Category Archives: How To

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:


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.

Jim Long
Madison, WI

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.


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 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!

Jim’s Elecraft KX2 leg mount

Many thanks to Jim (WU3K) who writes:

Hi Thomas,

I recently came up with a new way (for me) to hold the KX2 when I am out in the field.

The set-up utilizes the Side KX KX2 mount and the RAM Body Mount for Legs.

This set up does a pretty good job for me.



This is absolutely genius, Jim! Besides the leg mount looking like a excellent solution, the Side KX mount could then be used for other mounting locations either at home or mobile!

Thank you for sharing!

Rich’s easy-to-build and incredibly affordable Field Clip Board V 1.0

Many thanks to Rich (KQ9L) who writes:

Hello Thomas,

I’ve attached couple pictures of V1.0 of my field clip board. I’ve been searching for the perfect clipboard to use in the field. The main requirements of the design include: lightweight, low cost and the flexibility to allow a comfortable operating position while securely holding a radio.

What I came up with is a based on an inexpensive fiber board clip board:

I chose to set it up somewhat unconventionally and designed it to use the clipboard “upside down”.  Setting it up this way provided ample space at the top to mount the radio while still providing room to attach a metal pad mounting point for paddles.

The radio is held securely in place with craft 3mm elastic bands. The bands were made with metal “toggles” so I can easily add more holes to the clipboard to accommodate varying rigs.

The metal pad is just a stick-on metal plate purchased from Amazon. I plan to add a leg strap in the future and will do so once I’m sure no other major modifications need to me made.

I’m pretty happy with the way the clipboard came out and would appreciate any comments or suggestions!


This is brilliant, Rich! I love both how affordable this board is and how easy it is to build. Having the clip at the bottom of the board is a fantastic way to secure your logging notebook as well. 

Thank you for sharing!

Charles’ simple solution to protect the MC-750 ground spike tip

Many thanks to Charles (KW6G) who writes:


I purchased an MC-750 from DXE last week…It arrived Monday….Great antenna; very nice workmanship….I have not yet deployed it, but that will be in the near future….

After reading your emails/posts and viewing the videos, I got to thinking…The real oversight in this antenna design is the fact that the manufacturer has provided no protection for the tip of the ground spike….I can see where it would not be long until it worked its way through one of the ends of the carrying pouch…

So with this in mind, I went off to the hardware store where I found a 3/8″ ID X 1 inch long nylon spacer which fit over the end of the spike perfectly — problem solved for all of 58 cents…

Here are a couple photos:

73’s de Charles, KW6G

What a great, affordable solution! Thank you for sharing this, Charles!

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

You’ve no doubt heard me brag about the Emtech ZM-2 ATU in previous field reports. I think it’s an accessory every field operator should have.

The ZM-2 is a very capable manual transmatch/ATU and is also one of the more affordable tuners on the market. It’s available as both a kit and a fully-assembled unit. Both well under $100.

I do believe the “manual” part of the ZM-2 scares off some and it really shouldn’t. We are used to simply pressing a button these days and allowing our automatic ATUs to do all of the matching work for us.

Manual ATUs do require some amount of skill, but truth is, the learning curve is very modest and intuitive.

Manual ATUs require no power source in order to operate–you adjust the L and C values by hand–thus there’s never a worry about the ATU’s battery being depleted. They also are easy to manipulate outside the ham bands because they require no RF in order to read the SWR–you simply make adjustments to the L and C until you hear the noise peak.   This is why many shortwave broadcast listeners love the ZM-2 so much. It’ll match most any antenna you hook up to it!

I also argue that everyone should have a portable ATU even if you operate resonant antennas. Think of an ATU as a First Aid Kit for your antenna: if the deployment is less than ideal, or if you damage it in the field, an ATU can help you find an impedance match your radio can live with. ATUs have saved several of my activations.

Mountain Topper MTR-4B V2

I’ve also mentioned that I’ve had an MTR-4B on loan from a very kind and generous reader for most of the year. He was in no particular hurry for me to send it back to him, but I wrote him in early November and said, “I’m doing one more activation with this little rig, then I’m shipping it to its rightful owner!”

He had a request, and it was a good one:

I think it would be a good little twist to the usual YouTube if you paired a random wire with the ZM-2 and the MTR-4B…showing how to tune the ZM-2 with a Mountain Topper…

I really liked this idea, so I made plans to to hit the Blue Ridge Parkway nearby and give it a go.

The first time I tried this in the field, I paired the MTR-4B with one of my Sony amplified speakers because the MTR-4B 1.) has no internal speaker and 2.) has no volume control. During the video, however, I realized that there simply wasn’t enough audio amplification so that the viewer would be able to hear a noise peak as I manually tuned the ATU. I decided to scratch that video and just do the activation on my own. I really wanted to show how the tuning process worked in the video.

I went back to the field the next week–on November 10, 2022–with my Sony in-line digital recorder knowing it would be much easier to hear how the L/C changes affected the band noise. Continue reading How to tune: Pairing the Emtech ZM-2 manual ATU with the Mountain Topper MTR-4B on the Blue Ridge Parkway