Old Tuner to the Rescue

According to the weather prognosticators, today is the start of a 4- or 5-day heatwave here in southeastern Pennsylvania. So, I wanted to get out early for some antenna testing before things heated up too much.

I planned to play around with the speaker wire end-fed halfwave antenna I built recently. To do this, I went back to my favorite antenna test range—my daughter and son-in-law’s property. 

I set up the formerly 66-foot wire (now about 63 feet) in an inverted-V configuration. Since the last time I used this antenna, I trimmed off a couple of feet to see if I could get my little Hendricks SOTA tuner to load it on 20M. 

I started with the SOTA tuner on the 40M band and worked a POTA activator in Indiana. I moved up to 20M, but the SOTA tuner wouldn’t tune below a 2.2:1 SWR. 

Before I left the house today, I had the forethought to pack an old antenna tuner I built about 25 years ago. I used it extensively years ago, but I relegated it to the shelf when fancier equipment came along. I switched to the old tuner, which I configured as an L-match. It loaded up nicely on 40, 20, and 15 meters. As a bonus, the old-school tuner gave a good match on 30 and 17 meters. 

My 25-year-old homebrew antenna tuner. It doesn't look like much, but it did a nice job with my end-fed halfwave antenna cut for 40M.
My 25-year-old homebrew antenna tuner. It doesn’t look like much, but it did a nice job with my end-fed halfwave antenna cut for 40M.

After I finished experimenting with the antenna, I set out to make a few contacts. It was a busy day for Parks-on-the-Air (POTA) activators. I worked 10 of them in 8 states plus Puerto Rico. Three of the QSOs were on 17 meters. It was nice to hear POTA activity up there. 

All in all, I was pleased with how my old homebrew antenna tuner performed. I don’t think it will be spending as much time on the shelf in the future.

73, Craig Wb3GCK

Memorial Day 2021

I was out of town visiting family for most of the weekend. However, I managed to get out for a brief QRP-portable outing this afternoon.

I headed back up to my daughter’s property and set up on top of a hill. The ground was a bit muddy from recent rains, so I set up in my truck. I set up my KX3 in the cab and mounted my 19-foot vertical on the back.

WB3GCK operating portable on Memorial Day 2021
WB3GCK operating portable on Memorial Day 2021

I started with an SKCC QSO on 40M with KG4GCX in North Carolina. I also had a chat with K4VSV in South Carolina. Bill was running 10W and was pounding into southeastern Pennsylvania.

I spent the rest of my time hunting for CW POTA activators and managed to work 5 of them: WD5GRW in Texas, K7CO in Utah, NG5E in Oklahoma, KD8IE in Ohio, and WB0TUA in Michigan. Thanks to these folks who took the time on a holiday to activate parks.

I hope all of my U.S. friends have a safe and enjoyable holiday. Please take time to remember those who made the ultimate sacrifice to defend our freedoms.

73, Craig WB3GCK

Speaker Wire EFHW Antennas

A while back, I challenged myself to see what kind of antennas I could make from a cheap 50-foot roll of two-conductor speaker wire. This time I made a couple of end-fed halfwave wires for the 40M and 20M bands. 

My aim with these projects is to make (nearly) full use of the 50 feet of speaker wire. I figured that would be enough for 66-foot and 34-foot radiators for the 40M and 20M bands, respectively. These dimensions work with the Hendricks SOTA Tuner (now sold by Pacific Antenna) I planned to use with them. 

Construction couldn’t be more simple:

  • Starting with 50 feet of speaker wire, separate the conductors.
  • Cut one of the wires into two lengths, 34 and 16 feet.
  • Splice the 16-foot wire onto the 50-foot wire. Now you have wires that are approximately a halfwave on 40M (66 feet) and 20M (34 feet).
  • I added spade lugs to one end of each wire. 
  • I used pieces of a used gift card to make end insulators that would allow for adjustments if needed. (See photo)
Speaker Wire EFHW Antenna diagram
Speaker Wire EFHW Antenna diagram

Of course, you’ll need an antenna coupler to match these wires to your rig. The SOTA Tuner I used worked fine, but each wire operated only on a single band. I cheated a bit and used some other scrap wire to make two short counterpoise wires, 5 feet for 40M and 3 feet for 20M. Of course, you could always use the 34-foot wire as a counterpoise for the 66-foot wire if you’d like. 

An improvised end insulator made from an old gift card. I used this so I could shorten the wire, if needed, by folding it back on itself.
An improvised end insulator made from an old gift card. I used this so I could shorten the wire, if needed, by folding it back on itself.

I haven’t tried it yet, but an L-network transmatch should allow the 66-foot wire to work on 40M, 20M, and 10M. A 49:1 transformer might also give you multiple bands with the 66-foot wire. You’ll likely need to adjust the length to obtain a match. You’re on your own here.

In the field, the SOTA Tuner provided a good match on both wires. I used the 66-foot wire as an inverted vee and the 34-foot wire as a sloper. I had no trouble making contacts on both bands with 5 watts.

Of course, you could build these antennas with any old wire. After all, it’s just wire. But, I enjoy the challenge of being constrained by the 50 feet of speaker wire. 

I have more speaker wire and more antenna ideas, so you’re going to be subjected to more of these crazy projects in the future.

73, Craig WB3GCK

Summer Weather Preview

The temperature climbed into the 80s (F) today, giving southeastern Pennsylvania a taste of the warmer weather to come. It seemed like a good day for some QRP-portable operating.

I had a couple of end-fed halfwave (EFHW) antennas I built last night that I wanted to try out in the field. So, I headed out to my daughter’s property and set up on the top of the hill. I set up my KX3 on a small table and set up a 40M EFHW antenna as an inverted vee. (I’ll do a separate post on these antennas.)

Taking advantage of the warm weather today
Taking advantage of the warm weather today

The band was somewhat noisy. I suspect it was coming from the power lines that cross the property. Undeterred, I started calling CQ on 40M near the Straight Key Century Club (SKCC) calling frequency. I soon received a call from WA2JMG in New York. Pete was operating outdoors from his deck.

Next up was a two-way QRP SKCC QSO with WN1MB in Connecticut. Jeff was running 2 watts and cutting through my local noise. I finished up on 40M by working a New England QSO Party (NEQP) station in Maine.

At this point, I took down the 40M wire and replaced it with a 20M EFHW configured as a sloper. Thankfully, the noise was slightly lower on this band. When I wasn’t playing around with the antenna, I worked a couple more NEQP stations.

At this point, I had lost my shade and had the sun beating down on my neck (and the KX3). It seemed like a good time to pack up and head home for lunch.

I’m looking forward to more weather like this. Next time I’ll set up in a spot with more shade.

72, Craig WB3GCK

First Camping Trip of 2021

We kicked off our 2021 camping season over the weekend. Although we had a few issues with the QRP Camper, we had a great time nonetheless.

As is our usual practice, we headed up to French Creek State Park near Elverson, PA, for our first trip. It’s close to home and a good place for our shake-down trip. It’s also a convenient location for our grandkids to come and hang out at the campsite. 

Radio-wise, I used my trusty Elecraft KX3 and a 29.5-foot wire vertical. I fed the vertical wire through the weather-resistant UnUn I built recently.

After getting things set up, I tested the antenna and had a Straight Key Century Club (SKCC) QSO with a station in Michigan. Convinced that everything was working, I headed out to enjoy the campfire on a chilly evening.

The "QRP Camper" at French Creek State Park
The “QRP Camper” at French Creek State Park

On Saturday, I decided to do an impromptu Parks on the Air (POTA) activation before all of the grandkids showed up for the day. Marginal cell phone service precluded me from spotting myself. So, I moved 1 KHz up from another POTA activator, hoping someone would stumble across me while looking for him. I got off to a slow start, but eventually, things picked up. I’m assuming some kind soul spotted me. I stayed on 40M and worked about 19 stations in an hour or so. 

Later in the day, I checked the bands and worked, WA1WCC from Cape Cod. WA1WCC was commemorating the Chatham Radio/WCC coastal station for International Marconi Day (IMD). I also heard Steve K0BWR activating a park in Missouri. Conditions were rough, but Steve hung in there with me to complete a park-to-park QSO. By this time, contest stations had flooded the band, and there was heavy static from rain headed towards us. So, I pulled the plug for the night.

Speaking of rain, my weather-resistant UnUn got its first real test in wet weather. We had about six or seven hours of steady rain overnight, and the UnUn came through unscathed. 

My weather-resistant 9:1 UnUn after 6 or 7 hours of steady rain. It came through unscathed.
My weather-resistant 9:1 UnUn after a night of steady rain. It came through unscathed.

Before packing up on Sunday morning, I finished the weekend with a chat with Bob N4QR in North Carolina. Bob was using a homebrew 3-tube transmitter, and it sounded great. He said he was using a DX-160 receiver, which was the receiver I used back in my Novice days.

I have a few minor repairs to do on the camper before our next trip, but it sure felt good to be camping in it again. 

73, Craig WB3GCK

Weather-Resistant UnUn

When camping or on vacation, one of my go-to antennas is a simple 29.5-foot wire and 9:1 unun. In these situations, the antenna is usually up for days, and I have to use plastic shopping bags to protect the unun from the elements. For this project, I attempted to build an unun that can withstand the elements.

I had been thinking about this for a while. I wanted something that would protect the internal parts and provide some protection for the coax connection. Eventually, my stash of PVC pipe odds and ends caught my attention. I figured if this stuff could keep water in, it should be able to keep water out. What I came up with is somewhat weird-looking, but it should do the job

This is the completed 9:1 UnUn.
This is the completed 9:1 UnUn.

Parts

Here are the major parts I used:

  • About 2.5 inches of 1.5-inch PVC pipe
  • (1) 1.5-inch PVC end cap (slightly rounded top)
  • (2) 1.5-inch PVC end caps with flat tops
  • (1) SO-239 panel-mount connector (along with some #4 hardware for mounting)
  • A 9:1 unun wound on a T130-2 toroid
  • (1) 10-24×3/4″ stainless steel screw (along with some #10 flat washers, nuts, wingnut, and lock washer)

I have to mention a few things about the parts. The PVC end-caps with flat tops are hard to find. If you search online for furniture-grade end caps, you might find some. For winding the toroid, the Emergency Amateur Radio Club in Hawaii (EARCHI) has excellent instructions you can download. 

Construction

I wasn’t sure how I was going to put this together until I started building it. So, these won’t be detailed, step-by-step instructions. They should, however, give you a general idea of how I ended up assembling it. 

  • First, I glued the two flat end caps together, end-to-end. 
  • While the glue was drying, I wound the unun. I left the leads a little longer than the EARCHI instructions, but I cut them back as needed during assembly. I used some #22 gauge solid hookup wire for the windings.
  • I drilled a 5/8-inch hole through the two attached end caps and installed the SO-239 connector. To keep things simple, I only used two screws to mount it. So, I only drilled two holes for the #4 machine screws for mounting. I also created a couple of weep holes to allow any condensation to drain out. I don’t know if these are needed or not, but they won’t hurt. 
  • I drilled a hole in the rounded end cap for the #10 screw. I made this hole a snug fit for the screw.
  • Next, I soldered the toroid input and ground connections to the SO-239. I left the toroid leads about 1.5 inches long. I used a small lug to attach the gound lead to one of the SO-239 mounting screws.
  • I then soldered a ring lug onto the end of the output wire (antenna connection) and attached it to the stainless steel bolt. I made sure that this output lead was just long enough to make the connection to the bolt. (You probably noticed a splice in this wire. I cut it by mistake, while installing the toroid. Stuff happens!)
  • I squeezed in some foam packing material on both sides of the toroid to hold it in place.
  • Finally, I press-fitted the top end cap. The end caps are on pretty tight, so I decided not to glue the parts together. With a little effort, I can still get inside of it if needed.
This is a view of the toroid. Before I closed it up, I wedged pieces of packing foam on either side of the toroid to hold it in place.
This is a view of the toroid. Before I closed it up, I wedged pieces of packing foam on either side of the toroid to hold it in place.

I don’t typically use radials with this setup, so I didn’t provide for an external ground connection. I rely on the coax shield for the necessary counterpoise. Should I ever need to, I can easily add a ground stud. 

This is a view of the bottom of the UnUn. I added two "weep holes," in case there's any condenstation inside. These probably aren't necessary.
This is a view of the bottom of the UnUn. I added two “weep holes,” in case there’s ever any condensation inside. These probably aren’t necessary.

Field Testing

I took the unun out for a test drive, and it performed as expected. With a 29.5-foot radiator and 25 feet of RG-8x coax, the internal tuner in my KX3 was able to load it up from 80M through 6M.  (This type of antenna is certainly compromised on 80M and 60M, but I have made lots of contacts with them.)

This is the weather-resistant unun in use. I used an adjustable bungee cord to strap it to the Jackite pole. The recessed connector helps to protect the coax connection from the elements.
This is the weather-resistant unun in use. I used an adjustable bungee cord to strap it to the Jackite pole. The recessed connector helps to protect the coax connection from the elements.

The Straight Key Century Club (SKCC) Weekend Sprintathon (WES) was in progress while I was out, so I made a few contest contacts. Running my usual 5 watts, I worked two French stations on 20M. I was also pleasantly surprised to have a station in Hawaii come back to my 5-watt CQ on 15M. So, it looks like it’s working. 

I also inadvertently tested the unun’s mechanical integrity. I accidentally dropped it twice before using it for the first time. No problems.

Conclusion

I admit I might have over-engineered this thing, but it was a fun project, nonetheless. Our first camping trip of the season is two weeks away. Hopefully, we won’t have any rain. But, if we do, my antenna will be ready for it.

73, Craig WB3GCK

More Fun with the Dollar Store Special

In a previous post, I mentioned an antenna of mine that went missing. The antenna in question was a variation of my old Dollar Store Special. After I built a replacement, I found the original in my truck. No problem; as the name suggests, it wasn’t a huge monetary investment. This antenna is just another example of what can happen with some extra speaker and too much time on my hands.

The original Dollar Store Special (circa 2005) was the first of several projects to see if I could build a usable antenna from a 50-foot length of inexpensive speaker wire. The resulting antenna was a 50-foot radiator and some counterpoise wires configurable for 40M, 30M, and 20M. I used one of these for years as a backup antenna. As with all random wire antennas, it requires a tuner and, of course, some way to get one end up in the air.

For this version, I went with a 50-foot radiator and two 25-foot radials. Besides being more simple to construct, it adds a little more flexibility. Space permitting, I can use the 50-foot wire in an inverted L, inverted V, or sloper configuration. When I need a quick way to get on the air, I can use a 25-foot radiator with a 25-foot counterpoise. (Elecraft documentation often recommends the 25-foot wires as a simple field antenna. [1][2])

My updated Dollar Store Special. In addition to this configuration, I sometimes use one of the 25-foot wires as the radiator and the other as a counterpoise.
My updated Dollar Store Special. In addition to this configuration, I sometimes use one of the 25-foot wires as the radiator and the other as a counterpoise.

I refer to this antenna—with tongue firmly planted in cheek—as the Dollar Store Special 2.0. That makes it sound like a bigger deal than it actually is. I should also note that I can no longer get speaker wire at my local dollar store. I have to spend a few dollars more now, but I kept the name anyway.

Construction is as easy as it gets:

  • Get a 50-foot length of two-conductor speaker wire. I use some inexpensive 24 gauge wire.
  • Separate the two conductors.
  • Cut one of the 50-foot wires in half.
  • I added a spade lug on one end of each wire and made a small loop in the other end.
  • I also added some Goop® sealant/adhesive to hold the end loops together and provide some strain relief to the spade lugs.

The 50-foot radiator and two 25-foot radials cover 60M through 10M using my KX3’s internal tuner. Feeding it through a 4:1 unun, I can cover 80M through 10M. A 9:1 unun works well with this length also. 

With a 25-foot radiator and a single 25-foot radial, my KX3 covers 40M through 10M with no problems. Adding in a 4:1 unun makes this a Rybakov 806 antenna that covers 60M through 10M. If you’re so inclined, you could partially unroll the 50-foot wire and use it as a second radial. 

These results, of course, are highly dependent on the tuner you’re using. There’s nothing special about the 50-ft length. You can trim the radiator back to a length that provides an easier match. I stayed with the 50-foot length since I wanted to make use of the entire pool of speaker wire for these projects. Go with whatever works for you.

I’ve had good results with both configurations, and I have been impressed with the 25-foot radiator and 25-foot radial configuration. Although it’s slightly compromised on 40M, it seems to get out pretty well. 

There’s nothing at all magical about this antenna; after all, it’s just three pieces of cheap wire. However, it makes a decent backup—or even a primary—antenna kit for portable use.

As I was writing this, I jotted down two more ideas for speaker wire antennas. Somebody stop me!

73, Craig WB3GCK

References:
[1] Elecraft KX3 manual, “Antennas,” p. 6
[2] Elecraft AX-Line Owner’s Manual, “Operating Tips,” p. 4

Antenna Testing in the Field

While other parts of the country are bracing for snowstorms, the East Coast has had a run of Spring-like weather. I took advantage of one of those days yesterday to do a little antenna experimenting.

I headed back out to the property that my daughter and her husband own. I wanted to play around with some end-fed wires that I plan to use as backup antennas. (The antennas were nothing exotic, but I’ll do a couple of future posts on them.)

I set up my equipment in one of my favorite spots and started experimenting with a couple of antenna configurations. It was a little breezy on top of the hill but nowhere as bad as it was back in January.

Field testing some end-fed wire atennas
Field testing some end-fed wire atennas

I spent most of my time playing around with antennas, but I did make some contacts. The monthly SKCC WES contest was underway, so I worked eight of my fellow members. I also heard a POTA activator in North Carolina, so I gave him a call.

I accomplished what I set out to do and made a few contacts in the process. So, I declared victory and packed up for the drive home.

One of the antennas I used today was the one that had been missing since November. This time out, I couldn’t find the replacement antenna I made up. As I was searching around in my truck for it, I found the missing original antenna. As luck would have it, I also found the replacement antenna when I got home. This time, I put both antennas in places where I’ll be sure to find them. Hopefully, I’ll remember where those places are.

73, Craig WB3GCK

Finally Portable Again

You can tell from the lack of posts here that February hasn’t been a good month for me, radio-wise. Between the snowstorms, freezing temperatures, and family obligations, I haven’t been out portable at all this month. I set out this afternoon to change that before the month ends. 

We’re in a stretch of moderate temperatures this week here in Pennsylvania. The good news is that the snow is melting away; the bad news is that mud is replacing the snow. Coupled with a rainy weekend forecast, I set out for somewhere paved where I could hunker down in the truck. 

That quest lead me back to Black Rock Sanctuary near Phoenixville, Pennsylvania, one of my usual haunts. I used my trusty 19-ft vertical on the back and my KX3 up in the cab.

Snow melting at Black Rock Sanctuary. The rain tapered off, but there was a heavy fog off in the distance.
Snow melting at Black Rock Sanctuary. The rain tapered off, but there was a heavy fog off in the distance.

I had no particular activity in mind for today. I set out to make a few CW contacts and maybe work a POTA activator or two. Since there’s going to be a full moon tonight (the Snow Moon), I also hoped to contact some of my fellow Polar Bear QRPers.

Well, Eric VA3AMX didn’t disappoint. My fellow Polar Bear from Ottawa was my first contact. The 40M band wasn’t great, but we managed to complete the QSO. Eric would be my only Polar Bear today.

I ended up with nine contacts in my log. Among these were three POTA activators (MO, IN, OH) and a SOTA activator in Quebec. I also logged a couple of contacts with South Carolina QSO Party stations. The highlight of the outing was a QSO with OZ8X in Denmark on 30M. 

Despite the lousy weather, it felt good to get out for some portable operating. I couldn’t bear the thought of going a whole month without getting out. Hopefully, Spring is just around the corner.

73, Craig WB3GCK

Winter Field Day 2021

Plans have a way of changing in a heartbeat. I originally planned to do my usual stationary-mobile setup for Winter Field Day. A trip to visit family in central Pennsylvania nixed that plan. Then, at the last minute, an impending snowstorm caused us to cancel that trip. And just like that, Winter Field Day was on again—at least some limited participation.

Due to the last-minute change in plans, Saturday was out of the question for me. Instead, I headed out Sunday morning for a few hours. I went out to nearby Black Rock Sanctuary, one of my regular haunts. I kept things simple and went with my usual stationary-mobile setup: KX3 at 5 watts and my 19-foot vertical on the truck. I also left the laptop at home, opting for paper logging. 

WB3GCK hunkered down for Winter Field Day 2021. Although it was in the 20s outside, it was a balmy 40F in the truck.
WB3GCK hunkered down for Winter Field Day 2021. Although it was in the 20s outside, it was a balmy 40F in the truck.

I made a few contacts on 20M, but 40M was more active. So, I spent most of my time on 40M. As is my custom for Winter Field Day, I dusted off my microphone and made a rare appearance on SSB. 

I found this device in my bag and used it for a few Winter Field Day QSOs.
I found this device in my bag and used it for a few Winter Field Day QSOs.

I was out for about 2 hours until the snow started coming down steadily. I ended up with 24 WFD QSOs—19 CW and 5 SSB. My toes were getting cold anyway, so I packed up and headed home. Although it wasn’t my best showing, I did better than last year. In any event, Winter Field Day is always a fun time.

Now it’s time to break out the snow shovels and get ready for the snow storm that’s coming.

73, Craig WB3GCK