Category Archives: How To

Antennas, How To, News, Portable, POTA, QRP

Videos: Mike’s Insights on the POTA20 Ground Spike and a Clever Tripod Antenna Hack!

2 Comments

Over the past few weeks, my buddy Mike (KE8PTX) has quietly made several YouTube videos I thought I’d share here on QRPer.com.

By the way, Mike is the fellow behind the new Explorer POTA20 Carbon Fiber Mast Ground Spike. You may have seen me use this in a recent field report and activation video.

Ground Spikes

In Mike’s first video, he describes the evolution of the POTA20 (and Carbon 6) ground spike system and its variations. As you’ll see, quite a lot of thought and engineering went into this simple design:

FYI: You can get the POTA20 mast at Gigaparts and one (or more) of the ground spike models at the Ham Radio Adventure Guy’s online store.

Tripod Hack

In this video, Mike demonstrates how you can easily hack a portable camera tripod to support a carbon fiber mast.

As Mike notes, “It’s a bit more to fiddle with than just a spike. But in the frozen north you have to deal with ground conditions. Get yourself a cheap tripod and give it a try. Will also work well when the park will not let you stick anything in the ground or use a tree.”

Click here to check out and subscribe to Mike’s YouTube channel.

How To, Morse Code, News

Choosing the Perfect Vanity Callsign: Tips for CW Operators

39 Comments

Yesterday morning, I replied to a message from a reader planning to obtain a vanity callsign. He asked, “Which [suffix] letters would make an easy callsign to send [in CW] and copy in your experience?”

This is a great question. I do have a few suggestions.

My previous call

I suggest avoiding ending your callsign with a “K.”

I speak from experience.

I was not an avid CW operator when I upgraded to General over two decades ago. I was auto-assigned the following callsign by the FCC: KF4TZK

It was a mouthful in SSB, especially when articulated phonetically: Kilo Foxtrot 4 Tango Zulu Kilo.

When I started operating in CW, I realized how confusing it can be to have the letter “K” at the end of one’s call. If your sending isn’t near perfect—or even when it is—people will assume the “K” is simply “OK, back to you,” and they copy “KF4TZ.”

I got tired of correcting my call by sending back “KF4TZK K” to let them know the K was part of my suffix.

If your call ends with a K, there’s no reason to change your callsign unless you also find it gives you trouble. If you have a ‘2 x 1 call  (a callsign with two letters, a number, and a letter) ending in K, it’s not a problem.

I would also suggest not combining too many letters similar in dit patterns, like “HSI” or “HSH.” Strings of dits can be complex for some to copy.

Best advice?

When I decided to apply for a vanity call and ditch KF4TZK, I consulted my dear friend and wise Elmer/mentor, Mike (K8RAT).

He said:

Write down all available callsign options you’re considering, then practice sending them. You’ll know which one “feels” right.

He was spot on: K4SWL felt right, and since SWL (shortwave radio listening) is what started my radio journey, it was a no-brainer.

If you feel comfortable sending a callsign—if the rhythm and cadence feel right to you—then it’ll likely be easy to copy on the other end.

Final thoughts

Remember, this is a fun and creative process. Enjoy the journey of deciding on a new callsign!

In the end, very few “bad” calls are out there. It’s incredibly rare that I copy a call and think, “Wow—that’s a stinker!”

Even if your call sounds a bit awkward in CW—many do—rest assured, others won’t have difficulty copying you if your sending—your pace and spacing—is accurate.

What do you think?

Do you have any suggestions? Feel free to comment.

Interested in applying for a US vanity call? Check out this article from the ARRL. 

Field Reports, How To, Morse Code, News, Portable, POTA, QRP, QRP Radios, SSB, Videos

Xiegu G106: From Unboxing to Your First POTA Activation (Beginner-Friendly Video!)

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Earlier this week, I mentioned that I purchased a Xiegu G106 in September. Its delivery was delayed because I had it shipped to my local post office, which, as you likely know, was flooded during Hurricane Helene.

With all the post-Helene chaos, I haven’t been able to do as much POTA as I’d like, so the G106 sat unopened in its box—until Wednesday, November 20, 2024, when I finally had a chance to take it out for its maiden activation at Lake James State Park (US-2739)!

Why the Xiegu G106?

Last year, Radioddity sent me a G106 on loan, and I wrote an in-depth review after taking it on several activations. That review was lengthy because radios like the G106—designed as price leaders—often have compromises that may not suit everyone. It’s essential to judge such radios based on their goals, not by comparing them to premium models like the Icom IC-705.

For the G106, the question I aimed to answer was: “Does this radio accomplish what it sets out to do?”

I believe its mission is to offer affordable field radio fun—capable of completing park or summit activations without excessive struggle, providing performance commensurate with its price point.

I decided to purchase the G106 because I had returned my loaner unit over a year ago, but questions about it kept coming from readers. Instead of requesting another loaner, I opted to buy one.

To my surprise, the pricing had dropped significantly. Here’s my order confirmation:

Interestingly, as I mentioned earlier this week, Amazon (at time of posting) has a Black Friday deal for the G106 (without accessories) $199 shipped for Prime members [QRPer affiliate link].

I’d have chosen that over the bundle I ordered had it been available at the time.

Unboxing to Activation

It was a rainy day at Lake James.

A common question from readers has been, “Would the Xiegu G106 work as a dedicated field radio for POTA activations?”

Perfect weather to set up in a picnic shelter!

Most of these inquiries came from newcomers to ham radio, so I decided to test the radio in the field by setting it up from scratch—straight out of the box. This included attaching connectors to the power cord, configuring the radio, setting up the antenna, and hopping on the air.

This is a lot of picnic shelter for such a small radio setup!

I started the activation using SSB (voice) and later switched to CW (Morse Code) to give a full “out-of-the-box” experience.

The resulting activation video (below) is lengthy but was incredibly fun to film!

Gear:

Note: All Amazon, CW Morse, ABR, Chelegance, eBay, and Radioddity links are affiliate links that support QRPer.com at no cost to you.

Radio

Antenna & Cable Assembly

Throw Line

Pack

Logging Supplies

Key and Cable

Battery and Power Distribution

Camera/Audio Gear

Misc

On The Air

This activation was nothing short of amazing.

I began in SSB mode, using only the default mic settings. Despite operating at just 5 watts, I logged 21 hunters in 17 minutes—woo-hoo! While most signal reports were low, no one mentioned issues with my audio. I suspect results will improve once I fine-tune the mic gain settings. Continue reading Xiegu G106: From Unboxing to Your First POTA Activation (Beginner-Friendly Video!) →

Antennas, How To, News, Portable, QRP

John’s Rainy Day Antenna Project Notes

11 Comments

Many thanks to John (N3AAZ), who shares the following notes from a recent antenna project:

Hi Thomas

For what it’s worth, here’s an easy, cheap, very lightweight, multi-band, no counterpoise antenna for portable ops.

This build took place on a rainy day at a campground in an 18ft RV and was inspired by an article written by Craig (WB3GCK): No Counterpoise Speaker Wire Antenna.

This antenna can be set up as an inverted V or inverted L.

I cut a 30/20 ft version to hang on a 32ft Jackite telescoping fiberglass mast. I read that several ‘random’ lengths, the 50/25 and 25/17, have also been successful.

Cut a 30 ft length of speaker wire (do not peel or separate it yet), then measured back 10 ft and peel off then cut only one side of the speaker wire twin lead. This will effectively create a 30-foot antenna with a 20-foot “balanced” feed.

You will then need a “BALUN” with unbalanced input and balanced output.

My 1:4 and 1:9 did not work because both ports are single-end BCN connectors soldered on a PCB.

Luckily, I also pack an MFJ 9211 (1:4 QRPocket Current Balun).

Using a NanoVNA and MFJ-902.mod.aaz (mod to form an L-network–more info on my qrz.com page) I measured less than 2:1 SWR on 40, 30, 20, and 15 meters.

The N7DDC ATU-100 reports…

    • 1.18 :1 SWR on 15M
    • 1.03 on 20M
    • 1.16 on 30M
    • 1.88 0n 40M

It loads well.

My first 20-meter contact was a POTA contact with W4TTU (approximately 700 miles away), who gave me a 559 at 5W–he was 579 and signed “72,” so I assumed running QRP as well.

Not too shabby for an impromptu rainy day project hi hi!

72
John
N3AAZ

Thanks for sharing these notes, John! This looks like a fun little antenna build.

How To, Kits, News, Videos

Video: Alan (W2AEW) Builds the CFT1 5-Band CW Field Transceiver

3 Comments

Our friend Alan (W2AEW) has just posted a video showing the process of building, adjusting, and aligning the CFT1 5-band CW portable transceiver. If you’ve been thinking about building a CFT1 kit, this video will help guide you [update: see note from Alan below]:

Click here to view on YouTube.

Thank you for making this tutorial, Alan!

Articles, Digital Modes, Guest Posts, How To, Portable, QRP, QRPp

Beyond the Beacon: Conrad Discovers the Unexpected Benefits of WSPR

33 Comments

Many thanks to Conrad (N2YCH) who shares the following field report:

QRPppppp….WSPR

By: Conrad Trautmann (N2YCH)

WSPR, or Weak Signal Propagation Reporter, is a digital mode you can select within WSJT-X. You can use the data that’s generated by the WSPR network to check your own antenna’s performance for transmitting and receiving and also to see what paths are open by band at a particular time of day from your QTH. Recently, I’ve been using WSPR to improve my own antenna systems and to help reduce local noise sources.

Originally developed by Joe Taylor, K1JT, an approximately two minute QRP transmission contains the originating station’s call sign, the maidenhead grid locator and the transmit power level being used. Stations typically use 250mw up to 5watts when they send these signals. WSJT-X allows you to select how often you want to send this transmission and what bands to transmit on. There’s an embedded schedule in WSJT-X that allows “band-hopping” for stations using a multiband antenna to transmit on different bands. When not transmitting, it listens for and decodes other stations transmitting and can post “spots” of those stations to the WSPR network database.

WSJT-X WSPR mode
WSPR Band Hopping Schedule (click to enlarge)

Here on QRPer.com, Thomas, K4SWL posted in this field report what the various flavors of QRP power levels are…

  • QRP: 5 watts to 1 watt (for some contest 10 watts = SSB QRP)
  • QRPp: Less than 1 watt to 100 mw
  • QRPpp: Less than 100mw

Did you know that there are more than 3,000 WSPR HF beacons running on all of the amateur bands all over the world at QRP power or less? Many are running 250mw or less. If you open up WSJT-X and select the WSPR mode, you’ll see that the pull down for power levels give you these options:

  • 37dbm = 5w
  • 33dbm = 2w
  • 30dbm = 1w
  • 27dbm = 500mw
  • 23dbm = 200mw
  • 20dbm = 100mw
  • 17dbm = 50mw
  • 13dbm = 20mw
  • 10dbm = 10mw
  • 7dbm = 5mw
  • 3dbm = 2mw
  • 0dbm = 1mw

You could transmit your own beacon if you choose to using WSJT-X. You can also receive many of the 3,000+ beacons that are on the air right now if you wanted.

Why, you ask?

Let me tell you about the WSPR journey I’ve taken over the past few months and how what I’ve learned has benefitted me, my station and my antennas. Here’s how extreme QRPpp signals can help all of us.

I’m an avid digital operator, and I’ve tested many of the digital modes that WSJT-X, FLDigi, VarAC and others have to offer.

WSPR (Weak Signal Propagation Reporter) is a program embedded as a mode in WSJT-X and you can set it to transmit at the various power levels I listed above and band hop to different bands if your antenna can support those frequencies. When it’s not transmitting, it will receive and post the beacons it hears to the WSPRnet.org web site. For anyone familiar with pskreporter.info, WSPRnet.org is similar in that it provides maps of where and when “spots” are received and the relative signal strength the signals were when received by station, the mode and frequency.

After setting my station to transmit and receive on WSPR and looking at my spots on WSPRnet.org that were reported by receiving stations over the previous day, it was a thrill to see my 250mw signal making it out all over the world. Amazing actually, that such a small amount of power could travel that far. 250mw to Antarctica? That’s pretty good.

I bought a QRP-Labs QCX transceiver and the external companion GPS clock, which supports running WSPR transmission stand alone, without tying up a computer. Then I learned about the Sotabeams WSPRLite Antenna Tester (a 250mw WSPR transmitter) and the various WSPR transmitters offered by ZachTek which can also run without needing a computer.

My goal was to have WSPR beacons transmitting on as many bands as possible. Combining them into a single, multiband antenna posed its own problems, which is a topic for another article. However, all of these solutions just transmitted. I was hoping to also be able to receive and post spots as well.

Then, QRP-Labs (shout out to Hans Summers) came out with the QDX and then the QMX, both of which connect to a PC and are controlled by WSJT-X to do the band hopping transmitting and receiving. Like FT8, WSPR does depend on timing to work best, so using an external GPS clock for the QCX or connecting a QDX or QMX to a computer that can get it’s time from the internet can help keep the transmission cycles in sync with the receiver sites for best reception results.

Various WSPR transmitters and transceivers

This is cool stuff, but still, what’s the point? That’s when a friend I made in the WSPR community, Tom, WA2TP pointed out how to use all of these beacons to improve my station’s receiving capabilities. I have a good HF receiver and a dipole antenna and a hexbeam on a rotor and I figured I was good to go. I was making contacts without any problems. Tom told me this: “It’s all about the noise.”

He recommended using a wideband SDR called a Kiwi that can view the entire HF spectrum from 0 -30MHz on a waterfall at one time. My ICOM IC-7610 can connect to a PC and work with HDSDR software which has a waterfall, but it will only show you the spectrum of the particular band you’re on, not the entire HF spectrum at once. The Kiwi shows the entire spectrum from 0 to 30 MHz and when set up just right, you can see noise in there…a lot of noise, emanating from all sorts of things.

If you’re trying to receive a 250mw WSPR beacon signal transmitting from Australia, the noise from the after-market, wall-wart switching power supply connected to your cell phone charger a few feet away from your antenna could be way noisier and will blank that VK beacon right out. Your antenna and ability to hear distant signals is only as good as how low or quiet the local QRM is that we all have to deal with.

So began my hunt for noise, with a lot of guidance from folks with experience at it. Continue reading Beyond the Beacon: Conrad Discovers the Unexpected Benefits of WSPR →

Digital Modes, Field Reports, FT4, FT8, Guest Posts, How To, News, Portable, POTA, QRP

Karl Heinz’s Pocket-Sized Digital HF Station

18 Comments

Many thanks to Karl (K5KHK) for sharing this guest post, which originally appeared on his blog, Karl Heinz Kremer’s Ramblings:

A Digital Station in Your Pocket

by Karl Heinz (K5KHK)

How small can a complete station to work FT4/8 be? With the QRP-Labs QMX, we have a transceiver that certainly fits the bill for a small station. By itself it can only be used for CW, to use the digital modes, one has to combine it with a computer. Even the smallest laptop is too big the fit into the pockets of my cargo pants – we are trying a pocket sized station after all 😉

In this article, I will describe how to use a QMX transceiver and an iPhone to activate a POTA park with FT8.

The Components

My QMX is the original that was released at FDIM 2023, so it covers 80m to 20m. Mine is serial number #20.

My iPhone is small enough, but unlike Android based phones, the QMX cannot be connected directly to the phone. Apple sells a “camera adapter”, which plugs into the phones Lightning port on one side and provides a USB connection on the other end. $29 for the original Apple part was a bit hard to swallow, so I opted for something cheaper straight from China’s “we clone everything” factories: https://amzn.to/3WDSfUc

[Please note: All Amazon links are affiliate that support QRPer.com.]

 

The picture shows both a USB and a lightning port on the adapter. This should allow the phone to be powered/charged while the adapter is being used – more about that later.

Another limitation is the antenna: The QMX does not have a built-in antenna tuner, and even my QRP sized ZM-2 would have to live in a different pocket 🙂 My plan is to use a resonant antenna so that I would not need a tuner.

The easiest antenna with a good match is a dipole, but that is a bit more challenging to deploy in the field, so I opted for an end-fed halfway (or EFHW) antenna with a 49:1 transformer. I 3D printed a winder that allowed a BNC connector and the transformer to be mounted on the wire winder:

The design came from Thingiverse: https://www.thingiverse.com/thing:2871679

Because I am using a different toroid for the transformer, I had to remove the “bump” that is holding the toroid in place. Going forward, I may change the design a bit more to have so that I can fit more wire on the winder.

For those familiar with the transformers usually used for EFHW antennas, the picture shows two things that are different: As I’ve already mentioned, I am using a different toroid (the Fair-Rite 2661102002 core, which is a type 61), and a different winding pattern. More about that in a future post.

To power my station, I am using a TalentCell rechargeable 12V power bank:  https://amzn.to/3snTyr8

First Test

With everything in place, I tried to make a quick FT8 contact from home with this setup, but with my “big” EFHW antenna in my backyard. Because it was just a quick test, I did not even bother to hook up the charging cable for my phone (more on that later).

The software I am using is iFTx, which supports both FT4 and FT8.

I connected the phone to the adapter from above, connected the adapter via a USB cable to the QMX, and connected the QMX to a 12V power supply (unlike anywhere else in ham radio, 12V here means 12.0V and not the usual 13.8V), and hooked up the antenna to an antenna tuner and then to the EFHW in my back yard.

I answered an FT8 CQ call and successfully completed the FT8 exchange. The software does the automatic sequencing of the different messages, so it is very straight forward to use. With this first contact, I verified that the iPhone/adapter/QMX setup does work.

The Real Test

The next attempt was while camping at Hamlin Beach State Park (US-2068). I set up everything just like at home, but because I was planning on being on the air for a while. I also hooked up the cable to charge my phone while I was operating.

I was able to receive stations, but could not transmit. What made the troubleshooting more complex is that during setup, I created some sparks (that is why I do not like the barrel connector for power). I was pretty sure that the QMX was not involved, but not being able to transmit kind of suggested that I killed the finals. So I put everything away and used my KX2 instead.

Back home, I did some troubleshooting and hooked up a straight key to the QMX and it worked: I was able to finish a few CW QSOS without a problem, so the finals were definitely OK. I then set up the system again for FT8, and sure enough, I was able to make a contact. Because it was a quick test, I did not bother to use the power cable for the phone. By now, most of you probably know what the culprit was, but because I did not spell things out like this, I was still in the dark.

Success At Last

Fast forward a few more days… We went back to Hamlin Beach State Park – but this time to the picnic area – and I set up my station again. And sure enough, once everything was set up, the QMX did not transmit. This is when I took a step back and reviewed everything I had done so far, and slowly I came to the realization that when I provide power through the adapter to the phone, the QMX would not transmit.

I was able to finish my FT8 activation with my pocket sized digital station. I did run into one problem however: iFTx allows to automatically determine one’s grid square – which of course is important for FT8. When I enabled that, it correctly put me into FT13 at first, but a few QSOs later it switched me to JJ00aa – I reported this as a bug to the developer.

Using iFTx with the iPhone

The connection from the phone to the QMX is audio only. iOS does not allow an application to open a serial port connection (unlike Android). This means that the QMX will not receive any frequency information from the phone, and also no PTT signal. For this setup to work, the operator has to make sure that the QMX is tuned to the correct frequency that the correct band is selected in iFTx, and that the QMX is set to VOX mode (this is in the Digi Interface menu).

When configuring iFTx, it is possible to select a “Special Interest Activity” like POTA. This is then added to the CQ call as in “CQ POTA K5KHK FN13”.

As I’ve mentioned before, the application will automatically sequence the correct messages when a station answers the call.
Once the QSO is completed, it will be logged to the iFTx internal log, which can be exported via the usual “send to” methods available in iOS (e.g. email the log, save as a file, …).

When exporting the log, there is a choice of exporting everything, or only the new QSOs since the last export. This will create an ADIF file, which can be submitted to the POTA program, or imported into any other logging program.

At the end, I was successful in building a “pocket sized” digital station based on the QMX, I just need a fully charged phone and cannot depend on charging it while operating.

Click here to check out more articles from Karl on his blog!

Accessories, Antennas, Guest Posts, How To, News, Portable, QRP

W2AEW’s Trapped EFHW Antenna Tutorial: Building a Smaller, More Versatile Solution for Portable Operations

8 Comments

Many thanks to Alan (W2AEW) for the following guest post:

Trapped EFHW antenna story (it’s all Vince’s fault)

by Alan (W2AEW)

One of my favorite antennas to use for POTA activations is a 40m EFHW wire.  When properly tuned and deployed, it can be used on 40, 20, 15 and 10m without the use of a tuner (although, I really don’t mind using a tuner when I need to).  Most of my activations are on 40 and 20m, so those bands are covered easily.  It can be used successfully as a sloper, an inverted vee, or a combination of these (whatever the trees or support structures allow).  It is efficient, inexpensive to build, lightweight and effective.

There are a few downsides to this antenna.  The first is that it is approximately 68 feet (almost 21 meters) long.  That’s a lot of wire to get in the air.  Some POTA sites just don’t have that much room or support structures to effectively use this antenna.  Another downside is that it doesn’t naturally support operation on the 30m band, another favorite of mine.

A few weeks ago, I watched a video from my friend Vince VE6LK entitled: “Discover the secret ingredients to build a trapped EFHW antenna”. This piqued my interest…

The video introduces a design for a 40/30/20m trapped EFHW.  The fact that it covers the three bands I use the most, and would be shorter than my trusty full-sized 40m, and give me 30m to boot, got me excited to learn more.

Vince used a pair of traps (30m and 20m) that are offered in kit form by Tim Sherry, N7KOM.  Here is a link to kit on Etsy.

Image Source: Tim Sherry, N7KOM

These are exclusively for use at QRP power levels – perfect for my application.  I placed my order immediately after watching the video.  The build instructions are very detailed, including how to tune the traps, which is critical in getting the antenna to work.

Image source: SparkPlugGear

He also used a 49:1 UNUN from SparkPlugGear.  I’ve had one of these in my POTA kit for a while, but only used it occasionally.  This was another good reason to proceed with this antenna build.

Of course, you could also use the QRP UNUN kit from KM4CFT that I made a video about earlier this year.

I created a video that showed how to assemble and tune the traps.  Tuning can be a little tricky, and then stabilizing the turns/spacing to preserve the tuning is critical – not hard, just takes a bit of patience.

With the traps built and tuned, the next step would be to build and tune the antenna itself.

I was able to find the time this weekend to do just that, and make a video of the process.

Details of the resulting wire segment lengths are in the video.  It is important to note that if you decide to build this antenna, your wire lengths will likely vary from mine.  Several factors will effect the resulting lengths (details of the UNUN used, the trap construction, etc.).  My video goes through the process I used to build, tune and test the antenna.

“The proof is in the pudding” as they say.  It was time to actually run a POTA activation with this antenna.  The overall length of the antenna was about 43 feet (about 13.1 meters), which is about 2/3rds the length of the 40m EFHW.  This opens the possibility of using my 12 meter Spiderbeam mast (video review) as a support rather than just relying on a tree branch.

The weather here in NJ has been oppressively hot and humid with heat indexes over 100F, so I opted for a morning activation, before the heat really built up.  The intent was to get some contacts on all three bands, even though 20m probably wouldn’t be very active.

I setup at my “home” park – Washington Rock State Park, US-1635.  I decided to setup the Spiderbeam mast as the support for the new antenna:

The rig was my trusty KX2 with the BamaTech TP-III paddles:

I only had about an hour to dedicate to operating before the family activities for the day, so I figured I’d start on 40m and get most of the “ten” there first, then move on to pick up a few on 30m and 20m.

I was able to put 14 contacts in the log, under “so-so” band conditions, which at least a few on each band, several of which were park-to-park contacts.

Here’s the map of the “reach” that the new antenna had during this short activation:

Overall I am quite pleased with the antenna’s performance.  The near ideal band coverage for my typical activations, and the ease of deployment compared to the full-sized 40m EFHW make this antenna a great addition to my POTA kit.  I suspect it will get a lot of use!

Resources:

Accessories, Antennas, Articles, How To, News, Portable, QRP

Construction Notes: VO1DR Monopod Antenna Mount

8 Comments

Many thanks to Scott (VO1DR) who shares the following guest post:

Construction Notes – VO1DR Antenna Mount for Camera Monopod

by Scott Schillereff,  VO1DR

Further to my article about radio during trip to Portugal, a number of readers asked for details on how I mounted my whip antenna system to my camera monopod for /P use.  Here are some photos and notes on this.

General notes:

  • This is a “straight-through” design.  Just direct connections from the BNC center pin to whip (via brass nut), and BNC housing to radial connector.
  • This is not a cook-book construction article, rather just a show-and-tell of how I built mine.  You can use what you have on hand to build something similar.
  • I suggest you start with your telescoping whip, so you know the size and threads for mounting bolt.
  • You could use any type of connector for the radial (wingnut, knurled nut, spade lug, alligator clip, whatever you like).  I prefer banana jacks since a) I can push in the radial banana plug fast, b) the plug is a weak release point (pulls apart if someone walks into the radial), and c) I can easily attach additional radial wires, if desired.
  • Use a strong case (metal clamshell or cast aluminum work well).  With the whip extended, there can be substantial forces (bending moment) from wind or handling. A tiny plastic case would be fractionally lighter but might fail.
  • For size, the one I used (25 x 25 x 50 mm; 1” x 1” x 2”) is about as small as I would go.  It needs to have a big enough footprint to sit firmly on a camera mount fitting.
  • Use high heat (e.g., Weller 100-140 W solder gun) when soldering the center pin wire to the brass whip mounting nut.  Solder the wire to the brass nut before you epoxy the nut.
  • I custom made the white plastic insulating bushing (where whip screws in). This was from a nearly-right bit from my junk box.  You can be creative here.  You could also epoxy on short piece of close-fitting, thick-walled PVC pipe around the outside of the whip mounting hole as a supporting sleeve to give some lateral support to whip when it is screwed in.
  • Dry-fit everything (before epoxying) to make sure nothing touches that shouldn’t and you can screw in the camera nut and whip fine.  Test proper continuity of center pin and radial connections to BNC fitting.  Once glued, there’s no going back!
  • For surfaces to be epoxied (metal nut sides and bottom, insides of mounting case), slightly roughen with sandpaper or jewellers file, then clean with isopropyl alcohol and Q-tip.  This will increase adhesion and strength.
  • Use good-quality, high-strength, long-cure epoxy (e.g., JB Weld), not el-cheapo 5-minute epoxy from the Dollar Store.  LET THE EPOXY COMPLETELY CURE BEFORE MESSING WITH IT!  Just walk away from it for a day… (your patience will be rewarded).

Figure 1 – VO1DR Antenna Mount, clamped onto top of monopod.  Coax goes to BNC on left; whip screws into top; raised radial connects by banana plug on right

Figure 2 – Antenna mount unclamped from top of monopod.  The black plastic fitting (at right, with wedge-shape) fits into slot on platform at top of monopod (at left) and clamps in with cam arm.  Large steel screw attaches wedge fitting to antenna mount case. Ruler shows scale of things.

Figure 3 – Antenna mount case (right) unscrewed from camera mount fitting.  Steel screw is standard camera mount size (1/4-20 thread size).  Black silicone cap keeps dust out of BNC connector.  If your camera mount does not have a detachable wedge fitting (like the one on the left), you would simply screw the camera mount screw directly into the bottom of the antenna mount case.

Figure 4 – Top of monopod dissembled to show (clockwise from top): black monopod tube with telescoping whip stored inside (stainless steel with 10 mm brass mounting bolt), antenna mount case, detachable camera mount fitting, and round top plate of monopod.  For my monopod, I had to remove one tiny screw and apply gentle torque to break a weak glue joint of this round piece on top of the monopod leg.  It remains a snug hand fit (no screw needed).

Figure 5 – Fully assembled whip antenna mount with wiring.  Radial (blue wire) with tie-off cord (yellow) at left; RG174 coax (5 m) at right.  Whip is only ever screwed in hand-tight.  Deploying in the field, I first tie off the monopod to something (park bench, picnic table, fence, tree), then screw the collapsed whip into the antenna mount and clamp mount on top of monopod, then plug in radial and tie the yellow cord off to something (straight out at 2 m height or slope down to ground anchor), and finally connect the coax to the rig.  When all in place, I carefully raise the whip (slowly, with two hands to reduce bending forces).  Take-down is all in reverse.

Figure 6 – Detail of antenna mount case.  Case is 50 mm x 25 mm x 25 mm aluminum clam shell box with square metal end plates.  These end plates are screwed in to hold the two halves together.  White plastic bushing provides additional lateral support for the whip when it is screwed in.  The bushing is glued to outside of case with CA (Krazy) glue.

Figure 7 – Inside of antenna mount case.  On left, a ¼-20 steel nut is epoxied to inside of case with strong JB Weld epoxy.  In main case, a 10 mm brass nut is epoxied to inside of case with an insulating washer beneath.  This brass nut connects to the whip and is “hot”, so must be insulated from the black aluminum case.  Yellow wire connects center of BNC to brass nut (soldered).  Black wire connects ground side of BNC to radial banana jack.  Use plenty of epoxy; there is a lot of force exerted on the steel and brass nuts.

Figure 8 – Detail of inside of case.  Note separation of banana jack solder post and edge of 10 mm brass nut.  Solder yellow wire to nut before epoxying in nut.

Hope you find this useful.  Just use what you have on hand and some ingenuity to make yours!

Best 72, Scott  VO1DR

Articles, Guest Posts, How To, News, Portable, QRP, QRPers, Travel

QRP in Thailand: Drew’s Journey to Get Licensed and On the Air

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Many thanks to Drew (W8MHV) who shares the following guest post:

QRP in Thailand

by Drew (W8MHV)

I travel to Southeast Asia each year and usually have a few weeks in Thailand, but this year we planned on a longer stay. My XYL (N8MHV) has family in Thailand and we own a condo in downtown Bangkok. This year I was intent on getting my Thai ham license; I have never previously been licensed there.

You might be surprised to know that Thailand doesn’t make it easy for a casual American visitor to be awarded a ham license, even though the country has a bilateral agreement with the US on licensing.

For starters, you must have a visa for a long stay. A visitor can stay in Thailand for 30 days without a visa, and I have always limited my stay accordingly. But this year we stayed for of two months and getting a visa was necessary. That wasn’t especially difficult once my Thai-speaking wife helped figure out the necessary paperwork. In Thailand my wife’s calls to government offices led to a contact with the Radio Amateur Society of Thailand (RAST). Once I joined the organization, they helped push through the application and award of the license.

The RAST Secretary whose nickname is Top was a very great help. I felt like this was a big achievement as there are fewer than 1,000 ham licensees with HF privileges in a country of about 70-million.

QRP operating from anywhere in Southeast Asia requires great patience. This is because if you operate in a DX location, then everyone you work is DX to you, as by definition there are few if any local stations!

I brought my newly-acquired Elecraft KH1 for on-air use. Its tiny size made it easy to pack for overseas travel. It worked flawlessly, but the built-in whip antenna was far less useful than a 20.5 foot random wire with counterpoise I included in my kit.

Operating the KH1 from my condo.

In my 12th floor condo noise levels were terrible—typically S7, but at the top of the building on the 24th floor there is a garden where the noise levels were a manageable S3. See the photo above.

I also operated from an island in the Gulf of Thailand at a resort and noise levels there were even more quiet, as you would expect. Also, this was a comfortable operating location as the photo shows.

During my stay propagation conditions were poor mostly and I struggled to work any stations. A typical example is my final night in Bangkok I repeatedly called a station in Hong Kong whose signal was about S5, but I never got an answer. It was about the closest station I heard, but the signal path was about the same as the distance between New York City and Caracas, Venezuela.

I have operated from other Asian locations with QRP radios many times and the results have varied, chiefly depending on the kinds of antenna I could erect. Sometimes it has been lonely, other times control of a big pileup has been a challenge.

Finally, a few thoughts about the KH1.

It is an unparalleled performer for its size. It has most features you would want and its ergonomics are good. The weakest point was the paddle set, and since returning, I have replaced them with the KM4CFT aftermarket set. That said, in my travel to Thailand next year, I think I will take a KX2. It offers a few more features at a small increase in packing size.

Thanks for listening es 73 de W8MHV