Category Archives: Articles

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.

Scott Builds a clever Icom IC-705 Paddle Mount

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

Paddle Mount for the IC-705

I kinda like the idea of being able to mount your paddle to your radio when operating portable. You can use the weight of the radio to help prevent the paddles from moving around and it frees your off hand for other tasks. We see examples of this with the Elecraft KX series of radios and there are some adapters for radios such as the Yaesu Ft-817/818.

I really like my IC-705. It is probably my best radio for POTA/potable operation. I think the only time I would leave it home is if weight became a problem or I needed to exercise one of my other radios. Recently, Begali came out with a mount to attach their Adventure paddle to the IC-705. It is a sweet set-up; however, the approx. $400 USD price tag got me looking for other alternatives. I have nothing against Begali, I own three of their paddles, and they are superb instruments. I think I wanted to tinker, and this gave me a good excuse.

For paddles, I have a set of Larry’s (N0SA) SOTA paddles. I love these paddles. When I go on an activation/Portable Operation, I bring these and my Begali Travelers. If I was going to do a SOTA activation, I would just bring Larry’s Paddles. Next was a trip to Tractor Supply Company (TSC) for a sheet of 16 ga. Steel. That set me back $16. I cut it to 3″ by 3 1/2″ using a cutoff wheel on my grinder.

I already have a stand I made out of 1″ x 1″ angle aluminum so I cut this to fit behind it.

The blue on the metal is Dykem Blue which is a layout fluid. In creating this project, I am only using hand tools. Power tools consisted of a grinder with a cut-off wheel. a hand drill, and my trusty Dremel tool. Here is a picture of me giving the mount a rough finish with a file. Continue reading Scott Builds a clever Icom IC-705 Paddle Mount

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

Using WSPR Data to Study Propagation 40 & 20 Meter Bands

Many thanks to Jim (KX4TD) who writes:

Hi Thomas,

I am a subscriber and ham radio operator circa 1974. Like you (and a lotta hams) I started as a SWL using a transistorized Lafayette Radio receiver.

Last evening, I listened to the April 2022 Wireless Flirt podcast from Ireland where you were interviewed about the comeback of SW radio. Well done Thomas! You are one articulate dude!

I currently have a uBitx that I use for base and portable operation. We share an interest in POTA and other QRP field operations.

My latest obsession is WSPR. Attached [linked below], please find some of my WSPR findings on 40 meters.

73,

Jim KX4TD

Click here to download PDF: “Using WSPR Data to Study Propagation on the 40-meter and 20-meter Bands”

Thank you so much for sharing this and for the kind words, Jim! It’s strange, but I’ve yet to dive into the world of WSPR. I actually have a QRPLabs QCX+ transceiver kit I purchased specifically to explore WSPR. I just need to find the time to build it now! 

Thanks again for sharing your amazing report!

Which to choose? The Venus SW-3B or the Penntek TR-35?

Many thanks to Pat (N0HR) who shared following question in a comment:

Thomas

I simply love your videos – both your impressions of the gear and the activations themselves. Great stuff.

I’m curious – now that you’ve played with both the SW-3B and the Penntek TR-35, which is the favorite? Seems like they’re both roughly in the same price range.

Thanks for your fantastic channel and website

73,
Pat N0HR

Thank you for the kind words, Pat, and great question! Several people have asked me variations of this very question recently.

I like both radios, so I’ll frame this in a way that might help others make a purchase decision.

Spoiler alert: You really can’t go wrong with either radio and I feel it’s more a question of operator preferences. Continue reading Which to choose? The Venus SW-3B or the Penntek TR-35?

A little off-grid radio and offline camping!

If you were hunting POTA contacts last week, you might have seen my callsign pop up in the spots quite a few times at New River State Park (K-2748).

Morning reading along with a proper brew in my C.R.A.Q. coffee mug!

Our family decided to take a little break from everything–including the internet–and simply enjoy the great outdoors and a little camping in our small travel trailer (caravan).

Our ferocious guard dog protecting the camp site from hostile invaders. Note that she’s actually awake and alert. A rarity indeed!

It was amazing fun.

In terms of radios, I limited myself to two. While we had room for more, I decided in advance I wanted to spend some proper bonding time with my Yaesu FT-817ND.

I’m so glad I did.

I also brought the Elecraft KX2 but primarily planned to use it when operating off-site. This way, I could keep the FT-817ND system hooked up and ready for action at our camp site.

In fact, the KX2 remained in my SOTA pack for the duration of the trip as a grab-and-go. I had an absolute blast with it activating the summit of Mount Jefferson.

Solar power

This camping trip gave me an excuse to use a station accessory I purchased last year: my Buddipole Powermini 2.

The Powermini 2 is a very compact and capable charge controller with an input for solar panels, a battery, two DC outputs, and even a USB power output. A genius little device.

I’ve been asked a number of times why I don’t do solar charging in the field during my activations. There are a few reasons, actually:

  • First of all, my activations tend to be short in duration–perhaps 45 to 75 minutes. I could easily operate for a few hours on one battery charge with most of my QRP radios. In other words, I rarely need to recharge in the field.
  • Often, my field activation sites are shaded by choice. Since I like to hang wires in trees, those same trees would block sunlight from ever hitting my panels.
  • Finally, unless I’m testing a new radio, I tend to take the least amount of accessories necessary to complete the activation. This is especially the case with SOTA activations. Since I’m unlikely to use solar panels, I leave them in the car or at the QTH. I do, however, keep them packed and at-the-ready should the need arise.

I paired the Powermini 2 with PowerFilm Solar folding panels I purchased many moons ago at Hamvention (I’m guessing in 2012 or so–?). These were blemished units and I snagged them for a brilliant price. Looking back, I wish I would have purchased a few more.

They’re only 5 watts each, but I run them in parallel to feed the charge controller with the equivalent of 10 watts.

QRP gear is so efficient, these modest panels actually do a respectable job keeping the battery topped off. At New River State Park it helped that our picnic table was in full sunlight most of the day.

Sure, we had shore power at the site, but where’s the fun in that?

QRM

During the week, the site had low levels of RFI/QRM. That all changed during the weekend when new campers moved in along with their leaky switching power supplies and noisy inverters.

On Saturday, I found it too frustrating to try making contacts from the campsite–the noise floor was a steady S7 with peaks around S9 simply washing over all but the strongest signals. I regretted not packing my Chameleon loop antenna.

Instead of fighting the QRM, I abandoned it. I drove to a large isolated picnic shelter at New River and set up the KX2 and CHA MPAS Lite antenna.

The site was noise-free and I had amazing fun.

Videos

I made quite a few activation videos, so I’ll eventually post them with abbreviated field reports.

Frankly, I am still catching up from having been offline so long.

Thank you

Massive thanks to my good friend Eric (WD8RIF) who took care of QRPer.com while I was gone. He’s been moderating comments and making sure scheduled posts published properly. In fact, my friend Robert Gulley (K4PKM) was holding down the fort over on the SWLing Post too. I’m so thankful to both of them.

Also, many thanks to all of the hunters who worked me on multiple bands and in multiple modes. A special shot out to NE4TN who was a life saver and spotted me on several occasions when the connection between the POTA site and Reverse Beacon Network were down. Many thanks, OM!

Of course, I’d also like to send a special thanks to those of you who have been supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement as my content will always be free, I really appreciate the support. Your support actually helps to make radio fun like this possible.

Here’s wishing everyone an amazing weekend!

Cheers & 72,

Thomas (K4SWL)

Antenna Challenge #2: K6ARK End-Fed Half-Wave paired with the Elecraft KX1

I mentioned in a previous post that my personal Activation Challenge for 2022 was “to build a new antenna each month and deploy it at least once that month during a field activation.”

In January, I built a doublet with a military fixture/winder.

For February, I decided to purchase and build a counterpoise-less end-fed half-wave kit from from Adam (K6ARK).  This kit is available on Amazon.com for a mere $19.95 (affiliate link).

The build itself is pretty straight-forward and not terribly complicated. With that said, you do need a fine soldering iron tip and a little dexterity to manipulate these super tiny components. Adam includes instructions for building an EFHW with a counterpoise, without a counterpoise, or a random wire antenna. The coil can be configured as a a 49:1 Unun, 9:1 Unun, or 1:1 Balun.

If you choose the EFHW route you will need to solder one surface-mount capacitor on the board. If you’ve never worked with surface mount components before, take your time and use a good magnifying glass.

Blue Ridge Parkway (K-3378 NC)

On Monday, February 21, 2022, on my way back from town, I hopped on the Blue Ridge Parkway and drove to one of my favorite roadside spots on a grassy hill surrounded by trees.

Since I configured the K6ARK kit as a counterpoise-less EFHW, I wasn’t entirely sure how stable the SWR would be in the field. For this reason, I was a wee bit nervous pairing it with my MTR-3B since that little radio lacks an SWR meter and really needs a good match.

I decided, instead, to pair the K6ARK antenna with my Elecraft KX1 which has a built-in ATU that can both monitor the SWR and find an impedance match if needed. Of course, I turned off the internal ATU for the activation, but if I needed it, I knew I could engage and use it. Continue reading Antenna Challenge #2: K6ARK End-Fed Half-Wave paired with the Elecraft KX1

Leo’s complete QCX-mini field kit and ZM-4 manual tuner kit

Many thanks to Leo (DL2COM) who recently reached out after watching my livestream with Josh at HRCC on the topic of QRP/CW portable. 

Leo shared some photos of a complete radio kit he built around the QCX-mini along with a ZM-4 ATU kit he also recently built. Leo has kindly agreed to share these on QRPer.com.

Leo notes:

Attached is a photo of my ultra light kit.

It consists of a QCX-Mini 20m version (self-built), K6ARK EFHW, Palm Radio Pico Paddle, Eremit 2Ah LiFePo battery, headphones and a few cables.

I usually also carry a small arborist kit and if there is still room also the 6m mast from Sotabeams, depending on what I think will work best.

I chose a hard case and went for the Peli 1060 Micro. It has room for everything I need and it could easily hold a bit of RG316 coax in addition (even more if I chose to shorten the 30m arborist line).

The main benefit for me is that I really don’t have to worry at all about what’s inside – compared to a soft pouch. So I can just shove it into my backpack or glove box and forget about it since this configuration is a lot more rugged and water proof – while being slightly heavier. Continue reading Leo’s complete QCX-mini field kit and ZM-4 manual tuner kit

Repairing Ruby: Dr. Vlado performs surgery on the Elecraft KX1

I might have mentioned in a previous post that I named my little Elecraft KX1 “Ruby.”

I name all of my field radios that are permanent; ones I never plan to sell or trade at any point in the future. Ruby is firmly in that keeper list.

Why do I anthropomorphize field radios? That’s perhaps a discussion for a different day but I reckon it’s because I feel they have a lot of character and are, quite literally, trusted companions. They go with me on travels, hikes, and all sorts of outings.

Ruby love

So Ruby is actually the second KX1 I’ve owned.

My first Elecraft KX1 also had a dedicated Pelican 1060 case. There’s even room to fit an external Whiterock paddle.

The first one I purchased in 2008 as a reward to myself for learning CW (see photo above). I enjoyed that KX1 until 2016 when I sold it to help fund the purchase of my KX2.

I immediately regretted selling it, although it helped that I sold it to an amazing person.

In October 2020, I purchased Ruby and wrote a post about how great it was to be reunited with this gem of a radio.

 

At the time, I had no idea what a great deal I had landed.

Ruby turned out to be a four band radio (it was advertised as three), included the built-in ATU, and the package came with a simple wire antenna, three different coaxial DC plugs, a Pelican 1060 waterproof case, earphones, and a set of KXPD1  paddles. All of this for $300 US shipped.

I took Ruby on a number of field activations and couldn’t have been happier

Intermittent issues surface

In the summer of 2021, I started noticing some odd behavior.

Sometimes, after turning on the power switch, the rig wouldn’t completely power up. Instead of the typical two clicks we KX1 owners are accustomed to hearing, I only heard one click and neither the display nor any of the functions worked.

This was an intermittent issue–the next day it might power up as it should.

I did a little troubleshooting: I completely disassembled it, visually inspected all of the solder joints, and removed/cleaned and reinserted the firmware chip. This had no effect at all.

So, I took Ruby to one of the best radio repair technicians in the world who also happens to be one of my best friends: Vlado (N3CZ). He actually does a lot of repair and even has a radio repair website.

Dr. Vlado

Vlado (N3CZ) draws a crowd during a joint park activation on the Blue Ridge Parkway a few years ago.

Vlado will be the first to tell you that the worst problems to diagnose are those that are intermittent; it takes much longer to trace the source of the problem.

A few days later, Vlado sent me a message notifying me that the patient (Ruby) was on the operating table and surgery was about to begin. (See why I call him “Dr. Vlado”–?)

Vlado checked the circuit board very carefully. He found a few solder joints that needed work including a couple on the chip holder. In fact, he completely desoldered the chip holder and soldered it back in properly. Keep in mind here that the KX1 was only ever available as a kit, so quality had everything to do with the skill of the original builder.

He re-assembled Ruby and she worked perfectly.

A second operation

I put Ruby back on the air for a few months, but then in December 2021, a variation of the same issue resurfaced. This time, the “two clicks” in startup took a couple seconds longer than it should. Then it simply stopped working altogether.

Vlado wanted Ruby back in surgery ASAP, so I dropped her off at his “Emergency Room.”

Since the problem was no longer intermittent, Vlado quickly sorted out the main issue: a faulty encoder.

I should note here that since the KX1 hasn’t been produced by Elecraft in many years, there’s always the fear that a replacement part might already be “unobtainium.”

I called Elecraft support and fortunately for KX1 owners everywhere, the encoder is one Elecraft uses in a few of their radios. They have a healthy inventory and the part costs less than $5.00. Woo hoo!

Admittedly, when I placed the order, I also order a few extra parts I thought could fail in the future and might be difficult to find: 3.5mm jacks, pots, and even the LED screen. If I was paying shipping anyway, why not add a few extras? The parts are all very reasonably priced.

The KX1 doesn’t seem to have a lot of unobtainium in it–I seem to recall though that the firmware chip can no longer be ordered from their website and neither can the pushbuttons.  I bet you could find other pushbuttons if needed, though.

I had the encoder shipped directly to Vlado and he completed Ruby’s operation in short order. Thank you, Vlado!

To the field!

I’m so happy to have Ruby back on the air! We’ve chased numerous parks and summits in the past week and I took her on an activation Monday, pairing her with my recently-built K6ARK EFHW antenna.

I’ll post an activation report and video in the coming weeks.

KX1 advice

Elecraft KX1s have become as rare as hen’s teeth lately. You’ve no doubt noticed this if you’ve been looking for one. I’m sure I could sell my KX1 package in a heartbeat for twice more than I paid a year and a half ago. It’s a little insane, really, but I get it.

If you’ve been looking for a used KX1, I would offer the following notes/advice:

  • Since these were only available as kits, you might ask the seller about the original builder and/or have them take photos of the soldering work inside prior to purchasing.
  • Assume issues might arise with time. With radios like this, I mentally set aside at least a couple hundred dollars for future replacement parts and/or repairs.
  • Keep in mind that as with any other radio that’s a bit long in the tooth, you may find that some components are simply no longer available. That’s the risk we take being custodians of these cool little rigs.
  • Actively looking for a KX1 at time of posting (Feb 2022)? Note that interest in particular radio models waxes and wanes over time. With a little patience, you’ll eventually find one. I’ve seen this happen with so many other radios over the years.
  • The KX1, as with most Elecraft radios, comes in a number of configurations and you need to be aware of this if purchasing. Some only have two bands, some have three, and some have four. I’m not certain if band modules are still available via Elecraft, so you might get stuck with the configuration you purchase.  Also, the internal ATU was an option; don’t assume the one you’re purchasing has the ATU.
  • KXPD1 paddles are very difficult to find these days. It’s a big bonus if your radio comes with them. Not everyone likes these paddles, but the version I have now seem to work really well, actually. N6ARA Tiny Paddles are a brilliant little replacement, but you might wish to make a 3D-printed holder to attach the the paddle point on the front of the radio to take a little strain off of the 3.5mm jack inside.

I should also add that Vlado is a brilliant repair technician and has worked on numerous Elecraft, Icom, Yaesu, Kenwood, and Ten-Tec models over the years–if it’s solid state, he can repair it. If you ever need his services he can be reached via his website HamRadio.repair.

Also, Dave (W8FGU) is an Elecraft employee that is devoted to their legacy radios like the KX1/KX1/K2, etc. He’s a great guy, brilliant resource, and I believe can also arrange repair, if needed.

Enough blogging: I think Ruby and I will chase a few summits now while I finish my morning cuppa’. 🙂