Many thanks to Mike (KE8PTX) who shares the following tip:
[Recently, I walked into a] big box store and this caught my eye:
When separated, they have very little memory.
So now we have four 25 foot radials. Bonus was all were different colors. Easy to untangle.
Performance, so far, is good. Total price with clip: 12 bucks.
That’s a brilliant tip, Mike! Thank you for sharing. Like you, I’m always on the look out for products that could serve double duty in the world of amateur radio. While one can find less expensive sources of wire, for 100% copper wire pre-cut to a standard radial lengths, this is a pretty good deal!
I did some searching and pricing varies between various suppliers.
Because I receive so many tips from readers here on QRPer, I wanted way to share them in a concise newsletter format. To that end, welcome to QRPer Notes, a collection of links to interesting stories and tips making waves in the world of radio!
HA8SA Stay At Home Transceiver
Many thanks to Pete (WB9FLW) who shares a link to HA8SA’s compact homebrew transceiver. As Pete notes, it’s a “very simple design but with a load of features!”
Had a lot of fun experimenting RMOOTA (Random Metal Objects On The Air) with the boat today.. The winds were so strong (sorry about the annoying wind/mic noise) and the noise of the engine kept us from actually driving while making QSO’s.. It was a challenge just the same being stationary in one location.
It was a big contest weekend and the QRM and Pileups were massive.. With my 5w and Random Metal Object as an antenna, it was difficult to get contacts.. I was able to catch them when they were short on business and looking for calls, lol..
We only achieved 4 QSO’s out of the 10 we wanted.. (40%) but, I’m happy with that.. I felt lucky to get one call, LOL..
Thanks for watching everyone.. We (the Skipper and Mate) hope you enjoyed watching it as much as we did making it. 73, Kevin ~ k0klb
The Lyrics written and sung by K0KLB
Many thanks to everyone for sharing their tips here on QRPer Notes!
Many thanks to Rich (KQ9L) for sharing the following field report:
Field Report: Testing a horizontally-polarized antenna at a high QRM POTA site
by Rich (KQ9L)
I wanted to give a quick follow up report from Santa Fe Prairie State Park (K-7839).
As you may recall I wrote up my POTA activation from this park on Oct 23, 2022. I made 15 Q’s that day but deep down felt I could do better. The setting of the park is quite industrial and consequently the man made noise is bad. Reflecting back on this activation, I feel that the limited the number of QSO’s I made that day was due to this QRM.
I resolved to try again but this time my objective was to figure out a solution to mitigate the effects of the QRM on my QSO count. Thinking about the problem, I recalled than manmade noise typically is vertically polarized and therefore for my second attempt, I decided to test this and use a horizontal antenna.
As luck may have it, here in Chicago we continue to experiencing unseasonably warm weather and my work schedule wasn’t too busy on Thursday, November 3, 2022, so it seemed like a great chance to put my theory to the test.
For the antenna, I decided to use one which I have owned for awhile, but have never used. I had purchased a RadioWaves Double bazooka from an online retailer some time back when they were on sale and planned to set up it a flattop dipole.
If you recall from my description of the Santa Fe Prairie State Park, there is a scenic overlook which has a tree mounted pulley system perfectly spaced to mount a 20m dipole. Although this would be the first time I used the system, it turned out to be a well designed and intuitive hoisting solution to use.
The “pulley” is actually an eyelet with paracord running through the eyelet. The paracord is in a continuous loop just like rope on a flag pole. By employing a simple overhand knot I secured the end of the antenna to the paracord and hoisted the antenna up into the tree about 20ft. It literally took a few minutes and I was ready to go.
Antenna was fed with my RG-316 feedline with built in common mode choke. Since a dipole is a balanced antenna system, it really doesn’t need the choke, but it was the coax that I had packed with me and I figured it wouldn’t cause any harm or negatively affect my test. I was QRV by 3:20pm, and anxious to get on the air. Continue reading Rich re-activates Santa Fe Prairie State Park with QRM-busting in mind→
Back in May I had to travel last minute for work to North Dakota. I typically bring radio gear in the event that I have some time to do a Parks On the Air activation. This trip presented the opportunity to activate a park in Minnesota as well as one in South Dakota. I didn’t have much time to plan these activations, but I knew I had an early enough arrival in the afternoon that I could likely activate a park in MN and then in SD. So, I picked out a park in MN close to my destination. I could go activate in MN then get over to a park in SD and activate there.
I found a nice looking State Park in MN. The idea was to activate as quickly as I could and then get back to a park in ND with enough time to activate before it got too late. K-2482 Fort Snelling State Park had 110 successful activations. That is always promising when planning out an activation. I got my rental car and headed to the park.
I also had recently purchased a HFJ-350m which is a base-loaded coil with an extendable whip. I found a tripod base I could print online and then designed an adapter so I could install a SO-239 and RG316 lead with a BNC connector. I had just tested this setup in the back yard and knew it worked, although I certainly knew it was a compromised antenna.
HFJ-350m setup on custom tripod in the backyard for testingCustom 3D Printed Tripod with BNC Connector
I typically bring my Raspberry PI4 loaded with Build-A-Pi and then run digital modes from my phone or Tablet. My plan was to activate this park with the compromised antenna running 5W on FT8 at the first park and then go to my second park and run a full half wave wire in a tree on SSB at 10W.
Not much to say about the activation in MN. The state park was nice but where I set up presented quite a bit of RF noise. Not so much of a problem since I was running digital. After a bit of adjustment on the whip I was tuned for 20m and started hunting a few FT8 stations. I did make a few QSOs while hunting but I then started calling CQ and had a bit more luck. I think because my signal was quite weak, calling CQ was a bit more efficient as only those who could hear me were calling back. While hunting, if those calling CQ were running a bit more power, I was unlikely to get in while running lower power and on a compromised antenna. I got the activation completed with 12 QSOs and packed it up and headed to the next park.
If you’ve been here long, you’ve no doubt noticed that I have a sizable collection of QRP radios I take to the field.
Although I have some favorites, I try to rotate all of my radios in the field and even pair them with different antenna combinations as much as possible. If I only owned one field radio, I’d shake things up by pairing my one radio with different antennas deployed different ways during my POTA/SOTA activations.
I get a real thrill out of testing different combinations, actually, and I feel like it keeps me on my toes because I don’t get too comfortable with any one setup in the field.
No doubt, using a wide variety of radios gives me a more informed perspective when beta testing or evaluating new radio models.
That said, there is one radio in my collection that has been overlooked too many times: my Icom IC-703 Plus.
Many of you have noticed this, in fact. I’ve gotten several emails and comments asking, “So Thomas…when are you taking the 703 out again–?” 🙂
When I purchased the ‘703 from my buddy Don a couple years ago, I imagined taking it to the field very regularly. I always thought it was a cool little radio and with its built-in ATU, it’s quite compact for a tabletop-style rig.
Thing is, each time I’ve taken it to the field, I’ve had issues with the electronic keying that I did not have when using it in the shack. It’s quite sensitive to RF, so end-fed antennas seem to create unwanted dits and dashes in the keyer.
The simple fix, I hoped, was simply using an in-line common mode choke to keep the RF away from the radio. Thing is, the IC-703 has an SO-239 antenna port and two of my common mode chokes are BNC. I meant to purchase a BNC-to-PL-259 adapter at the Shelby Hamfest, but picked up the wrong item (I should have been wearing my glasses).
Many thanks to Sam Duwe (WN5C) who shares the following guest post:
A (surprisingly good) tabletop HF antenna
by Sam Duwe, WN5C
I recently built a tabletop QRP HF antenna for 17 and 20 meters, in the spirit of the Elecraft AX-1, so I could operate at lunchtime on the campus where I teach. My wants were something small, that would fit in my work bag, that didn’t require a tuner, and could work on a couple of different bands. But on a lark I decided to attempt a POTA activation at Lake Thunderbird State Park (K-2792) pairing this antenna with my Penntek TR-35 QRP CW transceiver. I figured I’d maybe get one or two QSOs and then switch to a long wire in a tree. But what happened amazed me.
I talked to seemingly everyone. Beginning at 9:00 AM September 26th I worked both 17 and 20 meters for an hour and a half and made 37 contacts from across the country. I even had a Swiss guy call me back on 17 but he faded before we could finish. This antenna, at least as a CW POTA activator, works. Granted conditions were very good, but I’ve replicated this multiple times in the past few weeks, just recently at a picnic table in the parking lot of the Route 66 Museum (K-8644) in Clinton, OK (there is quite a thrill in urban activations).
It has also reasonably low profile and very quick to setup and take down. It is also quite a conversation piece when I set it up at school. I elevated the counterpoise by attaching it to a nearby oak and an interested undergrad sheepishly asked if I was listening to the tree!
The build is pretty simple. Physically the antenna consists of a small painters pole from Walmart and an old tabletop camera tripod. I found a nut that fit the screw portion of the tripod and hot glued it into the orange connecting section of the pole. That way the tripod can then be screwed onto the pole. The RF parts of the antenna consist of a 38” telescoping whip that I scavenged from the rabbit ears antenna that came with my RTL-SDR. It connects using the original connector which was hot-glued into a hole I drilled into the top of the painters pole. I found similar small 3 or 4-foot whips from AliExpress for cheap and these would probably work fine.
I then soldered a long length of speaker wire that was wound into two coils: the top for 17 meters (24 turns) and the bottom for 20 meters (25 turns plus the former 24-turn coil). The speaker wire was the soldered to the center of a BNC connector which I hot glued and taped to the pole. I soldered a short piece of wire from the shield of the BNC for the counterpoise and added an automotive spade connector to attach to a 17-foot length of wire. I also included a switch between the coils and the BNC connector to select either just the top coil (17 meters) or both coils (20 meters) using solder, hot glue, and tape. I then covered my shame in silicone tape.
The most time-consuming aspect of the project was tuning the antenna. It required trial and error to first tune the number of turns on the 17-meter coil and then the 20-meters coil. I extended the counterpoise (for me it’s best when slightly elevated) and the telescoping whip. I performed the tuning with the whip not fully extended to give room to tune in the field. Using a nanoVNA was useful here, as was soldering a pin to the wire to poke through the wire at various parts of the coil to find the best SWR.
In use, the antenna can be affected by both body capacitance and how the counterpoise is situated, so I found that an in-line SWR meter was helpful in making sure all was well. Once set up it is easy to fine tune by just adjusting the whip length. 1.5:1 SWR is about how well I can tune on average. Obviously if you have a tuner you would just have to get it close.
There are a million variation on a small base-loaded vertical antenna, and you can definitely improve upon this design. And, besides the super well-built and elegant AX-1, QRP Guys sells an interesting looking kit, and there are some good 3D printed designs I might want to try out. But regardless how you go about it, it might be worth giving a tiny antenna a shot.
Also, inspired by your post, I dragged my OM0ET magloop up a mountain today for a POTA activation. I used a 3D printed tripod adapter of my own design that allows me to mount it on the collapsing legs from the Buddistick Pro. It makes the whole package a lot more manageable and light weight than carrying a camera tripod.
I had a successful activation of K-4454 on 20 meters, and thought you might enjoy some photos of the setup:
I’ve uploaded the design to Thingiverse at this address:
Wow! Thank you Jonathan. That short demonstration prompted me to order the K7QO noise bridge kit from QRPguys this morning. In fact, I plan to build this and keep it with my loop antenna as it’ll pair so nicely with my IC-705 and TX-500!
Thank you, also, for sharing those 3D files! I love that field setup at K-4454!
I’ve used this loop a few times in the field and even once from inside a large brick community building while doing an FT8 demo.
Loops are a brilliant solution when you have:
QRM from local noise sources,
limited space to deploy an antenna,
or need a very low-impact and small footprint antenna (very handy for those historic and archeological POTA sites).
The trade-off, of course, is that they have a high “Q”–meaning very, very narrow bandwidth. Basically, anytime you move frequency? Yeah, it’s time to re-tune.
The environment around a loop can also have a pretty significant impact on your ability to tune it as well. For example, metal support structure in a building, window frames, metal poles, vehicles–anything like this nearby can have an impact on your ability to tune a loop and obtain a low SWR.
It’s for this reason I use them so little in the field–where I live, wire antennas are so easy to deploy and use.
But sometimes loops are the perfect tool, so knowing how to efficiently and effectively use them is important.
The F-Loop packed
I thought I had posted an activation video using the F-Loop, but looking back I realize I have not.
Yesterday, I decided to pack the F-Loop in my larger Spec-Ops Brand T.H.E. Pack which can easily hold the entire loop, folding tripod, and antenna analyzer.
I always fully set up an antenna before packing it in a new pack just to make sure I’ve included all components. I used this as an excuse to improve my loop tuning skills by intentionally chasing POTA stations across the HF bands. I worked all of the stations I hunted (five, if memory serves).
Twice I obtained a brilliant match just by using my ear (listening for the HF band noise level to increase as I tuned the variable cap) and the rest of the time I turned to my RigExpert handheld analyzer to find a low SWR.
I’m looking forward to taking the F-Loop to the field soon just to see how well it performs. After my practice today, I do believe I’ll keep the antenna analyzer packed with the loop–it makes it so easy to find a good match.
I find the F-Loop a wee bit easier to tune than my W4OP loop. The W4OP loop is also a brilliant loop if you can find one–I recently gifted mine to a friend. Here’s my review from a few years ago.
I’ve used an AlexLoop once and was impressed as well. That’s another antenna I may review at some point.
Commercially-produced mag loops are pretty expensive though. I do plan to build a 20M mag loop antenna before end of year. They’re surprisingly easy to build if you have a good variable cap.
Curious how many of you regularly use mag loop antennas. If you do, what make and model? Or is your loop homebrewed? Please comment!
Turns out, if you go to Canada for nearly two months, when you return home you’re going to have about two months worth of catch up.
It’s all explained in one of Einstein’s theories. If memory serves, Einstein stated:
“One cannot simply ignore stuff for two months and expect no repercussions. Time lost must be accounted for due to the principles of the conservation of energy. Plus…what in creation were you thinking?”
When we returned from Canada in early August I had some pretty big plans about the parks and (especially) summits I would hit here in North Carolina. But after returning, I quickly realized I had so much work to do around the house and a number of DIY jobs I’d postponed at our investment property. They all immediately took priority.
Indeed, in the one month span after returning from Canada, I only performed three park and no summit activations. There was a three week period of time without activations of any sort. I simply didn’t have the time to fit anymore in my schedule. This all gave me a serious case of activation withdrawal.
If you’ve been following my field reports, you’ve no doubt noticed that I never do multi-hour activations at one site unless I happen to be camping at a POTA park.
I’m asked about this fairly regularly (why I don’t do longer activations to achieve Kilo awards, etc.) but the truth is I make POTA/SOTA fit in my busy family schedule. This often equates to short (30-60 minute) activation windows.
Then quite often, I’m on the road or doing errands in town and realize I have a short opening for an activation, so I squeeze it into the day. This is why I always have a fully self-contained field radio kit in my car. At a moment’s notice, I can set up a station, and play radio.
In a way, I find this style of quick activation fun, too. “Can I seriously validate a park during this short window of time–?”
These activations remind me of that scene in A Christmas Story where the father gets a small thrill out of timing himself as he changes a flat tire on the side of the road. I totally get that.
Except with me it’s deploying antennas instead of managing lug nuts.
Hamfest time!
Friday, September 2, 2022 was a big day for me. On the way back from visiting my folks that morning, I spent a couple of hours at the Shelby Hamfest.
The Shelby Hamfest typically has the largest outdoor tailgate market in all of North Carolina and likely one of the larger ones in the southeast US. I had no items on my wish list, I just wanted to see what was there.
This was the first hamfest I’d attended in a little over a year. It was a lot of fun and I got to meet a number of friends and readers/subscribers.
Driving home after the Shelby Hamfest that early afternoon, I realized I was passing dangerously close to the Clear Creek access of South Mountains State Park.
I had a couple of errands to run back home before the post office closed at 17:00 that day, but in my head I believe I had just enough time for a quick activation. The total amount of detour driving would only be about 15 minutes; I’d just need to keep the activation (including most set up and pack up) under 45 minutes or so.
At the last minute, I took a right turn and headed to the park!
Fortunately, the one lonely picnic table at the Clear Creek access was unoccupied.
I grabbed my IC-705 kit and a new antenna!
The MM0OPX QRP End-Fed Half-Wave (EFHW)
A few weeks prior, Colin (MM0OPX) reached out to me and asked if I would consider testing a new high-quality, highly-efficient QRP EFHW he’d designed.
Of course, there’s nothing new about an EFHW–it’s one of the most popular field antenna designs on the planet–but Colin’s goal was to make one with the lowest insertion loss possible in a compact, lightweight (50g), and durable format.
I say he succeeded.
In fact, this activation was actually the second one where I used Colin’s QRP EFHW. The previous day, I paired it with a then very Beta version of the Penntek TR-45L at Tuttle Educational State Forest (K-4861).
In short, the antenna made for a wildly successful QRP activation. Here’s the QSO Map (you’ll need to click and enlarge to see the number of contacts):
QSO Map from the previous day with the MM0OPX QRP EFHW
The Penntek TR-45L was still quite new at the time and even though I got John’s (WA3RNC) blessing, I didn’t post the activation video and mini overview on YouTube. Keep in mind the TR-45L was still in Beta so not all features had been finalized.
As I mentioned in a previous post, I’ve now invested in a Pro account with Vimeo that allows me to post completely ad-free videos that my Patreon supporters can enjoy and even download. I recently discovered that YouTube unfortunately inserts ads even though I have monetization turned off. I pay for Vimeo’s bandwidth and server space, so I also can control the ad experience completely (basically eliminating any possibility of ads!).
My Patreon supporters are the ones making it possible for me to pay the annual $420 fee to Vimeo and I am incredibly grateful, so I pass along the benefit to them.
The entire time I was in Canada this summer–about two months–I used two field transceivers: the Elecraft KX2 and the Discovery TX-500.
I did sneak in two extra radios under the floor of my trunk/boot space, but they both were limited to three watts and conditions were so rough during many of my activations, I wanted the option of a QRP “Full Gallon” (5 watts). Thus, I stuck with the TX-500 and KX2 (which are both actually capable of 10 watts output).
When I got back to the States, I was eager to do a POTA activations with my other radios–many of you know I like to rotate them–but there was one, in particular, I was eager to put back on the air…
The Mountain Topper MTR-4B.
This MTR-4B V2 is on loan to me from a very generous reader/subscriber. In fact, get this: he ordered the MTR-4B early this year and had it drop-shipped to me directly from LnR Precision. He knew I’d be in Canada for the summer, so has been incredibly flexible with the loan period (basically leaving it open ended).
My review of the MTR-4B will be published in the November or December (2022) issue of The Spectrum Monitor magazine. Then I’ll be sending the MTR-4B to its rightful owner!
In the meantime, I built an ultra- compact field radio kit around the MTR-4B and in my Tom Bihn HLT2 EDC pouch.
This kit is nearly identical to the one I made for my MTR-3B (just a different color, really).
It contains the radio, a battery, an antenna (although I used a different one during this activation), fused power cord, paddles, earphones, RF choke, RG-316, logbook, pencil, and even a full throw line and weight. I’ve listed all of the components with links below.
It’s hard to believe it all fits in such a compact kit and it works so well. It’s nice to know that with the kit it in my backpack, I’ve got everything I need to play SOTA or POTA at the drop of a hat.
South Mountains State Park (K-2753)
On August 8, 2022, I drove to my hometown to check in on my parents. I didn’t have a lot of time, but I wanted to fit in a quick activation with the MTR-4B along the way.
One of the easiest parks for me to hit en route is the South Mountains State Park Clear Creek Access–it’s maybe a 10-15 minute detour off of Interstate 40.
The weather was amazing that day, although I’ll admit I had to get used to the heat and humidity after spending so much time in Canada this summer!
This access point of South Mountains only has one picnic table. I’m always prepared with a folding chair if that table is occupied, but so far it’s always been available. I’m sure the reason is because this particular South Mountains access point is way less popular than the main entrances. Most of the visitors here come to fish at the reservoir.
Setting up
The great thing about having your whole station in a pouch is that setup is quick and easy.
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Many thanks to Mike (KE8PTX) who shares the following tip:
