So it’s been a while since I posted here, nearly a year! That’s not to say I’ve been sitting on my hands. Since my last post I built a QMX, activated a park in Italy, completed a few more POTA awards, and built a few more filters.
For Christmas I got a DX Commander and plan to use it for Field Day. I spent some time color coding the elements and making it easier to get on the air. I have some final tuning to do, but liking the antenna. I decided to use zip ties instead of the heat shrink tubing due to being in Florida and the very hot days we’ve been having.
I’ll post some contest reports from ARRL International Digital Contest and ARRL June VHF Contest in the next few weeks. Spoiler alert: I more than doubled my score from the 2023 ARRL June VHF Contest!
For the past several Field Days, I have enjoyed operating with my friend Ian, W4NAI. Last year on Field Day we ran into issues with multiple radios side by side. The interference was really bad on 20 meters from another radio on 40 meters. This year we wanted to get a jump on it as we have a unique Field Day location planned. After doing a bit of a survey, I landed on the kits from VA6AM. While I could buy filters, I find it more fun to construct the filter myself. In this kit alone I’ve greatly improve making tight wraps on toroids and learning how to fix issues.
I had a few project boxes and standoffs already so I started off with the mechanical layout. I used the PCB to figure out the mounting holes and a melted SO-239 for the holes on the coax connections. To get the hole large enough, I used a step bit. It should be noted that the enclosure is the ground and is connected to the PCB by the standoffs, so it was critical to have those be conductive.
The instructions started off winding the input/output toroids. These are unique in that they are actually a transformer and the secondary coil has a proportional number of wraps to the first.
With the toroids made, I soldered on the input/out put capacitors and mounted the toroids. VA6AM has you tune the circuits to the same frequency. This is done by soldering on a bit of coax and reading it on the VNA. I ended up spreading the coils a bit for them to match and spent a while playing with them. If you look at the photo, you can see there wraps are not super tight. In the end, that cost be a bit of insertion loss (about 0.2 dB) and out of band attenuation (about 6 dB). The filter pictured is for 20 meters, but the 40 meter filter had better results (about 0.4 dB insertion loss and my out of band attenuation was on par with expected).
My construction wasn’t perfect. I accidentally mounted one set of capacitors wrong and had to fix it. It isn’t pretty, but it is functional. The good news is I only made this mistake on one set of capacitors and made sure I was correct on the remaining ones.
You might notice some Kapton tape in the photo. I used the tape to protect the toroids that sit above the solder joints from getting scratched. I use Kapton tape a lot with 3D printing, but it is also helpful for electronics as it resistive to heat and durable.
The final assembly of the filter was a success. I achieved less than 0.5 dB of insertion loss on both filters across the band. I saw at least 53 dB of rejection on adjacent bands. So these two filters achieve about 100 dB of attenuation between 20 and 40 meters. Testing with the radio, noting got hot with my usual 35 watts of FT8 or 100 watts of SSB and the SWR was 1.2 at the worst, so very happy with how everything came together. I labeled all the details on the project boxes for reference so we know what to expect on Field Day.
With the success of the these two filters, I’ve order 10, 15, and 80 meter kits to assemble before Field Day!
After a missing Hamvention last year due to my wedding and the previous years in person due to Covid, I was able to venture back to Dayton Hamvention this year! Like previous trips, I was part of the ARRL team supporting the ARRL Collegiate Amateur Radio Program with my brother Tony, KD8RTT.
Tony and I managed a booth in the ARRL Expo. On Friday we were able to explore the expo a bit as students from Missouri S&T, W0EEE volunteered to man the booth.
Friday proved to be fruitful as I was able to secure a 50 watt dummy load for $5 and get my ARRL Life Member badge. Tony and I wanted the swap meet a few times and it is still recovering from Covid. It didn’t have the attendance or the density of items it had prior to the pandemic.
The commercial booths were busy as always with Kenwood showing off their new TH-D75A and Icom with their ID-50A. Both radios were announced at or just before Hamvention. The real star of the show (and the one commercial item I purchased) was the QRP Labs QMX radio kit. This a true kit and something I will be building and documenting (on here and probably on a YouTube video).
Besides the purchases, I was able to connect in person with Ward Silver, N0AX (the resume is too long to list, but literally an expert in all things radio), Neil Rapp, WB9VPG (host of Ham Talk LIVE and runs Region 2 YOTA Camp), Jason Johnston, W3AAX (the man behind Parks on the Air), and of course Bob Inderbitzen, NQ1R (again the resume is too long to list, but he is one of the key people at the ARRL), just to name a few. There were countless other hams as well and it was awesome to put faces to call signs!
Overall Hamvention was a great event. I got to meet a few friends I haven’t seen in years and make some new ones. I’m looking forward to going back next year!
I’m very lucky in that my wife (who is not a ham) is pretty cool with POTA. On the way back from a day in Tampa for a Dachshund race (or pups had a blast!) we decided to make a minor detour to Hillsborough River State Park.
At this point, I have my POTA setup down to a science and I can load the car in under a minute with the 3 cases I need. I can also setup in under 10 minutes. Hillsborough River State Park is a nice little park with lots of picnic areas. I was able to find a table among some trees and setup.
This setup had some nice high trees that worked great for the end fed antenna. After using some arborist line and a weight to get it up in a tree. I use a 9:1 balun and a little over 60 feet of wire for the antenna and it tunes up well.
Band conditions for this activation were not great. After trying to call CQ for a bit to no reply, I was forced to switch to FT8. I was able to secure 13 contacts between 15 and 20 meters over the course of about an hour. After that, Kirsti and the dogs wanted to head home.
I really liked Hillsborough River State Park. It is a nice area with lots of shade. It seems popular with locals as there were several picnics that started after I got their. There is access to the river to kayaking and canoeing. Overall it was a great experience!
April 1st and 2nd was Florida State Parks on the Air. For this event I ventured down the road again to Lake Louisa State Park. However this activation was a bit different.
POTA is a lot of fun, but it’s always more friends. This time I brought Ian, W4NAI, with me for his first activation. Ian is a seasoned ham, but doesn’t have a station at home, so he takes advantage of any opportunity to get on the air.
Ian did many of the initial contacts while I logged. He wasn’t used to getting a pileup and having to work a bunch of folks calling the park.
Again I used an end fed antenna, but this one was home made. I first used this setup for Field Day 2022 and decided to use it again for this activation. The antenna is a long wire with a 9:1 unun. There is also a 1:1 choke before the tuner. This setup tunes well on anything from 6 meters to 80 meters. (And I can sometimes get 160 meters if I have enough coax.)
The antenna was put with some arbor line and a weight. We did have the antenna come down mid way through when I was trying to adjust it. This took us off the air for about 20 minutes. We were going to try Ian’s Buddipole but didn’t have the adapters to use with the FT-817.
Overall we operated for about 4 hours and made over 100 QSOs. We worked a ton of Georgia parks and only connected with one other Florida park. We worked states as far north as Minnesota and as far west as Oklahoma. It was a great experience and we cannot wait to do it again!
Another quick, mobile POTA activation from March 23rd, 2023. I was driving from my house in Clermont to Tallahassee for a FIRST Robotics Competition event (congrats to my team FRC5816 GraV for winning the FIRST Impact Award and advancing to Championship in Houston, Texas!) and decided to make a quick stop on the way up.
I used to live in Gainesville. In fact, I earned my license while a graduate student at the University of Florida. So Paynes Prairie was a familiar park. When I first got an HF rig, I spent a couple Saturdays operating portable from this park (if only I would have kept the logs separated to label them a POTA).
With my new organization strategy mentioned in my last POTA Report, it was super easy and convenient to grab the case and go. I brought my FT-857 and operated from my car, a familiar setup. I knew I only had a little time to active the park and got to work with some FT8 and some SSB contacts. I quickly made about 40 contacts (11 digital and 29 voice) before getting back on the road.
I have things pretty efficient with my FT-857D sitting on my center arm rest and then a logging laptop/digital modes on my lap. I’m setup and ready to go in under 5 minutes and it’s just as quick to pack up. With evening stored in the pelican case, it makes it easy to pick up and take to my hotel room.
I was finishing my last QSO just as the sun was setting. I had a pileup on both SSB and FT8 while I was on the air. Paynes Prairie Preserve is not a super common park to see on the air and there aren’t usually a lot of parks on a week night (I was traveling on a Thursday), so it was quite popular. As it got dark bugs were starting to get bad and I had to pack up and get back on the road to Tallahassee.
It might be hard to see in the photo, but I was also running APRS for my drive. I like to beacon APRS with my mobile digipeater on longer drives.
Overall the setup worked like a dream. I’ve really streamlined the setup. I still prefer being able to setup at a picnic bench or something out in nature a bit more, but these quick activations are still fun. This coming weekend is Florida State Parks on the Air so we will see what I get on the air to activate.
On March 12th I ventured a few miles down the road to Lake Louisa State Park again for another POTA activation. This time my wife joined me along with our dachshunds, Daisy and Max.
I decided to venture away from my car and setup on a picnic table. I strongly prefer getting out of the car and connecting with nature. This was also an opportunity to test out a new organizational strategy and a few cases I picked up at Orlando Hamcation.
For this activation I wanted to work both data and voice. I brought my usual portable FT-857D and matching tuner as well as an end fed antenna. The radio, tuner, Signalink, and associated cables live in one Pelican 1520 case. I used a another case to hold the antenna, coax, and arbor weights and lines.
I used my solar power case (another Pelican 1520) with a 60 watt panel and 15 Ah battery. The power setup is well tested with past ARRL Field Days and worked fantastically. I threw the end fed up in the tree using some arbor weights and line. The antenna tuned up well on 15 and 20 meters. This end fed is only 29 feet long, so I could greatly improve my efficiency by using a longer wire. I do have another end fed that I used on ARRL Field Day last year and I do intend to give that a try next time.
My wife took the dogs for a walk, but Daisy got tired and decided to spend some time with me. She was my “Bark Ranger” and patrolled the antenna. I really liked being able to do radio with my family.
In the end I made 94 contacts, of which only 25 were FT8. This was a ton of fun as I had several pileups. I also ventured on to 15 meters and made a few contacts on FT8. I consider this a huge success for a POTA. My goal is to earn a Kilo award for Lake Lousia and I’m well on my way with over 125 QSOs to date. With the park less than 5 miles from my QTH, I expect to hit this goal either this year or early next year depending on where my next activation takes me!
This is a review of an ATU-100-OA tuner from Amazon. First, it should be known this tuner is the same as the open source N7DDC tuner. Basically a company in China is manufacturing them and selling them on Amazon (affiliate link below).
The tune does work and can tune reasonably well. I found success with my end fed antenna with my California POTA back in October. However, the tuner required some tweaking first. The manufacturer is running the 3.1 firmware on the tuner with the default settings. This means the tuner needs 5 watts to tune. On my California POTA activation I was running QRP with a max of about 5 watts from my FT-818. In order for the tuner to work, I had to change the firmware to tune with less than 5 watts. This change required me to open up the tuner, solder on some lead wires and modify the EEPROM.
I set my tuner to work around 3 watts. There is some conflicting reports on the accuracy at lower power and I felt confident I could reasonably get to 3 watts to first tune the antenna. That change was smooth, but required a PicKit to do the programming. I’m putting in an affiliate link to the one I used below in case you also want to do the modification.
So why go though this hassle? This tune is small. If you look at the title image, you can see its about as wide as my key and about twice as long. It packs up nicely with my FT-818s. It also does not require any interface with the radio to work. It has a fairly large matching range and easily works with an end-fed half wave antenna. So this little things checks a lot of boxes.
But there are some things to be warned: the tuner has issues holding a charge and its particular on its cables. The battery drains if not plugged in, so for a quick trip it is great, but for longer treks, plan to bring a USB-C cable and a power pack. Also you cant use just any USB-C. It seems to only like USB-A to USB-C cables.
Overall its an okay bit of kit. It can be made serviceable if you’re willing to tinker (and I suggest you upgrade the firmware while you have it open) and it has a small size. But I’m not sure I would depend on this tuner. The battery draining on its own is really an issue. I really wanted to like it, but I think the manufacturers needs to spend a little more time polishing their product. Note there are a bunch of folks selling this tuner or clones of it, so who knows, you might find one that works better. That said, the seller for this one did link me to the open source project to tinker with it. So while not super useful, at least they did respond.
In my last post I mentioned that a mobile POTA is not as fun as setting up at a picnic table. Well this is another mobile POTA, but I tried to make it feel a little more connected with nature.
While driving back from Jacksonville for a conference and before heading to Magic Kingdom with my wife (going to Disney World after an activation seems to be somewhat of a trend) on February 4th, I decided to stop an active a park. I wanted to pick something close to I95, but also something where I could have a greater connection to nature. I found Faver-Dykes State Park. What attracted me to this park is how it is not as popular and had a parking area in the woods by the water.
I had only 30 minutes or so for this activation, so mobile was key. I had my car setup within a few minutes of arriving. The weather was fantastic and I enjoyed exploring a little bit before getting on the air.
The bands were busy and I was able to secure 14 FT8 QSOs before needing to tear down. I’ve noticed I prefer FT8 while in parks. I think that is maybe the quiet that it affords me. I saw some deer and some birds during this activation. Had I been making noise doing SSB, I don’t think they would have gotten as close.
Overall this was a quick and exciting POTA activation. As my third activation, I’m starting to get the hang of POTA. I’m really liking the activation side. I have had a good portable power case that I use for Field Day, but I’m now developing a good setup for the radio and antennas.
For my next POTA activation I hope to bring back my satellite operating and see if I can do some satellite contacts. I have also been taking the CW Ops classes and hope to bring my (improving) CW skills to make contacts. I might try some CW on my next activation as I have a good portable key. For now I’ve been having a great time and looking forward to Hamcation. Hopefully I can connect with some POTA friends in person.
I wasn’t able to get out for Winter Field Day, but I wanted to get out and do a quick POTA on Sunday 1/29. I had about an hour before a trip to Epcot with friends, so had to do a quick setup and tear down. I live near K-1893 Lake Louisa State Park in Florida and it make for a quick trip.
I keep a lip mount on my trunk for hamsticks and I keep a tote with my solar panels and battery and another tote with my radio and some other supplies. I tossed them in my Honda and was on my way. My brother Tony, KD8RTT had gotten me a Florida State Park Annual Pass for Christmas so I decided to put that to good use.
I was able to setup my FT8 station within minutes in my car and was on the air. I put my Solar Panel on the roof to supplement the battery, but I knew there was no way I would drain it in the hour or so I was at the park. I came ready with both 20 and 40 meter hamsticks, but I stuck to 20 meters. I immediately had a pileup running just 30 watts.
I ran FT8 for about an hour and made 28 QSOs. It was fun, actually quite challenging to keep up with things. Some folks hiked by on the trail and asked what I was doing and ended up in some great conversations. I might have missed replying to a few folks calling me on FT8 while I chatted about the hobby. (Sorry if I missed you!) FT8 was super successful with 3 park to park QSOs. (My first ever park to park QSOs!) I made sure to send them a QSL card as working park to park is both challenging and fun!
I wanted to make some SSB QSOs before I packed up. My mobile setup is a FT-857D and it was super easy to stand outside and enjoy the nice weather. I have an extension for the microphone and I have the control head setup on a custom made (and VERY long) remote cable. With the laptop on the hood of my car, I connected with two stations. My favorite being a challenging park to park QSO with AB9JT in Indiana. It was my first time working him and at only 30 watts, was a challenge. I could have bumped up the power, but I like a challenge.
So while it was a successful POTA, it wasn’t as fun as my first activation. For a quick trip, working from my car was fine, but I really enjoy the outdoor aspect of POTA and taking in the park. This wont be my last mobile POTA activation, especially with Lake Louisa so close to home. However, I will be putting in some extra effort to hike a little bit and find a picnic table to an area to sit on the ground and really enjoy both amateur radio and nature.
