Category Archives: QRP

Pairing the Elecraft KX2 and Chelegance MC-750 for a quick QRP POTA activation

After a fun “discovery” activation with the TEN-TEN R4020 on the morning of November 12, 2022–click here to check out that report and video–I realized I had just enough time to squeeze in another activation on my way back to the QTH.

I picked Lake James State Park (K-2739) because it was the most conveniently located; only a 20 minute detour.

When I arrived, the park was very quiet even though it was a Saturday no doubt because the ground was still saturated after the two days of rains we received from the remnants of Hurricane Nicole.

I grabbed my radio gear: the Elecraft KX2 and the new MC-750 vertical antenna sent to me (at no charge) by Jesse at Chelegance. This was only the second time I’d used the antenna–the first time was with the X5105.

I knew the MC-750 would be quick to set up and that was a good thing because I only had a max of about 45 minutes for the entire activation including set-up and take-down.

I walked down to a picnic table by the lake and deployed the station.

The MC-750 took me all of three (casual) minutes to set up.

Next, I set up the Elecraft KX2 and my CW Morse Outdoor Paddle with Steel Base for one-handed picnic table operating.

Of course, I also needed to prepare a log sheet even though I planned to live log everything in the HAMRS app on my phone. Continue reading Pairing the Elecraft KX2 and Chelegance MC-750 for a quick QRP POTA activation

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

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

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

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

A Few Field Radio Gift Ideas for Less Than $100!

I received an email from a reader’s spouse asking about gift ideas for the holidays and beyond; ideas that could not only be used this month, but also tucked away for the future. They weren’t looking for the obvious things like a transceiver–they were looking for accessories that might enhance their significant others’ field radio fun.

Being the enabler I am, I was happy to oblige and, in fact, decided to turn my reply into a post (since it quickly turned into a very long email) with their permission. For obvious reasons, I’m keeping their ID secret! 🙂

Here’s a rather random sampling of things that came to mind. I tried to limit this to items that retail for less than $100 US. Note that some of these product links are affiliate links:

A quality LiFePO4 battery

Being a QRPer, I don’t need a large battery to enjoy hours of radio fun per charge. My favorite battery chemistry is LiFePO4 due to its weight, safety, shelf life, and recharge cycles (which is in the thousands as opposed to hundreds).

For me, a 3Ah battery is more than enough capacity to keep my QRP radios on the air for 3-5 activations per charge (depending on length of activation, etc.).

I’m a big fan of Bioenno batteries. Their customer support is excellent. You can purchase their 3Ah 12V battery for $64.99 US including the charger. If you already have a charger, the battery alone is $49.99. Click here to check it out.

If your significant other likes to push 100 watts, consider a larger capacity battery. I also have a 15Ah Bioenno battery for this purpose, though it exceeds the $100 gift price threshold). Click here to check it out.

A very affordable Li-Ion rechargeable battery


One of the most affordable rechargeable battery packs for the QRPer in your life is the TalentCell Rechargeable 12V 3000mAh Battery Pack. This pack typically costs around $30 US and is sometimes even less expensive.

This little pack is great because it will not only output 5V to recharge USB devices, but it also outputs 12 volts which is brilliant for QRP radios like the Elecraft KX series, TX-500, FT-817/818, Mountain Toppers, Penntek TR-35,  Venus SW-3B, and many others. I actually now pair this with my QCX-Mini. The battery comes with the charger and standard barrel connectors on the included DC cord which fits Elecraft and Penntek field radios among others.

This is a small battery, so can only be paired with efficient QRP radios.

While I don’t consider this a high-quality solution like a Bioenno battery, it is insanely useful and affordable. Click here to check it out.

Morse Code Keys!

I could easily write a series of articles about Morse Code keys. That’s not what you’re looking for, though, right? You want some quick suggestions. Here is a sampling of some of my sub $100 favorites listed in alphabetical order.

If your budget is flexible, you might also consider these paddles which are still less than $200:

Okay, so if you don’t mind pushing more than $200, I highly recommend any key made by the amazing Begali family. Their Simplex paddle was my first set of paddles and I still use them today. I plan to buy their Traveler next year. They’ve a massive selection of models and styles. Continue reading A Few Field Radio Gift Ideas for Less Than $100!

Taking the new Chelegance MC-750 vertical on a POTA activation at Lake James State Park

Back in September, I was contacted by Jesse Chen (BD7LLY) who has been a long-time reader of QRPer.com. Jesse is also the founder of Chelegance (a.k.a. JNCRadio): a company that has been producing ham radio gear and accessories since 2020.

Jesse reached out and asked if I would consider evaluating a couple of the field portable antennas he designs and produces in China.

In truth, I get a lot–and I do mean loads–of requests to evaluate products and I pass on 97% of them. I only have so much time and I simply don’t bother with gear I think is unnecessary or that could be cheaply made.

Before replying to Jesse, I did a little research on Chelegance and discovered that DX Engineering now distributes their products. I decided that if DX Engineering liked the quality well enough to add Chelegance products to their catalog, then it must be up to a decent standard. I’ve never purchased anything sub-quality from DX Engineering.

I also like the fact that Jesse is a real amateur radio operator.

After checking back in with Jesse, he decided to send me two of his portable HF antennas: the M-104 and the MC-750. In full disclosure, he sent these to me at no charge–i.e. free–with the idea I could do a proper evaluation and share my thoughts both with him and with my readers.

He knew that both of these antennas had the potential to compliment my style of portable operating. I also told Jesse not to rush ship them to me as I was quite busy. I received both antennas at the end of October.

The first antenna I wanted to try was the MC-750.

The Chelegance MC-750

When I received the parcel from Jesse, I was very impressed with the MC-750’s custom soft-sided case. The stitching and quality of it are much better than I would have expected. The interior is custom designed to hold all of the MC-750 antenna components. There’s enough extra space in it, in fact, that I can also carry a 40′ RG-316 feedline inside.

Product Photo by Chelegance

The antenna basically consists of the following components in the supplied padded bag:

  • A heavy stainless steel ground spike and matching unit
  • 40 meter coil
  • 50 cm antenna arm/extension
  • 5.2 meter telescoping whip
  • 4 yellow counterpoise wires with a wire winder board

The price for the antenna system is $250 via DX Engineering and 219€ via WIMO. Moonraker in the UK is also a Chelegance distributor, but doesn’t seem to have the MC-750 listed in their inventory at time of posting (Dec 5, 2022).

The only antenna I have that might compare with the MC-750 is the Chameleon CHA MPAS Lite which is one of my favorite portable HF antennas for its quick deployment, and overall quality. For reference, the CHA MPAS Lite retails for about $360.

I thought the best way to test the MC-750 would be to take it on a POTA activation. Continue reading Taking the new Chelegance MC-750 vertical on a POTA activation at Lake James State Park

Cheap POTA thrills with my new-to-me TEN-TEC R4020 QRP CW transceiver!

Last year, I made an impulse purchase.

You’re shocked, right–?

Right.

You see, I did something I’d never suggest others do: in a moment of boredom, I casually cruised the classifieds listings found on QTH.com.

One of the very first listings was for a TEN-TEC R4020 CW QRP transceiver. The price, if memory serves, was $120 (+/- $10) shipped.

Ten-Tec Model R4020 (Product Photo: Ten-Tec)

Without even thinking, I sent a message to the seller:

I’ll buy it if it’s still available!

He responded noting I was the first to reply to the ad, so it was mine if I wanted it.

I did, of course.

The R4020 arrived that same week, I opened the box, applied power to confirmed it powered up, then placed it on the top shelf in my shack.

At the time, I had a mountain of review and evaluations in process along with several articles in the pipeline for TSM and one for RadCom, and simply didn’t have time to properly explore the R4020. I thought it might be fun saving it as a little reward for meeting my deadlines.

Then, frankly, I just forgot about the R4020. This spring was a very busy time for me family-wise, then I spent the summer in Canada, and most of this fall has been all about catching up after having spent the summer in Canada. Funny how that works!

Fast-forward to November 11th, 2022 when I was packing a field radio kit to take on an overnight trip and I noticed the R4020 on the top shelf! My reward, finally–!

I quickly packed the R4020 in my Spec-Ops Order Pouch along with a 3Ah Bioenno LiFePo4 battery and a power cable.

South Mountains State Park (K-2753)

On Saturday, November 12, 2022, I jumped in the car and headed to South Mountains State Park with the R4020.

This past year, I’ve mostly set up at South Mountain’s Clear Creek Access on the west side of the park, but this time I decided to make my way to the equestrian picnic area near the main entrance and ranger station.

Continue reading Cheap POTA thrills with my new-to-me TEN-TEC R4020 QRP CW transceiver!

Mountain Topper MTR-3B: A quick POTA activation before leaving camp!

View from Yonah Mountain the previous day.

As I mentioned in previous field reports, the W4G SOTA Campout was amazing fun this year.  I enjoyed hanging with Joshua (KO4AWH) as we activated a total of three summits and a few parks–plus it was great meeting so many fellow SOTA activators at the Saturday evening potluck!

On Sunday morning, October 16, 2022, it was time to pack up the campsite and hit the road.

Although I was a little pressed for time, I decided to fit in one more activation as Joshua packed up his tent and before we took down the 40 meter Tufteln end-fed half-wave.

Chattahoochee-Oconee National Forest (K-4473)

Fortunately, our campsite was within Chattahoochee-Oconee National Forest and since all I needed to do was to connect my rig to our campsite antenna, setup took all of two minutes.

I pulled out the Mountain MTR-3B for this activation. It had been quite some time since I used this wee radio because I had only recently finished a review of the MTR-4B V2 (look for that review on QRPer.com very soon).

The MTR-3B is now permanently at-the-ready inside my MTR-3B ultra portable field kit, but since there was already an antenna and key in place, I only needed the radio, power cord, logging items, and battery.

Continue reading Mountain Topper MTR-3B: A quick POTA activation before leaving camp!

Guest Field Report: K3FAZ, K3STL, and K3ES POTA in the Cold with a Bonus Gear Report

Many thanks to Brian (K3ES) who shares the following field report:


K3FAZ, K3STL, and K3ES POTA in the Cold with a Bonus Gear Report

K3STL and K3ES at the entrance to K-0621.

by Brian (K3ES)

K3ES Perspective

Saturday November 19 dawned clear and cold in northwest Pennsylvania, but the truth is that I was up well before dawn.  The third Saturday of each month, I try to make the 2 hour drive south to help with Skyview Radio Society’s monthly Volunteer Examiner (VE) testing session for new or upgrading licensees.  Clear skies (which matched the forecast) meant that road conditions would not be a problem.  So, shortly after 5 am I pointed the truck south.

One of the creature comforts I appreciate about our VE session is meeting for breakfast before the test.  It was obvious on arrival at the restaurant that the VEs would greatly outnumber the test candidates, but many hands make light work.  Coffee and an omelet definitely helped fuel the effort.  Since the test sessions normally last less than 2 hours (and that held true this time), three of us VEs had made plans for post-test session POTA.

Before launching into the field report, let me acknowledge that K3STL’s photography was instrumental in providing a report with visual appeal.  Personally, I almost always forget to take the pictures.

POTA Plan

John “Tall Guy” K3STL, Steve K3FAZ, and Brian K3ES in the parking lot at K-0621.

The plan for the day was to attempt activation of two POTA sites, Beechwood Farms State Conservation Area (K-0620) in suburban Pittsburgh, and Todd Sanctuary State Conservation Area (K-0621) about 20 miles further to the northeast.  John “Tall Guy” – K3STL and Brian – K3ES would do a short activation of K-0620, then meet Steve – K3FAZ at K-0621 for the rest of the afternoon.

Knowing it would be a cold day for mid-November (temperatures peaked for the day just barely above freezing), each of us made plans to adjust for operating from our vehicles. That meant that we would be doing parking lot activations at both locations. While we each normally activate with slightly different operating styles that are suited to outdoor POTA operations, some tweaks made it possible to have wind and weather protection for this outing.  In hindsight, it was a perfect choice.

Operating Methods

K3FAZ works an SSB contact.

K3FAZ operated his treasured Kenwood TS-50 using SSB mode with an EFHW antenna in a tree.  Rather than setting up with a table and chair, Steve configured his station to fit in the front seat of his SUV. Continue reading Guest Field Report: K3FAZ, K3STL, and K3ES POTA in the Cold with a Bonus Gear Report

Quickie Field Report: Pileups at Desoto Falls with the Penntek TR-45L and two 28 foot wires

I mentioned in a previous post that I’m quite behind publishing activation videos. Much of this has to do with the fact that I’ve been a pretty busy activator (by my standards) the past couple of months.

While I don’t make field reports and videos for each of my activations, I usually do one or two per week. Two is typically the max I can post because my field reports take 3-4 hours each to write-up and publish; it can be difficult carving that kind of time out of my busy schedule!

In order to catch-up, I’ve decided to post shorter format field reports from time-to-time; especially for reports like this one where I give quite a lot of info and detail in my activation video.

Desoto Falls National Recreation Area (K-7473)

In the previous field report (from October 14, 2022), I recounted two amazing SOTA activations in north Georgia (Big Cedar and Black Mountain) with my buddy Joshua (KO4AWH) during the annual W4 SOTA Fall Campout.

Immediately after wrapping up our SOTA activations on Black Mountain, we decided to hit a park on the way back to the campground. Desoto Falls National Recreation Area made for a short detour and a nice way to relax after a few miles of hiking that day.

We pulled into the parking area of Desoto Falls and set up our stations in the picnic area placing some distance from one another to help with any interference.

I pulled out my trusty Penntek TR-45L and two 28’/8.5m lengths of 24 gauge wire.  I extended the radiator vertically and unrolled the counterpoise on the ground. The wires were connected to the binding posts on the back of the TR-45L (red=radiator, black=counterpoise). I used the built-in manual Z-Match tuner to match the impedance in short order.

Continue reading Quickie Field Report: Pileups at Desoto Falls with the Penntek TR-45L and two 28 foot wires

Rand’s “Shotgun!” Mobile QRP Station

Many thanks to Rand (W7UDT) who shares the following guest post:


 ‘Shotgun!’ My Mobile QRP Station…

by Rand (W7UDT)

I’ll confess, at our overly stylish home, sadly, I don’t have a shack… my XYL has “concerns.”  So, in an attempt to keep my operating license and man card active, I happily practice portable QRP field operations at my QTH and afield.

This time of year however, with winter bearing down on us, I choose to deploy via my ‘Shotgun!’ mobile QRP station.  Simply, a quarter inch sheet of birch plywood, cut and finished nicely to fit suspended from the grab bar and headrest of my Jeep Wrangler’s passenger seat.  Ergo, ‘Shotgun!’

Grab, hang, stow and go!

It’s not a new idea, but I must say, it has become a very good solution to the chilly problem of posterior frostbite and hypothermia.

I’ll elaborate…

Continue reading Rand’s “Shotgun!” Mobile QRP Station