Category Archives: Accessories

Field Report: Testing the bhi Dual In-Line with the (tr)uSDX, making a big blunder, and P2P with Teri!

On March 30, 2022, I took my factory-assembled (tr)uSDX transceiver on a POTA activation at South Mountains State Park.

It was a “test flight” of sorts since I’d only had the (tr)uSDX for a few days and had not taken it to the field.

I wrote up an assessment from that initial POTA activation mainly to give other potential (tr)uSDX owners an idea of how well one of these super-affordable radios might perform.

Difficult to critique

It’s difficult to critique a 5 band HF radio that you can purchase as a kit for less than $100 and fully-assembled and tested for less than $150…shipped!

On the one hand, I think it’s one of the most amazing portable HF radio innovations of the past decade. It simply blows my mind that the developers (DL2MAN and PE1NNZ) could make this modest radio hardware do so very much. It’s truly a triumph of engineering and a fun little radio.

On the other hand, this isn’t a high-end radio, so we can’t expect performance like we’d see in an Elecraft, Icom, or Yaesu field radio, for example. I never expected this, in fact, but was very curious if the performance would be “good enough” for POTA or SOTA.  So many had asked me about buying a (tr)uSDX as their dedicated POTA radio.

I found using the (tr)uSDX for POTA was actually quite fun, and I certainly achieved my goal of activating a POTA park with it.

So yes, it’s good enough!

That said, I haven’t reached for the (tr)uSDX to do POTA or SOTA since last March because I prefer the performance characteristics of my other radios.

My biggest complaint, frankly, is that the audio fidelity is pretty poor. The noise floor of the (tr)uSDX is higher than most HF radios and audio amplification is very basic. I notice a lot of electronic noises (pulsing, etc.) in my unit. I find it a bit fatiguing to listen to for long sessions with my headphones. The internal speaker isn’t really a viable speaker for doing an activation–it’s more akin to an emergency speaker, if anything.

When plugged into an external amplified speaker, the audio is much improved. The pops and internal noises are still there, but it has better overall fidelity and the volume can be raised enough to hear weak signals (this can’t be easily done via the internal speaker).

It struck me that a DSP device might clean up the (tr)uSDX’s audio and noise floor a bit.

Enter the bhi Dual In-Line DSP filter

Sometime during the beginning of the pandemic, I reached out to bhi Noise Cancelling Products and asked if I could test one of their DSP units as a loaner. I’ve always felt that bhi manufactured the best DSP products in the amateur radio market.

At the time, I wanted one of my friends and contributors on the SWLing Post blog to test the bhi unit and see if it might help out a QRM situation that popped up at his QTH. I thought it would make for a great evaluation since I have little to no QRM at my home.

Graham, at bhi, kindly sent me a unit–the Dual In-Line Noise Eliminating Module–and as I prepared to forward it to my friend, his noise was no longer an issue. I can’t remember the details now, but there was no need to send it to him.

I notified Graham that I would like to test it myself, but that my plate was so full it would take time. What ended up happening, though, was I completely forgot about it due to a busy family life at the time.

I re-discovered the unit this year and spoke (apologized) to Graham at the 2023 Hamvention. Of course, he had no issue at all and was very forgiving. He’s a great fellow.

I thought pairing this bhi DSP unit to the (tr)uSDX would be a great way to, perhaps, cut down on the listening fatigue.

Fort Dobbs State Historic Site (K-6839)

On Wednesday, July 5, 2023, I had an opportunity to test the (tr)uSDX/bhi pairing at Fort Dobbs State Park. Continue reading Field Report: Testing the bhi Dual In-Line with the (tr)uSDX, making a big blunder, and P2P with Teri!

POTA with the Penntek TR-45L and importance of quality cable assemblies!

On the morning of Wednesday, June 14, 2023, I left the QTH with a goal in mind: fit in a POTA activation before taking my sweet mom to an appointment that afternoon. As I’ve mentioned in the past, there are about four park options that are easy detours off the 1.5 hour drive to my parents’ home, so it was very much doable.

I decided to go to Tuttle (K-4861) since it would be very close to one of my favorite lunch spots (Food Matters in Morganton). I figured I could fit in an activation, then grab lunch after, and still make the appointment with time to spare.

In almost every case, this is how I do POTA these days: it’s all about fitting in activations with weekly travels and errands. It’s rare that I simply plot out an activation or two the day before. More often than not, I schedule my activation a max of 30 minutes before I arrive at the park.

I arrived at Tuttle around 11:30 AM and had the park to myself. There were no other guests there, just park rangers. And lots of birds.

PSA: Buy/Build quality cable assemblies!

A couple days prior, I received a cable assembly sample in the post: a 25 foot RG-316 cable with BNCs on both ends and three series 31 in-line ferrites from ABR Industries. These slim in-line chokes are a new option ABR is offering, hence the reason they send me the assembly.

I speak about this at length in my video below, but I’ve been a customer of ABR Industries for well over a decade now. ABR is a USA supplier of high quality cable, cable assemblies, and other cable components. I’m a huge fan. In fact, I wrote about them separately on the SWLing Post a couple years ago.

Full disclosure: ABR Industries sent me this cable assembly (and one other I’ll feature in a future report) free of charge. They are not a sponsor (although I’d love for them to be) and I’ve no other relationship with them other than being a customer.

I go into greater detail in my video, but I learned a while back just how important it is to use high-quality cable assemblies, adapters, and connectors in the field and at the QTH.

As a field operator, I know my cable assemblies are essentially consumables. With all of the winding, deployments, packing, being outdoors, rough handling, etc. they will eventually fail. (In fact, Alan made a point of this in his latest field report when a mishap in the field broke a good assembly.)

High quality cable assemblies will not only provide better longevity and better durability, but also less loss and overall higher performance. It’s worth the cost because when I hike to a summit, the last think I want to discover is that my cable assembly has failed.

Note that I also build my own cable assemblies (indeed, I feel like all radio ops should learn this simple skill) and try to use quality components and best practices to make the best assemblies I can.

Take-away is: don’t skimp on your cable assemblies. I no longer buy my cable assemblies from random suppliers on eBay or Amazon, I buy them from companies that build and test their assemblies within our hobby; companies like PackTenna, Tufteln, Messi & Paoloni, and ABR Industries.

Here ends my PSA…let’s get on with the activation!

Tuttle Educational State Forest (K-4861)

I spent quite a bit of time talking about cable assemblies, then I moved straight into setting up my field gear. I launched a line and deployed my cannibalized 40m EFHW again and connected it to the Penntek TR-45L. Continue reading POTA with the Penntek TR-45L and importance of quality cable assemblies!

KO4WFP: The Final Countdown and an Innovative Solution for My Nova Scotia Trip

Many thanks to Teri (KO4WFP) for the following guest post:


The Final Countdown and an Innovative Solution for My Nova Scotia Trip

by Teri (KO4WFP)

As I finalize preparations for my trip to Nova Scotia, during which I plan to activate six or seven parks, I ask myself “How the heck did I get here?” Those of you who read my first field report in this series know that Thomas Witherspoon’s decision to activate parks in Canada last year was my motivation. I admit it is gutsy of a relatively new op to believe I can undertake such a venture.

The necessity of traveling to Nova Scotia by plane drove the decision of what equipment to take. QRP became the name of the game, a great option for a CW op. I purchased the Elecraft KX2, a rig with a great reputation. Once it arrived in early May, I spent the next month and a half acquiring the necessary accessories and skills for this adventure. The final step before I leave is ensuring I have what I need and the room for it. Given others might want to undertake a similar venture, I will share what equipment I have chosen to take and how I am packing it.

I know most people prefer a roll-on suitcase, but after a trip to New York City last summer, I had enough of schlepping wheeled suitcases up and down the many flights of stairs we  traversed. Upon my return to Savannah, I immediately purchased an Osprey Fairview 55 pack. The Fairview pack can be carried as a suitcase by a handle on its side or as a backpack (my preference). As for its size, it meets airline carry-on dimension requirements for domestic flights and has a few points to attach items you might carry if actually using it for hiking. And, best of all, it is made for YLs!

Included with and attached to the front of the pack is a smaller backpack that can be used as a daypack. I figured this would be perfect for most of my ham equipment and proceeded to find a way to fit everything in it. The larger Fairview pack would serve as my carry-on and the smaller daypack as my personal item for the flight.

As you can see, the daypack has a fair amount of room. In the main compartment I have the gorillapod tripod for mounting the AX1 on top of the rental car or a picnic table, the carrying case for Craig, my KX2, and his accompanying items, and two Tom Bihn travel bins. There are two additional compartments inside the daypack – a mesh, zippered pouch and a slot for a laptop or iPad.

When I first began CW POTA activations, I used a notepad to track contacts. However, to save time, I switched to a refurbished laptop with N3FJP loaded to log contacts in real-time. Juggling it and the key didn’t prove as difficult as I originally thought. Also in the laptop slot are documents I don’t want bent like my license (not pictured), band plan, UTC conversion chart, and call sign prefixes for European countries. I am also taking a small steno notepad as a backup for logging contacts as well as making notes for the trip reports I’ll write afterwards.

In the zippered, mesh pocket are the Elecraft manual that came with the rig and my two longer lengths of RG-316, one 25’ and the other 50’. Continue reading KO4WFP: The Final Countdown and an Innovative Solution for My Nova Scotia Trip

A Nifty Internal Battery Mod for the Elecraft KX1

A Nifty Internal Battery Mod for the Elecraft KX1

by Leo (DL2COM)

I was very happy to learn more about an interesting internal battery solution that came with my recently purchased Elecraft KX1. The original owner, Rolf DF2FK, built this KX1 himself and has a background in electrical engineering. He wanted an internal solution that is safe and delivers the full power output with this transceiver.

elecraft kx-1 internal lipo battery pack
KX1 with custom balanced 4S Lipo battery pack

Disclaimer: Working on custom battery solutions can be very dangerous, esp. with Lipo batteries (possible fire, explosion when handled improperly etc.). Please take safety precautions when attempting to build the following solutions and make sure you stick to the safety instructions of the batteries you work on. Everything happens at your own risk – just like always in Ham Radio 🙂

So he developed an idea around a 4S Lipo pack consisting of 4×3.7V Lipo cells each with a capacity of 820 mAh and each with an own battery management system (BMS). Of course all four are connected in series. The individual BMSs help a great deal in keeping the Lipo cells safe such as avoiding deep discharge, excess charge etc. Continue reading A Nifty Internal Battery Mod for the Elecraft KX1

POTA QRP: Testing the new JNCRadio CS-818 ATU with my upgraded Yaesu FT-818ND

I love testing new stuff in the field and on Tuesday, May 2, 2023 I had a great opportunity to test a number of new items.

FT-818ND Upgrades

I mentioned in a previous post that I purchased a new Yaesu FT-818ND from DX Engineering on December 28, 2022. It smacked of an impulse purchase only in that I had not planned to purchase the radio that very day.

Thing is, Yaesu announced they were discontinuing the FT-818 and I always planned to purchase one to replace out one of my two FT-817NDs. I didn’t want to miss the opportunity to buy a new one under warranty, so I bit the bullet on short notice.

Within a few days of purchasing the FT-818ND, I also purchased another 500 kHz CW filter, a WINDCAMP 3000mAh LIPO battery and a WINDCAMP Anderson PowerPole Adapter.

I planned to make the FT-818ND my primary HF radio and use the other FT-817(s) for full duplex satellite work (and HF too, of course, especially since one is now in a TPA-817 pack frame).

I had all of the upgrades in hand by mid-February, but that Yaesu FT-818ND sat in its box under my radio bench until late April. I was so busy evaluating other gear and keeping up with my busy family life,  it had almost slipped my mind. Well, that and I received the incorrect narrow Collins filter from a seller on eBay; instead of sourcing a replacement, I decided to steal an original 500 Hz filter from one of my other radios while waiting on a replacement.

Those narrow Collins filters? They’ve become pure unobtainium over the past couple of months. At one point, eBay was chock full of them. No longer…

It had actually been a very long time since I pulled out a brand new (non-loaner) radio from the box. It’s funny because I remember opening my first FT-817 back in…what…2001? The box and packaging were identical some twenty one years later!

I unboxed then immediately opened the chassis of the FT-818ND to add the Collins filter, attach my Portable Zero side rails (stolen from my FT-817), add the Windcamp battery pack, and add the Windcamp Anderson PP adapter.

JNCRadio CS-818 ATU

Around the same time, Jesse, with Chelegance, also sent me his latest ATU: the CS-818 which is specifically designed to work with the FT-817 and FT-818 series radios. To be clear, Jesse sent the MC-818 at no cost to me to evaluate.

The CS-818 actually works with any radio, but it ships with the command cable for the FT-817/818 for full integration.

The CS-818 can handle up to 30 watts of power, so it’ll pair nicely with any QRP radio. If using it with a QRO radio, you’d have to be very careful not to push more than 30 watts.

NOTE: Due to the frame rate of my camera and the refresh rate of the OLED display, only a portion of the display shows up in my shots.

In truth, ATUs don’t get me terribly excited. I’m quite content with my Elecraft T1 and Emtech ZM-2; these two portable ATUs match anything and everything I use in the field. Continue reading POTA QRP: Testing the new JNCRadio CS-818 ATU with my upgraded Yaesu FT-818ND

Guest Post: EmComm and FunComm!

Many thanks to Scott (KK4Z) who shares the following post from his blog KK4Z.com:


EmComm and FunComm

by Scott (KK4Z)

As I have said earlier, I practice EmComm to prepare for natural or man-made disasters when normal means of communication fail. FunComm is pretty self-explanatory, it’s things I do for fun. Fun things may include POTA, Field Days (winter and summer), supporting bike rides, and other club activities. I always like it when I can blend the two together. When I participate in POTA either for a weekend camp-out or a day activation, isn’t it kind of a practice run for an EmComm event? I use the same antennas and most of the time the same radios. My equipment gets a good exercise and I learn more about how they operate under different conditions.

Recently, I bought a new camper, the old one wasn’t working well for the things I like to do. The new camper is so much better but not without its growing pains. I had to find a better way to use the radios inside the camper. To save words, here is a picture of what I have been using. It works okay but because it uses part of the bed, it made sleeping uncomfortable. After this last camp out when I woke up all sore and twisted feeling, I decided it was time to find a better way.

The new desk stacks the radio and power supply above the computer. This reduces the overhang on the mattress. The desk area for the paddle does overhang a little but sliding the desk to the right when not in use alleviates that.

The other thing I did was make a cut-out on the door side to make it easier to get my legs out. This works really well and does not impair the stability of the desk.

The last thing is the main desk is 30″ deep and the shelf is 20″ deep. This leaves plenty of room for the radios and enough room to slide the computer under the shelf if I need the desk space for something else.

Sitting behind the desk, the radio controls were easy to get to.

The desk is made from one sheet of 3/4″ plywood with (2) 1×3″x8″ boards. The stain was a can of Minwax I had laying around, I think it was Golden Oak.

Construction was simple, using hand tools found in most garages. It is not a piece of art, I don’t have the time. My philosophy is that “Perfection is the enemy of good enough”. The desk is glued, screwed, and nailed without any fancy joinery. If I waited until I had time to do a better job, the wood would still be at Lowe s.

I tried it out in the driveway and everything works and feels good. The radio is easy to get to and the computer is a little high but not uncomfortable. With the cut-out, it is easy to get in and out of the camper. The next test will be at the end of the month during my next camping trip. Hope to hear you out there. 73 – Scott

Philip shares battery sizing calculator spreadsheet and POTA radio survey results

Many thanks to Philip (KA4KOE) who shares the following two notes:

Battery sizing calculator

I developed the following spreadsheet as a response to all the folks asking “what size battery should I get“?

That’s one of those questions one can’t answer accurately without more information, so I created a spreadsheet.

Click here to download the spreadsheet (Rev 1 updated Feb 1, 23).

Popular POTA radios

I also recently ran a poll on the Facebook POTA group asking what radio they primarily used for POTA. The sample size was 1,148 votes.

Here are the rankings by percentages:

1. Yaesu FT-891: 25%
2. Xiegu G90: 9%
3. Icom IC-7300 and IC-705: 7%
4. Yaesu FT-857D, FT-991A, FT-817/818: 4%
5. Xiegu 6100, Yaesu FT-897D, Elecraft K/KX series: 3%

I cut off the poll at below 3% as there were 60 entries for various radios.

I’m not really surprised by the top 3 rankings.

POTA Field Report: Testing my CP Gear Tactical Aircrew/Pubs Bag with FT-817ND and Armoloq TPA-817 Pack Frame

Last year, during a Black Friday sale, I took a calculated risk and purchased a bag I hoped would accommodate my Yaesu FT-817ND that has been outfitted with an Armoloq TPA-817 Pack Frame.

CP Gear Tactical Aircrew/Pubs Bag

Rod (VA3ON) first introduced me to CP Gear Tactical–a  military pack manufacturer based in New Brunswick, Canada.

I’d had their their Aircrew/Pubs Bag with Padded Tablet Pocket on my wish list since the Ham Radio Workbench podcast episode where we talked about backpacks and pouches. CP Gear Tactical manufactures a wide variety of gear primarily for the Canadian military market. Everything is made either in Canada or the US (or both).

I contacted CP Gear Tactical shortly after outfitting my FT-817 with the TPA-817 pack frame. I measured the frame carefully and asked if the interior padded pocket (which is actually designed to hold a tablet–might fit my radio.

I never heard back from them. I could have called them, but on Black Friday, when it was on sale for 20% off and free shipping, I decided to throw caution to the wind and simply purchase it. My total price in USD was something like $62 shipped.

As soon as I opened the CP Gear pack, the first thing I did was check to see if the FT-817 with pack frame would fit in the interior pocket.

Much to my surprise, it fit it perfectly!

Indeed, it’s as if the pocket were specifically designed to accommodate the FT-817ND/TPA-817 combo.

Even the middle Velcro strap fits precisely in the middle of the radio between the pack frame side extensions. The strap holds the rig securely; once, I accidentally fumbled while holding the bag and even though it was upside down, the FT-817 remained securely inside. The strap held it in place.

The bag has loads of room inside. In fact, you can very easily transform it into a fully self-contained field radio kit.

I actually give a small tour of this pack in my activation video below, so if you’d like to see some of the exterior pockets, I would encourage you to check it out!

Zebulon B. Vance Birthplace (K-6856)

On Tuesday, April 11, 2023, I once again popped by the Vance Birthplace for a leisurely POTA activation–I thought this activation, in particular, would be a good one to test my new Aircrew/Pubs bag! Continue reading POTA Field Report: Testing my CP Gear Tactical Aircrew/Pubs Bag with FT-817ND and Armoloq TPA-817 Pack Frame

Testing my new Headrest QRP POTA Field Kit!

I love field radio kits.

If you’ve read my “Anatomy of a Field Kit” series, you’ve likely gathered that field kits are a bit of an obsession. [Yeah, understatement alert!]

My field kits roughly fall into two main categories: modular and fully self-contained. My modular kits are ones where components like the battery, antenna, throw line, key, and radio are in separate pouches and can easily be combined to make a complete station before I leave for an activation.

My fully self-contained kits are ones that quite literally have everything needed to perform a park or summit activation in one pouch or box. A good example that I’ve documented here is my MTR-3B field kit.

For more on this, again, check out my “Anatomy of a Field Kit” series.

Vehicle kit

If you’re a devoted park and/or summit activator, I think it’s important to keep a dedicated kit kit in your car at all times. Why?

  • It’s ready to grab for impromptu activations
  • It’s handy in case of road-side emergencies in remote areas
  • It’s always  accessible to demonstrate amateur radio to those who are curious
  • It’s always always there for those times when you hadn’t planned to play radio, but the opportunity presents itself

I always have a full radio kit in my Subaru and over the years, I’ve changed and adapted it. For the most part, though, it’s been located in the trunk/boot and lives with anything and everything else I keep back there. Sometimes, it’s in the way when we need to fill that trunk space with family items for a trip or when we’re hauling things around town. Other times, it’s floating/sliding around freely in the back.

On long family trips, I’ve been known to store radios under the floor, but it’s a true hassle to remove them because I have to remove anything in the trunk before lifting the floor.

Contraband I hid in the car during our two month Canada trip last year.

I’ve always wanted a way to store my kit in the car in a dedicated space. In the past, I’ve tried to make a kit that could fit under the driver’s seat–thinking that might be ideal–but there’s very little clearance under it and it’s difficult to remove.

Enter the BROG Headrest Pouch Kit

Before I placed my initial order for the Blue Ridge Overland Gear (BROG) Gadget Bag, I checked out other items on their website. One that immediately caught my attention was their Headrest Kit.

It consists of a Velcro panel that fits around a vehicle headrest and a pouch (or pouches) attach to it.

BROG caters to Overlanders and vehicle storage/organization is huge in that community. The headrest kit makes a lot of sense: it’s using space that’s accessible, doesn’t interfere with any passengers, is off the floor, and is otherwise underutilized!

The big questions, of course:

  1. would the pouch offer enough space to store an entire radio kit,
  2. and would the kit weight too much for the Velcro back to hold it in place?

I asked for the Headrest Pouch Kit ($47.99) to be sent with my Gadget Bag order.

BTW: Big thanks to BROG for giving me flexibility with this order. Since I had no experience with their gear, I asked that they send me a list of items and allow me to evaluate them, then pay (full price) for what I decided to keep. 

Would it work?

I knew I’d need to store a very small transceiver in this dedicated pack. A few could potentially fit the bill–namely the:

  • Mountain Topper MTR-3B
  • Venus SW-3B
  • QCX-Mini
  • TEN-TEC R4020

I eliminated the QCX-Mini from this list because it’s mono band (mine is set for 20M) plus, I really love the field kit I already designed for it. Same for the MTR-3B–the kit I built for it is now time-tested and I love it as-is. The R4020, while quite compact, is the largest in this group of wee rigs. Continue reading Testing my new Headrest QRP POTA Field Kit!

Coax cables I used for SOTA/POTA – A horror story

by Thomas (DM1TBE)

I think every portable operator thinks about their coax cables and how to use more light and flexible types. During the last few activations, I have switched from my rigid Aircell 5 to the lightweight and flexible RG316. I have bought a couple of different lengths, mainly from Chinese online sellers at AliExpress.

However, I had some hard to define issues like the vague feeling that I am not getting out as good as I should, or a changing SWR during an activation. So I thought I should check my cables before looking at other parts of my equipment.

My professional and educational background does not have anything to do with electronics, and I don’t have the equipment to measure the cable loss directly. But my goal was to check if the cables were faulty, not to measure the exact attenuation.

I have an SWR and Power meter from DJ9PK as per image below. It can measure PEP and has, according to the seller, an accuracy of +/-4 percent.   You can find more details about it here in German or here in English (Google / auto translated).

My KX3 with a CW paddle served as signal source. As large differences are easier to spot than smaller, I switched to the 10-meter band as the HF band with the highest attenuation.

I then measured a short cable with a very low loss, a 1 m / 3.3 ft RG213, which should have an attenuation of less than 0.1dB (excluding plugs).

I simply checked how much power came out at the other end of the cable. That value I have used as reference. This cable (and all others) was plugged directly between the KX3 and the power meter, no ATU involved anywhere. The power meter was set to measure PEP. Continue reading Coax cables I used for SOTA/POTA – A horror story