Taking the Mountain Topper MTR-4B on a quickie activation at South Mountains State Park!

The entire time I was in Canada this summer–about two months–I  used two field transceivers: the Elecraft KX2 and the Discovery TX-500.

I did sneak in two extra radios under the floor of my trunk/boot space, but they both were limited to three watts and conditions were so rough during many of my activations, I wanted the option of a QRP “Full Gallon” (5 watts). Thus, I stuck with the TX-500 and KX2 (which are both actually capable of 10 watts output).

When I got back to the States, I was eager to do a POTA activations with my other radios–many of you know I like to rotate them–but there was one, in particular, I was eager to put back on the air…

The Mountain Topper MTR-4B.

This MTR-4B V2 is on loan to me from a very generous reader/subscriber. In fact, get this: he ordered the MTR-4B early this year and had it drop-shipped to me directly from LnR Precision. He knew I’d be in Canada for the summer, so has been incredibly flexible with the loan period (basically leaving it open ended).

My review of the MTR-4B will be published in the November or December (2022) issue of The Spectrum Monitor magazine. Then I’ll be sending the MTR-4B to its rightful owner!

In the meantime, I built an ultra- compact field radio kit around the MTR-4B and in my Tom Bihn HLT2 EDC pouch.

This kit is nearly identical to the one I made for my MTR-3B (just a different color, really).

It contains the radio, a battery, an antenna (although I used a different one during this activation), fused power cord, paddles, earphones, RF choke, RG-316, logbook, pencil, and even a full throw line and weight. I’ve listed all of the components with links below.

It’s hard to believe it all fits in such a compact kit and it works so well. It’s nice to know that with the kit it in my backpack, I’ve got everything I need to play SOTA or POTA at the drop of a hat.

South Mountains State Park (K-2753)

On August 8, 2022, I drove to my hometown to check in on my parents. I didn’t have a lot of time, but I wanted to fit in a quick activation with the MTR-4B along the way.

One of the easiest parks for me to hit en route is the South Mountains State Park Clear Creek Access–it’s maybe a 10-15 minute detour off of Interstate 40.

The weather was amazing that day, although I’ll admit I had to get used to the heat and humidity after spending so much time in Canada this summer!

This access point of South Mountains only has one picnic table. I’m always prepared with a folding chair if that table is occupied, but so far it’s always been available. I’m sure the reason is because this particular South Mountains access point is way less popular than the main entrances. Most of the visitors here come to fish at the reservoir.

Setting up

The great thing about having your whole station in a pouch is that setup is quick and easy.

In truth, I didn’t use an antenna packed in the compact kit this time, I used the 40M End-Fed Half Wave (EFHW) my buddy Steve (MW0SAW) made. Also, I think I might have used my mini arborist throw line kit since it was in the backpack already.


The pouch/pack:

  • Tom Bihn Handy Little Thing (HLT) Size 2This little guy retails for $75, but keep in mind that it’s designed and made in the USA. It also carries a lifetime warranty from a company that offers best-in-class customer service.

Inside, I’ve the following items:

In the main interior mesh pocket:

In the exterior pocket:

  • 25 meters of Marlow KF1050 Excel 2mm Throwline, and an 8 oz Weaver throw weight. After a lot of experimenting, I find that 25 meters is an adequate amount of throw line for 90% of my antenna deployments. It’s certainly more than enough for mountain summits where trees tend to be short and for parks where there are so many trees to choose from.
  • Elecraft KXBT2 battery pack

To be clear: I’ve made much less expensive field kits, but I do like the level of quality in these components: the radio, the antenna, the throw line, the pouch, the cables…they’re all of excellent quality and should last for ages.

Don’t feel like you have to invest this much in order to make a compact field kit–it can be done with a few dollars! That said, I do like having quality kit when I can afford it. Use what you have and slowly upgrade it if you feel the desire to do so!

On The Air

My 40 meter EFHW is resonant on two of the MTR-4B’s bands: 40 and 20 meters. I could easily tune 30 meters with an external ATU and possibly even 80 meters although efficiency would suffer.

I started on the 20 meter band.

For the past two months I had been sending my Canadian call: VY2SW. I had to get my brain and fist used to sending K4SWL again. I did slip up a couple of times!

Time to start calling CQ POTA de K4SWL!

I was very happy to log seven stations in 12 minutes. Not bad at all considering band conditions!

After a few unanswered CQs on 20M, I moved to the 40 meter band.

On 40 meters, I worked three more stations in 5 minutes. This gave me the total of 10 logged contacts I needed to validate the park activation.

Since I had very limited time for the activation, I called QRT and packed up.

This amounted to a short amount of time on the air, but an awfully fun activation.


Here’s what this activation looked like when plotted out on a QSO Map:

Activation Video

Here’s my real-time, real-life video of the entire activation.  As with all of my videos, there are no ads (I turned off monetization) and I don’t edit out any parts of the on-air activation time:

Click here to view on YouTube. Please consider subscribing.

Also, please read my message about videos now being offered to Patreon supporters for download and viewing via Vimeo.

Thank you!

Thank you for joining me on this brief activation!

I hope you enjoyed the field report and my activation video as much as I enjoyed creating them.

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 certainly not a requirement as my content will always be free, I really appreciate the support.

New: Vimeo videos

Screenshot of the Vimeo platform

I’m currently in the process of upgrading the Patreon experience allowing supporters to view all of my videos without any default YouTube ads.  This will be available to all Patreon supporter levels.

Although I do not monetize my YouTube channel with ads, YouTube has started adding their own  ads regardless, which forces me to re-think how to offer you an ad-free experience.

I’ve started a subscription with Vimeo that will allow me to post my videos there as well as on YouTube. Since I pay for Vimeo, I have total control over there being no ads; in fact, I can even allow users to download my videos.

Vimeo’s streaming service comes at a cost of $420+ per year. Since Patreon supporters make this possible and there’s a way to directly connect Vimeo with Patreon, I will also post videos on Vimeo moving forward.

Thank you so very much for making this all possible. I try to take the support you send me to make your reading and viewing experience the best possible. I’ll continue to post on YouTube, of course, and that will always be free for everyone, but I can’t control the ads YouTube places in videos.

I’ll share more about this in the near future once I learn the ropes at Vimeo!

Cheers & 72,

Thomas (VY2SW / K4SWL)

2 thoughts on “Taking the Mountain Topper MTR-4B on a quickie activation at South Mountains State Park!”

  1. Hi Tom. The CW audio might still be a phasing issue perhaps. It could be out of phase with itself. That is, if it’s recorded in mono, but then converted to stereo in the editor by copying the mono track into a set of left and right tracks, but one track is inverted, making it a mirror image of the other, they will then cancel each other out when played back in a mono device. A fix may be to go into the editor and invert just the left or right CW track.

  2. Hi Tom

    Have you ever looked into jackets that would allow you to carry everything in pockets as opposed to a bag?

    I know you like your packs, but there are some wonderful and well made jackets with amazing pocket options that would do a great job especially with a mountain topper setup.


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