All posts by Thomas Witherspoon

Guest Post: A QRP Labs QDX POTA Field Portable Report

(Photo: QRP Labs)

Many thanks to Conrad (N2YCH) who shares the following field report:


QRP-Labs QDX Field Report

K-1716, Silver Sands State Park, Milford, Connecticut

January 13, 2023

By: Conrad Trautmann, N2YCH

A digital mode multiband transceiver for $69? Yes! QRP Labs has the QDX kit available for $69 US. Add $20 if you would like a very nice black anodized aluminum case to mount it in and if you want it assembled and tested add another $45. Visit the QRP Labs web site for all of the details (QDX 4-band 5W Digi transceiver (qrp-labs.com)

How well can a $69 digital transceiver work? Read on…

I ordered my QDX kit back in May 2022. It arrived in June, I assembled it and ran some tests at home. It worked well on FT8 into my home antennas. It interfaces nicely with WSJT-X and I liked the idea of using a low power transceiver to band hop on WSPR. My QDX is an early four band version, which does 20, 30, 40 & 80 meters. I set it to band hop on all four bands not remembering that my multiband offset center fed dipole is not resonant on 30 meters. Since the QDX does not have a tuner, it didn’t like the higher reflected power of a two minute long WSPR transmission into a bad load and smoke resulted. I was fortunate that the failure was isolated to the RF power amplifier transistors and replacing those got me running again. This was my own fault, not the transceiver. Now, it band hops on 20, 40 and 80 meters with no issues, I eliminated 30 meters from the hop schedule.

I share this important story at the beginning of my field report as a warning to anyone considering using a QDX to be very careful when connecting an antenna to it. Since the QDX does not have an internal antenna tuner, you either need a resonant antenna or must use an external tuner to provide a 50 ohm load with low SWR to the QDX. The QRP Labs groups.io site has a number of posts from users with different tuner suggestions.

Now comes the fun part. I visited Silver Sands State Park, K-1716, located on Long Island sound in Milford, CT on January 13, 2023 in the afternoon. While it was Friday the 13th, I had nothing but good luck. Knowing I would be running QRP power, I decided to use what I consider to be my best 20 meter antenna. It’s a modified version of a Buddipole, which I call my “no coil” Buddipole dipole. I use a Buddipole VersaTee mounted to a WILL-BURT Hurry Up mast, which is a push up mast that extends to about 25’ high. The dipole consists of two Buddipole 32” accessory arms, one for each side of the VersaTee and two MFJ 17’ telescoping whips, extended to just about 17.5’. This provides a very broad bandwidth and low SWR on 20 meters. See the screen shot of my antenna sweep from the RigExpert analyzer below.

Here’s a photo of the antenna in the air.

The temperature on this January day was a mild 55 degrees so I was able to set up my equipment in the back of my Jeep. Here’s everything I needed to do the activation. Since the antenna is resonant, I did not use a tuner.

My iPhone gives you an idea of just how big the QDX is, which is sitting just to the right of it. There are only three connections needed, the antenna cable, a 12V power cable and the USB cable. I was using my Bioenno 9ah battery for power. I brought the Bird Model 43 with a 25 watt element in it to monitor the output power and also to measure the reflected power, which barely even nudged the meter. It was effectively zero watts reflected. In the photo above, I was in a transmit cycle and you can see the power meter just a touch above 5 watts. On the computer, you can see a mini pile-up of six hunters in the queue. One thing to note about the QDX is that you can’t adjust the power by lowering the PWR slider in WSJT-X. It’s recommended to leave that at maximum. The way to adjust output power is to adjust the power supply voltage. In this case, the Bioenno had a full charge, so the radio was running full power.

I began the activation without spotting myself, just to see who’d hear me. Here’s a map of the pskreporter showing my spots.

I eventually spotted myself so hunters would know what park I was at. I was amazed that during my activation, I never ran dry or had to call CQ POTA, there was a steady stream of hunters the entire time. The QDX does a fine job receiving, here’s a screenshot of WSJT-X including the waterfall to show what it was receiving.

So, how did the $69 radio do? In a one hour and 17 minute activation, I completed 46 FT8 QSO’s. Here’s my coverage map.

I managed to complete three park to park QSO’s, too. One park called me and I called the other two who heard me and answered. I use JTAlert which helps me keep track of the order of who called. I always try to answer the hunters in the order they called me. I’ve set up a Directed CQ alert in JTAlert for anyone calling “CQ POTA” which helps me to see who else is at a park while I’m activating. If I’m able to contact them, I use the POTA spot list to include their park number in the SIG_INFO field of my log, which is N3FJP. N3FJP is handy to use since I start a new log for each activation and I’ve configured it to upload to LOTW and QRZ when I’m done for the day.

Another thing worth noting is that there is no speaker on the QDX. I’m one of those digital operators who actually listens to the cycles while I’m on the air. It provides a certain cadence to hear each cycle go by so you know what to be looking at or clicking on and when. With no sound coming out of the QDX, it forces you to find that cadence by looking at the computer screen. For me, it means watching the receive audio levels and the progress bar to see if I’m transmitting or receiving. The QDX does have a single red LED on the front panel that will flash during transmit cycles, which is also a helpful indicator.

I’d say the results shown here speak for themselves. I had a steady stream of hunters, I had just one or two QSO’s that needed a second RR73 to confirm and the coverage was as good as most activations I’ve done with more expensive radios and more power. Despite the self-inflicted hiccup I experienced at the beginning, I’d say that If you’re looking to try activating digital for Parks On The Air or even for your home, the QDX certainly works very well and provides a lot of value for the money.

New Year’s Day POTA: New VK3IL Pressure Paddle, New FT-817/818 Narrow Filter, and New TPA-817 Pack Frame!

I try to start each year by doing a POTA or SOTA activation on New Year’s Day.

POTA actually issues a certificate for completing an activation on New Year’s Day so there are typically loads of activators and hunters working the bands. It’s an ideal time to play radio.

This year, we had a number of family activities on New Year’s Day, but I made a little time to fit in an activation during the late afternoon at my most accessible spot on the Blue Ridge Parkway: the Southern Highland Folk Art Center.

As with my last activation, I suspected I would be operating in the dark, so I brought my LED lantern along for the ride.

Although not intentional, this New Year activation had a lot of new-to-me stuff involved!

New VK3IL Pressure Paddle

The prior evening–on New Year’s Eve–while my wife and daughters were watching a classic movie movie marathon, I used the time to heat up the soldering iron and work through a few kits and projects that had been sitting on my desk.

One of those projects was a Pressure Paddle designed by David (VK3IL).

Michael (G0POT) sent me the Pressure Paddle circuit board and heat shrink via Andy (G7UHN) several months prior. [Thank you so much, fellas!]

To my knowledge, the VK3IL Pressure Paddle isn’t available in complete kit package, but it’s quite easy to source everything yourself.

On his website, David provides the Gerber files you’ll need in order to purchase the circuit boards from your favorite manufacturer (I’m a huge fan of OshPark here in the States).

Next, you simply need to order the components. Here’s the list assuming you’re using DigiKey:

  • Quantity of 2: 732-7579-1-ND (CAP CER 10000PF 10V C0G/NP0 0805)
  • Quantity of 2: BSS806NH6327XTSA1CT-ND (MOSFET N-CH 20V 2.3A SOT23-3)
  • Quantity of 2: 311-470KCRCT-ND (RES 470K OHM 1% 1/8W 0805)
  • Quantity of 2: 1738-SEN0294-ND (RP-C18.3-ST THIN FILM PRESSURE S)
  • Quanity of 1: Three conductor wire with a (typically) 3.5mm plug (note that I had one of these in my junk drawer)

Keep in mind: the components are surface-mount. If you’re not used to working with SMD components (ahem…that would be me) I suggest buying a few spares of each in case you lose or damage one or more during the build.

It also helps to cover the finished board in heat shrink not only to protect the board and make it easier to grip, but most importantly (if you’re me) hide your electrically-sound yet unsightly surface mount soldering job.

The build might have taken me 20 minutes.

New FT-817ND Narrow CW Filter

Some time ago, I purchased a second FT-817ND with the idea of doing full-duplex satellite work. I later realized I could be taking the second FT-817ND out to the field more often if I simply had another narrow CW filter installed, so I built one.

This New Year’s Day activation was actually the first time I’d taken this particular FT-817ND and its new narrow filter out to the field!

New Armoloq TPA-817 Pack Frame

Earlier this year, I also decided that I wanted to outfit my 2nd Yaesu FT-817ND with an Armoloq TPA-817 pack frame. The idea was to experiment with building a rapid-deployment field kit around it.

This is actually one of the big projects I’m working on in 2023. I’ve yet to sort out the antenna mount I’d like to use with this frame based on how I plan to deploy it. Continue reading New Year’s Day POTA: New VK3IL Pressure Paddle, New FT-817/818 Narrow Filter, and New TPA-817 Pack Frame!

QRPer Notes: TR-45L Overview by K2OM, 8 Year Old Isabella Works the ISS, and POTA with the CW Flea

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!


K2OM’s overview of the Penntek TR-45L (YouTube)

Click here to view on YouTube.

Tony (K2MO) adds, “I suggest adding this link to your TR-45L [videos in the field]


Isabella Payne’s amateur radio contact with NASA astronaut Kjell Lindgren on the ISS (YouTube)

Click here to view on YouTube.


POTA with the CW Flea/Belka twins (AE5X)

Check out this short article by John (AE5X) where he uses a CW Flea transmitter and Belka-DX receiver for a QRPp POTA activation. I love what John’s done here and I think I may have to give the CW Flea a go too someday.

Here’s the video that accompanies his blog post:

QRP by Lantern Light: A CW/SSB sunset POTA activation at Lake James State Park

The one thing about doing POTA activations in the winter is being aware of just how short the days are. It seems like, lately, I’ve had a number of activations that have spilled over well beyond sunset.

With POTA, running out of sunlight really isn’t a big deal. As long as I have a headlamp (I always do) and/or a lantern, I can continue operating as long as the park is still open to guests.

With SOTA, running out of sunlight can develop into a serious situation, especially if you’ve bushwhacked to a summit in unfamiliar territory. Even with a headlamp, it can be difficult finding your way back to an established trail.  I’ve never scheduled a SOTA activation that pushed sunset unless I’m comfortable with the path to the summit.

If I’m being honest, I think a part of me actually enjoys doing POTA activations after sunset. It feels a lot like camping.

On Sunday, December 4, 2022, I was on the road once again and could not help but squeeze in a POTA activation at Lake James State Park.

It was late afternoon and I knew I’d be pushing sunset, but I had my little LED lantern just in case I ran out of sunlight (hint: I did!) and I was ready to play some radio: both CW and SSB!

Lake James State Park (K-2739)

It was a grey, chilly day and there were no other cars in the parking lot at the Catawba River Access. I had the whole park to myself until closing time at 7:00PM.

I chose a picnic table by the lake, putting some distance between me and the visitor’s center which has been known to spew radio interference (QRM) in the past.

I brought along my Elecraft KX3 for this activation.

The KX3 is one of my top field portable radios, but I rarely take it to the field these days for a couple reasons:

  1. It’s my main shack radio and is hooked up to my KXPA100 amplifier 100% of the time (although I rarely run enough power that the amplifier engages). I do much of my park/summit hunting from home with the KX3.
  2. Since I purchased my KX2 in 2016, I tend to take it to the field instead since it’s *that* much more portable. It’s like a smaller version of the KX3 with nearly the performance and only lacking 160 and 6 meters.

But I do love my KX3. It’s a benchmark radio–and one of the best field transceivers on the market.  You will see a few field reports with it each year since I try to give all of my radios a regular dose of fresh air!

Setting up

After recording the intro to my activation video (which I tried to do before the sun actually set), I decided to film the antenna deployment as well.

I debated which antenna to use at the site. I decided upon the super easy-to-deploy 28.5′ “no transformer” random wire antenna by Tufteln (see link in the Gear section below). I first demoed this super simple antenna on Mount Mitchell during a SOTA activation. It’s basically two lengths of 28.5 foot 26 AWG wire connected to a BNC connector on a small 3D printed mount which provides strain relief.

This antenna is basically my super simple speaker wire antenna, just in a more compact form factor.  Since there’s no transformer, the antenna relies on an ATU to do all of the heavy work of sorting out impedance matches. Continue reading QRP by Lantern Light: A CW/SSB sunset POTA activation at Lake James State Park

Can you ID this QRP SSB radio? (Update: solved quickly!)

Many thanks to Todd (KH2TJ) who writes:.

Hey have a question about a QRP radio that a friend of mine acquired from an SK estate. I was thinking this radio might be a Mountain Topper or maybe one of an early N6KR radios, but a search has come up empty. Maybe you could help identify it? Thanks in advance for any info:

Todd’s friend also noted:

It works on the phone portion of the 20 meter band with about 5 watts out. When the “Spot” button is pressed the radio reports the tuned frequency in CW.

I’m not terribly familiar with SSB QRP transceivers. Perhaps a QRPer reader can chime in with an answer for Todd? Please comment!

UPDATE:

This was solved rather quickly by readers. This is, of course, a White Mountain Series SSB Transceiver by the amazing Dave Benson (K1SWL)!

As soon as I read the first reply, it jogged my memory. I believe the photo Todd sent above face-on threw me a bit; I think I would have recognized more readily had it been a shot showing the size of the radio.

Dave (K1SWL) is a regular here on QRPer and he might even have more comments about this fine mono-band SSB radio!

Long Island CW Club featured on BBC Radio 4 PM

Many thanks to a number of readers who noted that Howard (WB2UZE) with the amazing Long Island CW Club was interviewed on the BBC Radio 4 program PM.

Although the show has already aired, you can listn to it for the next few weeks on BBC Sounds by clicking here.

Note that the segment with Howard starts at 51:42.

Keith’s Recording

Update: Many thanks to Keith (GW4OKT) who captured this live, off-air recording of this segment via his Icom IC-705:

Click here to listen on YouTube.

Pairing the Penntek TR-45L and PackTenna 20M EFHW for a Quickie POTA Activation

We need to do a little time-travel in this short field report…

In 2022, I accumulated so many activation videos that I have a small backlog and some that got lost in the shuffle. The following activation report is one that I meant to post in November, but it got lost in the shuffle.

So let’s time-travel…

On October 20, 2022, I pulled into Tuttle Educational State Forest to enjoy quick a POTA activation with my Penntek TR-45L.

I remember now that I wanted to hold off publishing this video until John (WA3RNC) at Penntek had time to ship the bulk of the radios from his first production run of fifty units. Demand has been very high for this sweet rig and for good reason: it performs brilliantly, is fun to use, sports amazing audio, and (with its Apolloesque design) strikes the right nostalgia chord for many of us.

Tuttle Educational State Forest (K-4861)

I had a very short window to do this activation–a maximum of 45 minutes or so.  You see, I still had a good 1.5 hour drive back to the QTH and needed to pop by the post office to pick up parcels before they closed at 17:00 local.

I had planned to pair the TR-45L with my PackTenna random wire antenna and use the 45L’s Z-Match tuner, but I discovered I’d packed the PackTenna 20M EFHW instead.

No problem there as the PackTenna 20M EFHW is very efficient and (of course) resonant on 20 meters, so I needed to make sure the TR-45L’s ATU was bypassed before hopping on the air! Continue reading Pairing the Penntek TR-45L and PackTenna 20M EFHW for a Quickie POTA Activation

Conrad packs the Elecraft KX3 and AX1 for a New York City POTA Rove

Many thanks to Conrad (N2YCH) who shares the following field report:


New York City Park Rove, December 30, 2022

Conrad Trautmann, N2YCH

After being bitten by the Parks On The Air (POTA) bug, I became an activator in early 2022. I was hooked. Digital, and specifically FT8 & FT4, is the mode I prefer. A lot of experimentation ensued until I was able to refine my POTA setup to an Icom IC-7300 powered by a Bioenno 20ah battery mounted in a four rack unit Gator case and a Buddipole dipole antenna on a push up mast.

As a radio broadcast engineer by trade, I was very focused on maximizing performance and coverage and after much refinement and trying different things, I feel like my POTA kit performs well. I’ve made contacts as far away as Indonesia, Japan and Israel using the POTA setup in a park… so mission accomplished.


The POTA kit above is not something I can easily take with me on a business trip however, especially by air, so I turned my sites to a Xiegu G90 and various end fed half wave antennas and fiberglass masts and more Buddipole parts to pack into my carry-on luggage. Now I could activate parks wherever I could fly to and I’ve completed successful activations in Wisconsin and Georgia.

Still, I needed to pack a second bag and check the luggage to do these trips. What I really wanted was something I could carry on the plane with me.

I knew I had to change my point of view on what I could achieve using a portable kit. A small radio and antenna wasn’t going to get me contacts in Indonesia, but I could transmit far enough to have someone hear me and get my ten contacts to activate a park. Researching my options online constantly brought me to videos and blog posts here on QRPer.com. Thomas loves his Elecraft KX2 and in a few field report videos he demonstrates an Elecraft AX1 antenna connected directly to the radio for some fast CW POTA activations. This setup was appealing because of the size and he always has a successful activation.

I researched the Elecraft options and the KX3 seemed like the right radio for my digital activations. It has a DATA mode, it can run split operation, it’s got a wideband filter setting and while Elecraft only recommends 5 watts for data modes, it can do up to 10 watts. I managed to find and purchase one gently used on eBay.

I installed the Pro Audio Engineering Kx32 aftermarket heat sink to be sure I protected the final output transistors from overheating and use a Signalink model USB SLUSBKX3 as a sound card interface to the computer. The Signalink can key the radio using the audio keying feature, but I chose to use the Elecraft KXUSB cable to use CAT control and let WSJT-X key it instead. It also allows WSJT-X to read and control the radio’s frequency for easy band changes. I have a Bioenno BLF-1209A 9Ah battery to run it rather than use the internal batteries and I haven’t come close to running the battery out on an activation yet.

Then I bought the Elecraft AX1 antenna with the 40 meter AXE1 optional antenna extender and the AXT1 tripod adapter. It is tiny. There’s really no other way to describe it. It’s a little, baby antenna. Fully extended, it is about four feet tall. I was highly skeptical of how this might perform given its size. I’m using a 25’ Buddipole RG-58 A/U 50 ohm MILSPEC-17 cable terminated to BNC connectors to get the antenna away from my computer because I’ve found that RF and USB do not play well together. I typically try to get the antenna situated in a nearby spot, with a little distance between it and the computer. I bought the Maxpedition Fatty Pocket Organizer Thomas suggested on QRPer.com and a little Amazon Basics Lightweight Mini Tripod.

The AX1, the adapter and tripod all fit in the organizer with room to spare and it fits into a backpack with the radio, battery, cables and my Lenovo Thinkpad 3 laptop. I’m also able to fit in the the Bioenno battery and laptop chargers. At the urging of my XYL, I also have a printed copy of my license in the backpack, too. I haven’t had to show it to anyone yet, but I’m ready, just in case. The backpack is a Mindshift model 18L, designed for photographers, but is easily adapted to contain all of the components I need for a portable activation. Here’s a photo…

So now I’ve got a completely self contained POTA kit in a backpack that can be carried aboard a plane. Continue reading Conrad packs the Elecraft KX3 and AX1 for a New York City POTA Rove

Breaking in my new-to-me Elecraft K2 and CW Morse SP4 paddles during a POTA activation

Radio addiction is a real thing.

We addicts often justify purchases knowing that, in the world of amateur radio, we can always sell gear we’ve purchased without losing too much money each time.

At least, in theory!

In November, last year, I was in touch with a friend who I recently purchased my second KX1 from; turns out, he had an Elecraft K2 he was willing to part with, as well. This is a radio he built (thus, the workmanship is top-shelf) and had updated over the years to be fully loaded the way I would want it myself: all firmware upgrades, all important upgrades for CW and SSB operation, and an internal ATU.

His was also a 10 watt (QRP) version of the K2; Elecraft owners call these “K2/10s.”

My first K2/10 next to the TEN-TEC Argonaut VI I was Beta testing at the time.

I owned a K2/10 between about 2008 and 2016. I sold the K2/10 to purchase another radio. The week after selling my K2/10, a local ham offered me an insane deal on a used K2/100 (a version with a 100W amp) from a club estate sale. No one in our local club wanted it and he really wanted to unload it. I purchased it and for a good three years it was my only 100 watt radio.

My K2/100

Then, in 2019, I sold the K2/100 for $800 and purchased an Elecraft KXPA100 amplifier with ATU for $800 to pair with my KX2 and KX3.

Using my KXPA100 during Field Day in 2020.

I’ve never regretted that decision because I do love the KXPA100 amplifier, although I seldom use it (so much so, I’ve even considered selling it). To date, it is the only device I own that outputs 100 watts.

I did miss the K2. It’s a fantastic radio to take outdoors and has superb receiver chops for the most demanding, RF-dense conditions.

When my buddy offered up his K2, I couldn’t resist. I made myself a goal, though: I had to sell enough stuff to fund the purchase. My friend was good with this. Even though I could have paid him immediately, I asked if he could wait for payment and shipping until I had gathered the funds from sales. I needed that dangling carrot because, frankly, I dislike selling things; I’d rather give away or donate stuff, but I did need to raise funds for this purchase. Continue reading Breaking in my new-to-me Elecraft K2 and CW Morse SP4 paddles during a POTA activation

POTA in Poland: Damian activates five parks in five hours

Many thanks to Damian (SP9LEE) who shares the following field report:


Field Report: 5 Parks in 5 Hours

by Damian (SP9LEE)

Okay, to be totally frank with you and as not to lose your trust, I have to admit that the title, however technically 100% true, may be slightly misleading. If you’re wondering to what extent, I suggest you keep reading 😉

I live in Krakow, the second-biggest city in Poland, and I’ve always complained about not having enough green areas there. But starting my QRP outdoor adventure and joining the POTA program helped me realize that I couldn’t be more wrong. I live in the city center (20 minutes walking distance from the Main Square) and as it turns out, there are 11 POTA parks within a 20-minute drive (outside rush hours, of course), and around 30 if you decide to drive 40 minutes.

That’s just crazy, especially compared to the places where some POTA Brave Souls live, giving Thomas (K4SWL) as an example – a few dozen activated parks, but only a couple of them in close range. Mine I could reach by foot or bike! I don’t like to waste anything (not only tangible goods, but also opportunities or this great potential that a lot of nearby POTA parks give), so I rolled up my sleeves and started activating one by one in May 2022.

But when December 31 comes, it tends to provoke reflections of the happenings in the last year. This happened to me as well. I asked myself: “Hey, isn’t it also a waste if you have a few parks clustered and never try to do them all in one day?” As you read this, you already know what the answer was. I decided not to hesitate and do it as soon as possible, on January 2nd, 2023.

Since I’ve never tried to do more than one activation per day, I felt quite insecure. What I do like during an activation is to practice quick antenna deployments (this may be useful one day), then experiment with different antenna configurations (such as sloper angles, heights, azimuths, counterpoise placement), and finally make as many contacts as possible during a given time limit. This time limit is usually set by my family schedule or other errands I need to run.

As you can see, that’s the complete opposite to the requirements that RaDAR or POTA Rover awards make: proficient antenna deployment, gathering 10+ QSOs for a valid activation, collecting the equipment, and speedy drive to a next spot. Sounds challenging? But isn’t it what the New Year usually brings? It’s just a matter of making proper adjustments in one’s procedures and attitude. At least, that’s what I thought.

I picked three park entities 20-25 minute car drive from my home, which in total would give me 5 POTA references:

  • SP-0997 Kowadza Protected Area (3-fer)
  • SP-0994 Skołczanka Nature Reserve (3-fer)
  • SP-2274 Skawiński Obszar Łąkowy Natura 2000 (2-fer)

They are all located on the territory of Bielańsko-Tyniecki Lanscape Park (SP-0993) and/or  Dębnicko-Tyniecki Obszar Łąkowy Natura 2000 (SP-2122). So now you know why the title might be a bit misleading – I actually planned to take advantage of having 2- and 3-fers around and work 5 entities in total from only 3 different spots.

Kowadza Protected Area (SP-0997)

I hopped into the car just after I left home (yes, some of us have work or school duties… and some of us have a day-off to play radio!). I’ve never been to the Kowadza Protected Area, so even after researching it on Google Maps, I wasn’t sure what to expect. Besides my standard set, I also packed my fiberglass 6m fishing rod in case there was no convenient place to mount the antenna, and my portable PV panels in case the LiPo 5Ah battery died. Continue reading POTA in Poland: Damian activates five parks in five hours