Scheduled Presentation for June 14, 2017 / 7:30 PM: Software Defined Radio and the DARPA Hackfest


The HacDC Amateur Radio Club is honored to have one of the former lead developers of the GNU Radio project in to speak with us about the exciting field of Software Defined Radio and the upcoming DARPA Bay Area Hackfest!

Our guest speaker, Dr. Tom Rondeau, writes: 

The DARPA Bay Area Hackfest, in partnership with NASA Ames, is all about exploring the electromagnetic spectrum in new and interesting ways that are likely to become consequential in both civilian and national security contexts. Toward that end, my team is putting a software radio onto a remotely piloted aircraft, a UAV, and we will make this model system available at the Hackfest to innovators in the community who we hope will develop exciting new opportunities to build better and more complex cyber-physical systems. 
The Hackfest, which is open to anyone, comprises three parts: a speaker series, a hacker space, and the Hackfest Missions. The speaker series and hacker space run throughout the week as open sessions for anyone to come to and interact with experts and enthusiasts in software radio and UAVs. In the Missions portion of he Hackfest, we are asking participating teams to solve specific technology goals based around the software radio-enabled UAV. Those wishing to participate in the Missions portion, however, must apply to do so. In this talk, I will describe the Hackfest in detail and specify how to participate in the Missions. 
By opening new ways for programming wireless systems, whether they are UAVs or internet-connected household appliances, software radio can provide the foundation for many future capabilities. This Hackfest provides an opportunity to make a big step in that exciting direction.

You can read about Dr. Rondeau’s experience in giving this presentation to the “Fat Cat Fab Lab” Makerspace in New York City, NY by going to:

A copy of Dr. Rondeau’s Biography may be found at:

We look forward to seeing you there!

“73” (Best Wishes) / Jeff Dahn – KB3ZUK / President

HacDC Amateur Radio Club

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HacDC ARC Again in Partnership with National Park Service Through Use of Amateur Radio at Public Event – May 19, 2017

Fort Hunt Day Flyer

The HacDC ARC is very pleased and honored to announce that we will again be in partnership with the National Park Service through use of amateur radio technology at a public service event. The George Washington Memorial Parkway Section will be hosting the, “History and Heritage Day at Fort Hunt Park” on May 19, 2017, from 2:00 PM-10:00 PM.

This park has a rich history of having served in secret operations during World War II, where amateur radio and Morse code technology were used at the facility. Because of our club’s relationship with the NPS in the National Capital Region, we were asked to help educate the public about amateur radio during this event. We are going to set up a working HF station and “activate” the park under the World Wide Flora and Fauna Parks on the Air Program (WWFF), unit number KFF-0670, and make contacts on various bands / modes / as conditions, operator availability and interest dictate. We will be trying to get as many “guest operators” on the air as possible to generate interest in the hobby.

We will be utilizing either call sign “W3HAC” or “KB3ZUK” in making our contacts, and anticipate running the station from 4:00 PM – 7:00 PM local time (2000-2300 HRS UTC).  We will post updates on spotting clusters and on Facebook groups for the WWFF Program if mobile coverage is available.

Additional information about the event may be found on the above listed link for the attached flyer, or by going to the link to the NPS website for the event, listed below.  We look forward to either meeting you at the event or hearing you on the bands!

73 de Jeff Dahn / KB3ZUK – President
HacDC Amateur Radio Club

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The Special Event and Presentation scheduled for today, Saturday, May 6, 2017 starting at 1400 HRS (1800 HRS UTC) at Rock Creek Park, featuring Stuart Thomas, KB1HQS, has been postponed due to rain local to the event that appears will not clear on time for needed advance set-up. A rain-date will be established and published as it becomes available. Thank you all for your interest.

73/44 de Jeff Dahn / President – HacDC ARC

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In lieu of the normal “second Wednesday of the month” club meeting scheduled for May 10, 2017 at 7:30 PM, we will be having a SPECIAL EVENT PRESENTATION occurring on Saturday, May 6, 2017 at 2:00 PM in Rock Creek Park. Stuart Thomas / KB1HQS will be our very special guest. During the 2016 ARRL National Parks on the Air initiative, Stuart earned top honors by racking up over 500 activations. He will be giving us a hands-on demonstration in the field of the types of equipment and antennas he utilized to help him achieve his first place status in the initiative.

In addition to being an accomplished author and experienced outdoorsman, Stuart is a recognized expert in the area of mobile and portable amateur radio operations. He wrote the section on Portable and Mobile Operation in the “ARRL Operating Manual – 11th Edition”; articles for “QST” Magazine; and has a book in progress with the League on portable and mobile operations. To find out more about Stuart, please go to his website:

After the demonstration station is set-up and the presentation is finished, we will use the opportunity to activate the park under the World Wide Flora and Fauna Parks on the Air Program – Park Number KFF-0656.

In the event of RAIN, we will be forced to cancel, as the equipment he will be utilizing is not water resistant.

We will be meeting at Rock Creek Park, near the benches in picnic area 23 (black circle with the number “23” in the picture), which is located just to the South side of the Tennis Stadium. Keep in mind that there are several ways in which to gain access to the area, but the physical address to the tennis center itself is:

4850 Colorado Ave, N.W., Washington, DC 20011

This should be a GREAT TIME! Lots to see, learn and do. ALL ARE ENCOURAGED TO COME AND PARTICIPATE. Even if you don’t have an amateur radio license, there will be licensed amateur operators available to help you make your first contacts on the air!!! Like all of our amateur radio meetings, this event is FREE TO ATTEND.

If you have further questions, you can email me through: or call:

(240) 304-9148.

Thanks. I hope to see you there!

“73” (Best Wishes) – Jeff Dahn – KB3ZUK – President – HacDC Amateur Radio Club

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Coming to the DC Area? Suggested Frequency Listing

If you happen to be traveling to the DC area for any reason, we are providing the attached frequency list as a courtesy reference for hams who may be frequenting the popular tourist area of the National Mall and want to know what frequencies work in the area. Our own club’s repeater (W3HAC) has only, “limited, unreliable coverage” on the National Mall, but is still useful for several areas of the city, including areas of popular hotel accommodations, in particular, in the North West quadrant of the city.

Despite the other information you may see, including on our own website about access to our own repeater, the information on this list is the most up to date and accurate information available. We are aware that there is contradictory information, including tone and code information contained elsewhere on the site. This is due to old administrative permissions allowing post access to certain areas of the site that are still being changed over and addressed internally within the club. We are working to address and correct the situation and apologize for any confusion this may cause.

All of these frequencies were field tested as of April 15, 2017 from the area from the National Mall and are accessible with a standard HT at 3 to 5 watts of output power, with the exception as noted above for our club’s W3HAC repeater. If you plan to operate in crowded pedestrian conditions, we recommend your use of headphones in order to maximize your ability to effectively copy traffic. We also recommend programming your transceiver with these frequencies in advance of potential operations in order maximize your effectiveness as an operator in the event of trying to operate in potentially crowded or stressful environments.

Many thanks to Arthur Feller – W4ART, for creating this list and field testing the frequencies.  The community owes Art a huge debt of gratitude for his service.

Welcome to Washington, DC! We hope that you have a safe and enjoyable stay in the area.

Very 73 de Jeff Dahn / KB3ZUK – President
HacDC Amateur Radio Club

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Meeting Presentation Announcement – April 12, 2017 at 7:30 pm

Some of our members recently purchased a solar powered, Arduino programmable, weather station kit from Karl, W4KRL at the Winterfest in Annandale, VA. Due to popularity of this kit, I invited Karl to come to our next club meeting to give a presentation all about it’s development, how the station works, etc. Karl has graciously accepted the invitation.

You may be surprised to learn that this is a new venture for Karl. For most of his career, as an electrical engineer, he designed large power electronics converters for rapid transit car propulsion systems. The Arduino project is the crossover between these two ventures. Planned areas of discussion include a presentation that focuses on the origin of the development of the kit, the challenge of designing a circuit board, and some of the unique technical issues involved with the design of this project.

Because of the content of this meeting, this should be of interest to not just the members of the HacDC Amateur Radio Club, but also to the general “Hackerspace”, “builder” and “maker” communities as well. All are invited and encouraged to attend.

As is the case with all of our events, there is no cost to attend. We look forward to seeing you at the meeting.

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Grabbin’ the Tiger by the Tail…

Grabbin’ the Tiger by the Tail…

Many thanks to Arthur Feller – W4ART, who led our first successful group build on the evening of March 22, 2017, of “Tiger Tails”, an antenna accessory to an HT transceiver that greatly improves transmit and receive performance.

This is the first of what are planned to be several “practical application” events. In these events, we will go beyond just learning about concepts and start to actually apply what we learn about a particular topic in a group setting in situations to enhance our skills as amateur radio operators.

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W3HAC and Members Heavily Involved in Inaugural Events in Washington, DC

The ARRL today published a story on their news page about the efforts of W3HAC members during the events of the Inauguration and the Women’s March on Washington. A link to the story can be found here:

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W3HAC Club Members Finish NPOTA Initiative With Rare Activation

img_2893On 12-31-16, several members of the HacDC ARC activated the highly sought after “Sewell-Belmont House” in Washington, DC to finish off the ARRL’s year long “National Parks on the Air” (NPOTA) initiative. This initiative was run in tandem with the Centennial celebration of the National Park Service. By encouraging use of amateur radio operations from and to these NPS facilities, the initiative helped promote the unique history of each park space and demonstrated the utility and diverse nature of the amateur radio service in these highly visible public settings. Thanks to all of those who attended and assisted in this and all of the club’s “NPOTA” activations throughout the year.

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[W3HAC] 10/15 Spaceblimp Launch at 09:00 EDT

Hello friends of HacDC and HARC. We are finally launching our first high altitude balloon in several years with callsigns W3HAC-11 & W3HAC-12 on ARPS 144.390@500mW and 433.500@1W respectively at 9am. W3HAC-12’s frequency may change the day of due to conditions which we will announce. There should be a digipeater on W3HAC-12 for the duration of the flight which should be between 2-2.5 hours. Feel free to track us at!call=w3hac-11 or directly yourself. We are flying 3 cameras, 3 sets of sensor packages with data to be recovered after landing, and an SD card “resiliency” experiment.

We are launching from Strasburg, VA unless morning predictions cause us to go further south. The Spaceblimp team has been planning this since July so we hope you track us. Pictures, video, and data will be available a few days afterwards at

Ethan Waldo

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