Category Archives: Accessories

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.

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 1, 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

Field Report: BROG Gadget Bag Tour, New Anker Speaker, & Pairing the KX3 w/the MC-750 for Serious QRP POTA Fun!

On Tuesday, March 28, 2023, I packed my Elecraft KX3 and took it to the Zebulon Vance Historic Birthplace (K-6856) for a nice, relaxing, early afternoon POTA activation!

It had been a few months since I’d taken the KX3 to the field and it really does deserve some outdoor time because…well…I still think it’s one of the best HF field radios on the market.

I’m spoiled, though, because I also own a KX2 and it does 80% of what the KX3 does, is much smaller, and sports a very long-lasting internal battery. Because of this, my KX2 gets way more field time and the KX3–hooked up to a KXPA100–is my main radio in the shack.

When I make an activation video in the field, I like using a speaker rather than recording from the line out of the radio. Besides the extra post-processing, sometimes the line-out audio from left and right channels are out of phase from each other and end up cancelling each other out in YouTube videos if listening in mono. I recently learned how to fix this, but I find the whole process just adds *that* much more time to post-processing and I’m always pressed for time.

The Elecraft KX3 has a built-in speaker, but it’s pretty anemic. I almost always pair the KX3 with an external speaker to amplify the otherwise excellent KX3 audio for my activation videos.

On this particular day, I had a new speaker to try as well: an Anker Soundcore Mini. I purchased this speaker on the same day I posted Mike’s speaker search and review of the Soundcore Mini. Although I have a Sony SRS-XB12 portable speaker and love it, they’re no longer produced and the battery life isn’t quite as good as the Soundcore Mini (Anker states up to 15 hours per full charge).

This activation would give me an opportunity to really test the Anker Soundcore Mini in the field. In the end, it did a brilliant job.

I should note that I also brought my Blue Ridge Overland Gadget Bag (see above) to the field that day, so I include a little tour and overview of this pack in my activation video.

I did recently post a review of the BROG Gadget Bag here on QRPer as well.

Zebulon B. Vance Birthplace (K-6856)

As I mention in my activation videos, Vance is a small park and, unless you plan to operate from your car, there’s really only one good site to set up: in the picnic shelter. Thing is, if a school, club, or civic group is scheduled to meet that day, the picnic shelter will almost certainly be reserved for them.

Each time I activate Vance, I ask the park staff in advance if the picnic shelter is reserved and if it’s okay if I perform the activation. Fortunately, the shelter is reserved only about 20% of the time. On days when it’s reserved, I simply activate elsewhere.

On the 28th, I had the site to myself and the staff encouraged me to activate as long as I wanted to. Continue reading Field Report: BROG Gadget Bag Tour, New Anker Speaker, & Pairing the KX3 w/the MC-750 for Serious QRP POTA Fun!

Scott builds a mobile desk for HF park-roving

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


Necessity is the mother of invention

by Scott (KK4Z)

Plato’s Republic he said that *our need will be the real creator* or the proverb as we know it today *necessity is the mother of invention*.  Recently, my friend Thomas K4SWL acquired a Yaesu FT-891.  During his YouTube video, he expounded on how much fun he had with it. It did indeed look like fun. During this time I was pondering about doing more day activations instead of overnights.  With the cost of everything still climbing, the need to conserve becomes apparent.  I thought an FT-891 might really be a great radio for these day activations. Then reality set in.

I already have a number of projects I am working on and misc things like maybe having to replace my old 33′ push-up pole, it was not in the stars nor was there a twinkle in my wife’s eye when I mentioned it. In reality, the IC-7300 is a great radio and does everything I need to do especially in the field. I don’t need another radio, I have three 100 watt radios and three QRP radios. I still wanted an easy setup for these one-day activations. I want to drive to a park, set up in a few minutes, operate, tear-down in a couple of minutes, and head for home or another park. I also wanted to make my day activations park ranger friendly. To me, that means trying to be inconspicuous.

I have two projects planned. The first is a desk for my truck. I am making a desk to sit over the center console and front passenger seat big enough to hold my IC-7300, a laptop and a CW paddle. My plan is to secure the desk to the truck and the radio to the desk. I also wanted to make this as cheaply as possible. I used stuff I had on the property such as a half sheet of plywood and some construction lumber. The only things I had to buy were some screws and eye-bolts, about 14 dollars worth.


The plywood was cut to 24 x 38.5 inches. The length covers the center console and front seat while still allowing me to get to the heat/AC controls. I gave the corners a generous radius and I broke the edges with a router. On the underside, I used a 2 x 12 to make a spacer for the center console where the cup holder is and a leg for the other side over the passenger seat. The spacer is glued and screwed to the desktop but the leg is not attached. This is to make it easier to store. I made a socket for the leg using 2 x 2’s. It’s probably easier to look at a picture than me to try to explain. I added eye rings to the rear of the desk and use a bungee cord to secure the desk to the passenger seat. The only other thing I did, sprayed the top with polyurethane. Note. I am not a carpenter or cabinet maker. I use rough hand tools to get the job done and I am often making do with what’s on hand or what’s the cheapest way to do it.

Continue reading Scott builds a mobile desk for HF park-roving

Steve tests the Gabil 7350T antenna, Gabil GRA-ULT01 tripod, and BaMaKeY TP-III paddles

Many thanks to Steve (MW0SAW) who shares the following field report:


Mini Field Report: Testing the Gabil 7350T and BaMaTech TP-III on a brisk SOTA activation!

by Steve (MW0SAW)

Went for an early walk/SOTA activation up Fan Fawr GW/SW-005 (734m) this morning (9/4/23). I think someone said it was supposed to be the hottest day of the year in the UK. It was about 5 deg celsius with a bitter wind chill of -2c on the summit! It’s very close to the highest peak in South Wales, Pen Y Fan (886m).

As I mentioned a couple of weeks ago in our emails, I wanted to test a new compact antenna I purchased recently, called the Gabil 7350T in the USA, and branded as the Sharman MD-3500 in the UK where I got mine. I also took the Gabil GRA-ULT01 MK2 tripod which I did purchase from the USA on Amazon.com.

The Gabil 7350T Compact Antenna and Gabil GRA-ULT01 MK2 tripod

Another first for the the activation was the Bamatech TP-III ultra compact paddle, Dinos were included 🙂

Starting my walk, the lovely view of the reservoir quickly disappeared and was the last view I would see ascending into the mist.

I took refuge in my Decathlon 1 man camping shelter, setting up the tripod and antenna close by.

The wind was howling and turning my back the antenna toppled over. This was quickly resolved with a tent peg on one of the tripod legs. Quick setting of the slider with the analyser got 1.2 SWR and so after a slurp of coffee, I started to call CQ on 20m CW. A nice stream of European qsos ensued with good reports (many 599), it was pleasing to hear with such a small antenna (about 8 ft). Just as the contacts were drying up, I was taken aback by a strong VK station! Always great feeling to get some dx like that but especially pleasing with this tiny antenna on its maiden voyage 🙂

I switched to 20m SSB for a few more QSOs but struggled with QRM on two frequencies. My allotted time was running low and my fingers were numb, so I packed up the HF and got the handie out to catch a few local VHF contacts.

So what can I summarise from this activation, well I can safely say I love the Gabil/Sharman antenna and Gabil tripod. They would make a really nice additional to a small go bag, they seemed to work almost as good as a full size 1/4 on 20m. Time was limited this trip and I was too cold to hang about to try more bands, but extremely pleased with the performance so far.

The Bamatech key is a pure work of art, beautifully made, sensitive and precise. Probably my best portable key to date in my collection.

Equipment:

(Note: Amazon links are QRPer.com  affiliate links.)

Thanks to all the chasers.
73
de MW0SAW/P

POTA at Fort Dobbs: Testing a BCI filter and depleting a battery!

Friday, March 17, 2023 was a dreary, rainy day.

It was the sort of day made for reading a good book by the fireplace or…in my case…activating a park!

I don’t let rain stop me from playing radio in the field. I carry a rain fly in my car pretty much all of the time so if push comes to shove, I can create a dry space to play radio.

That said, a number of parks I frequent have large covered picnic shelters, so why not use what’s already there?

That particular Friday, I had one particular park and one particular goal in mind.

G106 + BCI Filter

As I mentioned in a post this weekend, I purchased and built a K9DP BCI Filter Kit.

If you’d like to see photos of the build, check out this post.

I built this BCI filter specifically to pair with the Xiegu G106 transceiver. Why? Because the G106 is prone to overload if you’re anywhere near an AM broadcaster.

The last time I visited Fort Dobbs State Historic Site (K-6839), a local AM broadcaster bled through the audio of the G106. I was able to complete the activation without any issues at all–in fact, it was a very successful activation (read the report here).

Still, I did feel that the receiver was a bit less sensitive due to the broadcaster overwhelming the front end of the radio.

That Friday, I wanted to pair my Xiegu G106 with the new in-line BCI filter to see if that might mitigate the interference I experienced before.

Fort Dobbs State Historic Site (K-6839)

After arriving at Fort Dobbs, and before taking my gear out of the car, I made my way to the park office (in the log cabin at the end of the sidewalk above) and asked for permission to use their picnic shelter. Continue reading POTA at Fort Dobbs: Testing a BCI filter and depleting a battery!

Assembling a K9DP BCI Filter Kit (Photos)


If you own a Xiegu G106, X6100, or any other radio that is prone to overloading when in the presence of an AM broadcaster, you should consider building an in-line BCI filter!

As many of you know, I’ve been testing the Xiegu G106 over the past couple of months for a review that will be published in the May 2023 issue of The Spectrum Monitor magazine.

One criticism of the G106 is that its front-end overloads when there’s an AM broadcaster within a few miles of where you choose to operate. The Xiegu X6100 is identical in this regard.

One quick way to remedy this is to build or buy a BCI filter. We’ve mentioned in the past how you can homebrew them and I planned to do so. After checking my parts drawer, though, I realized I needed to buy a capacitor, toroids and at least one of the two BNC connectors needed if I wanted an in-line filter in a small project box.

I decided it would be much easier to simply buy a kit and, based on a tip from a reader here on QRPer.com, I purchased one from Dan (K9DP). Continue reading Assembling a K9DP BCI Filter Kit (Photos)