Category Archives: QRP

POTA at Fort Dobbs: Testing a BCI filter and depleting a battery!

Friday, March 17, 2023 was a dreary, rainy day.

It was the sort of day made for reading a good book by the fireplace or…in my case…activating a park!

I don’t let rain stop me from playing radio in the field. I carry a rain fly in my car pretty much all of the time so if push comes to shove, I can create a dry space to play radio.

That said, a number of parks I frequent have large covered picnic shelters, so why not use what’s already there?

That particular Friday, I had one particular park and one particular goal in mind.

G106 + BCI Filter

As I mentioned in a post this weekend, I purchased and built a K9DP BCI Filter Kit.

If you’d like to see photos of the build, check out this post.

I built this BCI filter specifically to pair with the Xiegu G106 transceiver. Why? Because the G106 is prone to overload if you’re anywhere near an AM broadcaster.

The last time I visited Fort Dobbs State Historic Site (K-6839), a local AM broadcaster bled through the audio of the G106. I was able to complete the activation without any issues at all–in fact, it was a very successful activation (read the report here).

Still, I did feel that the receiver was a bit less sensitive due to the broadcaster overwhelming the front end of the radio.

That Friday, I wanted to pair my Xiegu G106 with the new in-line BCI filter to see if that might mitigate the interference I experienced before.

Fort Dobbs State Historic Site (K-6839)

After arriving at Fort Dobbs, and before taking my gear out of the car, I made my way to the park office (in the log cabin at the end of the sidewalk above) and asked for permission to use their picnic shelter. Continue reading POTA at Fort Dobbs: Testing a BCI filter and depleting a battery!

Brian’s Reflections on Activating a Not-so-New Park

Many thanks to Brain (K3ES) who shares the following guest post:


The Visitor Center at Kinzua Bridge State Park (K-1366) is well worth a visit.  It provides an excellent overview of the history, use, and collapse of the railroad bridge that gave the park its name, and it provides an excellent view of the pedestrian skyway built on the portion of the bridge that remained standing after the tornado that caused the collapse.

Reflections on Activating a Not-so-New Park

by Brian (K3ES)

Monday, April 3 was one of those beautiful, warmish (60ºF or 16ºC) sunny days in northwest Pennsylvania that remind us that spring is really here.  Only a week earlier, we had an unexpected snow fall that covered the ground (and it will likely not be our last snow of the season).  So my wife, her father, and the dogs all looked forward to getting out of the house to enjoy the weather.  We packed for a picnic, and drove through bright sunshine to Kinzua Bridge State Park.

After a picnic lunch, and while Becky and her dad explored the visitor center and walked the dogs, I set up for a Parks on the Air (POTA) activation of K-1366.  This would be my first activation of the park, but not my first visit.  I have been there several times before, including an excursion trip behind a steam engine that took me across the railroad bridge over Kinzua Creek and back.

A view from the visitor center of the pedestrian skyway.  It was constructed on the structure that remained after the bridge was struck by a tornado in 2003, causing its partial collapse.

An Historic Park

Kinzua Bridge State Park has an interesting history.  The railroad bridge that gives the park its name was originally built of wrought iron in 1882.  At the time it was built, the 301 ft (92m) high and 2052 ft (625m) long railroad bridge was the highest in the world.  It was rebuilt in place in 1900, replacing iron with steel, to strengthen it for the heavier trains that needed to cross.  The bridge remained in commercial service until 1952, and was later sold to the Commonwealth of Pennsylvania for a State Park.  The bridge continued to support excursion trains and pedestrian traffic until 2002, but was struck by a tornado in 2003, causing its partial collapse.  Today, the remaining part of the bridge has been rebuilt as a pedestrian skyway, complete with a glass floor at its end to look down at the valley far below.

The visitor center provides an excellent multimedia overview of the economics, technology, and history of the structure.  It is well worth a visit.  Similarly, the skyway gives a spectacular view of the structure, the collapsed towers, and the surrounding Pennsylvania forest.  The park has picnic facilities and hiking trails, and a trailhead for the rail trail that has repurposed the old railroad right-of-way.

This is a view of the picnic pavilion from my operating position.  The picnic area also has a number of other open picnic tables and a playground area for the younger crowd.

The Setup for Activation

I stopped into the visitor center to let the staff know of my intention to activate.  I found them to be friendly and accommodating, which always makes activating a pleasure.  I do my best to be a good ambassador for amateur radio and the POTA program.

For activating, I set up at a remote picnic table.  Three tosses got the throw line over a good branch to support my Tufteln 9:1 random wire antenna.  A 15 ft RG-316 cable connected the antenna to my Elecraft KX2.  Completing the station were a 3 Ah LiFePO4 battery, a set of generic earbuds, and VK3IL pressure paddles.  I used a clipboard to keep my notepad from blowing around in the breeze, while I logged with a mechanical pencil.

The picnic table operating station used to activate K-1366.  Included are the KX2, VK3IL pressure paddles, clipboard and log.

The Activation

As I finished getting the station ready to go, it occurred to me that I had a frequency-agile-antenna and rig, a bit more than an hour to operate, and no other operators in the area.  So, I took the opportunity to try for contacts on as many bands as possible, inching my way toward the POTA N1CC Activator award for making contacts on 10 bands from 10 parks.  The park has good cell coverage, so I was able to use my phone to spot myself.  After that, I mostly left things to the Reverse Beacon Network and the POTA spotting gateway, but I was able to use the phone to confirm that my changes in frequency were picked up.

In 70 minutes of CW operation at 5 watts, I made total of 26 contacts, including at least one contact each on the 10, 12, 15, 17, 20, 30, and 40m bands.  An apology to the hunters may be in order, because I was harder-than-usual to contact.  After making a contact on each band, I would QSY to the next at the first significant lull in the action.  I look forward to another trip back to K-1366 to try for contacts on the 3 additional bands needed to complete its activation toward my N1CC.

As you might guess, by using multiple bands, the contacts came from both far and near:  as far as Spain to the east and Oregon to the west, and as near as New York, Pennsylvania, Ohio, and Michigan.  Middling distances were also well represented in the log.

It was a good day in the park, and here is the contact map from a 7-band activation of K-1366.

Equipment

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Conclusion

This outing made for a fun and productive afternoon that was all the more enjoyable for sharing it with my family.

It also made for a great opportunity to shake off the winter blahs, and it held the promise of beautiful spring and summer days for more park activations.

Best 73 de Brian – K3ES

Here is a bonus picture of another semi-famous bridge in northwestern Pennsylvania (it actually has its own Facebook page).  This is Nebraska Bridge, which provides a convenient shortcut across Tionesta Creek.  We knew we would have to take the long way around, but stopped for a look anyway.  Unfortunately the bridge floods several times a year (sometimes becoming completely submerged), because it is located in the upstream end of the reservoir behind the Army Corps of Engineers’ Tionesta Creek Dam.  We had over an inch of rain last week, so the bridge is partially under water.  On the brighter side, 100 miles downstream, the City of Pittsburgh did not flood.

Assembling a K9DP BCI Filter Kit (Photos)


If you own a Xiegu G106, X6100, or any other radio that is prone to overloading when in the presence of an AM broadcaster, you should consider building an in-line BCI filter!

As many of you know, I’ve been testing the Xiegu G106 over the past couple of months for a review that will be published in the May 2023 issue of The Spectrum Monitor magazine.

One criticism of the G106 is that its front-end overloads when there’s an AM broadcaster within a few miles of where you choose to operate. The Xiegu X6100 is identical in this regard.

One quick way to remedy this is to build or buy a BCI filter. We’ve mentioned in the past how you can homebrew them and I planned to do so. After checking my parts drawer, though, I realized I needed to buy a capacitor, toroids and at least one of the two BNC connectors needed if I wanted an in-line filter in a small project box.

I decided it would be much easier to simply buy a kit and, based on a tip from a reader here on QRPer.com, I purchased one from Dan (K9DP). Continue reading Assembling a K9DP BCI Filter Kit (Photos)

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