Category Archives: How To

Scott builds a mobile desk for HF park-roving

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


Necessity is the mother of invention

by Scott (KK4Z)

Plato’s Republic he said that *our need will be the real creator* or the proverb as we know it today *necessity is the mother of invention*.  Recently, my friend Thomas K4SWL acquired a Yaesu FT-891.  During his YouTube video, he expounded on how much fun he had with it. It did indeed look like fun. During this time I was pondering about doing more day activations instead of overnights.  With the cost of everything still climbing, the need to conserve becomes apparent.  I thought an FT-891 might really be a great radio for these day activations. Then reality set in.

I already have a number of projects I am working on and misc things like maybe having to replace my old 33′ push-up pole, it was not in the stars nor was there a twinkle in my wife’s eye when I mentioned it. In reality, the IC-7300 is a great radio and does everything I need to do especially in the field. I don’t need another radio, I have three 100 watt radios and three QRP radios. I still wanted an easy setup for these one-day activations. I want to drive to a park, set up in a few minutes, operate, tear-down in a couple of minutes, and head for home or another park. I also wanted to make my day activations park ranger friendly. To me, that means trying to be inconspicuous.

I have two projects planned. The first is a desk for my truck. I am making a desk to sit over the center console and front passenger seat big enough to hold my IC-7300, a laptop and a CW paddle. My plan is to secure the desk to the truck and the radio to the desk. I also wanted to make this as cheaply as possible. I used stuff I had on the property such as a half sheet of plywood and some construction lumber. The only things I had to buy were some screws and eye-bolts, about 14 dollars worth.


The plywood was cut to 24 x 38.5 inches. The length covers the center console and front seat while still allowing me to get to the heat/AC controls. I gave the corners a generous radius and I broke the edges with a router. On the underside, I used a 2 x 12 to make a spacer for the center console where the cup holder is and a leg for the other side over the passenger seat. The spacer is glued and screwed to the desktop but the leg is not attached. This is to make it easier to store. I made a socket for the leg using 2 x 2’s. It’s probably easier to look at a picture than me to try to explain. I added eye rings to the rear of the desk and use a bungee cord to secure the desk to the passenger seat. The only other thing I did, sprayed the top with polyurethane. Note. I am not a carpenter or cabinet maker. I use rough hand tools to get the job done and I am often making do with what’s on hand or what’s the cheapest way to do it.

Continue reading Scott builds a mobile desk for HF park-roving

How to optimize low solar activity days for your activations

by Vince (VE6LK)

(As is Vince’s usual, this article is full of educational and fun links – click on as many as you wish)

Picture this ..  you are getting a bit twitchy due to lack of POTA activation and you have run out of Potaxxia. Further, You publicly stated a New Year’s eve goal to make at least 200 POTA CW activation contacts per month for 2023 (there may have been beer involved), and now you must stay accountable to your goal and you are currently behind plan. It’s too early in the season to be lawn mowing while listening to podcasts such as QSO Today, Ham Radio Workbench, ICQ Podcast, AP/DZ or Soldersmoke. Thus, chasing contacts is [always] a good use of your time.

Lastly, if you are like me, the the solar indices are still an art form being learned and the numbers for today aren’t all in the green zone.

One of many charts that help decode the magic behind propagation values – click through for source webpage

So you begin to wonder just how much effort it’s worth to load up your gear and try to activate. You think to yourself that there won’t be much action on bands other than 20m which has been noisy lately, so why bother as it’s at least a 45 minute trip to the nearest POTA entity.

With this background, on Saturday I placed myself in the city at the nearest-to-home spot I could park in the south part of Calgary adjacent to VE-5082, the Trans-Canada Trail. I was trying to make the best of what I perceived to be a rough conditions day and had no real plan except a convenient location requiring minimal effort for a minimal return. My expectations were, sadly, met in this regard.

The author in a suburban and *very* RF noisy place that he won’t return to.

I was at the edge of suburbia with large homes on my left overlooking the ravine and pathway on my right. To say it was RF noisy would be a colossal understatement. I made 18 painful contacts in an hour and I’m sure people called me but I didn’t hear them given the S7 noise floor on 20m. At least I made one DX contact to Denmark along the way. Overall feeling frustrated, I went back home.

Sunday morning rolls around and again I wonder “is it worth it”?

Continue reading How to optimize low solar activity days for your activations

Video: Alan’s method for winding toroids

After posting my article about the K9DP BCI filter kit build, Alan (W2AEW) commented:

If you dislike winding toroids, the method I show in this video makes it a lot easier!

This is an excellent way to handle the toroid while winding. Check out his video below:

Click here to view on YouTube. 

Alan has a massive library of instructional videos on YouTube. If you haven’t already, subscribe to his channel!

Assembling a K9DP BCI Filter Kit (Photos)


If you own a Xiegu G106, X6100, or any other radio that is prone to overloading when in the presence of an AM broadcaster, you should consider building an in-line BCI filter!

As many of you know, I’ve been testing the Xiegu G106 over the past couple of months for a review that will be published in the May 2023 issue of The Spectrum Monitor magazine.

One criticism of the G106 is that its front-end overloads when there’s an AM broadcaster within a few miles of where you choose to operate. The Xiegu X6100 is identical in this regard.

One quick way to remedy this is to build or buy a BCI filter. We’ve mentioned in the past how you can homebrew them and I planned to do so. After checking my parts drawer, though, I realized I needed to buy a capacitor, toroids and at least one of the two BNC connectors needed if I wanted an in-line filter in a small project box.

I decided it would be much easier to simply buy a kit and, based on a tip from a reader here on QRPer.com, I purchased one from Dan (K9DP). Continue reading Assembling a K9DP BCI Filter Kit (Photos)

Bob pairs his ATS-20 with the Zachtek “Flea” CW transmitter

Many thanks to Bob (K7ZB) who shares the following guest post:


ATS-20 configured with Zachtek “Flea” CW transmitter

The ATS-20 in HF CW Transceiver Mode

by Bob Houf (K7ZB)

I picked up an ATS-20 last summer and played with it on SWBC and the ham bands but found the telescoping whip antenna to be marginal.

The unit I purchased from Amazon turned out to be solid: no problems have surfaced after 9 months of intermittent listening. By default, I have enjoyed it primarily listening to FM in my office.

When I used my long wire antenna, the performance on shortwave greatly improved – easy copy of DX and the value of the receiver began to impress me.

Recently I came across a Swedish ham who co-developed a line of radios covering a broad range of WSPR and associated designs built to a very high standard.

Already having a WSPR setup I was intrigued by a very low power CW transmitter that Zach co-developed with KB9RLW which puts out 300mW on 40, 30 and 20 meters at a price point that is less than the ATS-20, and – most interestingly – the design of the radio allows it to work in transceive mode with the receiver by providing a T/R switch when used with the proper SMA-BNC cable arrangement.

I bought a “Flea” and configured it with my ATS-20 then used an external antenna tuner to make sure the transmitter had close to a 1:1 SWR.  The “Flea” advertises that it is robust to high SWR and looking over the schematic that is evident, but for the sake of a trial I went with the ATU. Continue reading Bob pairs his ATS-20 with the Zachtek “Flea” CW transmitter

Jim’s “WD-PT-PB” AX1/AX2 table/bench clamp mount


Many thanks to Jim (N9EET) who writes:

Thomas:

I look forward to all your videos and am enjoying how you use the Elecraft AX-1 in the field.

I have built the “WD-PT-PB” attachment for my AX-1 antenna.

That is, it is for Windy Day-Picnic Table-Park Bench use. It can be set up horizontally or vertically on the edge of a picnic table or at any angle on the back of a park bench and is a secure attachment for the AX-1 off the radio.

[I] bought the bolts straight and put them thru a random C clamp secured with a nut or wing nut and then bent one in my vise. Loosen the wing nut and angle the bolt any way I want and tighten the wing nut.

The pictures show it better than paragraphs of a description.

73,
Jim Long
Madison, WI
N9EET

That’s brilliant, Jim! I love how versatile the clamp is and that it even fits in your Maxpedition pouch! No doubt, it’ll help the AX1 (or AX2, or any similar antenna) survive the windiest of deployments.

Thank you for sharing.

Penntek TR-45L: Adjusting the sidetone level

Many thanks to David (KQ4CW) who writes:

I received my Penntek TR-45L on Friday.

Just for your info: if anyone wishes to adjust the sidetone level there is a way to do that:

TR-45L Internal Sidetone Adjustment

The sidetone level adjustment can be accessed by removing the front panel assembly from the rear case.

First, remove the six screws that secure the panel to the rear case half. Separate the panel assembly and lay it face down on the table. Be careful with the interconnecting cables.

While operating the unit, adjust the sidetone level pot (circled in red) for the level of your liking. Reassemble the panel to the case rear. You may need to squeeze hard on the corners to make the panel fit. Be careful with the dress of the internal cables.

Thank you so much for sharing this, David. This is a very simple procedure and shows, also, how WA3RNC designed the boards so that the pot is accessible without having to pull apart the two main boards!

In Pursuit of the Top Band: Brian describes how he built and tested a field-portable 160 meter EFRW antenna

Many thanks to Brian (K3ES) who shares the following guest post:


The VK160 Antenna packed on its Winder/Feedpoint for storage, transport, and deployment.

Building and Testing the VK160 Antenna

by Brian (K3ES)

The ability to set and achieve long- and short-term goals keeps me interested and active in the Parks on the Air (POTA) program.  Often these goals are associated with POTA awards.  Currently, I am working slowly to complete the activator version of the James F. LaPorta N1CC award, which requires an activator to make QSOs on 10 amateur bands from 10 different parks.  With my operating style, I have found it achievable to make QSOs on the 9 available HF bands (80m, 60m, 40m, 30m, 20m, 17m, 15m, 12m, and 10m), and this has become easier with the rising solar cycle.  I have completed QSOs on non-HF bands using 2m and 70cm simplex.  The other options to pick up 10th band QSOs include the 6m band and the 160m band.

I have found it difficult to make unscheduled POTA contacts on 2m and 70cm, and scheduled contacts can be difficult to arrange in parks that are remote from population centers.  I have built a 6m antenna, but contacts are seasonal (and for me very elusive).  So I started looking for a way to add 160m capability to my portable station.  Ultimately that resulted in homebrewing a new antenna that I now call the VK160, and here is its story.

Objective

I needed a field-deployable 160m antenna.  My operating style requires that the antenna system be both light and compact.  QRP power levels are sufficient for my purposes.  I am very comfortable deploying wire antennas in the Pennsylvania woods, and QRP wire antennas can be both light and compact.  I have found that end-fed antennas are simpler to deploy in the field, because they can be configured as an inverted V or as a sloper, using only one point of support.

An end-fed half wave (EFHW) antenna would be naturally resonant, but would need to be over 250 ft (76m) long.  A wire antenna of that length would be challenging to deploy, even in more open areas.  So, I decided to pursue a 9:1 unun-based end-fed “random wire” (EFRW) antenna.  In fact, I have two commercial EFRW antennas available, but have never been successful in tuning them for 160m using the ZM-2 tuner in my field kit.  So, I concluded (probably incorrectly, but more on that later) that I needed to build a 9:1 random wire antenna with a longer radiating element than the 71 ft wire built into my largest existing EFRW.  I also wanted to build this antenna myself, using available components, so that it would be both inexpensive and customized to my needs.

I broke the task into four parts:

First, I needed to build a 9:1 unun suitable for use at QRP power levels.  The 9:1 unun is an autotransformer that reduces antenna feedpoint impedance by a factor of 9, hopefully a level that a wide-range tuner can match to the 50 ohm transceiver impedance.

Second, I had to design and build mechanical elements of the antenna system, incorporating the electrical components needed for the feedpoint.

Third, I needed to select a suitable non-resonant wire length for the radiator.

Finally, I needed to deploy and test the finished antenna on the air.  If successful, testing would culminate in completing an on-air QSO with the antenna being driven at 5 watts or less.

Building the 9:1 Unun

While I have built successful 49:1 ununs as the basis for EFHW antennas, I had no experience building 9:1 ununs.  Accordingly, I started with the ARRL Antenna Book, then a web search.  VK6YSF’s excellent web page provided very detailed instructions for 9:1 unun construction. His 9:1 Unun design was based on a FT140-43 toroid wrapped with heavy gauge magnet wire, with design power rating around 100 watts.  My application was focused on 10 watts maximum, and I wanted a lighter-weight solution to the unun design.

Looking at the components I had available, I found FT50-43 toroids and 24 AWG magnet wire in my inventory.  I had used those during construction of successful 49:1 EFHW antennas.  The VK6YSF design, built with the smaller toroids and lighter magnet wire, seemed to be a good (and cheap) starting point.

The “50” portion of the FT50-43 toroid designation specifies its 0.50 inch (1.27 cm) outside diameter.  The “43” portion designates nickel/zinc composition that is suitable for high frequency inductive applications.

The next problem that presented itself was a problem with translating the winding technique to smaller wire and a smaller toroid.  Put simply, my fingers do not have the dexterity to wrap three parallel 24 AWG wires around a ½ inch OD toroid without getting them crossed, twisted, or worse.  So, why not twist the three conductors from the start, and wrap the toroid with “trifilar” windings?  It would be simple enough to identify the mating wire ends after wrapping, just with a set of continuity tests.  That would facilitate proper connection of the wires to yield the final auto-transformer configuration.

FT50-43 toroid with three-10 inch (25.4 cm) segments of 24 AWG enameled magnet wire staged for construction of the 9:1 unun.

I posed the “trifilar” winding question to my friends over on the QRPer.net discussion board.  Nobody identified a significant flaw with the proposed method, but neither did anyone have experience that would assure success.  So, I decided to use the “trifilar” winding technique to construct my 9:1 unun, with the full recognition that its success would be uncertain, and only proven by testing the finished product. Continue reading In Pursuit of the Top Band: Brian describes how he built and tested a field-portable 160 meter EFRW antenna

Flying With Ham Gear and Navigating TSA

Many thanks to Michael (N7CCD) for sharing the following guest post:


Flying With Ham Gear

by Michael (N7CCD)

I often get asked “how hard is it to fly with ….”, or “what does TSA say about …” as my job has me flying a fair amount throughout the year. In fact, I’m writing this now while waiting to board my flight for a week in Georgia and Alabama, after having just gone through TSA.

In a recent QRPer post by Thomas, I posted a comment about my frequent travel with ham gear and Thomas gave me a gentle “hint hint” nudge to write up my experiences on the matter. I thought this trip would be a good time to share my experiences in traveling with ham gear in my check-on baggage, as well as my carry-on baggage and my process for each. I’m always interested in learning from other’s experiences, so if you have some ideas for the good of the community, please share them in the comments below!

Before starting this article, and out of curiosity, I checked my past calendar and figured out that I passed through TSA screening about 26 times in 2022. I would say that, since starting my current role four years ago, I have at a minimum hit that number each year.

To address the main question I get about ham gear (antennas, radios, batteries, etc.) and TSA, surprisingly TSA has very little interest in any of it.

In all of my trips through the x-ray machine, TSA has never once pulled my bag out to further investigate what was inside. They have asked about my thermal camera, but never my ham gear. Full disclosure, I am TSA Pre-Check which does exclude me from having to remove laptops, iPads, etc. However, on a recent non-business trip with my wife and kids to visit family in Mexico, I wasn’t pre-check and they still didn’t care about any of my radio gear.

Since I’m limited on the amount of stuff I can physically carry on the plane, and my work gear requires me to check a bag anyway, I have divided my radio gear between what I want with me on the plane, and what I’ll just pick up when I collect my bag at baggage claim.

I have settled on a hard sided suitcase after having to replace some of my work arc flash PPE (personal protective equipment) when baggage handlers cracked my arc flash face shield. After upgrading to a hard sided suitcase, I started adding more ham equipment I would otherwise worry about getting damaged. In the image below you can see what, at this point, I’ve included in my checked bag.

From top left to bottom right: Raspberry Pi kit (more photos on that below), CWMorse paddle in a dollar store container with cable, Buddipole PowerMini, charging cradle for HT, SignalStuff mag mount for HT in rental car, hand mic for HT for use in rental car, throw line and weight, AlexLoop w/ Amazon Basics tripod, US Road Atlas

The idea behind the Pi and AlexLoop antenna is I can work HF digital no matter where I am. This is more fun than watching TV in a hotel, but also gives me digital capabilities to send emails or texts over HF if I am stranded without service of any kind. The mag mount and HT hand mic allow me to use my HT in my rental car as a mobile radio. The same SignalStuff antenna on my HT can be transferred to the mag mount easily once I step into the car. Continue reading Flying With Ham Gear and Navigating TSA

André’s “Let’s Learn Morse Code” online practice tool

Many thanks to André (PY2KGB / VE2ZDX) who shares a link to his web-browser-based CW practice tool. André notes:

I’m writing to share a tool I wrote to help myself with learning CW. I recently found out that people have been enjoying this tool so I’m sharing it with you and if you think it’s something worth sharing feel free to do so.

It was made mobile first and if you can’t hear the sound, disable the silent mode. It outputs the sound the same way WebSDRs do so it has that little issue with the sound that SDRs do, but it is browser related.

Click here to check out André’s online CW practice tool.

Thank you, André! I love how simple this tool is to use and the fact that no app is needed. Again, thank you for sharing this with the community at large!