Category Archives: Reviews

Breaking in my new-to-me Elecraft K2 and CW Morse SP4 paddles during a POTA activation

Radio addiction is a real thing.

We addicts often justify purchases knowing that, in the world of amateur radio, we can always sell gear we’ve purchased without losing too much money each time.

At least, in theory!

In November, last year, I was in touch with a friend who I recently purchased my second KX1 from; turns out, he had an Elecraft K2 he was willing to part with, as well. This is a radio he built (thus, the workmanship is top-shelf) and had updated over the years to be fully loaded the way I would want it myself: all firmware upgrades, all important upgrades for CW and SSB operation, and an internal ATU.

His was also a 10 watt (QRP) version of the K2; Elecraft owners call these “K2/10s.”

My first K2/10 next to the TEN-TEC Argonaut VI I was Beta testing at the time.

I owned a K2/10 between about 2008 and 2016. I sold the K2/10 to purchase another radio. The week after selling my K2/10, a local ham offered me an insane deal on a used K2/100 (a version with a 100W amp) from a club estate sale. No one in our local club wanted it and he really wanted to unload it. I purchased it and for a good three years it was my only 100 watt radio.

My K2/100

Then, in 2019, I sold the K2/100 for $800 and purchased an Elecraft KXPA100 amplifier with ATU for $800 to pair with my KX2 and KX3.

Using my KXPA100 during Field Day in 2020.

I’ve never regretted that decision because I do love the KXPA100 amplifier, although I seldom use it (so much so, I’ve even considered selling it). To date, it is the only device I own that outputs 100 watts.

I did miss the K2. It’s a fantastic radio to take outdoors and has superb receiver chops for the most demanding, RF-dense conditions.

When my buddy offered up his K2, I couldn’t resist. I made myself a goal, though: I had to sell enough stuff to fund the purchase. My friend was good with this. Even though I could have paid him immediately, I asked if he could wait for payment and shipping until I had gathered the funds from sales. I needed that dangling carrot because, frankly, I dislike selling things; I’d rather give away or donate stuff, but I did need to raise funds for this purchase. Continue reading Breaking in my new-to-me Elecraft K2 and CW Morse SP4 paddles during a POTA activation

QRPer Notes: Mike’s POTA Bag Load Out, CHA F-Loop Remote Tuning Mod, and KB6NU’s review of the Ailunce HS2

Because I receive so many tips from readers here on QRPer, I wanted way to share them in a concise newsletter format.  To that end, welcome to QRPer Notes, a collection of links/videos to interesting stories and tips making waves in the world of radio!


511 Deployment 24 POTA radio bag (KE8PTX)


CHA Loop Remote Tuner | K7SW ham radio


The Ailunce HS2 has lots of potential (KB6NU)

Just before Thanksgiving, I received an email from Cara Chen at Retevis. She wrote,

I am responsible for the radio review cooperation. We have a SDR radio HS2 for review cooperation. Are you willing to test and write a blog about it?

When I asked her what that meant, she said that she would send me an Ailunce HS2 SDR Radio, if I would review it here on my blog. When I told her that I would be brutally honest in my review, she seemed OK with that and sent me the radio.

What follows is an honest review. It’s not a QST-style review. I don’t have the test equipment that they do, nor did I have the time to put the radio through all its paces. Even so, I did operate the radio on HF and VHF, phone and CW, enough to make the review worth reading, I think.

If you don’t want to read the rest of this review, I can sum it up as follows: The Ailunce HS2 is a fun, little radio, with lots of potential. It’s not perfect, though. The buttons are too small, the display is too small, and the manual needs work. More about all those below.

What’s in the box?

As you can see below, the radio came with a handheld microphone, a DC power cord, and a USB cable.

First impressions:

  • It’s really small. It’s 45 mm H x 120 mm W x 190 mm D (1.77 in H x 4.72 in W x 7.5 in D)
  • The carrying case is kind of nifty. If you’re going to operate portable, it’s nice to have.
  • The extruded metal case include a nice heat sink.
  • There are a lot of connectors on the rear panel, including the power connector, an SO-239 for HF and VHF antennas, an SMA for a GPS antenna, two USB connectors, an Ethernet connector, and four 3 mm phone jacks.

Continue reading on KB6NU’s website…

Guest Post: Reviewing the Chelegance MC-750 (Part 1)

Many thanks to Charles (KW6G) who shares the following guest post:


Product Review: Chelegance MC-750 Portable Ground Plane Antenna, Part 1

by Charles Ahlgren, KW6G

I recently purchased a Chelegance MC-750 portable ground plane antenna from DX Engineering.  Essentially, the antenna system provides a ¼ wave portable vertical antenna with 4 counterpoise wires that operates on 20 through 10 meters.  The antenna will also operate on 40 meters with the provided loading coil.  The manual states the antenna will support 6 meter operation, but no instructions are provided on how to do so.  30 meter operation is not supported.   It appears from our initial testing that no ATU is required.

Here are some of my thoughts on the antenna.

Product Description

The MC-750 comes with the following components:

  • GROUND ROD / ANT BASE
  • 50 CM ANT ARM
  • 5.2 M WHIP
  • 7 MHZ COIL
  • 4  COUNTERPOISE WIRES (radials)
  • COUNTERPOISE WIRE COLLECTOR BOARD
  • CARRY BAG

As provided, it is designed to operate on  the 40, 20, 17, 15, 12, and 10 meter bands without any modifications.  Six meters is also supported per the manufacturers manual, but no guidance on how to do that is offered in that document.   However, finding the proper length of radiator for 6 meters should be straightforward using a tape measure to set the proper whip length.

[Update: Chelegance notes that to operate 6 meters, simply extend the last segment only of the whip (see photo) and for 30 meters extend the last four segments of the whip and 15cm on the 5th segment (see photo).]

I checked the ground rod / antenna base with a magnet and confirmed it is made from stainless steel as both components are not magnetic; a characteristic of stainless.   Both the ground rod/ antenna base and the 50 cm antenna arm (which was also non-magnetic) had a hefty feel (together, they weigh about 2 pounds), therefore I think it safe to assume that these components are made of stainless steel.  Since most ops will undoubtedly use the antenna arm as an aid to inserting / extracting the ground rod into / from the ground, it seems a prudent decision by the manufacturer to have this piece fabricated from a strong, stiff  material such as steel.  The machine work used to fabricate these parts appears to be quite good – the fit and feel were excellent, with no sharp or ragged edges to cause problems in the field.

I measured the whip while set at the various position marks for 20 through 10 meters.  The band markings on the whip were accurate – giving a 1/4 wavelength radiator when combined with the 50 CM ant arm length…On 40 meters, the whip and rod measured about 1/8 wavelength.  The required the loading coil needs to be inserted between the whip and the rod (at approximately 1/10 the total 40 meter whip height above the base).  If you want to operate this antenna on 30 meters, it appears that you need to provide an extra 1.4  meter of additional rod as a quarter wavelength ground plane at 10.1 MHz  requires a 7.1  meter radiator.  Six meter operation would require a whip of around 4.7 feet.  With the whip fully collapsed, the length of the rod and antenna arm measures 40-1/4”.  Therefore, if 6 meter operation is contemplated, extending the whip about 16 inches from fully collapsed should suffice.  However, I don’t think that an antenna configuration such as that would be a very good performer unless it were elevated from ground level; or maybe it would be good for a SOTA activation? Continue reading Guest Post: Reviewing the Chelegance MC-750 (Part 1)

Testing a new QCX-Mini Field Kit built in an Evergreen 56 Watertight case

In early November, I happened up a new waterproof case called the Evergreen 56. As with Pelican cases, it’s waterproof and also made in the USA. Like Nanuk cases (that are also waterproof and made in Canada) Evergreen cases have a built-in locking mechanism to keep the latch from accidentally opening during transport.

I thought the price for the Evergreen 56 at $28 US was fair and in-line with the Pelican 1060 and Nanuk 903 which are similar in size. I grabbed one made of a clear material with one radio in mind: my QCX-Mini!

There are a number of color options available for this Evergreen case, but I like the clear polycarbonate one because it makes it so much easier to see what’s inside (for a quick gear check) but also to confirm that no one part of the kit is being pressed too hard inside the case after the lid is sealed.

After receiving the Evergreen 56, I was very pleased with the quality–again, on par with what I would expect from Pelican or Nanuk.  It is incredibly solid and the seal is watertight.  The Twist Lock Latch (see above) is easy to operate and the case comes with two “keys” for adjusting the inner lock.

The Evergreen case has a soft egg crate-like rubber boot interior as opposed to the pick foam material you’d typically find in a water tight case. The case also has a hammock-like rubbery webbing on the inside of the lid that can be used to organize smaller contents (I knew instantly I’d use this to hold the antenna!).

The QCX-Mini fits in the Evergreen case perfectly–this was no surprise–but I was eager to see if my other station components could also fit. Note that I didn’t buy anything specifically to be used in this case; I used components I already owned. I could minimize the contents even further if I used a smaller battery, antenna, and key.  Here are the components of the first version of the QCX-Mini Field Kit: Continue reading Testing a new QCX-Mini Field Kit built in an Evergreen 56 Watertight case

Video: W2AEW’s review of the Penntek TR-45L

Many thanks to Ron (W6AZ) who notes that W2AEW has posted a review of the TR-45-L on his excellent YouTube channel:

I meant to post this video earlier when I saw that Alan published it, but forgot. Thanks for the reminder, Ron!

Click here to subscribe to Alan’s YouTube channel.

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

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!

N0SA SP4 Mini Morse Magnetic Paddles Review

You might recall my previous announcement about the new  N0SA SP4 POTA/SOTA Mini Morse Code Magnetic Paddle from CW Morse.

The first production run of these paddles sold out very quickly, but I just received the following message from CW Morse about the new paddles:

We’ve finally gotten caught up and will be shipping out Monday & Tuesday [Nov 21/22]! Also have a few more in stock. Making another batch as well.

CW Morse sent me a set of these paddles to evaluate at no charge to me (keep in mind, they’re both a sponsor and affiliate of QRPer.com) and I got a chance to use them Thursday afternoon.

In short?

I love these paddles!

In fact, I think these may become my preferred compact paddles.

I like the size of the finger pieces/pads.  They’re large for such a tiny paddle, which I believe gives them a solid feel while keying. I prefer a larger contact surface area as opposed to thin finger pieces.

The response is very precise, too, and the action can be adjusted by a supplied Allen wrench.

I agree with a few readers who’ve already received their paddles and noted that the carbon fiber reinforced PETG material make the key grippy and very easy to hold.

The size and design is very similar to the SOTA paddle N0SA sold out of last year in a matter of a few hours.

Bonus POTA Activation!

Thursday afternoon, my daughters attended a two hour meeting not even a stone’s throw from the Blue Ridge Parkway. I had *just* taken delivery of the new N0SA paddles, so grabbed the shipping box from CW Morse, my new-to-me Elecraft K2/10 (more on that later!), and my PackTenna Random Wire antenna.

I only discovered that my daughters’ meeting was so close to the parkway about 10 minutes before leaving the QTH. This was one of those bonus activations that deserved a little happy dance, especially since I could spend a good 1.5 hours on the air–a proper luxury for this busy father!

I’ll post a full field report and activation video in a couple of weeks, but in a nutshell, 30 meters was on fire. I’d planned to work 20, 30, and 40 meters (to test the K2’s internal ATU) but 30M was so dang busy, I never had time to QSY.

I had not put the K2/10 on the air yet, so all of the settings were default and it had been a few years since I used a K2, so had to re-familiarize myself with the settings. Thirty meters was so consistently busy, I didn’t have a breather to tinker with the settings.

The new N0SA SP4 paddles worked flawlessly.

I expected nothing less from an N0SA design, but still–the feel and action is superb.

I think this paddle may become the new benchmark for where price and quality meet.

I feel like CW Morse could be charging  $112.95 instead of $82.95 for these and I would still be very pleased with that price. I’m glad they’re not, though, because sub-$100 pricing does give new CW ops an affordable quality mini paddle option.

Based on so many reader recommendations, I purchased a BaMaKeY TP-III paddle recently. It’s also a wonderful paddle, but cost me 157.25 Euro which is nearly twice the price of the SP4 paddles. While I think the TP-III paddles are brilliant (and I’ll soon post a review) I actually prefer the N0SA SP4 paddles (note that this is my own personal preference–both are amazing keys). I prefer the SP4’s larger finger pieces.

Size comparison: CW Morse CNC Machined Aluminum Paddles (left) N0SA SP4 Paddles (right)

The great thing about CW Morse is that they have the capacity to handle customer demand of the SP4 paddles–this is something N0SA couldn’t do as a one-man show. I think CW Morse also has economies of scale working in their favor and, no doubt, this is how they continue to be the market leader in terms of quality for price.

If you’ve been looking for quality mini paddles for your compact field kit or shack, look no further. These are a no-brainer. You’ll love them.

Click here to check out the new N0SA SP4 SOTA/POTA paddles at CW Morse.

The enduring Yaesu FT-817 and FT-818 series transceivers

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


The enduring Yaesu FT-817 and FT-818 series transceivers

by Thomas (K4SWL)

Last April, our family went on a camping trip at New River State Park in Ashe County, North Carolina; we had an absolutely brilliant time.

Naturally, as with any camping trip or extended travel, I’d put a lot of thought into choosing the portable transceiver and field kit to take along.

The great thing about camping at a state park is that I can “activate” that park via the “Parks On The Air” (POTA) or “Worldwide Flora and Fauna” (WWFF) programs pretty much anytime: early morning, late afternoon, or even in a late shift well into the night. Or, of course, all of the above.  Since my activation site is also where I’m eating and sleeping, my radio usually gets heavy use.

Before leaving on that April camping trip, I knew what radio I wanted to operate the bulk of the time: my Yaesu FT-817ND. For a lot of reasons which  I’ll delve into later, I think the FT-817ND (or its latest iteration, the FT-818ND) is an amazing QRP field radio.

Despite unstable propagation and a little campground QRM that moved in over the weekend––no doubt from a neighboring RV, chock full of noisy switching power supplies––I found the FT-817ND activation to be a most enjoyable experience. I posted a few field reports and activation videos from my New River activations on QRPer.com

The thing is, each time I publish a field report using the FT-817ND, I receive a string of questions from subscribers and readers. Questions such as…

  • Should I buy a new FT-818 or a used FT-817?
  • Why do you like the FT-817ND so much?
  • What’s the difference between the 817 and 818?
  • How does the FT-817/818 compare with _____ radio?

Most queries, however, are a version of this comment from reader David:

“We have such a wide array of QRP rigs available to us these days, I’m curious what brings you back to the Yaesu for activations? It’s bigger than our more modern radios, with no ATU and more current draw.   I’m just wondering if there is something that you find it does particularly well, or if it’s just ‘because I like to use it,’ which to me is an entirely valid reason, too! My 897 served me well, as does my 891; I’ve had Yaesu handhelds forever, so I’m certainly a fan. I don’t own an 817/8 but they have a devoted following so I just wanted to get your perspective on it.”

Or as another subscriber distilled the question:

“Why choose a legacy design like the 817/818 when newer QRP transceivers have better overall field specs and features?”

Of course, these types of questions are simple enough when it comes to asking, but when it comes to answering, much more complex.

Of course, as I said in my recent TSM article about choosing a field radio, one’s love of a particular radio is by definition quite subjective, and this certainly applies to my response…we all have our own personal preferences.  But behind these preferences are objective facts, such as product’s unique features, specifications, and form factor; let’s take a look at these.

Continue reading The enduring Yaesu FT-817 and FT-818 series transceivers

What are my favorite QRP field radios in terms of audio quality–?

Many thanks to QRPer.com reader, Charles, who recently sent me the following question:

Thomas, I’ve watched a number of your videos and read your activation reports. I’m studying for both my Technician and General class license right now and hope to pass both in one session later this month. I’m also learning CW.

I consider myself an audiophile and appreciate good audio fidelity. I know that amateur radio modes are narrow and by their very nature have less audio fidelity than commercial broadcast modes. 

I’ve already obtained a Kenwood TS-590G for the shack. It was practically given to me by a friend. I’m very pleased with its audio fidelity especially when I connect it to an external speaker.

Next year, I plan to buy a dedicated QRP field radio. Out of the radios you’ve owned, what are your favorites in terms of audio fidelity. Also, what are your least favorites?

Thank you.

What a great question, Charles!

Being an audiophile, I’m sure you understand that this is a very subjective area: one person’s idea of good audio might not match that of someone else’s.

I can only speak to how I evaluate a transceiver’s audio.

What makes for good audio?

A lot goes into what I would call “good audio” in an amateur radio transceiver.

To me, “good audio” means the radio

  • produces clear accurate sound,
  • has stable AGC (Auto Gain Control),
  • has audio properties that benefit amateur radio modes like CW and SSB,
  • has enough audio amplification to be heard in noisy field conditions,
  • and has little to no internally-generated noises leaking into the audio amplification chain. (In other words, a low noise floor.)

In contrast, radios with poor audio

  • sound noisy/harsh,
  • have a high noise floor or produce audio hash making it difficult to hear weak signals,
  • have speakers that become distorted at higher volume levels,
  • have poor AGC characteristics which lead to pumping,
  • and are simply fatiguing to listen to during extended on-air sessions (like long activations or contests).

I would add that a good receiver front end is an important part of audio because it keeps imaging and overloading at bay, thus producing a less cluttered and noisy audio experience.

My field audio favorites

I’ll keep this discussion limited to QRP field portable radios. There are numerous 100 watt desktop radios with excellent audio because those models aren’t trying to limit their current consumption like field radios typically do. They can use more amperage to benefit audio amplification and push a much larger speaker.

In addition, I’ll limit the scope to field radios with built-in speakers. There are some great CW-only radios out there that lack an internal speaker but have great audio (thinking of the Penntek TR-35 and the Elecraft KX1, for example); choice of earphones or headphones can have a dramatic effect on audio. That’s a different discussion altogether!

Best audio: My top three picks

The following are three of my favorite portable field radios in terms of audio quality. I limited myself to three simply because all of the radios I use regularly in the field have what I would consider good and acceptable audio.

The following are simply stand-outs, in my opinion:

Continue reading What are my favorite QRP field radios in terms of audio quality–?