Getting To Know You Series: The Mountain Topper MTR-3B — My thoughts, notes, and a POTA activation!

I’m very fortunate in that in the past few years I’ve accumulated a number of QRP radios that I use in rotation when I do park and summit activations.

I’m often asked for advice on choosing radios, and as I’ve mentioned in the past, I feel like the decision is a very personal one–everything is based on an operator’s own particular preferences.

Over the years, I’ve written formal reviews about most of the field radios in my collection. In those reviews, I try to take a wide angle view of a radio–to see how it might appeal to a number of types of operators. I highlight the pros and cons, but I don’t focus on my own particular take because, again, my style of operating might not match that of readers. I try to present the full picture as clearly as I can and let the reader decide.

The Getting To Know You series gives me an opportunity to highlight one radio at a time and showcase what I love about it and why it’s a part of my permanent radio collection. After we spend a bit of time talking about the radio, we’ll do a park or summit activation with it!

The Mountain Topper MTR-3B

The fourth radio in my Getting To Know You series is the Mountain Topper MTR-3B by LnR Precision.

And, spoiler alert: I think the MTR-3B is one of the most ingenious little QRP transceivers ever made.

In truth, all of the Mountain Topper series radios are outstanding if you’re a CW operator and into truly portable, ultra-lightweight, field radio activities.

Steve Weber (KD1JV), the designer behind the ATS and Mountain Topper series, created a brilliant platform that has only been improved upon over time.

I’ve only ever operated the MTR-3B and MTR-4B. That said, I’d love to add a high band MTR-5B to my field radio collection someday.

The Mountain Topper MTR-4B V2. Read the review here.

I recently reviewed the MTR-4B (see photo above) and I absolutely love it, but in truth? I prefer the more compact MTR-3B simply because it’s rare that I operate 80 meters in the field and I like the even more compact from factor of the 3B. It’s literally the size of a pack of playing cards.

That said, I wish the 3B had some of the later model MTR-4B upgrades like easy-access sidetone adjustments and power/SWR metering, but I still prefer the MTR-3B.

What? A second MTR-3B?

Confession time: last month, a good friend and patron/supporter offered to sell me his MTR-3B for a very fair market price. He could have put this on eBay or in ham classifieds and surely commanded a much higher price, but he knows how much I love this radio and offered his never used MTR-3B to me.

It didn’t take long for me to accept his offer–like quicker than the blink of an eye quick.

I’ve been looking for a second MTR-3B because 1.) these radios are no longer manufactured and 2.) if something happened to my one and only MTR-3B, I would sob uncontrollably.

I should state here that I blame my buddy, Vince (VE6LK), for introducing the “Two is one, one is none” slogan. Over time, I’ve convinced myself to keep two copies of my favorite radios such as the KX1, FT-817, and MTR-3B.

Vince, by the way, is a card-carrying, certified enabler!

Holmes Educational State Forest (K-4856)

On Friday, August 25, 2023, I made my way to Holmes Educational State Forest to play a little POTA with the MTR-3B.

The site was very quiet. The new school year had just started,  so it was too early for school field trips at the park.

I had my pick of spots to set up, so I chose a new-to-me picnic table.

First thing I did was deploy my antenna: a 40 meter end-fed half-wave made by my buddy, Steve (MW0SAW). The 40M EFHW is resonant on two (40/20M) of the three bands (40/30/20M) the MTR-3B sports. Between 40 and 20 meters, I knew I’d be covered!

Next, I set up the Mountain Topper which is carried in my Tom Bihn HLT-2 pouch.

Set up is quite simple, actually. Attach the paddles, the antenna, the 9V battery LiFePo4 3Ah battery, and a speaker (since I was recording a video).

Time to hop on the air!


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

On The Air

I’ll begin by saying this was a most satisfying “breaking in” of the new-to-me MTR-3B!

I hopped on 20 meters and starting calling CQ POTA with my blowtorch three watts.

Within eight minutes, I worked the ten stations necessary to validate my POTA activation. Woo hoo!

I continued calling CQ and worked a nice string of stations (thanks, hunters!)

All-in-all, I worked a total of 20 stations in 20 minutes. If I didn’t have other plans, I would have stayed on the air much longer that day!


Here’s what this three watt 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, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.

Note that Patreon supporters can watch and even download this video 100% ad-free through Vimeo on my Patreon page:

Click here to view on YouTube.


So if you’ve been around here for very long, you’ll know that I name radios I intend to keep in my permanent collection.

I named my first MTR-3B “Tuppence” after the Tommy and Tuppence books by the late, great Agatha Christie. I can’t take full credit for the name, because my buddy Eric (WD8RIF) made the suggestion and I immediately adopted it.

I thought it would only be fitting if my second MTR-3B was named Threepence.

So there we are!

Threepence isn’t going to sit on the sidelines. In fact, I’m thinking about building a super compact POTA kit around her that’ll fit in the EDC laptop bag (a Tom Bihn Stowaway for the pack geeks out there) I take with me on-the-go!

No doubt, there’ll be an article about this in the future!

Thank you

Thank you for joining me on this activation and Getting To Know you video! I’d love to hear comments from Mountain Topper owners, or from those of you who’d love to own one!

I hope you enjoyed the field report and my 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.

Thanks for spending part of your day with me and have an amazing weekend!

Cheers & 72,

Thomas (K4SWL)

21 thoughts on “Getting To Know You Series: The Mountain Topper MTR-3B — My thoughts, notes, and a POTA activation!”

  1. LNR would likely do quite well with an updated MTR-3B “v3” that includes the improvements from the 4b that Thomas mentions and perhaps add a the ability to tolerate more than a 13V dc power supply. Also, I would like the key jack on the edge opposite the rest of the connectors, KX1/2 style.

    Personally, I’ve never had any issue at all with the sales and support from LNR. I ordered my MTR-4B when it became available and received it a few days later, and thankfully haven’t had a need to communicate with them further. That’s said, I get the impression that the company isn’t really staffed or organized to produce and support radios as popular as the MTR series is. maybe that “hard to get” reputation is part of their mystique.

    73 Matt

    1. Hi Matt,
      To be honest, it is hard to order MTRv3 from Europe.
      I would like to buy MTRv3 but have no chance due to very limited number of produced items.
      Also, I am looking forward to have QRP-Labs QMX for 20-10 meters bands and rebuilt it (if possible) for 40-20-10/15 meters bands.
      I thinks market now is lack of rigs for upper side of HB band and it is strange for me why MTRv4 has 80m band instead of e.g. 10m or even 15m band. There is a good and very interesting propagation on 15m this summer. 80m on QRP CW rig is strange for due to very big antennas and very high noise floor.
      What do think?

      1. Hi OM,

        I agree that that there is a hole in the market for a radio that covers the high side of HF and is in the style of and price point of the MTR.

        On the MTR-4B the option to go to 80M doesn’t really do much for me, but I would like the chance to move up to 17 or 15 meters to avoid congestion or try for some DX. Maybe I will feel differently when the solar cycle is at the minimum, but there is still the issue with antenna size.

        Perhaps I should consider 80 meters to be a challenge for me to get on that band and get some production there for POTA or SOTA rather than see it as a band that is of no use.

        The QMX radio looks very interesting. I’m watching and waiting for a few revs for the kinks to get worked out.

        73 Matt

        1. You know, 80 meters is a wonderful band for those later evening POTA outings. I use 80M in the field primarily when I’m camping at a park.

          Come to think of it, I need to make a random wire antenna that can be matched on 80M but also long enough to be efficient. 🙂

          Thanks for the comment!

  2. Thruppence is the more common spelling and pronunciation of the threepence coin. It also goes better with tuppence!
    Just saying…

  3. The MTR series has always been hard to get. I have one of the rare MTR-3 prototypes that KD1JV released as a kit through his email reflector. In order to get it, I lurked on the list for a few months reading updates about the rig’s design, then pounced in to order one as soon as he announced its availability. The entire run of kits (200 or so, as I recall) sold out in a few hours. It was a complex but very fun rig to build, which really got me comfortable with handling and soldering surface-mount parts.

    1. Lol glad I found this comment. I went down a little rabbit hole. I’m in St. Louis, and I always find an urge to look up zero-land or MO calls I find in the wild like this. I looked up W0SL and QRZ shows he became SK in Feb 2022, and I found his obit. I played it back and it definitely sounded like W0SL…so I was like “oh no! Is it a pirate?!”

      Happy to hear it was just a keying goof, happens to the best of us!

  4. Great video on your portable QRP adventure. Please keep them coming. Radio’s I use are a QRP PLUS ++ And a Icom 703.

    1. I also had a QRP ++ for quite a few years. I really loved that little radio. I called it my “cube.” 🙂


      1. Bought a new QRP Plus when they first came out and then sold it and last month had a chance to buy the QRP Plus Plus at a great price and really love this little radio.

  5. I might be wrong but I think Vince might have got the “Two is one…” phrase from YouTuber Tracey VE3TWM, who I think borrowed it from the US Marine Corp and uses it frequently when describing his Outdoors on the Air adventures featured on his channel.

  6. I use the older revision with a single digit display which is a lot more cryptic to use, but works nonetheless. I keep this in my ultralight backpack for SOTAdventures. In order to keep it lighter I also use a smaller battery that is capable to provide many QSOs while maintaining the light weight. I normally use a 3Ah 4-cell LiFePO4 (Bioenno) when using my heavier KX3, but with the MTR3B I use a LiPo 3-cell pack that is about the same size as a standard 9V battery. Of course, I’ve also powered it with 9V batteries also! The battery I use is no longer listed but is similar to this one:

    The actual one I use is I think this one:

    Also, if I feel like I need a lower frequency band for more in-state and near-state QSOs I just add the QCX-Mini for 60m and two radios covers four bands (since I don’t have an MTR-4B and the MTR series does not cover 60m anyway).

  7. To be honest, I feel like it would be much better to take time to review radios that are not ghosts and are actually available. Such as QMX and QCX-Mini. For example how your kit turned out after assembly, what was difficult, what was easy. All that can help Hand to improve his product. It would be also of interest to more people as it is actually available…

    1. So as I mention in each of my videos, I have made formal reviews of most of the radios in my collection. In this case, I most recently reviewed the MTR-4B and mentioned the differences between it and the MTR-3B (there are few).

      But at the end of the day, I’ve had some of these radios quite a while and it’s true that some radios are no longer manufactured. Manufacturers often discontinue models in order to produce new ones with upgraded features or when parts are no longer available and the BOM must change. This is pretty common in the world of amateur radio, but especially in the world of consumer electronics. Just the nature of the beast.

      My suggestion would be to simply skip the videos you don’t care to watch because I’ve many more I’ll be posting and there are more radios that are no longer in production but very much available on the used market.


  8. I totally agree with your fondness of this magnificent radio. Steve Webber designs a superb performers with what you need to be successful in the field with a fly-weight kit. I lamented over not using the 30m band and then decided to cut in a 30m link on the 40 EFHW. Best decision that I ever made. With my antenna, with 26ga Polystealth, the link is 42′-7″ from the transformer. Your mileage my vary.

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