Fishing for Radio Signals With the Moxon Antenna


[Bill Meara] has finished his latest project, a Moxon antenna for HF on 17 meters. [Bill] is well-known here on Hackaday. When not building awesome radios, he can be found ranting about ham radio. His new antenna turned out to be a true hack. He even used a hacksaw to build it!

The Moxon antenna is named for the late [Les Moxon, G6XN] who first described it in “Two-Element Driven Arrays”, a QST magazine article published in July of 1952.  [Bill] built his Moxon loosely based on [Jim/AE6AC's] excellent instructions. The design is incredibly simple – a two element directional antenna using crappie fishing poles as spreaders. That’s crappie as in the fish, not the quality of the pole. Crappie poles are typically made up of telescoping sections of graphite or fiberglass  in common lengths of 14, 16, and 20 feet. The poles can be bought for under $20 at sporting goods stores. [Bill] used 16 foot poles purchased from Amazon.

The antenna is created by connecting all four poles at their bases in an X shape. The wire elements are stretched across the ends of the poles. The entire antenna bends up as the stiff poles hold the driven and reflector elements in tension. [Bill] used some scrap wood and U-bolts to attach the fishing poles, and bungee cord ends at the tips. Since the antenna is directional, [Bill] added a TV antenna rotor to spin the beam around. The antenna is so light that one could get by with a couple of cords and the “Armstrong method” of antenna rotation.

Once up on the roof, [Bill] found his antenna really performed. He was easily able to cross the Atlantic from his Northern Virginia home to France, Belgium, and Latvia. The mostly horizontal antenna makes it a bit more unobtrusive than other directional designs. [Bill] mentions that his neighbors haven’t revolted yet, so he’s continuing to enjoy the fruits of his antenna labors.

Guest Rant: Ham Radio — Hackers’ Paradise


Editor’s Note: This is a guest post written by [Bill Meara]

The suits at Hack-a-Day reached out to SolderSmoke HQ and asked me to send in a few words about why their readers should take a fresh look at ham radio. Here goes:

First, realize that today’s ham radio represents a tremendous opportunity for technical exploration and adventure. How about building a station (and software) that will allow you to communicate by bouncing digital signals off the moon? How about developing a new modulation scheme to send packets not down the fiber optic network, but around the world via the ionosphere, or via ham radio’s fleet of satellites? How about bouncing your packets off the trails left by meteors? This is not your grandfather’s ham radio.

You can meet some amazing people in this hobby: Using a very hacked-together radio station (my antenna was made from scrap lumber and copper refrigerator tubing) I’ve spoken to astronaut hams on space stations. Our “low power, slow signal” group includes a ham named Joe Taylor. Joe is a radio astronomer who won the Nobel Prize for Physics. He’s now putting his software skills to use in the development of below-the-noise receiving systems for ham radio. Join me after the break for more on the topic. [Read more...]

WSPRing across the Atlantic


Host of the Soldersmoke podcast, [Bill Meara], contributed this guest post.

WSPR is a new communications protocol written by radio amateur and Nobel Prize winner [Joe Taylor]. Like the very slow QRSS system described in a previous post, WSPR (Weak Signal Propagation Reporter) trades speed for bandwidth and allows for the reception of signals that are far below the level of radio noise. WSPR takes “low and slow” communications several important steps ahead, featuring strong error correction, high reliability, and (and this is really fun part) the automatic uploading (via the net) of reception reports — [Taylor]‘s WSPR web page constantly gathers reports and produces near real-time Google maps of showing who is hearing who. The WSPR mode is very hack-able: [Bill Meara] is running a 20 milliwatt homebrew transmitter from Rome, Italy that features an audio amplifier from a defunct computer speaker pictured below. This contraption recently crossed the Atlantic and was picked up by the Princeton, New Jersey receiving station of WSPR’s esteemed creator, [Joe Taylor]. [Read more...]