(Source: Southgate ARC)

Antennas come in many shapes and sizes, with a variety of characteristics making them more or less suitable for various applications. The average hacker with only a middling exposure to RF may be familiar with trace antennas, yagis and dipoles, but there’s a whole load more out there. [Eric Sorensen] is going down the path less travelled, undertaking the build of a self-tuning magnetic loop antenna.

[Eric]’s build is designed to operate at 100W on the 20 meter band, and this influences the specifications of the antenna. Particularly critical in the magnetic loop design is the voltage across the tuning capacitor; in this design, it comes out at approximately 4 kilovolts. This necessitates the careful choice of parts that can handle these voltages. In this case, a vacuum variable capacitor is used, rated to a peak current of 57 amps and a peak voltage of 5 kilovolts.

The magnetic loop design leads to antenna which is tuned to a very narrow frequency range, giving good selectivity. However, it also requires retuning quite often in order to stay on-band. [Eric] is implementing a self-tuning system to solve this, with a controller using a motor to actuate the tuning capacitor to maintain the antenna at its proper operating point.

If you’re unfamiliar with magnetic loop builds, [Eric]’s project serves as a great introduction to both the electrical and mechanical considerations inherent in such a design. We’ve seen even more obscure designs though – like these antennas applied with advanced spray techniques.

Read the full article
https://hackaday.com/2019/03/17/building-a-magnetic-loop-antenna/

With the arrival of summer weather, the outdoor ham radio season is upon us! Outdoor operating is an important part of my ham radio hobby and I plan to participate in the following field events in a big way.

Saturday-Sunday, June 27-28, 2015: ARRL Field Day

Field Day is the ARRL’s biggest operating event and, with a history going back to 1933, is one of the ARRL’s oldest operating events. Field Day is the “big daddy” of portable operating events and more than 40,000 hams are expected to participate this year. Operate QRP or QRO. Operate CW, SSB, or digital; operate with a local club, a group of friends, with a single friend, or alone. The important thing is to set up a station and operate!

Full rules and other materials can be found here:
http://www.arrl.org/field-day.

I will be participating with the Athens County Amateur Radio Association’s Class 1A, solar-powered operation at the Athens County (Ohio) Fairgrounds.

Sunday, July 26, 2015: The Adventure Radio Society’s Flight of the Bumblebees

The Adventure Radio Society’s Flight of the Bumblebees hasn’t been around since 1933 but it has been an annual event since 1997, which is a long time these days. Flight of the Bumblees is a four-hour event held annually on the last Sunday of July. Both home-based and portable operations are allowed but those who operate from the field are the Bumblebees and are worth a 3x multiplier. Bumblebees are encouraged to reach their operating locations principally under their own power by walking, bicycling, kayaking, etc.; the distance traveled using human-power is up to the individual operator’s discretion.

Full rules and instructions for receiving a Bumblebee Number can be found here: http://www.arsqrp.blogspot.com/.

I have participated in Flight of the Bumblebees most years since 1997 and look forward to participating again in 2015. I plan to bicycle with my KX3 Travel Kit (info) from my home to my operating location somewhere in Athens County, Ohio.

Sunday, August 9, 2015: New Jersey QRP Club’s Skeeter Hunt

This year marks the 4th annual running of the Skeeter Hunt, a four-hour sprint-type event whose objective is to get QRPers out of their shacks for the day and into fresh air and sunshine. Those who operate outdoors qualify as “Skeeters”.

Full rules and instructions on receiving a Skeeter Number can be found here: http://w2lj.blogspot.com/p/njqrp-skeeter-hunt.html.

WD8RIF has participated in every Skeeter Hunt since the first one in 2012 and has enjoyed the event every year.

Over the next thirty days there are three QRP field operating events to take part in.

This coming Sunday, July 13,  is the second annual Scorch Your Butt Off event. This six-hour event is like the more familiar wintertime Freeze Your B___ Off event except for this event the score multiplier goes up the hotter the temperature recorded at the key or microphone. The rules for Scorch Your Butt Off can be found here:

http://www.qsl.net/sybo/Scorch_Your_Butt_Off/SYBO.html

Sunday, July 27, is the date of the Adventure Radio Society’s Flight of the Bumblebees, an event with a long and storied history. For this four-hour sprint, those who use human-power to get to their operating locations earn the right to a “bumblebee number”; each contact with a “bumblebee” counts as a score multiplier. The rules for Flight of the Bumblebees will be posted here Friday, July 11:

http://www.arsqrp.blogspot.com/

Sunday, August 10, is the date of the 3rd annual New Jersey QRP Club Skeeter Hunt. Those who operate in the field can request a “skeeter number” and are worth more points than “non-skeeters”. This year there’s a score multiplier for using homebrew or kit-built equipment. The announcement and rules for the Skeeter Hunt can be found here:

http://w2lj.blogspot.com/p/njqrp-skeeter-hunt.html (announcement)
http://www.qsl.net/w2lj/ (rules)

So—three good reasons to take a QRP rig and field-antenna outdoors and have some fun!

… one hears behavior on the air that reminds one that courtesy can still, occasionally, be heard on the HF bands.

I’ve made it a goal this year to earn a Worked All States (WAS) certificate working only the ARRL Centennial Celebration W1AW/portable stations using CW and QRP power levels. I’ve managed to work W1AW/portable stations in 27 states so far–I started a few weeks late and missed the first few states but will pick them up in the second half of the year–but I’ve heard some atrocious pile-up behavior while doing so.

This evening, while trying to work W1AW/1 (NH) or W1AW/2 (NJ)–I can’t remember which because I  eventually worked each on several bands before turning the rig off for the night–I neglected to put my KX3 back into split-mode after changing bands, so on my first call to the W1AW/portable station I was transmitting on his frequency, not up as I was supposed to be. Before I could even realize my mistake, I heard someone send a simple “IF UP”–the last two letters of my callsign and “UP”–just once, on the W1AW/portable station’s frequency. Not the “UP UP UP” we  hear far too frequently these days or even “UP UP UP LID“. Just one transmission of “IF UP” to tell me, WD8RIF, that I had made an error. One short, polite, courteous transmission.

I have no idea who this polite ham was. If I did, I would send him an email thanking him for his short, polite message to me.  Maybe he’ll stumble upon this posting on QRPer.com and learn how much I appreciated his simple transmission to me.