Category Archives: QRP

QRPp POTA: How many hunters can I possibly log with only 100 milliwatts–?

As I walked out the door on the morning of Tuesday, March 21, 2023, I grabbed my Elecraft KX2, MM0OPX 40 meter end-fed half-wave, and a key I hadn’t yet taken to the field: my Bamakey TP-III!

I had a full day of errands, appointments, and carting my daughters to/from school, but I also had a good 90 minute window to play radio!

As I’ve mentioned previously, the Vance Birthplace (K-6856) is incredibly convenient this particular school term. I pass by it twice a week, and I feel incredibly fortunate because it’s a wonderful POTA site with POTA-friendly staff. They all know me quite well there at this point.

The Vance site is a small park and the only negative (from the point of view of a POTA activator) is if you have poor timing, you might arrive only to find that a large school group has taken over the site. This is especially a concern on weekdays during school hours–in other words, the time I usually activate Vance.

I pulled into the Vance site that morning and there were no vehicles there other than park staff. A good sign so far!

The only appropriate spot to activate at Vance (if you operate a portable HF station) is in or near the picnic shelter. The rest of the site is where visitors wonder through the old homestead and take guided tours.

I never set up my station in the middle of park activities or in a viewshed.

At the end of the day, we represent all Parks On The Air activators and the amateur radio community at large when we’re in public spaces. The last thing we want to do is detract from others’ park experience.

Before pulling any gear out of the car, I walked into the visitor center and asked the park staff for permission to set up in the picnic shelter. I always do this because if a school or tour group is scheduled to visit the site that day, they almost always need the picnic shelter and have it reserved.

Fortunately, no one had scheduled the picnic shelter, so the park ranger told me, “It’s all yours! Have fun!

Proper POTA Flea Power!

I like shaking up each new activation in some small way so that it’s not a carbon copy of any previous activation.

Since, like most POTA activators, I visit the same local parks the bulk of the time, it adds a little extra challenge and fun to try different gear combinations, experiment with new antennas, or even (as in this case) try different power settings–! Continue reading QRPp POTA: How many hunters can I possibly log with only 100 milliwatts–?

Quick test of a homemade 20-meter band antenna at a beautiful POTA location

by Thomas (DM1TBE)

Intro

You may, or may not, know the situation when you are invited for the birthday of your mother-in-law and the whole day is just a chain of meals. As the SOTA activation of the Wasserberg the day before was rather short, I needed to escape and do something outdoors. An antenna test at a nice POTA location would be perfect.

When I started with amateur radio, many fellow hams told me that a real ham must build its own stuff. This is not easy when you have 10 thumbs like me. However, from time to time I try smaller projects. When I am operating portable, I usually have a 10 m / 33 ft mast with me. I have a 30/15-meter- and 12/17-meter band antenna, both with coils and shorter than my mast, and a homemade 10-meter band antenna which I can raise vertically on my mast. A mast with one of these wire antennas can be used on most of the locations I have visited.

However, I was missing something for the 20-meter band. I have a 10 – 80-meter 5 band antenna that covers 20-meters, but raising it as a sloper with a length of app. 24 m / 79 ft is tricky sometimes.

Building

So, I thought it would be a good project for me. As a half-wave for 20-meters is exactly the length of my mast, and I did not want the feed point at or too close to the ground, I wanted to add a short coil. I had a finished 1:49 mini-impedance transformer from K6ARK available from a project I’ve never finished. So, I just needed a screw, a cable and a piece of a PVC electrical conduit.

I have cut the PVC electrical conduit in three parts, one for the coil, one for the upper-end to allow easier mounting at the mast, and one for a simple strain-relief. My wife was a bit nervous when I used her best knife for cutting it, not sure if she worried about me or her knife. The dimension of the coil is based on pure guess. Bringing the whole antenna then into resonance was easy – just cutting step by step. After completing, the antenna still looks a bit makeshift.

Testing

So, I used an opportunity between two meals to leave my mother-in-law’s birthday and drove to the next POTA park, which is the Kaltes Feld (DA-0410). However, this time I did not go to the SOTA southern activation zone for Kaltes Feld (DM/BW-659), but to the opposite direction, where I have not been before.

The weather was nice, and the way was without any ascent. Behind me, a bit higher, was the SOTA summit Kaltes Feld and on the right the SOTA summit Bernhardus (DM/BW-848).

On Google Maps, I have seen that there is a viewpoint with a wooden bench and table. It was not too hard to find, and the place will probably become one of my favorites. Continue reading Quick test of a homemade 20-meter band antenna at a beautiful POTA location

Finally did it! First POTA activation with my new-to-me Yaesu FT-891

Yep. I finally did it.

Over the past few years, I’ve received numerous requests to check out the Yaesu FT-891 HF transceiver. Almost all of my ham friends have one and they are widely considered one of the best 100 watt HF radios for park activators. Indeed, I bet it is *the* most popular 100W radio among POTA activators.

I’ve been tempted to ask Yaesu for a loaner model and I even came within one button click of ordering a new FT-891 from DX Engineering during a Black Friday sale in 2020.

I’ve resisted the FT-891 temptation, though, because I tend to use smaller, more portable QRP radios in heavier POTA rotation. I knew if I purchased an FT-891, it just wouldn’t get a lot of field use. It also demands a beefier field battery due to its current requirements and, frankly, it’s so rare I run more than 5 watts (and 5 watts is the lowest power setting on the ‘891) I would simply have a lot of radio for my needs.

A few weeks ago, however, a friend reached out because he wanted to sell his FT-891 and 30Ah Bioenno battery and downsize to a smaller field portable radio like the Xiegu X5105. Long story short, we worked out a trade/purchase which included the ‘891 and his battery. I had been thinking about a large capacity battery to use as a backup in the shack, so this worked out well for both parties.

Zebulon B. Vance Birthplace (K-6856)

On Tuesday, March 14, 2023, I once again had an hour to fit in an activation at the Vance Birthplace before picking up my daughters at school. I’ve really enjoyed the opportunity to play radio at Vance so much during this particular school term; next term, it’s unlikely I’ll have this opening, so I’ll enjoy it while I can!

I deployed the Chelegance MC-750 vertical again. I’ll admit that it’s so convenient keeping an antenna in the car trunk/boot that can be made resonant so easily from 40 meters and higher.

I was going to show the antenna deployment again in my activation video, but received a call and decided to deploy the antenna while finishing up the phone call. It only takes a couple of minutes to set up.

Next, I connected my 15Ah Bioenno battery to the FT-891. Even though I was only using five watts, the ‘891 needs more capacity than the 3Ah packs I normally carry with my QRP rigs.

I also connected the Begali Traveler key–I do love this key (thanks again, Jackie!). Continue reading Finally did it! First POTA activation with my new-to-me Yaesu FT-891

SOTA with two PAC-12 antennas in a JPC-7 dipole configuration on the Wasserberg

Berndm aus g, CC BY-SA 4.0, via Wikimedia Commons

by Thomas (DM1TBE)

Intro

Nearly a week has passed since my last activation and the AWS–the Activation Withdrawal Symptoms–started to kick in. Furthermore, I received an antenna during the week which I wanted to try. However, the weather was unsettled, and showers were forecasted over the whole weekend. This did not prevent me to try at least an activation with the new antenna.

So, I started to the Wasserberg (DM/BW-664) on an early Saturday morning. The summit has a height of 750 m / 2460 ft and a wooded peak. The parking place is already elevated, so there was only 1.6 km / 1 mi left to walk with an ascent of 166 m / 540 ft.

The peak is wooded, but you can enjoy the view at the beginning of your hike, just after parking.

The trail is well-developed and easy to walk, except for the high incline at the beginning.

You come along something that looks like an old wall, but it is probably a place where stones have been taken from in earlier times.

The forest still looks like winter, and you can see the landscape through the trees

But if you look close enough, you see that the spring is not too far anymore.

Although the way to the peak diverts from the well-developed trail half way, I followed the way to visit the Wasserberghaus (it basically means “house on the water hill”, with “water hill” being the name of the hill).

Europe has an extensive hiking network. It ranges from European long-distance paths, with trails up to 10,000 km / 6,200 mi, over national routes to small hiking path networks operated by local municipalities. This is a hiking guidepost at my trail to the summit. Continue reading SOTA with two PAC-12 antennas in a JPC-7 dipole configuration on the Wasserberg

Propagation changes make for a relaxed 17 meter POTA activation at Pilot Mountain State Park

On Saturday, February 18, 2023, I had a rare opportunity: a full day to play radio.

Instead of doing a five park POTA rove, I chose instead to do a summit activation followed by a park activation.

I published the summit activation on Moore’s Knob (W4C/EP-001) a couple weeks ago and planned to immediately follow that up with this report from my POTA activation at Pilot Mountain State Park (which I activated the same day).

In the process of moving my videos from the camera, to my laptop, and then to PC where I do my remote uploads (my bandwidth at the QTH is far too poor to upload large videos) I somehow managed to delete this particular video file.

I was quite frustrated, actually, because this particular POTA activation was challenging. Lately, I’ve had so few examples of just how quiet a band can be when propagation is less stable.

The SOTA activation I performed only a few hours earlier had some of the deepest pileups I’ve ever experienced. By the time I started my POTA activation a couple hours later, all of this had changed–at least on the bands above 20 meters and I’d chosen 17 meters (a WARC band) since a contest was in progress on 20 and 40 meters.

I’m incredibly pleased that I stumbled upon the raw video files on my backup drive. I was able to reproduce the video in its entirety.  I’m so pleased it wasn’t lost!

This is why it’s a little out of sync date-wise with my other reports.

I hope you enjoy this field report:

Pilot Mountain State Park (K-2750)

After capping off a beautiful 4+ mile hike and SOTA/POTA activation at Hanging Rock State Park, I put my SOTA pack in the car and drove 30 minutes to Pilot Mountain State Park.

It being a gorgeous Saturday afternoon, the park was so full of guests the parking lot was completely full.  A park ranger had incoming cars form a line and he allowed cars in as guests departed one by one. When I arrived, there were five cars in front of me. I was very tempted to do a three-point turn and head back down the mountain to the visitor’s center to do the activation. There was plenty of parking there. Continue reading Propagation changes make for a relaxed 17 meter POTA activation at Pilot Mountain State Park

From idea to kit: Adam introduces the Arduino Digital Modes HF QRP Transceiver (ADX-S) kit

Many thanks to Adam (BD6CR) who shares the following guest post about his latest project:


From Open Source Project ADX to Kit ADX-S

by Adam (BD6CR)

BD6CR @ CRKits.COM

Original Design: WB2CBA

Modification and Kitting: BD6CR

I knew Barb, WB2CBA from his uSDX design a few years ago and I introduced both DL2MAN and his designs in my blog. So, when I came across the ADX – Arduino Digital Xcvr a few months ago, I immediately ordered both the ADX (through hole) and the ADX UNO (surface mount) PCB samples.

I started building the ADX UNO and put it in a dental floss case and made a few contacts on park bench. However, the soldering is too much for my eyesight. So, I turned back to the ADX because I don’t need to solder any SMD parts, since both the M328P and SI5351 are module based. I could build the project in 3 hours and it worked the first time.

However, I felt unsatisfied with the strong BCI since the CD2003 radio receiver chip was connected as a direct conversion receiver. JE1RAV mentioned in his QP-7C modification project that he tried JA9TTT’s idea to build a superhet SSB receiver with the TA2003 or CD2003, so I tried and it worked very well. I have decided to name the new circuit as ADX-S, where S stands for Superhet.

I shared the great news with Barb and he encouraged me to carry the flag to make it a kit, since my design D4D was his first digital radio and he loved it.

You can refer to Barb’s page on ADX here.

My hardware modification can be outlined in this schematic. I have added an FL1, PFB455JR ceramic filter by Murata and a C25 coupling capacitor from CLK2 of SI5351 module. The RX audio comes from pin 11 instead of pin 4.

I modified it by cutting two traces on the ADX PCB and it looked ugly, so I redrew the PCB. Continue reading From idea to kit: Adam introduces the Arduino Digital Modes HF QRP Transceiver (ADX-S) kit

Guest Post: Extreme QRP–Testing the AX1 with WSPR and 20mW

Many thanks to Keith (KY4KK) who shares the following report:


Extreme QRP – Testing the AX1 with WSPR and 20mW

by Keith (KY4KK)

Thomas, thanks for all of your activation videos related to the Elecraft AX1 antenna.  I ordered one the day you announced the package deal, and it arrived in less than a week.  I’ve activated a few parks with it already (20m SSB).  Like you and many others, I’m impressed.

I was very interested in Thomas Barris’ (DM1TBE) March 12 QRPer post using WSPR to test his POTA antennas in Germany.  Then I saw Bob’s (K7ZB) post about his ZachTek Flea with 300 milliwatts in CW mode.  To me, extreme QRP represents some of the magic of HAM radio.  I’d like to share one of my most recent WSPR experiments related to the AX1.

About a year ago, a friend (NG4S) loaned me his pair of WSPR transmitters and suggested that I explore building and comparing antennas. I’ve been hooked on antennas of all kinds and WSPR since then.

I began doing WSPR tests on the AX1 the day after it arrived.  With two transmitters set to the same frequency and power output, you can do direct comparisons between two antennas under identical propagation conditions.

I’ve already done a couple of comparisons between the AX1 and other commercial antennas.  But I think the test I just completed might be of particular interest because it pits the AX1 against an antenna I’ve seen you use many times – a 28.5’ end fed with a 28.5’ counterpoise.  I used 24 AWG silicone insulated wire. The end of the radiator was placed on a 19’5” telescoping fishing pole.  This is my preferred POTA mast when I can’t use a tall tree.

I spent some time trying to control other variables so that the only significant difference during the test would be the antennas themselves.

For example, the SOTA Beam WSPRLite Classic transmitters don’t have an ATU.  So, I had to make the antennas resonant on the 20-meter WSPR frequency of 14.097 MHz.  For the AX1, Thomas’ videos helped a lot.  I used a clip-on capacitance hat and adjusted the counterpoise to 15’ 2”.  This gave me an SWR of 1.17:1.  For the end fed, I tried the two UNUN’s I had available and settled on the 49:1, which got me the closest (2.2:1).  I then used a manual tuner to achieve an SWR of 1.29:1.

I also wanted to deal with the difference in power output between the two transmitters.  Although they’re identical, and both set to 20 milliwatts, there is no way to ensure both are actually producing that output level.  Based on tests by NG4S, one of the transmitters runs at 19 milliwatts.  The other actually outputs 27 milliwatts.  So, my plan was to run the test for 48 hours. At the end of 24 hours, I would switch the transmitters (and callsigns) so that both antennas would benefit (relatively equally) from one of the transmitters being stronger.

At the end of Day 1, I reviewed the data from the two transmitters on dxplorer.net/wspr.  The end fed averaged a 5.7 dB gain over the AX1 based on reports from receiving stations that spotted both transmitters in the same 10-minute block (simultaneous spots).

On Day 1, the stronger transmitter was on the end fed.  The maps below are from WSPR.rocks.

AX1 – Day 1

End Fed – Day 1

I was pretty impressed that the AX1 got into Europe and Africa on only .019 Watt!  I always have good luck with end feds, so was not too surprised to see this one perform well. Continue reading Guest Post: Extreme QRP–Testing the AX1 with WSPR and 20mW

QRP POTA from 10 to 20 Meters with the Chameleon Tactical Delta Loop and Icom IC-705

I do my best to shake up each field activation I perform. Even if in some small way.

While it would be way more efficient to deploy the same radio and antenna combination at each park and summit I visit, I get a thrill out of trying different radio and antenna combinations.

I should add that I’m fully aware how fortunate I am to have a lot of radios and even more antennas to pair in various combinations. I keep reminding myself that building and buying radios and antennas is still cheaper than restoring a 1940s era Willys CJ-2A.

Recently, a reader reached out and asked my opinion about the Chameleon Tactical Delta Loop (CHA TDL) antenna. I think the TDL is a brilliant antenna system, actually, and the one I recommend the most from Chameleon because of its versatility.

Not only can it be deployed as a multi-band vertical delta loop but it has all of the parts needed to be an MPAS Lite vertical as well, save the counterpoise.

The CHA TDL comes with a 25 foot wire that connects the two 17′ whips into a loop configuration, but the clamps on the end of that wire can’t connect to the ground lug on the MPAS ground spike terminal as-is. That said, you could easily make a short connector cable or connection point that would allow the CHA TDL wire to clamp to the ground spike terminal. Else, of course, you could cut a dedicated 25′ counterpoise from pretty much any wire you might have around the shack.

You can buy the same counterpoise used with the MPAS Lite package, but it’s more affordable just to build your own since there’s no magic in the counterpoise. And, FYI, configured as the delta loop, there’s no need for a separate counterpoise; only if you configure it as a vertical.

This same reader also has an Icom IC-705 and an mAT-705 Plus antenna tuner. He was curious how well that combo might work with the CHA TDL. I knew that the combo would work well, but I thought, “why not try it?”

I realized that it has been ages since I last deployed the CHA TDL in the field.

Zebulon B. Vance Birthplace (K-6856)

Tuesday, February 28, 2023, was a gorgeous day weather-wise, although it was a bit gusty at times.

I arrived at K-6856 and decided to film the full set-up of the CHA-TDL.

For an antenna with a fairly large profile when deployed, it’s actually very compact, albeit a bit heavy (mainly due to the weight of the solid stainless ground spike and TDL hub). That said, I did take this same CHA TDL setup on an 11 mile round-trip SOTA hike once and didn’t find it too heavy.

I placed my Icom IC-705 on the table in the picnic shelter and connected the mAT-705 to it with a 2′ BNC-BCN RG-316 cable and the ATU control cable. Continue reading QRP POTA from 10 to 20 Meters with the Chameleon Tactical Delta Loop and Icom IC-705

A story about a gluttonous dragon, a princess, a knight, and many DX contacts to the US from a volcano in Germany

by Thomas (DM1TBE)

Intro

If you have read my previous activation reports, you may remember that the temperature was more often than not below 0° C / 32° F. I am tired of the winter. So I was very pleased when the weather forecast indicated 18° C / 64° F on a Saturday.

In one of my previous posts (How I found the best antenna for my SOTA/POTA activations) I have outlined, that I like using the 30-meter band for being reliable on short and medium distances – in my case, Central Europe. However, I wanted to try an activation with an antenna that is more appropriate for DX. The wire winder for my 30-meter antenna had plenty of space left, so I decided using a commercial 12/17-meter band wire antenna that I have discussed briefly in the report linked at the beginning of this paragraph.

The day before, I built a 20-meter end-fed with parts that I found in my basement and a tiny 1:49 transformer from K6ARK. I added a short coil, so the feed point wouldn’t be at or too close to the ground when using my 10 m / 33 ft fiberglass mast. I know it needs some polish.

The Limburg

The Limburg is a conical summit about a 30-minutes drive from my home. It can be activated for a couple of programs like SOTA (DM/BW-110), POTA (DA-0203), WWFF and COTA.

The Limburg is, or better was, a volcano; technically, a volcanic vent of the Swabian Volcano, a volcanic area of 50 km / 31 mi radius with over 350 volcano vents. Seventeen million years ago, it produced massive gas and dust explosions. Be careful when ramming your antenna groundspike into the ground ;-). So it became a steep summit, elevated around 200 m / 650 ft over its surrounding area.

Earliest traces of population around the summit date to 3000–1800 BC.

Around the year 1050 Duke Berthold I., picture below, built one of the oldest Romanesque castles on the top of the summit. It was the seat of the House of Zähringen, who were related to the House of Hohenstaufen, about whom I wrote in an activation report here earlier: DM1TBE Field Report: Shivering with 18 WPM on the ruins of the medieval Hohenstaufen Castle

Around 50 years later, his son Berthold II. built a new castle some 150 km / 90 mi away and moved the seat of the family. Shortly thereafter, the castle was destroyed (probably, nobody knows exactly). It was rebuilt and destroyed again in 1130 and rebuild again. After the year 1150 a new, larger castle was built not too far away and this castle lost its importance and, eventually, gave up. Continue reading A story about a gluttonous dragon, a princess, a knight, and many DX contacts to the US from a volcano in Germany

Huge 30 Meter Pileups: Beautiful day for a SOTA & POTA Activation at Hanging Rock State Park

There are a few reasons I love Summits On The Air (SOTA):

  1. I love hiking.
  2. I love going truly portable with my radio gear; packing an entire minimalist station in my backpack along with first aid supplies, water, and a bite to eat, then hitting the trail.
  3. I love the views.
  4. I love the sense of accomplishment (hiking to a summit doesn’t happen every day).
  5. I also love that post-hike feeling–my body telling me, “Hey, T, thanks for doing something today!

No kidding: If I could, I would do a SOTA activation at least twice a week. Maybe when I retire, I will.

Living in the mountains of western North Carolina, I have no shortage of summits to activate–indeed, one is within (strenuous) hiking distance of my QTH.

So why don’t I activate more summits?

It’s because they are much more difficult to fit in my active schedule.

You’ll notice that the bulk of my POTA activations take place within a one hour window of time. This includes set-up, on-the-air, and pack-up time. The brilliant thing about POTA sites is that they’re so accessible in my weekly travels. (Plus, I absolutely love POTA too!)

My average SOTA activation, on the other hand, requires at least a three hour window of time. In fact, it’s usually much closer to four or five hours.

The view from Dogback

Drive-up summits like Anderson Mountain and Dogback Mountain are the exceptions. There’s no hiking time involved, so they are pretty easy to fit into my schedule.

On Saturday, February 18, 2023, a rare thing happened: an entire day opened up for me to play radio. The only real obligation I had was to set-up and participate in a live stream with Josh (KI6NAZ) on the HRCC channel that evening.

At first, I thought about doing a five park POTA rove, hitting four parks and one game land all that eight hour window of time. It was very doable and I knew it would be fun.

But then again, park roves allow very little time for hiking–typically, they’re wham-bam style short activations.  It was also a gorgeous day weather-wise so I scrapped the idea of a POTA rove. (This time!)

Instead, I had a hankering to do a SOTA activation and hike. I took a quick look at SOTL.as and remembered how much I enjoyed my last activation of W4C/EP-001 (Moore’s Knob) at Hanging Rock State Park (K-2753). And hey! It’s both a SOTA and POTA site!

It’s been nearly two years since I’d visited Hanging Rock SP because it’s a two hour drive in a direction I rarely travel.

Hanging Rock  a beautiful park and I truly enjoyed the hike to Moore’s Knob.

As a bonus, Hanging Rock State Park is less than a 30 minute drive to Pilot Mountain State Park. I knew I’d have time in the schedule to do activate both sites! Score!

Hanging Rock State Park (K-2753)

I pulled into Hanging Rock that morning and made my way to the parking area by the lake.

Since it had been nearly two years, I consulted the hiking trail map at the trail head to confirm I was taking the correct loop (Moore’s Wall Loop). Continue reading Huge 30 Meter Pileups: Beautiful day for a SOTA & POTA Activation at Hanging Rock State Park