Tag Archives: QRP

Why I send “72” instead of “73”

If you’ve been watching my field activation videos for long you’ve no doubt noticed that, at the end of an exchange, I’ll often send “72 de K4SWL” instead of “73 de K4SWL.”

“73” much like “CQ” has a very distinct sound and cadence in CW. Even during one’s earliest days of learning CW, the sound of “73” is sort of burned into the brain and instantly recognized.

I’m sure that’s why when I send “72” some believe I’m sending it by mistake–it’s very conspicuous even to new CW operators.

Perhaps this is why one of the most common questions I receive from new YouTube channel subscribers is:

“Thomas, why are you sending 72 instead of 73?”

The answer is actually very simple…

72 is the QRP version of 73

“72” isn’t a new ham radio abbreviation but according to my light research, it doesn’t date back to the earliest days of wireless either (please correct me if I’m wrong).

The late and great George Dobbs (G3RJV) notes in his book “QRP Basics” that 72 has been in use since the late 1980s as a way some operators identify that they’re running QRP or low power (generally 5 watts or less).

You’ll find it referenced in numerous abbreviation guides like the CW Ops CW guide and in QRP communities like QRP-L and the QRPARCI. In the past, I’ve heard 72 used in QRP contest exchanges too. I suppose it’s also a bit of a “handshake” among QRP operators.

That said, 72 isn’t as commonly used to convey “Best Regards” as the more standard 73. Not by a long shot. I’ve gotten messages from passionate radio purists who’ve told me to stop using it, in fact, since it’s not as standard as 73. I get where they’re coming from because keeping our abbreviations standard makes communication that much clearer.

I’ll admit that I’m a bit this way with the international phonetic alphabet: I like sticking to the script for reasons of clarity and simplicity.

I almost unconsciously go back to using “73” if I suspect the op on the other end is new to CW.

Then again…

72 is simple and clear

The main reason I choose to use 72 during many of my POTA/SOTA activations is because I believe it conveys a message in the most concise and clear way possible.

Sending “72” allows me to communicate my power level without having to send any extra elements/words like “3 WATTS” or “/QRP” after my callsign–especially since communicating power output isn’t typically a part of a SOTA/POTA exchange.

Sending “72” might also help to explain why my signal strength might be a bit lower, or surprise a DX contact if I’m being received 599.

While it’s true some on the other end might scratch their heads and have to look up the meaning of “72,” once they know it, they know it.

And if sending “72” isn’t your thing or you don’t agree with its use, that’s perfectly okay too! You’ll hear me using it most of the time I’m running QRP in the field, but I don’t expect anyone else to.

To each their own, I say!

When I do hear another op use 72? I know the contact was QRP on both ends and that’s kind of cool in my book!

72,

Thomas (K4SWL)

New River Gorge: Pairing the Tufteln 9:1 Random Wire with the Elecraft KX2

When Eric (WD8RIF) and I hatched our plan to do a mini POTA expedition in West Virginia, there was one site I wanted to activate more than any other: New River Gorge National Park.

More specifically, I wanted to activate the park by way of the scenic one-way road that starts near the New River Gorge Visitor’s Center and descends down to the Tunney Hunsaker Bridge (the “old” New River bridge).

Why? Because in December 2016 during the National Parks On The Air (NPOTA) program, I passed through West Virginia and activated some very rare parks on my way to a multi-day park run with Eric in Ohio. I fully intended to activate the New River at this very spot (underneath the “new” New River Bridge) after hearing how amazing the drive was from Eric.

Unfortunately, I happened to time my trip through West Virginia on a day when we received about an inch of snow. Even though (at the time) I was driving a Toyota minivan with nearly bald tires, the snow didn’t pose a problem at any other site, save this one. I had to change my plans and activate the New River in a spot where the access had less elevation change on a narrow snow-covered road. With my Subaru, this wouldn’t have been an obstacle in the slightest.

I was looking forward to going back to this site and was very pleased to see that Eric and his son, Miles, had already planned this trip in the draft itinerary!

New River Gorge National Park (K-0696)

On the morning of May 20, 2022, Eric, Miles, Theo the dog, and I left our campsite at Babcock State Forest and made our way to the New River Gorge Visitor’s center next to the New River Bridge.

If you’re ever in this area, I’d highly recommend checking out this visitor’s center as it has some well-designed exhibits detailing the impressive engineering that went into the construction of the New River Gorge Bridge.

There are also some fantastic views from the visitor’s center and from its short gorge overlook trail.

From the trail overlook at the visitor’s center we could see the spot where we planned to activate near the Tunney Hunsaker Bridge deep in the gorge (see photo above).

The drive into the gorge was quite scenic with a number of spots to park and take in the enormity of the New River bridge.At the bottom of the gorge, the view was pretty spectacular as well!

My partners in crime: Eric, Miles and “The Great Warg” (Theo the dog)

Tufteln 9:1 EFRW (End-Fed Random Wire) antenna

I mentioned in a previous post that long-time QRPer.com reader and supporter, Joshua (KO4AWH), runs an Etsy store with a wide range of products primarily designed for field operators.

Besides the Elecraft T1 protection case I mentioned previously, he also sent a couple of his QRP field antennas for testing and evaluation (to be clear: free of charge). Thanks, Joshua!

I decided to break in his EFRW QRP Antenna Long Wire at New River Gorge. Since Eric and I would be operating pretty close to one another, I wanted to use a random wire antenna that would give me a bit of frequency agility to hop around and avoid harmonically-related bands Eric might be using. This Tufteln antenna fit the bill! Continue reading New River Gorge: Pairing the Tufteln 9:1 Random Wire with the Elecraft KX2

Choosing a Field Radio: How to find the perfect transceiver for your outdoor radio activities!

The following article was originally published in the June 2022 issue of The Spectrum Monitor Magazine:


Choosing a Field Radio

by Thomas (K4SWL)

At least ninety percent of all of my radio operations happen in the field. Whether I’m in a park, on a summit activation, or I’m out camping, I’ve always thoroughly enjoyed “playing radio” outdoors. In fact, it was the joy of field radio––and the accompanying challenge of low-power operations––which launched my labor of love in the world of ham radio.

I’ve been running QRPer.com now for fourteen years, and during that time, the questions I’m asked most deal with selecting a field radio. Turns out, it’s an incredibly difficult question to answer, and we’ll touch on why that is before we dive into the reasons one radio might hold appeal over another for you.

Instead of offering up a list of field radios on the market, and reviewing each one—and, to be fair, there are so many these days—I’ll share with you a series of questions you might ask yourself before making a radio purchase, and follow up with a few bits of advice based on my own experience.These deceptively simple questions will help hone your decision-making. Finally, I’ll note a few of my favorite general coverage field radios and share what I love about each.

But, first…

Spoiler alert: It’s all about the operator, less about the specs

When searching for a new radio, we hams tend to take deep dives into feature and specification comparisons between various models of radios. We’ll reference Rob Sherwood’s superb receiver test data table, we’ll pour over user reviews, and we’ll download full radio manuals before we choose.

While this is valuable information—especially since radios can be quite a costly “investment”—I would argue that this process shouldn’t be your first step.

I’ve found that enjoyment of any particular radio—whether field radio or not—has everything to do with the operator and less to do with the radio’s actual performance.

A realistic assessment of yourself

The first step in choosing a field radio is to ask yourself a few questions, and answer them as honestly as you can. Here are some basic questions to get you started in your search of a field radio:

Question 1:  Where do I plan to operate?

If you plan to operate mostly at the QTH or indoors with only the occasional foray outdoors, you may want a field-capable radio that best suits you indoors—one with robust audio, a larger encoder, a larger display, and more front panel real estate.

On the other hand, if you plan to take your radio on backpacking adventures, then portability, battery efficiency and durability are king

Of course, most of us may be somewhere in between, having park activations or camping trips in mind, but overall size may be less important as we may be driving or taking only a short walk to the activation site. When your shack is a picnic table not too far from a parking lot or even an RV, you have a lot more options than when you have to hike up a mountain with your radio gear in tow.

Question 2:  What modes will I operate the most?

Are you a single mode operator? If your intention is to only use digital modes, then you’ll want a radio designed with easy digital mode operation in mind.

If you plan to focus on single sideband, power output may be more important and features like voice-memory keying.

If you plan to primarily operate CW, then the radio world is your oyster because it even opens the door to numerous inexpensive CW-only field radios.

If you plan to primarily operate CW,  I would strongly suggest going low power or QRP. I’ve often heard that 5 watts CW is roughly equivalent to 80 watts single sideband. I tend to agree with this. CW field operators hardly need more than 5 watts, in my experience.

And if, like most of us, you plan to operate a variety of modes, then you’ll want a radio that is multi-mode. Continue reading Choosing a Field Radio: How to find the perfect transceiver for your outdoor radio activities!

Fitting in some QRP SOTA & POTA on Mount Jefferson!

Looking back at last year (2021), if I had to pick out one of the easiest SOTA activations I made, Mount Jefferson would be near the top of the list. It’s a very accessible summit although not technically a “drive-up” summit because you will need to walk a short distance up a service road to the activation zone (AZ).

Mount Jefferson (W4C/EM-021) is located on and protected by the Mount Jefferson State Natural Area (K-3846), so when you activate Mount Jefferson for Summits On The Air, you can also claim the activation for Parks On The Air and World-Wide Flora and Fauna as long as you work at least 10 contacts.

What I love about POTA and SOTA “2-fer” sites like this is that you can set things up to be spotted in both systems (and often the WWFF system, too!) which increases your audience of hunters and chasers, thus increasing your odds of achieving a valid activation in all programs. It’s especially desirable if you’re a CW op and know you may potentially be in a spot with no mobile phone service for self-spotting; if, for some reason, RBN auto-spotting functionality is down with one program, the other serves as a backup.

Mount Jefferson is at least a two hour drive from my QTH, but it was easy pickings on April 29, 2022 because it happened to be within spitting distance of New River State Park where I was camping with my family.

Mount Jefferson (W4C/EM-021)

The drive to Mount Jefferson took all of 20 minutes which was a good thing because our family had other activities in store that day including some extended hikes!

Hazel (above) was so excited to to check out the sights and smells at this new-to-her park! Continue reading Fitting in some QRP SOTA & POTA on Mount Jefferson!

Scott runs some QRO v QRP numbers!

Many thanks to Scott (KK4Z) who shares the following post from his blog KK4Z.com:


QRO SCHMURO

There is always a lot of talk about QRP vs QRO, 5 watts vs 10, ad nauseam. So today I thought I would run the numbers and see what the real deal is. First we need a few definitions. An S-unit in general terms is the minimum change in signal strength to be just noticeable (k3wwp.com). In more technical terms it equates to approximately 6 db in change. The decibel (dB) is a logarithmic number. Each 10 dB represents a factor of 10 difference. This may be a little out there for some so we will cut right to the shortcut. There are two types of logarithms. For calculating dB, use the common logarithm which is base 10. To see if your calculator uses the right one. Punch in 100 and then log. The answer should be 2 which equates to 10 to the second power which equals 100. This is not a technical paper but an entry way to see how changing the power levels affect the signal level of your transmitting signal. As you guessed, it is not linear.

Let me introduce an equation:

Where Power P1 is the power you wish to evaluate and reference power P2 is your starting power. Let’s take going from 5 watts to 10 watts. The equation would look like this:

We take 10 and divide it by 5 which give us 2. Then we hit the log function on our calculator which gives us 0.301. Multiply that by 10 and you have about 3 dB in gain or about one half of an S-unit (remember 1 S-unit is equal to 6 dB). Let’s do one more by hand and tackle the QRP/QRO debate. How many S-units will increasing power from 5 watts to 100 watts give you? The equation looks like this:

Take the 100 and divide by 5 to give you 20 and then hit the log function to give you 1.301. Multiply by 10 for 13.01 dB. Divide 13.01 by 6 dB and you have 2.17 S-units. Going back to our definition that one S-unit is the minimum change in signal strength to be just noticeable shows that going from 5 watts to 100 watts is not that great of a change.

Let’s let the other shoe drop. What about going from 5 watts to 1500 watt? That will give you 4.13 S-units of gain vs 1.96 S-units going from 100 watts to 1500 watts?

This gives you a fairly easy equation to help you evaluate your needs based upon empirical data. Running 20 watts over 5 gives you 1 S-Unit. Using less power means less drain on the battery for longer operation. This is only part of the equation. Propagation, antenna, mode used, and station efficiency all play a part. Have fun and maybe don’t toss the QRP radio yet. 🙂

Click here to read this post and more at KK4Z.com.

Pairing my new Xiegu X6100 with a 31 foot speaker wire antenna (and avoiding RX overload)

Regular readers of QRPer.com might question the wording in my title since I’ve already posted several field reports and even a full review of the Xiegu X6100. So why would this X6100 be considered a “new” radio–?

Since I go over this in more detail in the activation video (linked and embedded below), I’ll give you the nutshell version here:

My activations with the X6100 early this year (2022) were all performed using a loaner unit sent to me by Radioddity. I kept that unit for a few weeks, shipped it on, and purchased one of my own.

In February, when I received the X6100 I purchased, I immediately noticed a small mechanical issue with the encoder.

This is the X6100 open. You can see the back of the encoder to the right of the ribbon cable.

I tried fixing it (with instructions received from Xiegu) but in the end had to return the transceiver for replacement.

The X6100 unit in this field report is my replacement–technically, the third X6100 I’ve had in my hands, and this was my first activation using it.

Many of you have asked why I haven’t taken the X6100 to the field more often this year and this is why. I basically didn’t have a functioning unit for most of February, March, and April. Radioddity was quite responsive to my issues with the X6100, but frankly I had a lot going on during that time frame so it took longer than normal to troubleshoot, modify, test, and send back the faulty unit.

Fortunately, the replacement X6100 has no encoder issues other than the brake is very tight. I’m not willing to break the warranty seal on this unit to adjust it, so I’ll just live with a much-tighter-than-I’d-like encoder.

[Update: Bob (W0BNC) points out that the tight brake is due to friction caused by a felt pad under the X6100 encoder knob. The remedy is to pull off the rubber ring around the encoder knob, loosen the set screw, lift the knob slightly off the body, and retighten. I’ll do this when I’m back with the X6100 after summer travels. Thanks, Bob!]

X6100 field kit test

This activation was also the perfect opportunity to test all of the components of a dedicated field kit I’m building around the X6100.

The kit consists of:

  • The Xiegu X6100 QRP transceiver,
  • a BNC binding post adapter,
  • paddles,
  • the X6100 battery charger,
  • a 31′ speaker wire antenna
  • 25 meters of 2mm throw line,
  • a weaver 8oz weight, and a
  • logging pad and pencil.

Everything, save the antenna, fits in my Red Oxx Hound EDC pack.

Eventually, I’ll replace the speaker wire with some thinner Wireman stuff and it should all fit in the Hound pack, albeit snuggly!

I’ve decided that the X6100 will live at my parents’ home in the NC foothills, so I’ll always have a field radio kit available while staying there overnight.

Lake Norman State Park (K-2740)

On May 9, 2002, an opportunity opened up in the afternoon to finally take my new X6100 to the field! Continue reading Pairing my new Xiegu X6100 with a 31 foot speaker wire antenna (and avoiding RX overload)

Rough conditions but serious QRP POTA fun at New River State Park

The New River (Photo by K4TLI)

You might recall from my previous field report that I took the family on a camping trip at New River State Park in April 2022.  During that trip, I made an activation of New River each day and also fit in a very fun SOTA activation (click here to read an overview).

Note that anytime you’re performing an activation over multiple days at any one park, you can only have one activation per UTC day.

The following brief field report is essentially my “Part 2” from April 28, 2022. Since I’d already worked well over my ten contacts in the previous activation session that UTC day, all of these contacts were simply icing on the cake!

Keeping this one brief(er)

I’ve an insanely busy day today, what with exam study, errands, splitting firewood, and prep for our summer travels.

That said, I wanted to squeeze in an activation video and field report because the rest of the week is even crazier. Continue reading Rough conditions but serious QRP POTA fun at New River State Park

A comprehensive review of the Penntek TR-35 four band QRP transceiver

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


“Look at this, Tom! Only the stuff I need and nothing more,” cheerfully noted my good friend and Elmer, Mike (K8RAT).  It was Field Day two decades ago, and Mike was gazing at his TEN-TEC Scout. I glanced over, and agreed. “So simple and so effective,” Mike added.

I’ve never forgotten Mike’s sage words. That Scout (Model 555) was about as simple as a then-modern HF transceiver could be:  it had a total of three knobs––one for AF gain and IF bandwidth, one for RIT and Mic gain, and an encoder. It also had three mechanical switches on the front: one for power, one for TUNE and NB, and one for CW speed and RIT. It also had an analog SWR/power meter. The Scout used plug-in band modules for each HF band and featured a large segmented bright green LED frequency display that was characteristic of so many TEN-TEC rigs of the day.

And Mike was right. For those of us who appreciate radios with a simple, uncluttered, and an almost utilitarian interface, the Scout was, in vintage parlance, “the bee’s knees.”  And that the Scout also performed beautifully was just icing on that cake.

When the Scout first appeared in 1994, embedded menu options and spectrum displays were not yet commonplace among amateur transceivers. Embedded menu items can open the door to near granular level control of your radio’s functionality and features. Then again, if those embedded menus aren’t well thought out, it can lead to awkward operation practices in the field, during a contest, or even during casual operation.

As a radio reviewer, I spend a great deal of time sorting out embedded menu functionality and design. Perhaps it’s for this reason that I so enjoyed reviewing a radio that bucks this trend and reminds me of a time that was simpler, not to mention, easier.

Enter the Penntek TR-35

The new Penntek TR-35 is a four-band CW-only QRP transceiver that is available both as a kit ($279) and as a factory assembled and tested unit ($379). Penntek transceivers are designed and manufactured by John Dillon (WA3RNC).

All of his transceiver kits are available at his website WA3RNC.com.

I was first drawn to the TR-35 after reading the opening paragraph of the product description:

“Compact but powerful 4-band, 5-watt CW transceiver kit that uses no tiny push buttons, and without those seemingly endless and hard-to-remember back menus. There is a knob or a switch for every function!”

Sold!

I considered buying and building the TR-35 kit, but I wanted my eventual review––this one!––to focus on the radio’s functionality and performance. So a factory-assembled and tested unit was right for this purpose, just so that any performance issues wouldn’t be a result of any shortcomings in my kit building skills.

I decided to reach out to WA3RNC and ask for a loaner. John very kindly sent a factory built TR-35 to me along with return postage and a very flexible loan period (thank you, John!). Continue reading A comprehensive review of the Penntek TR-35 four band QRP transceiver

John’s trip and POTA field reports from Nova Scotia

Many thanks to John (VE3IPS) who shares the following guest post:


Nova Scotia POTA After-Action Report

by John VE3IPS

We had planned a vacation trip out to Nova Scotia to get our lobster fix. As I always do, I prep my radio with local repeaters, look up local radio clubs, museums and check the POTA and SOTA map for locations to operate from.

I noticed that several park locations had not been activated. Thus I had an opportunity to be first activator and to get some much needed Nova Scotia parks in the Hunters logs. I printed the map and noted the park identifiers. I decided to just activate the parks that were never activated. I could have worked more parks but you have sights to see and can’t be behind the mic all the time. My antenna was prepped to be rapidly deployed in a few minutes and torn down accordingly.

I also was able to attend the Halifax ARC Hamfest on June 4, 2022.

So a vacation with ham radio elements to keep me excited with some objectives in mind.

We did visit Peggy’s Cove, Burnt Coat Head to watch the tides in the Bay of Fundy, local wineries, Lunenburg (a movie shoot was underway), the Halifax Citadel and of course eat lobster every day. I spent over $200 in gas as we did a lot of driving around (gas is just over $8 a gallon CAD), retail tax at 15% and prices for food and restaurants up by 30%. Nova Scotia is a bit more expensive than other cities.

I decided to bring my Icom 705 with a LifePO4 battery to offer 10 watts instead of the FT-891 or FT-818. Why? Because it offered a voice memory for calling CQ Parks, built in SWR meter and better IF filters over the FT-818. I wanted to cover the Marine and VHF/UHF repeaters as well and that ruled out the FT-891.

Due to the Kleenex box form factor I ended up using a Lowe Pro Omni Trekker camera bag to use as a carry on. This included a Nikon V1 camera and Binoculars.

Continue reading John’s trip and POTA field reports from Nova Scotia

Solar POTA: Pairing the Buddipole PowerMini 2 with folding panels and the FT-817ND at New River State Park

Photo by K4TLI

I’m often asked if I ever charge my LiFePo4 batteries in the field via solar energy.

Truth is, I’m a big fan of solar, but I’m rarely in the field long enough to need to recharge my batteries via solar when performing SOTA and POTA field activations. It’s easier to charge them at home in advance (often via the solar system at our QTH).

In fact, one of my 3 Ah LiFePo4 Bioenno batteries can easily take me though 3-5 activations or possibly more, depending on the length of the activation and the rig I’m using.

Photo by K4TLI

For longer forays into the field, however, I love going solar.

Indeed, every few years, my family will stay in an off-grid cabin on Prince Edward Island (Canada) for up to 6 weeks at a time. Solar is the only practical way to stay on the air that length of time.

Of course, I also like having a solar option, when doing proper primitive/off-grid tent camping.

In the past, I’ve used a very simple portable solar charging system based on a variety of rigid and folding panels, a Micro M+ charge controller, and sealed lead acid batteries. The batteries are of course heavy, but they work brilliantly for fixed operations.

These days, I’m fully invested in LiFePo4 batteries and my Micro M+ charge controller is not really designed to pair with the BMS (battery management system) in my Bioenno packs.

Bioenno sells a number of affordable solar charge controllers, but most resemble units that are used in permanent installations.  I wanted something more portable and, ideally, something with Anderson PowerPole connections.

Late last year, I discovered the Buddipole PowerMini 2:

Photo by Buddipole

I contacted Buddipole with a few questions about the unit and to find out when they would be in stock again (at the time, they were on back-order and indeed they are at time posting this report).

Turns out, they were to be restocked the next day, so as soon as inventory was showing on the site, I ordered one. Continue reading Solar POTA: Pairing the Buddipole PowerMini 2 with folding panels and the FT-817ND at New River State Park