Tag Archives: Mountain Topper MTR-4B

Field Radio Kits, News, Portable, QRP Radios

Field Radio Kit Gallery: VE6JTW’s lightweight SOTA kit

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Many thanks to Jesse (VE6JTW) who shares the following article about his portable field radio kit which will be featured on our Field Kit Gallery page. If you would like to share your field kit with the QRPer community, read this post.

VE6JTW’s lightweight SOTA kit

Good Day Thomas & all readers of QRPer.com,

I was Licensed Late in 2020 and I have been actively doing Summits on the Air since early 2021 here in Alberta, Canada. I started out using a Xiegu G90 but realised very quickly that CW operations where much more efficient especially in VE6 land where our 4 point summits sometimes have 1000+ meters of gain (3280 feet), your knees get tired fast on those big descents with a pack that can easily start weighing in the 30lb range.

So I started teaching myself CW a few months into activating and also started looking into the QRP world. How awesome is it to make worldwide contacts with 5 watts and a wire from a mountain top, am I right?

VE6VID EFHW

I started activating CW that fall and I have gone through a couple of different radio setups. My first QRP rig was a QRP Labs QCX-mini for 20m which I did not use for long. Then my wife bought me a Venus SW-3B for Christmas and that little rig is excellent in my books; it is very basic but effective. I used that for quite a long time with a trapped EFHW Malen (VE6VID) made for me. It covers 40, 30 and 20m, along with the very last N0SA SOTA paddle ever made by Larry.

Venus SW-3B in a custom enclosure

Fast Forward to 2023 and My SOTA kit contains the LNR Precision MTR-4B. This radio is amazing as the receiver is strong and I can pull callsigns out from the noise very well.  My antenna is still the trapped EFHW, and I now use the Bamakey TP-III paddle. For audio I have a set of JBL headphones for when it is super windy out and I also use an Amazon speaker as seen in the photo. Everything that fits in the bag weighs just 2 pounds and 4 ounces. The bag that holds all the gear is from Colonel Mustard.ca.

The whole kit in use on a summit

My mast is a fiberglass telescoping fishing pole from Amazon with a fishing eyelet at the peak to run the wire through. I lashed some line to the base of the mast with three loops then epoxied them to the fiberglas so they won’t move when guying the mast.

I carry two 1100 MAH 3s 11.1v LIPO batteries and get about 2 really good 30 min activations per battery,  they are both from Amazon.

Last but not least my hiking pack is a Mystery Ranch Bridger 35l.

73 de VE6JTW, Jesse

Field Reports, Guest Posts, News, Portable, POTA, QRP

Matt’s “Crackadawn POTA” Field Report

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Many thanks to Matt (W6CSN) who shares the following post  from his blog at W6CSN.Blog:

Crackadawn POTA

by Matt (W6CSN)

This is the weekend in October that features the U.S. Navy’s Blue Angels taking to the skies over the Bay Area. The air show takes place over the Bay waters, which means the beaches and shorelines around San Francisco will be packed with people and traffic. Since my usual POTA operating location is right by East Beach, I had pretty much given up on the idea of activating K-7889 this weekend.

Lights of the Golden Gate Bridge reflecting off the still Bay waters.

The airshow is on Saturday and Sunday, but the Blue Angles practice on Thursday and Friday, weather permitting. So here I was on Friday morning, awake at 5AM watching K4SWL on YouTube doing POTA when the idea of getting out for an early activation got into my head.

It was still dark when I tossed my backpack, which was already loaded for POTA from the previous activation, into the car and headed down to the East Beach in the Presidio of San Francisco National Historic Site (K-7889).

The sky getting lighter in the East before sunrise.

Given the early hour and low light conditions I didn’t relish the idea of doing my usual picnic table and tripod antenna setup. Not long ago I had acquired one of those “mirror” antenna mounts with the jaw clamp arrangement, and this was a great opportunity to try it out. Between the parking lot and the beachfront promenade there is low fence constructed of short steel posts and strands of stainless cable. The fence post was a perfect place to attach the clamp and the MFJ-1979 17 foot telescopic whip, which is a quarter wave on 14 MHz.

Close up of the MFJ-1979 whip antenna clamped to steel fencing.

I was ready to string some radials out to give the antenna a ground plane to work against, but wondered if the post, being sunk into the ground by the Bay and the steel fencing cables might provide enough of a counterpoise. A quick check of the SWR on the meter built into the MTR-4B showed a 1.2 to 1 – no need to even bother with radials with an SWR like that right out of the box.

Low SWR on the quarter wave vertical as the Bay wakes up.

The other advantage of this antenna setup was that it is right next to the car. However, I don’t really like operating from my vehicle as it’s not very sporting nor is it comfortable. Instead, I simply set the station on the trunk lid and completed the activation from a standing position. The other advantage of this arrangement was that I could closely guard the RG-316 coax going from the radio to the antenna to keep any humans or canines from getting entangled. Continue reading Matt’s “Crackadawn POTA” Field Report →

CW, Field Reports, Guest Posts, News, Portable, POTA, QRP, Travel

Matt’s Summer Vacation Mountain POTA

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Many thanks to Matt (W6CSN) who shares the following post  from his blog at W6CSN.Blog:

Summer Vacation Mountain POTA

by Matt (W6CSN)

Our family regularly enjoys a summer vacation in the mountains. There is no shortage of mountains along the Pacific Coast, but if you refer to “The Mountains” around our house everybody knows you are talking about 5500 feet up the western slopes of the Sierra Nevada along Highway 4 near the town of Arnold.

Summer Cabin

Last year’s trip to “the mountains” was my first foray into portable QRP operating and I successfully hunted a few Parks On The Air stations. In the year since, I’ve become much more involved with (some would say addicted to) POTA, especially as an activator.

The cabin sits on a small lake.

For the “base” operation of hunting other stations, I set up the FT-818 with an EFHW strung between the deck and some trees adjacent the nearby lake. The 26 ga polystealth wire antenna literally disappeared into the trees, the only giveaways being the 64:1 transformer floating in space off the deck rail and, more likely, the the bright orange arborist line used for the downhaul at the far end.

I made a few hunter QSOs during the morning hours from the cabin, but this location wasn’t hearing particularly well. Signals weren’t strong and I sent more than a few 229 reports. However, this “hunter mode”operation was secondary to my main objective of activating some new to me parks while on this trip.

Hunter QSOs from the cabin

On the first full day in the mountains we headed back down the hill a ways to visit Railtown State Historic Park in Jamestown, CA. After riding the excursion train and enjoying lunch by the roundhouse, I brought up the possibility of an activation. However, with the July heat well into the triple digits, the family wasn’t in the mood for dads radio obsession. Quite frankly, I wasn’t too excited about setting up the station in the heat, so it was an easy choice to put this one off for another time.

No activation attempt at Railtown this time

The next POTA activation opportunity came when we had made plans to head up for a day at Lake Alpine. We chose to go up to the lake around 10AM on Monday, hoping for smaller crowds. Also, we had plans to visit Calaveras Big Trees SP the following day.

This gave me an idea: I could make the short drive from the cabin up to Calaveras Big Trees (K-1134) in the morning while everyone was sleeping in and try to get the activation done before heading to Lake Alpine. This way the family visit to Big Trees wouldn’t be interrupted by dad playing radio. Continue reading Matt’s Summer Vacation Mountain POTA →

Announcements, News, QRP Radios

LnR Precision taking orders for the next batch of MTR-4Bs

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Many thanks to Jim (N9EET) who notes that LnR Precision is now taking orders for the next batch of the Mountain Topper MTR-4B V2.3.

LnR notes the following on the MTR-4B order page:

Update: 2/24/22: MTR4 V2.3 online ordering is now active! We are releasing 100 units and they will be available as first come, first served. We have a handful of units built now but are expected to quickly have a 3-4 week lead-time before they ship. This could be LONGER and we can’t guarantee shipment in that timeframe but will do our best. We have enough parts in hand for 250 units so there will be another release of this model once we have shipped the first 100.

Also, the MTR4b pricing was increased slightly (up $20) to cover part cost increases. The overall costs were much higher but we know how bad overall inflation has been so we want to be as reasonable as humanly possible. Thanks so much for your continued patience and we know you will enjoy this radio!

This is great news for those of you who have been wanting to reserve an MTR-4B.

If you’re on the fence about ordering one, consider checking out my full review here.

Click here to check out details on the  MTR-4B order page.

Thanks for the tip, Jim!

Articles, CW, News, Portable, POTA, QRP, QRP Radios, Reviews, SOTA

A review of the LnR Precision Mountain Topper MTR-4B ultra-portable QRP transceiver

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The following article originally appeared in the November  2022 issue of The Spectrum Monitor magazine:

A Review of the LnR Precision Mountain Topper MTR-4B V2

by Thomas (K4SWL)

I confess, there is something that I’ve come to believe is almost a rite of passage in the SOTA (Summits On The Air) community. And, no, I’m not talking about activating an All Time New One (ATNO) summit, or completing a particularly challenging activation on a snow-capped peak.

I’m talking about owning one of the iterations of the amazing “Mountain Topper” pocket-sized QRP CW transceivers designed by Steve Weber (KD1JV).

This little radio first caught my attention at a Four Days In May (FDIM) QRP conference over a decade ago: a ham friend in the SOTA community proudly showed me a very early version of the Mountain Topper that he built from a kit. The first thing that struck me was how impossibly small and extraordinarily lightweight it was. But when he showed me the 9-volt battery he used to power it––a power supply not only small, but convenient––I was mesmerized.

Over the years, the Mountain Topper has evolved.  There have been many models, ranging from two bands to five. To my knowledge, they’re no longer offered in kit form, but LnR Precision manufactures and tests these in North Carolina, and they’re better than ever in terms of features and performance.

At present, the MTR-4B V2––the second version of the four-band Mountain Topper––is the only model in production, and if you’re hoping to acquire one, due to supply chain issues (at time of publishing) there’s a rather long wait time. They retail new for $350 US, and frankly, the used ones I’ve seen posted in ham radio classifieds ads have been equal to, or even over, the listed price for a new rig.  Obviously, demand for these radios is much higher than supply.

So, how could it be that this minuscule QRP radio performs well enough to produce some serious DX from a remote summit…so well, in fact, that people are willing to wait in line for one?

Magic or method?

As any CW operator will tell you, the magic is in the mode. CW is such an efficacious mode that it cuts through the ether like a knife, even when conditions are less than favorable.

Obviously, pint-size radios like the Mountain Topper are QRP––low power––so designing them around such a simple mode is a very smart choice. CW transceivers are much less complex than a similar SSB transceiver, thus have less components, less mass, and are in general more affordable (when compared to those with similar receiver performance).

My comprehensive MTR-4B field kit (the MTR-4B is in the mesh pocket).

In addition, the Mountain Topper is designed with the field activator in mind:  specifically, SOTA activators, but of course, POTA (Parks On The Air), WWFF (World Wide Flora and Fauna), IOTA (Islands On The Air), or any other popular “-OTA” field activity. As a field activator in one of these programs, you are the DX. This means chasers and hunters are actively seeking your signal, and thus you are not competing with blowtorch stations to punch through a pileup.

I can also assure you that standing on a tall summit also gives you a brilliant starting point for your QRP signal. Some of the best DX I’ve ever worked has been from a summit.

So, for the average CW SOTA activator, QRP is preferred because QRO simply isn’t necessary––indeed,  in my opinion it’s a bit of an overkill. At least that’s been my experience now with my few hundred SOTA, POTA, NPOTA, SOTA, and even one Lighthouse On The Air activations.

So this brings us back to the wee Mountain Topper series and the model being reviewed here in the pages of TSM: The Mountain Topper MTR-4B. Continue reading A review of the LnR Precision Mountain Topper MTR-4B ultra-portable QRP transceiver →

Antenna Tuners, Antennas, Field Reports, How To, Kits, News, POTA, QRP

How to tune: Pairing the Emtech ZM-2 manual ATU with the Mountain Topper MTR-4B on the Blue Ridge Parkway

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You’ve no doubt heard me brag about the Emtech ZM-2 ATU in previous field reports. I think it’s an accessory every field operator should have.

The ZM-2 is a very capable manual transmatch/ATU and is also one of the more affordable tuners on the market. It’s available as both a kit and a fully-assembled unit. Both well under $100.

I do believe the “manual” part of the ZM-2 scares off some and it really shouldn’t. We are used to simply pressing a button these days and allowing our automatic ATUs to do all of the matching work for us.

Manual ATUs do require some amount of skill, but truth is, the learning curve is very modest and intuitive.

Manual ATUs require no power source in order to operate–you adjust the L and C values by hand–thus there’s never a worry about the ATU’s battery being depleted. They also are easy to manipulate outside the ham bands because they require no RF in order to read the SWR–you simply make adjustments to the L and C until you hear the noise peak.   This is why many shortwave broadcast listeners love the ZM-2 so much. It’ll match most any antenna you hook up to it!

I also argue that everyone should have a portable ATU even if you operate resonant antennas. Think of an ATU as a First Aid Kit for your antenna: if the deployment is less than ideal, or if you damage it in the field, an ATU can help you find an impedance match your radio can live with. ATUs have saved several of my activations.

Mountain Topper MTR-4B V2

I’ve also mentioned that I’ve had an MTR-4B on loan from a very kind and generous reader for most of the year. He was in no particular hurry for me to send it back to him, but I wrote him in early November and said, “I’m doing one more activation with this little rig, then I’m shipping it to its rightful owner!”

He had a request, and it was a good one:

I think it would be a good little twist to the usual YouTube if you paired a random wire with the ZM-2 and the MTR-4B…showing how to tune the ZM-2 with a Mountain Topper…

I really liked this idea, so I made plans to to hit the Blue Ridge Parkway nearby and give it a go.

The first time I tried this in the field, I paired the MTR-4B with one of my Sony amplified speakers because the MTR-4B 1.) has no internal speaker and 2.) has no volume control. During the video, however, I realized that there simply wasn’t enough audio amplification so that the viewer would be able to hear a noise peak as I manually tuned the ATU. I decided to scratch that video and just do the activation on my own. I really wanted to show how the tuning process worked in the video.

I went back to the field the next week–on November 10, 2022–with my Sony in-line digital recorder knowing it would be much easier to hear how the L/C changes affected the band noise. Continue reading How to tune: Pairing the Emtech ZM-2 manual ATU with the Mountain Topper MTR-4B on the Blue Ridge Parkway →

Comparisons, QRP Radios

Photos: Comparing sizes of the Mountain Topper MTR-4B, MTR-3B, and Elecraft KX1

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After sharing a few photos by request comparing the size of the  Mountain Topper MTR-3B, MTR-4B, and Elecraft KX2 yesterday, I took a few pmore photos by request comparing those same radios with the Elecraft KX1.

I decided to simply post these on QRPer.com in case they could also be of help to someone else:

Mountain Topper MTR-3B v Elecraft KX1

Mountain Topper MTR-4B v Elecraft KX1

Elecraft KX1 v KX2

News, QRP Radios

Photos: Comparing sizes of the Mountain Topper MTR-4B, MTR-3B, and Elecraft KX2

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A reader/subscriber just asked for photos comparing the size of the  Mountain Topper MTR-3B and MTR-4B. I know they were also curious how the MTR-4B might compare in size with the Elecraft KX2. Of course, one can look up the actual sizes, but sometimes a photo adds more context.

I decided to simply post these on QRPer.com in case they could also be of help to someone else:

Mountain Topper MTR-4B vs MTR-3B

Mountain Topper MTR-4B vs Elecraft KX2

How To, News, QRP Radios

Why does the Mountain Topper MTR-4B (& 3B) have three separate band switches?

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A question I’ve received several times since sharing my last field activation with the MTR-4B is “why do Mountain Topper radios have three individual band switches–?”

That’s a great question and the answer is actually in the product manual.

The following comes from the MTR-3B manual but also applies to the MTR-4B (save the 4B has four band positions instead of three):

The band is selected by three, three position slide switches. For proper operation, all three switches must be in the same
column[…]. It’s easy to get into the habit of flipping each switch in sequence from the top down.

The top switch tells the processor which band to operate on and connects the Receiver input filter to the first mixer. The
middle switch connects the transmitter low pass filter output to the antenna and connects the antenna to the receiver
input filter. The bottom switch connects the output of the transmitter PA to the low pass filter.

The manual is correct: it’s easy to get in the habit of sliding all three switches with band changes. It becomes second nature in very short order.

It’s easy to tell that all of the switches are in the correct position as well because without all three switches selected, the receiver sounds deaf and audio muted. With them in position, the receiver sounds “alive.”  (That said, the noise floor is so low on these radios, it’s quite possible you might think they’re not engaged properly if there aren’t many signals on the band!) Of course, it’s very easily to visually inspect the switches and confirm they’re in the correct position.

Side note: On the Mountain Topper series, each band switch is an independent mechanical switch. On the Venus SW-3B (which was no doubt inspired by the Mountain Topper) the two band switches are bound together as one:

You can’t tell from looking at the photo above, but if you slide the top switch, you’re also sliding the bottom switch: the two switches are only one mechanical piece. An interesting design choice!

Side Note: The (now discontinued) Mountain Topper MTR-5B had a more complex series of six switches. Here are the instructions for it along with a drawing from the MTR-5B manual:

I hope this helps clarify how/why the Mountain Topper series uses multiple switches for band changes!

Accessories, Antennas, News, Portable, POTA, QRP, QRP Radios, Videos

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

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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.

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