AX1 Test using American Radio Supply AM-801 Window Mount: POTA Activation at Stuart B. McKinney Wildlife Refuge, K-0228
February 19, 2023
By: Conrad Trautmann (N2YCH)
If you’ve been reading the posts here on QRPer.com lately, you probably already know that the Elecraft AX1 has proven to be an excellent antenna for POTA activations for CW, SSB and Digital modes.
Personally, I used it for a New York City POTA rove I did at the end of 2022 and was able to activate four parks in one day all over Manhattan.
Recently, Alan, W2AEW contributed a story to QRPer.com detailing how he used a window bracket he constructed with an AX1 to do a CW park activation from his car. I’ve actually done a few digital activations from the car using the AX1, however, I used the tripod with the Elecraft tripod adapter and ran coax to it out the window and draped the counterpoise down the hood or trunk. This has worked well except for windy days where it would blow over. I was intrigued by the possibility of using the window mount and a number of the commenters to Alan’s post suggested sources for these types of mounts. I ended up ordering an AM-801 from American Radio Supply.
Since the AX1 depends on a counterpoise wire to operate properly, the first thing I did after receiving the AM-801 mount was to drill a hole in the base for a screw and a wing nut. The base is painted black, so I got my continuity meter out to double check that the screw was making a good ground, which it was. I had to bend the mount up slightly for the antenna to be vertical, since my Jeep windows don’t have much of an angle to them. I’m sure it would be just right for most cars.
Many thanks to Brian (K3ES) who shares the following guest post:
Building and Testing the VK160 Antenna
by Brian (K3ES)
The ability to set and achieve long- and short-term goals keeps me interested and active in the Parks on the Air (POTA) program. Often these goals are associated with POTA awards. Currently, I am working slowly to complete the activator version of the James F. LaPorta N1CC award, which requires an activator to make QSOs on 10 amateur bands from 10 different parks. With my operating style, I have found it achievable to make QSOs on the 9 available HF bands (80m, 60m, 40m, 30m, 20m, 17m, 15m, 12m, and 10m), and this has become easier with the rising solar cycle. I have completed QSOs on non-HF bands using 2m and 70cm simplex. The other options to pick up 10th band QSOs include the 6m band and the 160m band.
I have found it difficult to make unscheduled POTA contacts on 2m and 70cm, and scheduled contacts can be difficult to arrange in parks that are remote from population centers. I have built a 6m antenna, but contacts are seasonal (and for me very elusive). So I started looking for a way to add 160m capability to my portable station. Ultimately that resulted in homebrewing a new antenna that I now call the VK160, and here is its story.
I needed a field-deployable 160m antenna. My operating style requires that the antenna system be both light and compact. QRP power levels are sufficient for my purposes. I am very comfortable deploying wire antennas in the Pennsylvania woods, and QRP wire antennas can be both light and compact. I have found that end-fed antennas are simpler to deploy in the field, because they can be configured as an inverted V or as a sloper, using only one point of support.
An end-fed half wave (EFHW) antenna would be naturally resonant, but would need to be over 250 ft (76m) long. A wire antenna of that length would be challenging to deploy, even in more open areas. So, I decided to pursue a 9:1 unun-based end-fed “random wire” (EFRW) antenna. In fact, I have two commercial EFRW antennas available, but have never been successful in tuning them for 160m using the ZM-2 tuner in my field kit. So, I concluded (probably incorrectly, but more on that later) that I needed to build a 9:1 random wire antenna with a longer radiating element than the 71 ft wire built into my largest existing EFRW. I also wanted to build this antenna myself, using available components, so that it would be both inexpensive and customized to my needs.
I broke the task into four parts:
First, I needed to build a 9:1 unun suitable for use at QRP power levels. The 9:1 unun is an autotransformer that reduces antenna feedpoint impedance by a factor of 9, hopefully a level that a wide-range tuner can match to the 50 ohm transceiver impedance.
Second, I had to design and build mechanical elements of the antenna system, incorporating the electrical components needed for the feedpoint.
Third, I needed to select a suitable non-resonant wire length for the radiator.
Finally, I needed to deploy and test the finished antenna on the air. If successful, testing would culminate in completing an on-air QSO with the antenna being driven at 5 watts or less.
Building the 9:1 Unun
While I have built successful 49:1 ununs as the basis for EFHW antennas, I had no experience building 9:1 ununs. Accordingly, I started with the ARRL Antenna Book, then a web search. VK6YSF’s excellent web page provided very detailed instructions for 9:1 unun construction. His 9:1 Unun design was based on a FT140-43 toroid wrapped with heavy gauge magnet wire, with design power rating around 100 watts. My application was focused on 10 watts maximum, and I wanted a lighter-weight solution to the unun design.
Looking at the components I had available, I found FT50-43 toroids and 24 AWG magnet wire in my inventory. I had used those during construction of successful 49:1 EFHW antennas. The VK6YSF design, built with the smaller toroids and lighter magnet wire, seemed to be a good (and cheap) starting point.
The next problem that presented itself was a problem with translating the winding technique to smaller wire and a smaller toroid. Put simply, my fingers do not have the dexterity to wrap three parallel 24 AWG wires around a ½ inch OD toroid without getting them crossed, twisted, or worse. So, why not twist the three conductors from the start, and wrap the toroid with “trifilar” windings? It would be simple enough to identify the mating wire ends after wrapping, just with a set of continuity tests. That would facilitate proper connection of the wires to yield the final auto-transformer configuration.
Many thanks to Brian (K3ES) who shares the following guest post:
Field Report: Winter Field Day with a New Antenna
Winter Field Day (WFD) 2022 found me operating indoors, despite my best intentions to get out in the field. I was recovering from a bad cold, and did not want to risk having complications arise from sitting out in the cold and damp. So for WFD 2023, outdoor time with my radio was a must. I wanted to operate a 1-Oscar station, and to do that I had to set up more than 500 feet from my home QTH. So a site next to the pond in our back field, about 800 feet from the house, became my WFD shack.
I started planning and collecting kit for the operation in mid-January, with the long term forecast hinting at near-freezing temperatures with the potential for rain or snow. Let me introduce you to my WFD station.
A shelter was needed to keep out rain and snow, and to provide a barrier against the winds whipping across the adjacent field. A few poles lashed together, and steadied by stakes, provided the frame to support the shelter. With a poly tarp secured to this frame, the resulting a-frame shelter, while not completely enclosed, did provide effective weather protection for both operator and equipment. There was about 3 inches of snow on the ground when I set up the shelter, and I was able to pile some of it along the bottom edge of the tarp to keep the wind from getting under it.
I know that when setting up a station, the antenna is not generally the first thought, but I had recently finished building a homebrew 9:1 random wire antenna with a 144 ft radiating wire, and I wanted to test it out. There are better ways to put a new antenna on the air, but the opportunity was a good one. Besides, I had backup antennas that could be quickly substituted if the need arose. In the event, things worked well, and the antenna proved agile and capable on all activated bands. I particularly wanted to see if it would tune on the 160m band. More on that later.
The goal of trying the antenna on 160m left me with only one choice for a radio. I would use the Lab599 TX-500 Discovery, because it is the only transceiver among my field rigs that is capable of operating on the 160m band. Since a tuner is required, I paired it with an LDG Z-11Pro II, a wide-range autotuner. I also included a Monitor Sensors Power and SWR Meter in the feed line to help assure that I was legitimately running less than 5 watts to qualify for the QRP power multiplier. Continue reading Brian puts a new antenna to the test during Winter Field Day!→
Many thanks to Alan (W2AEW) who shares the following guest post:
New AX1 POTA Activation
by Alan (W2AEW)
I have to admit, I have been bitten “hard” by the POTA bug! (I blame Thomas!) It started for me in August 2022 while I was on vacation at the Jersey shore. Since that time, I have completed 48 activations at 19 different parks. All of these have been QRP, and almost exclusively on CW. This story is about one of my recent activations, which was unique for a couple of reasons. Read on…
My job puts me on the road, covering a large portion of the northeastern United States. When my schedule permits, I’ll hit the road earlier than needed in order to potentially stop for a quick activation along the way (usually giving up a lunch-on-the-road stop in favor of a bit of QRP CW operation at a park).
This particular park was not your typical state park. It wasn’t a nature preserve, or a mountain lake, or a hiking or picnic paradise. No, this park is decidedly urban, occupying 2 blocks in the city of Holyoke, MA. This is K-2439, Holyoke Heritage State Park. According to the state park website, this park celebrates the rich industrial heritage of the city of Holyoke. The park also includes a Children’s Museum, a Volleyball Hall of Fame and a restored antique Merry-Go-Round.
The park is situated along a canal that once powered some of the mills that were located on the property.
It certainly is not like any other state park that I’ve been to!
One of the reasons I chose to stop at this park is that it had only been activated 4 times in the past. In retrospect, I suppose this could’ve been because of the city/industrial setting. Was it going to be noisy? Maybe this was a bad idea.. Thankfully, it wasn’t… Another thing that appealed to me is that it had not been activated on CW before. So, my activation would be a CW ATNO (All Time New One) for this park, which is kind of cool.
Many thanks to Jonathan (KM4CFT) who shares the following guest field report and video:
Chatfield State Park (K-1212)
January 20, 2022
by Jonathan Kayne (KM4CFT)
The honorable Yaesu FT-817/818. You all know it and love it. I had been wanting to get myself one for a while but after just buying myself a shiny new ICOM IC-705, I had been planning on getting myself an 818 in the spring to play around with. December came and I find out that Yaesu was going to discontinue the 818, so I went and bit the bullet and bought one from Ham Radio Outlet.
I had been getting into CW for portable operations lately after wanting to learn CW for a while and my friend Zach Thompson (KM4BLG) had pushed me to learn it. I learned it over the course of two months through an app called “Morse Machine” and listening to Thomas’s YouTube videos while working so as to get used to the exchanges and pick up words. Then I activated and all the rest is history! (If you want to see my 3rd time activating see this video here.)
Why is this important? Because the FT-818ND does not have a narrow 500 Hz filter for CW operation by default, and since I consider myself to be still a newbie I wanted to install a Collins Filter before I take my new 818 into the field. Since these filters are hard to obtain, I went with the build your own route. The method I used has been outlined in this blog and I have made a video of it here.
Now that I had my radio all ready to go with a filter, side rails, and Windcamp Battery, I wanted to get it in the field as soon as possible. Unfortunately due to a snow storm, the temperature in the Denver area was quite cold.
Many thanks to Dan (W9SAU) who shares the following field report:
My first Straight Key POTA Activation
After 3 weeks of working Straight Key for SKCC, SST, and POTA QSOs, and a lot of practice, I wanted to try a Straight Key POTA Activation, using a Cootie paddle.
My Cootie/Sideswiper is a modified Vibroplex Single paddle, with a switch installed. Converting a paddle to a Cootie is done by jumpering the dot and dash wire connections. Then turn the Electronic Keyer off. The switch allows for Cootie or Keyer operation.
Pullman National Monument (K-7917) is only 10 minutes from my QTH. Pullman is unique, with the National Park borders surrounding a portion of the Pullman factory and neighborhood. You can operate from anywhere within these borders. I operated from the parking lot of the Pullman National Monument Exhibit Hall.
In this busy area in the City of Chicago, the noise floor was near S-Zero. There is occasional interference from a passing Illinois Central Electric Train, with QRN that obliterates everything. Not many trains on a Sunday morning.
With snow falling, my operating position was inside the vehicle, using a Yaesu FT-891 set to 5W for QRP, with a Shark 20 meter Hamstick on the roof.
Some anxiety, starting at 13wpm, but I quickly became comfortable with 15wpm. My goal was to complete the Activation with 13 or 14 contacts.
I finished with 22 in the log in 35 minutes. I appreciate the patience of all who slowed down for me.
I had plenty of protection from Chicago’s Finest! Across the street are the Pullman Horse Stables. All employee and visitor horses were housed and cared for here, in the late 1800’s.
Working the Cootie is a lot of fun! I find it easier than the traditional up/down key. But each character still has to be formed manually. I will be doing more of this type of POTA Activation.
A bonus is Ops who sometimes initiate a SKCC QSO when I work them for POTA. I was happy to accommodate them, but using a Keyer, I could not take SKCC credit. With the Cootie, I can use the credit to work towards the next SKCC achievement level. All while working Parks On The Air!
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.
Many thanks to Brian (K3ES) who shares the following field report:
Recipe for a Failed Activation at K-0619?
by Brian (K3ES)
A couple of days before Christmas, high winds came, temperatures dropped, and 3 inches of snow made a real nuisance of itself by blowing around and re-covering anything that was swept or shoveled. With daily high temperatures below zero (Fahrenheit) and wind gusts over 40 miles per hour, the weather just didn’t make for much fun outdoors. In fact, we hunkered down and didn’t get beyond the end of the driveway for four days. So when the winds calmed and temperatures rose, I really needed to get out of the house for a bit. What better way than to walk up the road and activate K-0619? Even with temperatures in the low 20s, I should be able to finish a quick activation. And so it was planned…
Of course just before walking out the door, it is always prudent to check on band conditions…
Alright, I really need my outdoor time. Even if it means that I fail to activate the park this time, I’m going for it!!!
Product Review: Chelegance MC-750 Portable Ground Plane Antenna, Part 1
by Charles Ahlgren, KW6G
I recently purchased a Chelegance MC-750 portable ground plane antenna from DX Engineering. Essentially, the antenna system provides a ¼ wave portable vertical antenna with 4 counterpoise wires that operates on 20 through 10 meters. The antenna will also operate on 40 meters with the provided loading coil. The manual states the antenna will support 6 meter operation, but no instructions are provided on how to do so. 30 meter operation is not supported. It appears from our initial testing that no ATU is required.
Here are some of my thoughts on the antenna.
The MC-750 comes with the following components:
GROUND ROD / ANT BASE
50 CM ANT ARM
5.2 M WHIP
7 MHZ COIL
4 COUNTERPOISE WIRES (radials)
COUNTERPOISE WIRE COLLECTOR BOARD
As provided, it is designed to operate on the 40, 20, 17, 15, 12, and 10 meter bands without any modifications. Six meters is also supported per the manufacturers manual, but no guidance on how to do that is offered in that document. However, finding the proper length of radiator for 6 meters should be straightforward using a tape measure to set the proper whip length.
[Update: Chelegance notes that to operate 6 meters, simply extend the last segment only of the whip (see photo) and for 30 meters extend the last four segments of the whip and 15cm on the 5th segment (see photo).]
I checked the ground rod / antenna base with a magnet and confirmed it is made from stainless steel as both components are not magnetic; a characteristic of stainless. Both the ground rod/ antenna base and the 50 cm antenna arm (which was also non-magnetic) had a hefty feel (together, they weigh about 2 pounds), therefore I think it safe to assume that these components are made of stainless steel. Since most ops will undoubtedly use the antenna arm as an aid to inserting / extracting the ground rod into / from the ground, it seems a prudent decision by the manufacturer to have this piece fabricated from a strong, stiff material such as steel. The machine work used to fabricate these parts appears to be quite good – the fit and feel were excellent, with no sharp or ragged edges to cause problems in the field.
I measured the whip while set at the various position marks for 20 through 10 meters. The band markings on the whip were accurate – giving a 1/4 wavelength radiator when combined with the 50 CM ant arm length…On 40 meters, the whip and rod measured about 1/8 wavelength. The required the loading coil needs to be inserted between the whip and the rod (at approximately 1/10 the total 40 meter whip height above the base). If you want to operate this antenna on 30 meters, it appears that you need to provide an extra 1.4 meter of additional rod as a quarter wavelength ground plane at 10.1 MHz requires a 7.1 meter radiator. Six meter operation would require a whip of around 4.7 feet. With the whip fully collapsed, the length of the rod and antenna arm measures 40-1/4”. Therefore, if 6 meter operation is contemplated, extending the whip about 16 inches from fully collapsed should suffice. However, I don’t think that an antenna configuration such as that would be a very good performer unless it were elevated from ground level; or maybe it would be good for a SOTA activation? Continue reading Guest Post: Reviewing the Chelegance MC-750 (Part 1)→
Many thanks to Scott (KK4Z) who shares the following post from his blog KK4Z.com:
by Scott (KK4Z)
Men in general, have a habit of naming things. All sorts of things, cars, body parts, you name it, we will cast our own nickname on it. I thought I would share some of the names I have given my radios. Typically, I don’t just throw a name on something. I am around it for a while, before I decide what I am going to call it. My poor dogs, when I first get them, I go through a plethora of names until I find one that fits. My latest dog, a boxer mix from the pound was named Hawkeye by them. I got him home. I had to get to know him.
He ended up being Andy but likes to be called pup-pup. Maybe his last owners called him that. He’s still very much a pup but is going to be a great dog.
I will start with my main radio which is an Icom IC-7610. It is my workhorse radio. It is probably the best radio I have ever owned. I have worked the world on it and it does everything I need it to do. I call it Zeus, the king of all my other radios. I believe there is not a radio out there that can do anything that Zeus cannot do. Any improvements over Zeus would be marginal.