snagged my first three stations, then I heard no other calls, so moved up to 40 meters where I worked a big pile-up of stations. It felt like a mini-DXpedition at times. I loved it!

I even hopped on the phone portion of the 40 meter band and worked a few stations, getting respectable signal reports despite unstable propagation.

This activation went so well and the weather was so ideal, I decided to fit in another park that was only a 30 minute drive and was new to me: Stone Mountain State Park.

The thirty minute drive was relaxing and reminded me how much I enjoy this portion of the NC foothills leading up to the Blue Ridge Parkway and escarpment.

By the time I reached the park it was 1:30 pm on a Monday and I essentially had the place to myself (even though in my head I was preparing for crowds).

I had my pick of picnic spots so I found the one with the highest branches. One shot with the arborist throw line and I snagged a branch that must have been 45-50 feet high.

I first deployed the Emcomm III by simply running the radiator over a tree branch and laying the counterpoise on the ground–much like I did in the first Emcomm III activation and deployment.

I started calling CQ and worked about 4 stations, then nothing. The bands simply died on me!

After 30 minutes, I reconfigured the Emcomm III into a similar “V” shape I used at Pisgah National Forest with the apex at about 40 ft and the center winder and counterpoise elevated about 3 feet.

After some persistence, I finished off my ten contacts and then packed up–I spent about 70 minutes on the air and needed to grab lunch!

I honestly believe I would have found this activation even more challenging if I didn’t have an antenna that could snag stations on the 80 meter band since it was in the best shape that afternoon.

Again, I was very impressed with how easy it was to reconfigure the Emcomm III.

Tuesday, September 22: Tuttle Educational State Forest (K-2754)

After staying two nights with my parents in the Piedmont of North Carolina, I made my way back home to the mountains Tuesday afternoon. Again, the weather lured me back out to make just one more activation! (Let’s face it: the weather is a bit of an excuse).

One of my favorite parks that’s only a 20 minute detour off my path is Tuttle Educational Forest. It’s never busy there and they have a large picnic area with ideal trees for hanging antennas.

After searching through my main field pack (a Red Oxx C-Ruck), I found a spare power cord that would work with the Mission RGO One transceiver.

I didn’t have a microphone, though. That’s okay: it would be a CW-only activation.

Although I had the park to myself, I didn’t want to take up a large portion of the picnic area by deploying the Emcomm III in a sloping configuration similar to my activation at Mitchell River. I decided, instead, to be space efficient and use the “V” configuration once again with the apex at about 35 feet and the counterpoise on the ground. By doing this, the antenna footprint could almost fit within my picnic table area (although my counterpoise did snake into the woods).

I can’t remember how long I was on the air, but I do remember it was a breeze logging contacts that afternoon. Very enjoyable. I do love the Mission RGO One–the receiver is amazingly quiet, sensitive, selective, and signals simply pop out of the ether. It also sports silky-smooth QSK. Again, although I’m 90-95% a QRPer, it’s nice to push the juice a bit when propagation isn’t kind. The RGO One will push 55 watts.

The Mission RGO One ATU also snags excellent SWR matches across the band with the Emcomm III.

Emcomm III initial impressions

This past week, I gained some serious respect for the Emcomm III.

What impresses me most is its versatility and robust quality.

Don’t get me wrong: it’s not a magic antenna or anything. It’s essentially a random wire antenna.

What makes it such a fabulous field antenna, though, is its configurability. That and its uncompromised military-grade construction.

I shouldn’t have been so concerned about the radiator length as it’s actually pretty easy to accommodate and helps make this an efficient antenna on the low bands. (Look for me activating parks on 160 meters this winter!)

I believe I can deploy the Emcomm III anytime I have a half-decent tree nearby. I believe I could also use my 31′ Jackite fiberglass pole to extend one end or even the middle of the antenna if I wanted to go NVIS, but I would have to be careful to accommodate strain relief since the Emcomm III Portable is made of heavier materials than my EFT Trail-friendly antenna, for example.

I’m not sure I’d ever reach for the Emcomm III for a SOTA activation when I’d need to take a close look at weight and size. But for POTA? It’s brilliant. And, of course, for emergency communications (as the model name implies). The Emcomm III would also be an excellent addition to a radio club’s antenna arsenal.

The Emcomm III, like all Chameleon products, is designed and made in the USA. Since they use military-grade components, you pay a premium.   The Emcomm III is one of their least expensive products at $139 US.  Is it worth the price? Absolutely. In fact, I’m thinking about buying a second one to keep in my camper.

Click here to check out the CHA Emcomm III Portable.

Moreover, the Emcomm III has earned its place in my main field radio kit.  Now let’s just hope Chameleon doesn’t ask for it back anytime soon!

Note that there are actually two models of Emcomm III antennas: the Portable version ($139) I reviewed here, and a Base version ($149) which is much larger designed for permanent installation.

Thank you, Chameleon Antenna, for sending me the Emcomm III Portable for a proper field evaluation. I’d also like to thank Chameleon Antenna for agreeing to be a sponsor of QRPer.com!