A few months ago, Mike (KE8PTX), contacted me with info regarding his latest 3D-printed creation: a compact housing for an end-fed half-wave balun.

He called it the “Oreo Balun.”

Once printed, and after he wound the coil and installed the BNC, he sent this photo:

It’s cute, isn’t it?

He then surprised me by putting it in a padded envelope and sending it to me as a gift. Wow–thanks, Mike!

Oreo plans

End-Fed Half-Wave antennas are popular portable antennas for a reason: they’re effective!

They’re compact, easy to deploy, and resonant.

I only needed to attach some wire to the Oreo Balun, trim it, and hit the field!

Earlier this year, my buddy Vlado and I built two doublets with some scrap wire I had in my antenna parts box.  I measured the amount of wire I had left from that same spool. I knew it wasn’t enough length for a 40 meter EFHW, but I did think there was enough for 30 meters.

After giving it a bit of thought, I liked the idea of having a dedicated 30 meter EFHW. For one thing, 30 meters is a great band for field deployments and in the past this band has saved my bacon when either 40 meters or 20 meters was wiped out. Thirty meters is also a refuge WARC band during contest weekends.  In addition, a 30 meter EFHW is short enough that it could be deployed on most SOTA summits (which often have shorter trees).

Fortunately, I had just enough wire for 30 meters. IN fact, after trimming the antenna, I only had about two feet of wire to spare. It’s as if I had planned it! I would have never guessed that spool of scrap wire would have made two doublets and one 30 meter EFHW.

The next logical thing to do was take the Oreo to the field and play radio!

South Mountains State Park (K-2753)

On Friday, February 11, 2022, I had just enough time to fit in a quick trip to South Mountains State Park for an impromptu activation and hike as I traveled back to the QTH.

The previous day, I took my Venus SW-3B on its maiden SOTA voyage and had a blast!  It was the only radio kit I’d packed on this overnight trip and, frankly, I was eager to get even more on-the-air time with it. Here’s my full gear list:

SW-3B Ultra-Compact Field Kit

• Tom Bihn Handy Little Thing (HLT) Size 2
• Venus SW-3B
• A 3′ DC power cord.
• Sony earbuds (affiliate link)
• KE8PTX’s Oreo EFHW antenna [Update: Mike notes, “If anyone wants a case I can print one for them With their call on the lid. Cost $12 US.” Contact Mike via QRZ.com.]
• Koh-I-Noor .9 mm Mechanical Pencil
• Moleskine Cahier Journal (affiliate link)
• N0SA SOTA paddles
• 20′ BNC to BNC RG-316 from PackTenna.
• 25 meters of Marlow KF1050 Excel 2mm Throwline, and an 8 oz Weaver throw weight.
• A Bioenno 3 aH 12V LiFePo Battery (Model BLF-1203AB)

Other Gear:

• Spec-Ops Brand T.H.E. Pack EDC
• Camera: OSMO Action Camera

Setup was quick and easy!

I’ll admit that I was a bit skeptical about completing a full activation on 30 meters that afternoon. Propagation that day was in the dumps; earlier, my buddy Eric (WD8RIF) had completed two activations in Ohio and noted that it took much longer to snag the ten needed for a valid activation. In this case, I was limiting myself to one band.

Audio recording

Of course, I made a real-time, real-life activation video at the park that day and since the SW-3B has no internal speaker, I paired it with my thrift store Sony ICD-PX-312 digital recorder for the second time.

I should note here that the SW-3B’s sidetone does pump a bit and you might hear this in the recording. I wish there was an easy way to lower the sidetone in the SW-3B just a touch. It’s not uncomfortable to me, I just like control of my sidetone volume. In the audio, you can hear a bit of lite popping as the recorder copes with the audio gain. Otherwise, I’m super pleased with the audio quality using the in-line recorder.

On The Air

I planned on this being a short activation mainly because I was eager to fit in a hike afterwards.

I hopped on 30 meters not knowing exactly what to expect. I started calling “CQ POTA” and after being spotted, I started working stations in rapid succession.

 

In the end, I worked a total of thirteen stations in 11-12 minutes before calling QRT. I’m certain had I taken an additional ten minutes, I would have picked up an additional 5 or so stations.

QSO Map

Here’s what about 5 watts into the Oreo EFHW can yield in short order:

Activation video

Here’s my real-time, real-life activation video–as always, without any YouTube ads:

Click here to view this video on YouTube.

 

Post activation, I did have a very enjoyable hike on the Clear Creek Trail.

No matter what time of year, the lake at Clear Creek is always beautiful.

Thank you

Thanks for joining me on this most rewarding activation!

Once again, I found that the SW-3B’s performance was admirable and tailored very nicely for the CW field op. The filter is the right width, the audio is pleasant (save the somewhat thumpy sidetone), and having that one CW message memory really helps with the workflow.

Again, if you missed out on on ordering a Mountain Topper MTR-3B from LnR Precision, then the SW-3B is a good alternative.

Of course, LnR Precision still produces the MTR-4B and I will soon have that little radio in the field thanks to a kind reader who sent it to me on loan. Interestingly, it has the 8o meter band which I don’t typically use in POTA, thus a good excuse to build something.

I’d like to send a special thanks to those of you who have been supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement as my content will always be free, I really appreciate the support.

I hope you get a chance to play radio in the coming days. Here in North Carolina, spring is definitely on the way and it’s always beautiful to the point of being completely distracting. It’s difficult to stay indoors in front of a computer. I’ve got so many field plans.

Have a wonderful week, friends!

72,

Thomas (K4SWL)