With the COVID-19 pandemic, I have been spending a lot of time at home lately. We had some decent weather today, so I went out to do some portable operating while practicing social distancing.
My daughter and son-in-law recently purchased an old farmhouse that they are restoring. The farmhouse is located on a large piece of property with plenty of room for QRP-portable operating. No one was there today, so I had all that acreage to myself. That made the social distancing thing easy.
I had a portable delta loop antenna that I built a year or two ago but never tested. Today seemed like a good time to try it out. I set the antenna up behind an old barn and operated my KX3 from a camp chair. (I’ll be doing a detailed write-up on this antenna soon.)
I spent some time seeing which bands the KX3 would tune. Once that initial testing was done, I tuned up on 20M and started calling CQ. After the third CQ, I received a call from fellow SKCC member F8FSC in France. We both struggled with fading, but I was thrilled that he heard my meager 5-watt signal.
I bumped my power up to 10 watts to improve my odds. I heard N3PDT calling CQ from Missouri and gave him a call. We exchanged SKCC numbers and chatted for a bit.
Tuning down the band, I heard F6HKA booming in from France. I sent my callsign once, and he got it the first time. Bert gave me a 549 and said I was peaking at 569. We exchanged SKCC numbers and chatted for about 10 minutes before signing. I’ve worked Bert many times, and it’s always a pleasure.
It was sunny but somewhat chilly and windy out there today. As I was working Bert, though, it started getting cloudy. I was starting to feel the cold, so I figured it was a good time to pack up and head home.
It felt great to be playing radio outside and not thinking about the pandemic.
In a recent post, I covered some (very) basic information about the venerable doublet antenna. This time around, I’ll cover some practical examples. These are antennas I have used and one unique design I know of.
Doublet Fed with TV Twinlead
My go-to portable antenna for several years was a simple doublet fed with 25 feet of that cheap, brown TV twin-lead. For the radiating elements, I used some #22 stranded hookup wire.
I first built the antenna as a 40M dipole fed with RG-174 coax. After a while, I wanted to cover multiple bands, so I removed the coax and replaced it with the twin-lead. I used a small piece of fiberglass perf board for the center insulator.
I have often used my homebrew Z-match tuner to load it up, although a 4:1 balun and a short run of coax to my rig’s internal tuner works fine, too. The whole antenna weighs next to nothing, and fits in a sandwich-sized Ziplock® bag.
Nothing fancy but it works great.
Up and Outer
The Up and Outer is simply a doublet with one vertical leg and one horizontal leg. I had done some experimenting with this old-time antenna and decided to build one to use while on vacation in the Outer Banks of North Carolina.
I planned to support the vertical leg with a 28-foot Jackite pole, so I made a simple modification to a 44-foot doublet I had on the shelf. I spliced 6 feet of additional wire to each of the elements down to 28 feet each, and I was in business. Like my 40M doublet, the Up and Outer is fed with TV twin-lead and uses a perf board center insulator.
This antenna always goes with me on our annual Outer Banks vacation. I’ve used it from numerous beach rental houses, and it’s perfect for use on a second story deck. I used it last summer with great results, connecting it directly to my KX3. And, if I need to, I can use it as a normal horizontal doublet.
Appalachian Trail (AT) Dipole
This design is the brainchild of my friend, Ed Breneiser WA3WSJ, and goes back about 20 years. Rich Arland K7SZ, wrote about it in his QRP column in QST  back in 2001 and devoted a few pages to it in one of his books .
In simplest terms, it’s a 40M doublet made from #26 copper-clad stealth wire. Ed used a 3/4-inch PVC end cap for the center insulator (see photo). After soldering wires to an SO-239 socket and routing the wires through the end cap, the inside of the end cap is potted with epoxy. This makes it pretty much bomb-proof.
The antenna is fed with 300-ohm ladder line, which is soldered to a PL-259 UHF connector. The PL-259 probably causes a slight imbalance, but in the field, you’ll never notice it. You can also feed it with coax and use it as a normal 40M dipole. Pretty cool, huh?
When I built mine, I went with some #22 stranded hookup wire I had on hand. Although I departed from Ed’s design a bit, this doublet has been a reliable portable antenna over the years.
WV0H Park Doublet
Myron WV0H designed a unique doublet that he dubbed The WVØH Park Portable Doublet. He uses two 50-foot pieces of wire to create a 60-foot doublet fed with a built-in open-wire feeder. I won’t attempt to offer a detailed description here; Myron’s blog post provides all the details you need to build one. Go check it out.
While I’ve never used Myron’s unique antenna, I can vouch that it works. I worked Myron a few years back while he was out in a park with his doublet. I can attest that it puts out a great QRP signal.
Well, that’s about it. If you need a reliable, easy-to-build, multi-band antenna, give the time-tested doublet a try.
73, Craig WB3GCK
References:  Arland, R. (2001, July). QRP Power – Antenna Time. QST, p. 100.  Arland, Richard K7SZ, Low Power Communication – The Art and Science of QRP, The American Radio Relay League, 2nd Edition, 2004, Chapter 6, pp. 6-36, 6-37
I was recently going through my stash of portable wire antennas and came across one of my old favorites—the doublet. I don’t see too many references to this type of antenna these days, but the doublet provides a great portable antenna option.
What is it?
The doublet, simply put, is just a dipole. The difference is that you feed it with a balanced feeder, rather than coax.
Hams have been using doublets for many years. The earliest reference I could find in the ARRL QST archives was from September of 1929. In this write-up, Clair Foster W6HM describes a 40M doublet fed with twisted wire lamp cord used for receiving.
Advantages of the Doublet
The balanced feeder provides some advantages. Depending on how it’s constructed, it can withstand higher SWR with lower losses than coax. Because of the low losses at high SWR, you can use the doublet as a multi-band antenna.
As a portable antenna, it’s hard to beat, especially as an inverted vee. Use a tree branch or telescopic pole to hoist up the center, tie off the ends, and you’re in business. 
This multi-band capability comes with some disadvantages, though. Fortunately, none of them are insurmountable.
First, you’ll need a transmatch that can handle balanced feedlines. Typical commercially-available feedlines have either 300 or 450-ohm characteristic impedances. For open-wire feedlines, the impedance can sometimes be 600 ohms or more.
You can also use a balun to transition from the balanced feedline to 50-ohm coax. While this isn’t an optimum approach, it works. Textbooks often recommend a 4:1 balun, and that’s a good starting point. If you go this route, I recommend keeping the coax as short as practical. If you run into matching problems on some bands, try another balun ratio (e.g., 1:1), or change the length of your feedline.
The second drawback is that you need to be careful of how you route balanced lines. You need to avoid getting it too close to metal or laying it on the ground. Both can upset the line’s balance. This can cause it to radiate or introduce losses. If you have excess line, don’t coil it up. Operating outdoors, I found these restrictions aren’t very difficult to work around; you just need to be mindful of them.
Building the doublet is pretty simple. Many folks suggest making the doublet a half-wavelength long at the lowest band you intend to use. I’ve built one for 40M and it worked well on 40M and higher. Depending on your tuner, it may also be usable on the next lower band.
L. B. Cebik W4RNL (SK) popularized the 44-foot doublet for 40M-10M. According to Cebik’s analysis, this length produces a more consistent radiation pattern across the bands.
Regardless of the size of the doublet, you should try to avoid certain feedline lengths. One rule-of-thumb suggests avoiding combinations of feedline electrical length plus one leg of the radiator that are odd multiples of an eighth-wavelength.  If you run into matching problems, you can try adjusting the length of either the feedline or the radiating elements.
You have several options here:
Commercial 450-ohm or 300-ohm ladder line. These are commonly available, and they work great.
Homebrew open-wire feeders. This is the most efficient option. If you do some Internet searching, you’re likely to find lots of ways to build open-wire feeders. SOTABEAMS has a great example on their website.
TV twin-lead. I’ve used the cheap, brown stuff quite a bit for portable doublets. Unfortunately, it’s nearly impossible to find these days. If you come across it somewhere, stock up!
Lamp cord or speaker wire. This works and I’ve seen folks use it for portable antennas. However, it can be lossy, compared to window line or open-wire feeders.
If you want more technical details on this antenna, information abounds on the Internet and in antenna books. In particular, Cebik wrote some great articles that are worth searching for.
In a future post, I’ll cover some practical examples that I have come across or used in the field.
73, Craig WB3GCK
References:  Foster, C. W6HM (1929, September). Experimenters’ Corner: The “Doublet” for Receiving. QST, p. 39.  DeMaw, D. W1FB (1991). Technical Bits & Pieces. In W1FB’s QRP Notebook (2nd Ed., pp. 157–161). Newington, CT: QST.  Heys, John D., G3BDQ (1989). Center-fed antennas using tuned feedlines. In Practical Wire Antennas. Bedford, UK: Radio Society of Great Britain, p 7.
[NOTE: This is an updated version of an old article from my QSL.NET website. In the interest of full disclosure: My local dollar store no longer sells the speaker wire I used. While it’ll probably cost you a few more bucks to build one, it’ll still be a cheap antenna. Although the original article has been on my website for 15 years, I still get the occasional email from folks who have built one.]
I love rummaging through our local dollar store. One of the biggest bargains in our local dollar store is speaker wire. You can get 50 feet of two-conductor speaker wire for a buck. Not too shabby. I always keep a bunch of the stuff on hand for antenna experimentation.
Using a single 50-foot roll of dollar store speaker wire, I made a simple 50-foot random wire antenna with counterpoise wires to cover the 40, 30 and 20-meter bands. I stashed the whole kit in a zip-lock sandwich bag and always keep it on hand as a backup antenna system whenever I operate in the field. With a simple antenna tuner of some sort, this will get you on the air in a pinch, should your primary antenna fail.
Here’s all you have to do:
Separate the conductors so that you now have two separate 50-foot wires.
For the radiator, take one of the 50-foot wires and crimp a small ring lug to one end—right over the insulation. This gives you someplace to tie a line to hoist it up. On the other end, just strip off a half-inch or so of the insulation. You can leave it bare or add whatever kind of connector you want; whatever works best with your tuner.
For the counterpoise wires, take the remaining 50-foot wire and cut it so that you have a 33-foot wire and a 17-foot wire. If you only want to work 40 and 20 meters, you can stop right here. You now have counterpoise wires for both of these bands.
To provide a counterpoise wire for 30 meters, take the 33-foot wire from Step #3 and cut it so that you now have a 23-foot wire and a 10-foot wire. Strip off about 1/2-inch of insulation from one end of the 23-foot wire. Install a quick-disconnect connector of some sort on the other end, so that you can join the 23-foot and 10-foot wire sections together. The idea here is that, with the two wires connected, you have a 33-foot counterpoise wire for 40 meters. With the two sections separated, you now have a 23-foot counterpoise wire for 30 meters.
[Note: If you only plan to operate with the radials laying on the ground, cutting them to resonance isn’t too important. You can simplify things a bit by going with just the 33 and 16-foot wires. I think two 25-foot wires would be sufficient, as well. Three 16.6-ft radials is another option to consider. Feel free to experiment here and see what works for you.]
In operation, just hoist one end of the 50-foot radiator up in a tree or other suitable support. Connect the other end to the hot side of your tuner. Connect the 33-foot and 17-foot counterpoise wires to the ground connection on your tuner and lay them out on the ground. When you want to work 30 meters, just disconnect the quick-disconnect on the longer counterpoise wire. Pretty simple, eh? Any type of simple L-tuner should work fine for this.
Please note that I wouldn’t recommend using this wire for a permanent outdoor antenna. It’s not suited for that kind of use. But for temporary outdoor use, it’ll do just fine. Besides, if the wire goes bad, you can always replace the whole thing for a dollar!
Nothing can bring a portable radio outing to a screeching halt faster than forgetting to pack a critical item—an adapter, a cable, or heaven forbid, a radio. Been there, done that. My solution is a detailed checklist for such occasions.
At some point in my life, I became an obsessive checklist maker. Back when I was still working for a living, I relied heavily on checklists for my daily to-do list, things I needed to prepare for meetings, and the like. I naturally carried that habit over into my ham radio hobby.
Ham Radio Checklists
I keep a variety of checklists handy for different types of operating. A few of my standard checklists are:
Stationary-mobile operating from my truck
Operating from the camper
I also keep some checklists for some special events:
Our annual summer vacation
For those one-off, ad hoc events, I sit down in advance to prepare a special checklist of things I need to take.
I know all this sounds like a no-brainer, but I wasn’t blessed with the greatest of memories. When I try to take a shortcut around this process, the risk of forgetting an important item goes way up.
Preparing the Checklist
When developing a checklist, I do a mental walk-through of my setup in the field. I simply try to visualize setting up and make a detailed list of the things I’ll need. This method works for simple setups. For more complex set-ups, I sketch it out on paper and make my checklist from that.
An even better approach is to assemble the equipment at home. Then you can do a detailed inventory of your equipment to form your checklist.
When I prepare a checklist, I first list out the containers (backpack, box, bag, etc.) that I’ll be using to carry the equipment. Next, I list out everything that needs to be in those containers. I indent these items on the checklist below the container.
As items are packed in a container, I check them off. Then, as the containers are loaded into my truck, they are checked off.
I also keep a list of things I need to do before the event. I call this my pre-flight checklist. I use this list to make sure batteries are charged, my truck’s GPS is programmed, and the like.
For years, I created my lists using a word processor. When it was time to pack, I just printed them out. That works fine, but I now use a paperless method.
I now use an application called Evernote to keep my checklists. My checklists are stored in the cloud, so I can access them from any of my computers and even my cellphone. I can check off items on my phone as I’m packing. After the event, I just go in and un-check the items, and the checklist is ready to go for the next outing.
You can get a basic Evernote account for free. There are paid options for folks (like me) who need additional capabilities and features.
Some “Pro Tips”
Here are a few lessons I’ve learned over the years:
Don’t be too quick to check off an item. If you check off an item before it is physically in the container or loaded into your vehicle, you’ll eventually run into problems. Don’t ask me how I know this; just trust me on this one.
After an event, take a few minutes to update your checklist, if needed. Was there something you wish you had brought or should have left at home? Some of my frequently-used checklists have been evolving for decades.
So there you have it. I know this is a somewhat mundane topic, but checklists have saved my bacon on several occasions.
With family coming in this weekend, I wasn’t sure if I’d be able to participate in this year’s Winter Field Day. I did, however, manage to get out for a couple of hours at the start of the contest.
It was raining cats and dogs when I arrived at Black Rock Sanctuary, one of my favorite operating spots. I had my usual stationary-mobile set up ready to go a few minutes before the starting time.
I mostly operated CW on 40M and 20M, but I did manage a couple of rare—for me, at least—SSB contacts on 40M. I ended up with 20 contacts in my log. There were quite a few familiar callsigns from previous Winter Field Days.
It was getting hard to find new CW stations to work, so I decided to head out and get some errands done. I hope everyone who stuck it out had a fun—and warm—Winter Field Day.
The weatherman was predicting snow, sleet, and who-knows-what for my area today. I figured I get out for my QRP-portable fix before the weather got too bad.
My location was Schuylkill Canal Park in nearby Mont Clare, Pennsylvania. It’s just across the river from Phoenixville, and it’s been a while since I operated from there.
By the time I got to the park, there was a coating of snow on the ground, and it was still coming down steadily. Except for a couple of mountain bikers and joggers, I had the park to myself.
After putting the antenna on the back of my truck, I tuned around on 40M and found W8BJO calling CQ from Ohio. Our QSO was interrupted by QRM, and I lost him.
I went up to 20M and worked K0RO from Mississippi. Ralph was operating as K3Y/5 in the annual SKCC K3Y event. Next, I called F6EJN, who was operating in the K3Y event representing Europe. Bob was very strong into Pennsylvania, and he gave me a 589 report. My last QSO was with fellow SKCC’er, WD5BVQ, in Louisiana.
The temperature was about 20°F, and I was starting to feel it. I started the truck once or twice for some heat, but that caused some noise in the radio. The accumulation was over an inch, and the road into the park was untreated. I figured I had better head out before things got worse.
It was a short but fun outing, but it was good to get home and warm up.
As in past years, we rented a cabin at the Mohican Outdoor Center (MOC) near Blairstown, New Jersey. This year’s crew included Ed K3YTR, Glen NK1N, Ed K3BVQ, John NU3E, Ed WA3WSJ, Walt KB3SBC, and me.
On Friday, some of the early arrivals headed out to Crater Lake to do some operating. The road down to the lake was closed, so they operated from the nearby Blue Mountain Lakes Trailhead instead. I arrived mid-afternoon as NK1N and NU3E were putting up an inverted L antenna outside the cabin. Glen had already set up a station inside the cabin. After settling in and catching up with old friends, we all drove into Blairstown for dinner at Buck Hill Brewery and Restaurant.
I volunteered to provide breakfast on Saturday, so I made breakfast sandwiches for everyone. (I refer to them as Craig McMuffins—with apologies to a certain fast-food restaurant chain.)
After breakfast, everyone took off in different directions. NK1N and NU3E hiked up to Raccoon Ridge on the Appalachian Trail. WA3WSJ went over to the Pennsylvania side to operate from some scenic overlooks. K3YTR did some experimenting with antennas back at the cabin.
I operated stationary-mobile at the Blue Mountain Lakes Trailhead to make some contacts in the SKCC Weekend Sprintathon (WES). I did a National Parks on the Air (NPOTA) activation from this spot back in 2016. K3BVQ and KB3SBC were parked about a half-mile down the road from me doing a Parks on the Air (POTA) activation of Delaware Water Gap.
I made about a dozen SKCC contacts, including K3BVQ down the road. (Ed was a solid 599, of course.) Later, while tuning around on 20M, I heard WA3WSJ calling CQ with the club’s callsign, W3BQC. Ed was across the river in Pennsylvania at a site overlooking Delaware Water Gap. We had some heavy QRM during our short contact, but we managed to complete the QSO.
Later that night, we went back into town for our customary Saturday night dinner at the Blairstown Inn. We had a few beers, great food, lots of tall stories, and plenty of laughter. That was a great way to end the day.
NU3E made his incredible Belgian waffles for breakfast on Sunday. John’s amazing waffles have become a Sunday morning tradition on these trips. After breakfast, it was time to pack up and clean up the cabin.
I always look forward to these Winter trips with my old QRP buddies. I think it’s fair to say everyone had a great time again this year.
I always try to start each year with some QRP-portable operating. In keeping with that tradition, I headed out to participate in the annual Straight Key Night (SKN) activities.
My destination was one of my usual Wintertime haunts, Black Rock Sanctuary. When I arrived, the temperature was about 35°F with cloudy skies and occasional flurries. I operated stationary-mobile from inside my truck with my faithful 19-ft vertical mounted on the back. My MS2 straight key was my weapon of choice.
There was enough activity on 40 meters, so I never changed bands. Band conditions were pretty good, and it didn’t take long to log my first contact of 2020. Thanks to Alan W4AMV in North Carolina for doing the honors.
At one point, a curious couple approached the truck. They were intrigued with my antenna, so I spent some time chatting with them about ham radio.
After I operated for about 2 hours—and exhausted my coffee supply—I decided to pack it in. I ended up with 10 QSOs in the log. All of them were fellow SKCC members.
So, another year is underway. I already have some interesting radio activities on my calendar. This year should be fun, ham radio-wise.
Today was the monthly Polar Bear Moonlight Madness Event (PBMME). While the weather had warmed up to a balmy 50°F, it came with a bunch of rain. The weather was lousy, but the bands were pretty good.
I headed back to Black Rock Sanctuary for today’s outing, and it rained the entire time I was there. So, I hunkered down in the truck for this one.
I started on 40M and was greeted with loud static crashes from the storm passing by. Despite the QRN, I had two-way QRP QSOs with W9ILF in Indiana, WI8J in Michigan, and fellow Polar Bear, Mike VE3WMB, in Ontario.
I ventured out in the rain to configure my 19-foot vertical for the 20M band. The pipeline to the West Coast must have been wide open. I worked two California stations and had a two-way QRP QSO with K7QF in Washington state. I also had an SKCC QSO with K5DMC down in Mississippi for good measure.
There was a 10M contest going on, so I headed up there to see what was going on. My vertical was only giving me a 2:1 SWR on 10M, but that was good enough to work a contester 5 miles away.
I went back to 40M for a bit before packing up and ended up with a nice two-way QRP QSO with K4JJW in North Carolina. Dick was really booming in with his 5 watts.
After tearing down the antenna in the rain, I got back in the truck to head home. As my luck would have it, the sun was trying to break through the clouds. That figures!
Nonetheless, I had fun today. Now it’s time to go dry out some antenna parts.