A Portable 20/30/40m Vertical Antenna

This post is cross-posted to my more general-purpose nerdery blog, jeff.glass/blog.

Following the Forth of July, I took a few days off of work to recuperate from a grueling work project that we pushed over the finish line on the third. And what better way to relax in the wake of a heatwave than getting out in the beautiful, low-70’s weather and working on a new portable HF antenna.

Pole.jpg
From eBay listing

The heart of the antenna is an inexpensive ‘7.2m’ telescoping fishing pole, which can be had for less than $30 with Prime shipping or for less than $10 if you don’t mind waiting. The pole weighs about 10 ounces, comes with a small fabric sheath, and collapses down to about 24″. I’ve been wanting to try out something like this since I stumbled across VK3YE and his squid-pole setups awhile back – Peter’s also featured these particular poles in another video. Be aware, a pole called “7.2m” may not actually be 7.2 meters from end to end: check the listings carefully:

rod
Note the difference between the “stretch” column and the “specification” column.

The length of the pole is enough for a quarter-wave vertical for 20m with some room to spare on either end. To allow for multi-band operation, I added a QRPGuys Tri-Band Vertical accessory to the bottom of the antenna. The piece is essentially just two loading-coils (in this case, iron-powder toroids) with slide-switches to short them out. The 20m configuration is a true quarter-wave vertical; one of the toroids is switched in series for 30m, and both are placed in series for 40m. Ultimately, not a complicated setup. While it would be easy enough to homebrew, the ergonomics of the switches, the hardware to attach the antenna wire and radials, and the clever PCB setup are enough to make it worth the $15 to just buy the darn thing. It even has little notches on the edges of the PCB for straps/ties/rubberbands to attach it to the vertical.

triband
From QRPGuys.com

Tuning the antenna is straightforward: you cut a piece of wire (a bit long) for a 20m quarter-wave, and lay out four 10′ radials. Then, you bit-by-bit trim down the vertical element to resonate at the desired point in the 20m band. Then you switch in the 30m coil and compress/expand its turns without changing the antenna length to resonate on 30m. Finally, switch in both coils and adjust the second coil to resonate on 40m without changing either the antenna length or the first coil. Voila, a tri-band, base-loaded antenna.

Unfortunately, my antenna analyzer is old school, and doesn’t have a frequency readout. It’s an old MFJ-207 that I scooped up at the SMCC Hamfest in 2016, and while it does have a port to attach a portable frequency counter, I couldn’t find my cheapie one on the day. But I do have a nice Heathkit IM-2420 Frequency Counter with an internal OXCO that I scored an amazing deal on at a hamfest last year (it had an intermittent power switch). So, I attached the MFJ to the antenna, tuned its analog VFO for lowest SWR, walked inside without touching the dail and hooked it up to the frequency counter to see where the center frequency was. Repeat for say the upper and lower 2:1 SWR ranges. Trim the antenna a little, and repeat measurements. Once 20m is tuned, repeat with adjusting the coils for 30m and 40m. A fairly cumbersome process, but for three frequency ranges on one antenna, it was a half-hour project at most.

IMG_4804

In the end, the antenna is less than 2:1 SWR across all of the 20m band, all of the 30m band, and all but the top 50 Khz of the 40m band.

I’ve glossed over the mechanical details of the antenna to this point – the base of the telescoping pole fits snugly-yet-easily into the a piece of 1″ schedule-40 PVC pipe. I bought a 5′ section from the local big-box store and cut off a ~10″ section to hold the antenna. I strapped two ground-stakes that I got at Hamvention this year to the bottom with a couple zip-ties and a couple rubber-bands. Finally,  I threaded a long 3/8″ eye-bolt though a matching hole about 2″ from the bottom of the pipe and secured it with a nut on either side – this acts as both a stop for the pole so it doesn’t fall out the bottom, and provides an easy hand- or foot-hold for pressing the stakes into the ground.

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The finished antenna mount. It may be getting a coat of high-vis paint in the near future.

The setup for the radials was something I stumbled across by chance while buying the PVC pipe. Our local big-box hardware store was having a sale on these RECOIL Brand cable winders that are meant for headphones or charging cables or similar. I’ve found that they can almost hold four 10′, 24-guage speaker wire radials. This is solving the problem of wires-getting-tangled-in-a-bag that I’ve had with all my antennas to date. Thank goodness!

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A few loose ends are worth it for the assurance that the wires won’t get tangled in transit.

It takes about 6 minutes to setup or tear down the antenna:

  • The stakes are driven into the ground with a firm foot.
  • The telescoping pole is unwrapped and placed in the base
  • The antenna wire is unwound from the QRPGuys winder and tied to the tip of the telescoping pole with a small bit of cotton-wrapped nylon line (what we’d call tie line). The top section the pole is very flimsy, so I add a second tie to the next-largest section.
  • The pole is pushed up to full height, taking the antenna wire with it, which leaves the QRPGuys rig hanging about 2′ off the ground.
  • The QRPGuys rig is tied to the pole with another bit of tieline.
  • The radials are unstrung from their winder, pinched to the ground terminal on the QRPGuys rig, and spread out.
  • Run coax to a nearby table/seat/rock.
  • Set up radio, battery, key, antenna, and logbook.
IMG_4810
The antenna fully set up and freestanding.

Of course, my very first time away from home with the antenna… I forgot the radial wires. D’oh! I was way out in the suburbs, too. I wasn’t about to drive an hour home and an hour back for 4 bits of wire, so I first tried out the antenna with no radials (just the coax as a counterpoise). This worked alright – I picked up K2D in CT in the 13 Colonies event on the second call (this at 5W QRP with the ATS-4), but was having trouble with other contacts.

Since I planned to swing by the local Fry’s Electronics on this adventure, I decided to pause operating for a while and make that run. Mostly I was picking up parts for an amplifier project (more on that to come), but while I was there, I looked for solutions to my radial problem. I found a 10′ section of RJ11 phone cord with 4 wires for $1.69 – perfect! Back out in a new park, I stripped the wires out of their jacket, spread them on the ground, and tied them to the antenna’s ground terminal. Instant radials!

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And such colorful radials too!

With the antenna back to spec, things really picked up – surely, being on 20m at sundown didn’t hurt either. I scooped K2A (NY), K2B (VA), K2H (MA), K2L (SC), and K2M (PA), as well as the 13-cols bonus station WM3PEN in Philly. Many of these I got on the first or second call, though K2L was a real struggle. There was a very patient operator on the other end though.

13cols
The 13 Colonies special operating event runs each year for a week around the 4th of July in the US.

I picked up a couple of other interesting stations along the way: PJ2/KB7Q out of Curacao (though the license gives away that he’s either an ex-pat or visiting), and CQ918FWC from Madeira Island (!) off the coast of Portugal. There were a number of these World Cup special stations on the bands this week as we close in on the finals. At 3800+ miles away, this was my best DX of the day, and a great proof of concept for the new antenna.

ord fnc
At QRP wattage ,this 3800 mile contact was made at 760 miles/watt.

Hear you on the air!

73

From DX with Love – RDXC 2017

In a further example of the benefits of DX contests for those looking to rack up new countries, this weekend’s Russia DX Contest served up another bounty of new DXCC entities on CW.

All in all, I landed 11 new DXCC entities. Since part of the fun of contesting is imagining the operator at the other end of the ionosphere – doing the same thing you’re doing, furiously decoding CW in front of a radio, thousands of miles away – I’ve included the names of the ops below where I could find them:

  • Switzerland (HB9ON – Radiogroup in Piancamara 7, a profilic DXpedition team)
  • England (M2G – not a special event station, just a contest call of John in the UK)
  • Croatia (9A7V – Eugen)
  • Poland (SN8B – Bobowsi)
  • Germany (DA0AA – A radio club in Germany. “Emergency Radio Station Frank Cut Switzerland”, says Google Translate…. so that’s something)
  • European Russia (RU1A, a contest station out of St. Petersburg)
  • Northern Ireland (MI5I – Colin)
  • Serbia (YT3X – Miki)
  • Sweden (SH1DX – could not find)
  • Argentina (L6HKA – could not find)
  • Slovenia (S51J – Janez)
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A bevy of new European countries worked during RDXC 2017. Argentina can come too.

I also connected with a second Alaska station, my first AK contact on 20m, which should help to cement that state for my WAS goal this year. (To be sure, KL7/VE7ACN has been tearing up the bands this week, since I heard him a week ago. But more contacts in the log never hurt.) As icing on the cake, I heard, but couldn’t contact, Arthur 4X2M in Israel . Still searching for that first elusive contact in Asia.

Unlike the ARRL DX contest, where contacts within the same country don’t count for anything, the Russia DX contest does award a (small) number of points for contacts in the same country. So I picked up a few stateside contacts on 40m later in the evening, just to add to the contact count and continue drilling my CW.

There’s a joke in radio circles about “contest propagation”, which is the notion that even when “the bands are dead,” they somehow “magically open up” when there’s a contest going on. Certainly, during major contests, when everyone who has one brings out their big amplifiers and aims their beams most precisely, contacts are more frequent.

But this weekend, I suspect that the ol’ ionosphere was actually on our side for a change – in the late afternoon, after I’d worked what there was to work on 20m CW and before 40m opened up, I dipped over onto 20M JT65. . After noodling around for about 20 minutes, I had landed both PD7RF (Frits in the Netherlands) and MC0CSO in Wales.

Two more DXCC in the log. That brings me up to 49 DXCC entities reached, with 30 confirmed.

And as a final sign of Sol’s grace upon the upper atmosphere, the following afternoon I heard (but could not reach) both Asiatic Russia (RA0CGY) and Japan (JM7OLW, JH1HRJ, JA1PSS, and 7K4GUR) on JT65.All are over 6000 miles away. They were way below the noise floor at -20 to -24 dB, about the limits of what JTDX will decode. But things look promising as the summer months move closer.

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Stations heard on 20m JT65, afternoon of 3/19/17. What a spread!
Image by PSKreporter.com

Hear you on the air, all over the world!

73

Heading in the Right Direction

I put a new DXCC entity in the log last week: Hungary

I ran across HG5F calling CQ TEST on morse code on 14.086 MHz on February 25th. This was smack in the middle of the UBA DX CW contest, which is actually a Belgian contest, but thankfully that awards points to non-Belgian countries making contacts with other non-Belgian countries. Admittedly, I wasn’t worth many points.

So, why did a Hungarian station come in at a solid 579 during the local afternoon on 20m, when he wanted to be talking to Belgium? There are two parts to unfolding that mystery. The first is John, HG5F’s, antenna; his QRZ page shows a large beam antenna (tribander?) in the foreground, on top of maybe a 30′-40′ tower. That would certainly have helped. (There’s also a small beam in the background of the picture, perhaps for 40m.)

hg5f_tower
HG5F’s antennas, from QRZ.com

The second and more interesting reason that HG5F was so audible has to do with geography. HG5F’s QRZ page lists his QTH (home station) as Jakabszállás, Hungary, a little Southwest of Budapest. If John was pointing his beam toward Belgium, (say toward Brussels in the center of the country,) his beam would have been pointed at roughly 300° ENE. If instead John had wanted to point his beam directly at me, he would have been aiming at ~310°. Put another way – by aiming his beam toward Belgium, John was also aiming toward the midwest United States.

These coincident transmission angles become clear when one looks at them with the proper map projection. Something like an azimuthal-equidistant map, which displays all points as proportionally equidistant from a center point, is perfect for this task. Check out the following AE map centered on Budapest:

hungary_ae_map

Notice that, from John’s perspective in Hungary, Belgium and the US Midwest line on almost the same Northeasterly line. Here’s the same illustration in a more familiar equirectangular map projection:

hungary_rect_map.PNG

So, I was quite a bit of an overshot for John, but I’m always happy to make a transatlantic contact – and on CW no less! That makes 35 countries in the log so far, and with the ARRL SSB DX contest this weekend, I’m hoping to hear and work several more.

Hear you on the air!

73

Be it Resolved: Work More States

Though I’m very late to the ballgame in New Year’s resolutions, it being February and all, I do have one that settled on at the beginning of the year that I’m ready to commit to. 2017 is going to be the year that I get my Worked All States award.

Worked All States, or WAS, is a certificate handed out by the ARRL for those who have worked all 50 states in some form or another. I’ll be going specifically for WAS Mixed, which allows contacts of any type – phone, CW, or digital – to count, though there are individual awards for working all 50 states with each one of those modes as well.

So far, progress is promising. Given that I only got on HF last summer, I’m already within striking distance of my goal. Only 7 states have eluded me so far: Alaska and Hawaii (no surprise), Nevada and Utah (far to the West with small populations of hams), North Dakota and Nebraska (see comment about the sparsity of hams), and Indiana (my signals must be skipping right over them). I’ve actually knocked three states off the list just recently: I picked up Idaho, Delaware, and Wyoming during the two January North American QSO parties.

Beyond that, there are 10 more states I’ve contacted but don’t have official confirmation for: Wyoming, Iowa, Missouri, Arkansas, Louisiana, Michigan, Mississippi, West Virginia, Massachusetts, and Rhode Island. The other 33 states are in the log and confirmed.

Here’s the current status of things, laid out in visual form (Grey is unworked, blue is worked and unconfirmed, green is confirmed):

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Here’s to 8 more states in 10 more months. Hear you on the air!

Stop Press: Between the time I wrote this post and the time it was scheduled to be posted, I made contact with Hawaii! Specifically with KH6LC on 21.0295 MHz during the ARRL DX CW contest. We’ll see if it gets confirmed, but that means only 6 states left to find. I also received confirmation for Rhode Island in an unrelated JT65 QSO. The map has been updated with these changes.

73

An Embarrassment of DX – ARRL DX CW 2017

After several months of being on the air, I’ve finally made contact with continental Europe! And contrary to my previous post of JT65 DXing, this one was with good old fashioned CW. At around 0204 on Sunday 2/18, I heard a CQ TEST call from EF7X on 20m , and after several back-and-forths and some resending, I had him in the log. Huzzah!

A few minutes later, I found the US Virgin Islands on the air with NP2P. Then the Madeira Islands off the coast of Morocco from CR3W. Then the Slovak Republic, of all places, via OM7M. Then, then, then….

All in all, I made a total of 55 QSO’s with 29 unique DXCC entities over the course of a few hours of operating on Friday, Saturday, and Sunday. Of those, 17 were All Time New One’s for me, bringing my total number of entities contacted (though not necessarily confirmed) to 34. I doubled my DXCC progress in one weekend!

The full list of new entities reached includes: Barbados, Spain, the US Virgin Islands, the Madeira Islands, the Slovak Republic, Jamaica, Portugal, Scotland, Italy, Ireland, the Balearic Islands (had to look that one up), the Bahamas, France, Hawaii (!!!), Belize, Cuba, and Cape Verde. The full map looks like this:

arrl_dx_2017

It’s no accident that this string of contacts came along during the ARRL DX CW contest, when all of the international contest stations have their beams and their amplifiers trained on the United States, and are looking for any stateside contacts. Even a relatively-dinky 100W into a random-wire and tuner is a valuable contact for DX stations in this contest. And I’m tremendously grateful to the stations that took the time to dig my signal out of the noise. One of the peculiarities of the ARRL DX contest is that non-US stations have their output power as part of their exchange. Almost everyone I worked was “K” or “KW” (1000+ watts), with a handful of 500 or 100 watt stations thrown in. Makes my 100 watts look like a pebble in a quarry.

My final claimed score is 55 QSOs & 45 mults, for 7425 points. Not too shabby! Here’s the breakdown by band and multiplier:

The ARRL DX SSB competition comes along in a couple weeks – I’ll surely have to be on the air then. Hear you there!

73

Firsts: 17m, Brazil, JT65

Earlier this week, I achieved two firsts in one QSO: my first contact on the 17m band (a  100Khz slice of spectrum starting at 18.068 Mhz), and my first contact with Brazil. Specifically, with PY6JB, JOÃO, in Salvador, Brazil, nearly 5000 miles Southeast of me. I’m not positive, but I think this marks my furthest contact on the air so far.

That I set a new personal distance record with JT65 is not surprising – the mode is designed for weak signals and long distances. It encodes up to 13 characters into a highly compact format of 72 bits. These are then run through a pair of Reed Solomon encoders, which translate the user data into a set of 126 bits for transmission with significant potential for error-correction. Reception of signals more than 20 dB below the noise floor is not uncommon with JT65.

braziljt65

As you can see in the screenshot of the popular JTDX program by UA3DY, even transmitting at around 35 Watts, my signal was still 17 dB below the noise floor by the time it got to Brazil. But that was enough to exchange callsigns and reports, and officially verify the QSO.

So, another new country in the log, and my first ever contact on the 17m band. Not a band way to spend a Monday afternoon.

Hear you on the air!

73

*UPDATE: The same afternoon I posted this, I made another contact with Brazil, but this time on CW – PV8ADI! Woohoo!