Category Archives: Accessories

Accessories, Antennas, Articles, Field Radio Kits, Field Reports, Grab And Go, Guest Posts, News, Portable, POTA, QRP, SOTA, Travel

Flying High and Keying Low: A Pilot’s QRP Adventures Across the USA

7 Comments

Many thanks to Micah (N4MJL) who shares the following guest post:

Elecraft KH1 Anytime and Anywhere Adventures

by Micah (N4MJL)

Anywhere and anytime—that’s how I like to describe my Elecraft KH1. This radio goes everywhere I go. As an airline pilot, I bounce from coast to coast and everywhere in between almost daily. Since I’m constantly on the move, my radio gear has to be small and compact.

I’m a third-generation ham radio CW operator. Anyone who’s heard me on the air knows I’m still quite new to CW. I only started running CW activations with POTA/SOTA in the spring of 2024. Here’s the gear that’s been working well for me, along with a few photos from the locations I’ve had the pleasure of activating.

I’ve found that the Pelican M50 micro case is the perfect “shack in a box” for my KH1. This setup goes everywhere with me. Here’s what fits perfectly in the M50:

  • Packtenna 9:1 random wire
  • 20 ft BNC coax
  • Panasonic ErgoFit earbuds
  • SP4 paddles from CW Morse
  • KH1 (fully loaded with internal battery and tuner)
  • 30 ft throw line
  • Write-in-the-Rain notebook
  • High Visibility Orange Cap-O-Matic Fisher Space Pen (with lanyard)
  • Desiccant silica gel pack

In pedestrian mobile configuration, the KH1 is a solid system. I’ve done several activations this way. That said, after 45 minutes of holding the KH1 in this setup, I’m ready to wrap up! Having a portable shack that lets me deploy a random wire that tunes 40-15m and a more ergonomically designed key drastically improves my capabilities.

In many urban environments where I activate POTA, pedestrian mobile is essential. Unfortunately, the security in urban parks can be unpredictable, and the KH1 allows me to operate on the go and quickly move if needed.

Some of you may be wondering what I did to the inside of my M50 case. Well, in my defense, it’s my wife’s fault. She left me unsupervised with a glue gun and a bit of alcohol. When my KH1 arrived this spring, solar conditions were poor, so I had a few days to think and decided to turn the case into a makeshift Faraday box. I used Polyken aluminum tape, cardboard, and a glue gun to line it. Now, I know what you’re thinking: there’s no electrical bonding between the lid and lower box due to the rubber seal, so will this really work as a Faraday cage? Maybe, maybe not—but it sure looks cool! What do you think?

In addition to the M50 case, I carry a support pouch (Magpul DAKA, size small). This heavy-duty, water-resistant pouch contains:

  • 31 ft counterpoise wire
  • AXE1 40m antenna extender
  • Bioenno battery 12V 3Ah (backup battery—“1 is none, and 2 is 1” if you know, you know!)
  • KH1 power cable
  • KH1 right-angle antenna mount

These items aren’t essential but are nice to have for longer activations.

When I’m done flying and ready to play radio, I pack all this gear into my Flash 22 day pack. This compact, minimalist pack takes up almost no room in my flight bag and even has a built-in whistle on the chest strap, which is perfect for California!

When conditions allow, I enjoy using the full five watts of power. My go-to antenna is the SOTAbeams Band Hopper III, which is a versatile half-wave linked dipole:

  • Rated 125 watts
  • Center-fed with 33 ft RG174 coax
  • Guying system included
  • Resonant on 20m, 30m, and 40m (no tuner needed, though the KH1 tuner will also tune up 17m and 15m)
  • Built-in balun
  • Weighs only 14 oz

The wire/guying winders are excellent, and I’ve used this system in all kinds of environments, from sandy beaches to mountain tops above the treeline. I replaced the aluminum tent pegs with plastic ones to keep TSA happier.

The SOTAbeams Tactical Mini Mast fits diagonally in my 22″ roller board. I wrap heavy rubber-coated wire around it to secure it to posts or shrubs when needed.

Along with this radio gear, I also manage to pack a change of clothes—usually enough for a five-day trip. I typically fly three trips a month, each lasting four to five days. My roller board carries me and my radio gear from plane to plane all week long.

On a short backpacking trip along the Appalachian Trail (June 3, 2024), I activated SOTA summit W4V/BR-007 Three Ridges and the Three Ridges Wilderness area (POTA US-9959). The mountain in the distance is The Priest (W4V/BR-002), which I activated earlier this year with my LNR Precision MTR4B.

The summit of Three Ridges is a densely wooded area, so I stopped below the summit to enjoy the view, grab a quick snack, and play some radio. I snagged two POTA-only QSOs with W8WZ in Louisiana and KU8T in Indiana using the KH1’s whip antenna. Once I reached the summit, I used the Packtenna 9:1 random wire for my activation. Continue reading Flying High and Keying Low: A Pilot’s QRP Adventures Across the USA →

Accessories, Morse Code, News

The QRPworks “Key Line MagPi” for KX2 and KX3 now available for purchase

2 Comments

Many thanks to Shel (KF0UR) who writes:

Remember the swivel paddle platform for the KX2 & KX3 my partner Steve KB3SII gave you at Hamvention last May? Well, it’s finally in production and shipping immediately.

https://www.qrpworks.com/key-line-magpi-store.html

It comes configured for the KX2, but includes the parts for the KX3 (a screw and a spacer) which is a very easy change to make. And for non-magnetic paddles it comes with 3M Dual Lock to fasten it. I used it with a magnetic BaMaKey for 800 QSOs on Field Day last year with my KX3. It worked great for me and the other ops.

Thanks for letting us know, Shel! I really love this key bracket and am happy to hear it’s in production.

If you want to see it in use, here are two activations from July when I used a prototype of the Key Line MagPi:

Carolina Beach State Park

Brunswick Town State Historic Site

Accessories, News, Portable, QRO, QRP, QRPer Notes

QRPer Notes: Foldable Stands for Small Radios, ’79 Okino Tori-Shima DXpedition, Another Watertight Case for the KH1, and Demystifying SWR!

4 Comments

Because I receive so many tips from readers here on QRPer, I wanted way to share them in a concise newsletter format.  To that end, welcome to QRPer Notes, a collection of links to interesting stories and tips making waves in the world of radio!

Foldable feet for small radios

Many thanks to Randall (K8UFM) who shares the following tip:

Thomas,

I found these on Amazon and they work great for small radios.

PONICOR 2PCS Zinc Alloy Mini Foldable Laptop Stand, Portable Computer Keyboard Riser with 2 Adjustable Angles, Self-Adhesive Invisible Notebook Stand and Keyboard Lift for Desk (Black)

https://amzn.to/4ewds8n [QRPer affiliate link]

Randall K8UFM

Video: OKINO TORI-SHIMA DXpedition

Many thanks to Wlod (US7IGN) who shares this 1979 film about the Japanese DXpedition to Okino Tori-Shima:

Click here to view on YouTube.

Apache case for the KH1

Many thanks to Tom (WW8D) who writes:

Hey Thomas,

This is Tom WW8D in Salem Va. I sure do enjoy your videos on youtube. I received a new KH1 yesterday and I just wanted to tell you that I have a clear waterproof case like the one you but its a slight bigger fromHarbor Freight. Its an Apache 550 and everything fits perfect in it.

Click here to check it out.

Note from K4SWL:

I purchased the Apache 550 a few days prior to Helene hitting our area. I intend to make a post or video soon showing how this apache case compares size-wise with my Pelican cases. It is, in general, a much larger case than the M40 I currently use with the KH1. See photo below. 

Video: Demystifying SWR

Many thanks to Vince (VE6LK) who writes:

Here is an EXCELLENT video explaining return loss, why lossy coax hides SWR issues and many other things:

Click here to view on YouTube.

Accessories, Field Reports, Morse Code, News, Portable, POTA, QRP, Videos

Morning on the Trail and On the Air: A Relaxing K2 QRP POTA Activation from the Campsite

6 Comments

I woke up around 6:45 on Saturday, August 24, 2024. That’s late for me, but I tend to sleep well when camping and it must have helped that the previous evening POTA activation by the campfire was pure bliss.

There were some noises in the campground that woke me up during the night (probably other campers scaring off raccoons), but aside from that, I slept peacefully in my rooftop tent.

As I lay there Saturday morning, I couldn’t decide whether to make breakfast and hit the air for an early morning POTA activation, or to take a nice hike before everyone else in the campground woke up.

I chose the latter option!

At 7:00 AM, I headed to the nearby trailhead for the Lake Shore trail. It was a very pleasant and quiet hike—roughly 5 miles in total.

Afterwards, I made some blueberry oatmeal and a cup of French-pressed coffee. It really hit the spot!

Next, I grabbed my Elecraft K2 and connected it to the MM0OPX 40M EFHW that I had set up the previous evening.

I realized it had been a while since I’d taken the K2 out into the field, which was why I packed it for this trip. I use the K2 quite often in the shack, but it needed some outdoor time. All radios (and their operators!) need outdoor therapy!

New Tufteln TP-III Protective Cover

My friend Joshua (N5FY) at Tufteln sent me this protective cover, at no cost to me, for the BamaKey TP-III.  Joshua has almost become a specialist in making bespoke protective covers for radios and accessories.

This cover is great. You insert four rare earth magnets (included) into four holes in the bottom of the cover. These work with the rare earth magnets on the TP-III to mag-lock the cover in place.

If you buy one of these for your TP-III, I would advice that you check the polarity of the magnets on the TP-III before inserting the magnets in the cover’s holes. I didn’t do this and found that I’d aligned a couple of the magnets in opposition, thus they repelled the magnets in the case. I had to dig the magnets out and reverse them–not a complicated procedure, but one I could have avoided had I simply thought about this in advance!

Anyway, I do like this cover! Thanks, Joshua!

Gear

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On The Air

I hopped on the air and started calling CQ POTA on the 40-meter band. I figured that at this time of morning, 40 meters should be in decent shape.

I was right! Continue reading Morning on the Trail and On the Air: A Relaxing K2 QRP POTA Activation from the Campsite →

Accessories, Morse Code, News

Len Tests a Signet Spring Straight Key

2 Comments

Many thanks to Len (W8VQ) who writes:

I have been working CW a bit in my upstairs QRP station. Last night, 40 meters was alive. Lots of POTA and general QSOs and a few SKCC. I used my new straight key. I thought you’d enjoy a critique.

I used the new key for two SKCC QSOs and three POTA hunter contacts. Here it is between my mini straight key and mini Iambic. Those are small keys, as the ruler shows;

It absolutely works, and I suspect by the way it is designed and manufactured, it will work well beyond my years. It would be excellent for travel as there is little you could do to damage it or throw it out of adjustment, short of using it to play catch.

It does not provide you with any sort of positive CLICK feedback when keying. A vintage Kent Morse Op like myself finds this a negative when keying. I like that positive click (or TAP if you prefer that description) on contact while using a straight key. This key is more of a touch-key because of the design.

If you look at the “Spring”, it’s a manufactured pseudo torsion disc spring that functions both as a spring and a stanchion for the key knob. It’s made to be both supportive and slightly flexible.

There is not enough flexibility in that spring nor space between contacts to give you enough smooth travel to get a positive click. You can get a click if you back the bottom contact screw all the way out, but it’s minimal and you have to hit the key harder than normal to get that minimal click. The spring is strong by design. This key is designed to give you more of a “Touch-Contact” that you hear via sidetone rather than feel via tactile feedback.

Some ops said that you best leave it at the factory setting, but I played with the contact set-screw in the bottom and I think I adjusted it a bit better for my fist. It comes factory adjusted with a very light touch, almost feathery. I now have it on a medium-to-light touch. There is just no “Click” or “Tap”.

Is it the best key (as one op stated in the reviews) I ever used? No.

Is it a cool and unique key that works well? Yes, as long as you don’t expect that mechanical click-on-contact that I like in a straight key for “Pounding Brass”.

There will be no brass pounding with this particular key. But I’m glad I added it to my collection. The fit, finish and manufacture is very well done, IMO. Especially for the price. And it’s unique. I may add it to my POTA kit instead of any other straight key.

Click here to check it out on AliExpress.

-Len

What a unique key! Thank you, Len, for the mini review!

Accessories, News

Elecraft KX2: Paul’s a fan of this “cool idea”

4 Comments

Many thanks to Paul (KE4SC) who writes:

Hi Thomas.

I thought I would pass along this idea for your readers.

I was using my KX2 on PSK31(and cw!) this weekend at the lake QTH. I felt the rig getting warm. I remembered that my wife bought several of these battery powered personal fans (Cold Sky) in the attached pics. She bought them from Amazon for less than $15 each including a charging stand [QRPer.com affiliate link].

It took me a few minutes to realize that the fan “head” will pivot which makes it a perfect cooling device for the rig.

I often though about purchasing after-market heat sinks but none are needed with this little device. It has 4 or 5 fan speeds and it really moves air and cools my KX2. With headphones, I could barely hear the fan.

I really enjoy your videos and website. I hope this helps you and others looking for a cheap way to cool the rig.

73 Paul KE4SC

Thank you for the tip, Paul! 

Accessories, Kits

In Stock: The Ham Radio Workbench Podcast DC Distribution Panel Kit

3 Comments

Many thanks to Mike (KG4MTN) who notes:

Hi Thomas,
Just a note to let you know that digikey has a supply of Ham Radio Workbench DC Power Strips in stock, 43 at the time I reviewed. Product number is HRWB101.

Thought you might want to let your audience know. These are neat little kits, I really like mine!
72,
Mike Serio
KG4MTN

Thanks for the tip, Mike! These will likely sell out quickly.

I may be biased, but I love mine! Such a handy accessory and easy kit build.

Click here to purchase one via DigiKey!

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, Field Radio Kits, News, Portable, POTA, SOTA, Videos

The Write Stuff: My pencil/paper weatherproof logging combo!

38 Comments

If you’ve followed my field reports in the past couple of years, you’ll know that I predominantly use Rite In The Rain notepads and mechanical pencils.

When I first started my POTA journey in 2019, I would print out log sheets for each activation just like I did during the National Parks On The Air program in 2016. It was a very inexpensive and organized way to manage all of my written logs.

Over time, though, I made a shift to small pocket-sized notepads (Moleskine, Moji, Mead…) basically any pad that took up less space and could remain in my QRP field kits.

Rite In The Rain

After a couple of moisture mishaps with Moleskine pads (which, by the way, I otherwise love) I decided to completely shift to using Rite In The Rain spiral-bound notepads.

I resisted doing this for a long time because Rite In The Rain pads aren’t cheap; they typically cost about $6-$7 US each, but they are made in the US and are very high quality. They don’t smudge or smear.

My father-in-law is a retired professor of Botany and the bulk of his research time was (literally) in the field–in the mountains of western North Carolina. He’s always been a huge fan of Rite In The Rain and we often purchased these for him as gifts.

I switched to Rite In The Rain and haven’t regretted it. Yes, they’re pricier than all of the previous options I’d used, but they are insanely durable, can survive getting wet, and they hold quite a lot of my 45-60 minute POTA and SOTA activations! One pad will typically last me several months.

There are two sizes of pads I use:

(Left) 3×5″ and (Right) 4×6″ Notepad

Please note that all of the Amazon.com links on this page are affiliate links that support QRPer.com.

The 3×5″ sixe easily fits in my Pelican 1060 case

I find that both sizes work well. I tend to use the larger 4×6 size most of the time, but I love the 3×5 size because it fits in some of my smallest field kits including the MTR-3B SOTA kit I highlighted last week.

When you use a Rite in the Rain pad, it will hold up in the rain if you are using any pencil, or one of their pens which has a special ink that bonds to the paper permanently.

I use mechanical pencils when I log, although I plan to start using pens more often only because it makes it easier for my YouTube video subscribers to read my logbook as I write (pencil can be more difficult to read from the camera angle, depending on reflection, etc.).

Mechanical Pencils

This is an area where (being fully transparent here) I can geek out a bit (understatement alert).

I’ve always had a place in my heart for mechanical pencils. It dates back to my high school years when I took drafting classes. These were the days when drafting desks, pencils, T-Squares, triangles, and templates were tools of the trade (CAD was just becoming accessible to students).

I found mechanical pencils to be an amazing piece of engineering and, while I couldn’t afford a lot of them, I would spend my hard-earned money to buy them. To me, visiting our local drafting store was like a trip to the toy store.

But I digress…

In the field, performing a POTA or SOTA activation, I don’t look for the same precision I needed in drafting class. Quite the opposite–I’m looking for durability and reliability.

Wooden pencils, to be clear, are both of those things and will serve you well in the field. What I love about mechanical pencils is that their leads are consistent when writing and there’s no need to pause and activation to sharpen them. Just click and keep going.

There are currently three mechanical pencil models I use.

My wife recently gave me a uni Core Keeps Sharp Mechanical Pencil as a gift. She did so after reading a comment from one of my readers (I had no idea she even read QRPer–I’ve got to be careful what I say around here!). 🙂

What makes this particular pencil unique is that it rotates the lead as you use it. This keeps the line looking sharp since the lead doesn’t wear to one side.

So far, I love it. This one has a .5mm lead, which is small–I tend to prefer .7 or .9mm because they’re more durable. Expect to see this in activation videos soon.

Next is the Zebra Mechanical Pencil, Del Guard, 0.7mm. This particular pencil lives in my MTR-3B SOTA field kit. The Del Guard has a double spring mechanism that acts as a shock absorber when you write.  If you apply a little too much vertical or angled pressure, it absorbs the energy thus saving your lead from breaking.

I find it works really well, in fact. I tend to have a heavy hand when I write in my log books and I find I have less lead breakage in the field.

Finally, the mechanical pencil I’ve adopted as my primary SOTA and POTA pencil is the amazing GraphGear 0.9mm 1000.

This pencil is the most durable mechanical pencil I’ve ever used.

Bruce (KO4ZRN) introduced this to me when he joined me on a SOTA activation of Craggy Dome a couple years ago. This pencil is incredibly strong. In fact, I’ve even used it in woodworking and carpentry projects to mark cuts on wood.

At this point, I think I probably own about six of these GraphGear pencils and I couldn’t be happier.

Video

I actually made a short (for me) video about my notepads and pencils:

Click here to view on YouTube.

Again, you don’t need anything fancy…

If you’re not into waterproof paper and mechanical pencils, just use what you have to log.

I remember once using the back side of an envelop and a pen I found in my car to log a NPOTA activation–it worked perfectly! I even remember another NPOTA activation using a pen to log and running out of ink, so I used the pen to log in the dirt on the ground. I only copied three or so more contacts then took a photo of the ground. (I can’t recommend this, but point is, practically anything can be used for logging!)

I just find that when I do something on a regular basis, I’m willing to invest in tools I love using. I feel they serve me well in the end.

How do you log?

I’m curious how you log. I know that a large percentage of POTA activations never write a thing on paper logs–they simple log directly to an app on their phone, tablet, or laptop.

I prefer making a paper copy of my logs, then taking a photo of them when the activation is complete. I worry less about my app crashing, phone running out of power, and, frankly, I just find the process of logging more fun on paper. Furthermore, rain can disrupt touch accuracy on capacitive touchscreen devices, making logging difficult in wet conditions.

I’m curious how you log in the field. Please comment!

Thank you

Thank you for reading this post!

Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon, and the Coffee Fund. While not a requirement, as my content will always be free, I really appreciate the support.

Have a brilliant week and I hope you run out of paper due to the number of contacts you must log!

Cheers & 72,
Thomas (K4SWL)

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