Category Archives: QRP Radios

Morse Code, News, Portable, QRP, QRP Radios, Reviews, Software Defined Radio, SSB

A review of the Xiegu X6100 portable SDR transceiver

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

A review of the Xiegu X6100 portable SDR transceiver

by Thomas (K4SWL)

Do you remember when band scopes and spectrum displays started appearing on radios?  It was a pretty phenomenal innovation. Being able to “see” what was in your neighborhood on a particular radio band was incredibly useful, especially to operators who like to hunt stations, and to DXers who wanted to follow the reply pattern of DX stations running split. Spectrum displays, among other things, gave operators an overall “big picture” of band activity, and it was truly insightful.

Additionally, the advent of SDR (software-defined radio) architecture made not only spectrum displays but also time-based waterfall displays accessible in radios of all price ranges.

From the perspective of both a ham radio operator and a shortwave radio listener, I can tell you that once you become accustomed to the benefits of a spectrum display, when you don’t have one, you feel like you’re cruising the band wearing blinders:  it’s just that essential.

As a result, many hams and SWLs have come to rely on these features. No doubt customer demand has pushed manufacturers to include spectrum displays on almost all new SDR-based transceivers––even portable transceivers!

Enter the X6100

In November 2021, China-based radio manufacturer, Xiegu, started shipping their latest SDR transceiver: the Xiegu X6100.

Xiegu has become quite a household name among HF field operators.  I’ve reviewed both the Xiegu G90 and the Xiegu X5105. The common theme is their affordability, portability, superb built-in ATUs, and impressive feature set. Admittedly, high-end performance––in terms of receiver as well as audio performance––is not their strong suit, but in the field you don’t necessarily need contest-grade performance. I’ve found that both the G90 and X5105 are quite effective and adept in the field and at home. Many a new ham operator has turned to Xiegu products to begin their foray into the world of HF.

Judging by appearance alone, you can tell that Xiegu was targeting the same operators who might consider the Icom IC-705. Cosmetically it’s strikingly similar in terms of knob, screen, and button placement on the front panel.

The X6100 also has Bluetooth and WiFi connectivity, like the IC-705: a first for the sub-$1,000 portable radio market. But unlike the IC-705, this functionality was not in place with the first production run of the X6100. It’s being slowly implemented via X6100 firmware updates.

But in my view, that’s where the similarities with the IC-705 stop. Based on the announced X6100 specifications, I could tell well before the X6100’s release that it would lack many of the features that make the IC-705 such a hit; features like a touch screen, D-star mode, VHF/UHF multimode, built-in GPS, built-in D-Star, built-in repeater directories that can auto-load the repeaters closest to the operator, advanced filter shaping, and so much more.

But the X6100 and IC-705 share enough similarities that field-portable HF enthusiasts have taken notice…Nonetheless, it’s one major difference that has really caught their attention. Continue reading A review of the Xiegu X6100 portable SDR transceiver →

Guest Posts, Hacks and Hints, How To, Portable, QRP, QRP Radios

Scott’s Icom IC-705 “Shock Box”

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Many thanks to Scott (KA9P) who writes:

Enclosed are a few detailed pictures of the system I’m using to protect my Icom IC-705 in the wild.

I wanted a system that would protect the radio from shock and vibration when I dropped it in use, or tripped over a cable, as well as when in transit.

Some research lead me to Sorbothane, a commercial vibration damping material available in small lots on eBay, and to a Sorbothane applications engineer. The engineer recommended that a good way to protect electronics is to use a “box-in-a-box” concept where the equipment resides in an inner box with vibration dampers between the inner box an outer box.

Sorbothane’s on-line calculators suggested that for the IC-705’s weight, some relatively small pads on each wall would be adequate.

So I started with the bottom 4.5 inches of a Harbor Freight ammo box, and added four 1/4 inch thick, 1 inch by 1 inch Sorbothane pads to the bottom and two long sides.

Then I added an aluminum plate to the inside side surfaces of the pads, and lined the plates with neoprene (see the drawing above). The neoprene adds a bit of additional padding, but primarily lets the 705 slide into “the inner box” while putting a little bit of pressure on the pads. The manufacturer recommends a slight loading pressure on the pads for proper damping.

The radio is fastened into the box with an adjustable depth 1/4-20 threaded locking knob, positioned to put a little force on the back wall vibration pads when tightened down.

The cover is made of aluminum angle stock and Lexan, and provides good protection for the front of the radio when not in use.

This “shock box” solves a lot of problems for me.

1) I can leave the cage on when operating, using dongles out the front for things I want to change like the antenna, mic, battery power, headphones or paddles. Leaving the radio in the box avoids field handling errors, to which I am prone.

2) If the internal battery needs to be changed in the field the radio comes out quickly by removing the single 1/4-20 knob and screw. But the battery can be charged in the case with a USB or power plug dongle, again avoiding handling.

3) The depth of the box protects the entire periphery of the radio front, much like the handles do for the sides of a cage, and the radio remains enclosed/covered on all sides except the front. I’ve used it in snow and rain without issues when the wind isn’t bad.

4) Impact protection is really high other than for a direct frontal panel hit within the box. The plastic box takes the first hit, deforming a bit and transferring the rest of the energy to the vibration damped inner box. Not worried about dropping the radio anymore.

5) The use of Sorbothane’s “box-in-a box” with vibration pads concept leaves a channel surrounding the radio to promote air flow and heat dissipation. For me this is much better than using the radio in a box cushioned with foam, which blocks air flow and can trap moisture.

6) The box provides a handle, which the 705 really does need in the field.

7) The footprint of the Harbor Freight box is just about a hand and glove fit in the bottom of most serious packs, making it easy to carry when backpacking.

On the downside, it’s a bit ugly, but it’s cheap, maybe $40 US to build. Other than wanting a gasket to provide better weather and dust proofing when closed, I’m happy with it.

-Scott (KA9P)

A bit ugly? Scott, I think it looks great!

I feel like shock absorption is one of the things lacking in many of the IC-705 cage solutions out there. I always feel like when a metal/aluminum frame is paired with a hard plastic chassis, in a field drop the plastic will be the weak point. 

This adds to the bulk of the IC-705 (in terms of overall size) but likely doesn’t add a lot of extra weight. In your manpack/chest pack situation, this is a great bit of engineered insurance for your $1300+ rig!

Thank you for sharing!

Field Reports, Morse Code, New Products, News, Portable, QRP, QRP Radios

Field Report: Testing the new Penntek TR-35 firmware during a POTA activation!

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Since I have a busy family life, I always look for opportunities to fit a little field radio time into my schedule.

My policy is to always keep a radio field kit in my car or truck so I can take advantage of any last minute opportunities.

On the morning of Wednesday, April 20, 2022, I was scheduled to take my car in for warranty/recall servicing at the dealership.  I decided in advance that if the service could be completed in two hours or less, I’d relax in their waiting room with my MacBook, drink a cup or two coffee, and attempt to make a dent in my email backlog.

If the service was going to take longer than 2 hours, I decided that I’d use one of their loaner/courtesy cars and activate a nearby park.

The dealership is about 45 minutes from my QTH and I’ve activated most of the parks nearby it, save one: Holmes Educational State Forest.  I’ve been wanting to activate this park for ages, but my travels these days simply don’t take me in the direction of the park very often; it’s a good 75 minute drive from my QTH.

Uncertain how long the dealership would need my car, I grabbed my SOTA backpack that had a full field kit inside based on the Penntek TR-35 transceiver.

TR-35 Upgrades!

Why the TR-35? Because I was testing new firmware that added a huge upgrade: two CW message memories!

I won’t go into details about the new upgrade in this field report since I describe it both in my activation video (see below) and in this post which relays the announcement from WA3RNC.

Suffice it to say, I was itching to see how well the new message memories work during a proper activation.

Front of the line

Since this upgrade was just made public, I thought those of you who either own the TR-35 or are plotting to purchase the TR-35, might want to see it in action. For this reason, I pushed this video and field report ahead of all of the others in my pipeline.

The really weird part about publishing this video so quickly is that one of my next field reports and videos will actually feature the first time I took the TR-35 to the field about 3-4 weeks ago! Back then, CW message memory keying wasn’t even on the table.

Activation time

I arrived at the dealership around 9:00 AM (local) and the first thing I asked was, “So how long do you think this will take?” The representative looked at the work to be performed and said, “Three or four hours, likely. If you’re in a rush, maybe two hours.”

I decided I wasn’t in a rush because I’d much rather be playing radio at a new-to-me park than sitting in a waiting room.

I asked if I could borrow one of their courtesy cars and he replied, “We assumed you might want one Mr. Witherspoon, so we already reserved one for you.”

Woo hoo!

Holmes Educational State Forest (K-4856)

The drive to Holmes Educational State Forest from the dealership took perhaps 30 minutes or so–it was a gorgeous day and a beautiful journey. Continue reading Field Report: Testing the new Penntek TR-35 firmware during a POTA activation! →

Announcements, News, QRP, QRP Radios

New Penntek TR-35 firmware adds CW message memory keying

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John (WA3RNC) has just announced a new firmware (V.0.24) upgrade for the Penntek TR-35 that will start shipping in all TR-35 orders starting Sunday April 23, 2022.

The new processor adds two new features:

  • The ability to record and playback two CW message memories
  • A function to toggle the display from black with blue characters to solid blue with black characters

Of course, the big upgrade–in my world–is the addition of CW message memory keying and I can confirm that it works very well. More on that below…

Obtaining the upgrade

As John (WA3RNC) states in his announcement:

The good news is that any TR-35 can be upgraded with a simple replacement of a properly programmed plug-in microprocessor, or with the reprogramming of the original microprocessor. No other hardware changes are required.

But…there is bad news. The availability of the Atmega328P-PU microprocessor has gone from “buy it anywhere for $1.95″ in mid-2021″ to “virtually unavailable anywhere at any price” today. Delivery dates are quoted as May of 2023 for orders that I placed last year. 

[…]Because of this critical chip shortage, I do not have a sufficient inventory of the Atmega part to be able to send out programmed microprocessors for upgrades. What parts I do have are destined for production of TR-35 and TR-45L transceivers.

Therefore, a TR-35 firmware upgrade will require that the transceiver be sent to me freight prepaid for reprogramming, along with funds for return shipping and insurance of $15.00.

Understand that there is no charge for the actual upgrade reprogramming, only for the cost of returning your unit to you.

I think is excellent customer service, actually, and a clever way to get around the chip shortage: use the chip you already have.

Again, if you’re buying a new TR-35, it’ll ship with the latest firmware.

If CW message memory keying or inverting the OLED screen colors aren’t important to you, it’s not necessarily worth upgrading because the new firmware only includes the new features.

Testing message memories

Recently, John sent me an upgraded chip with an early Beta version of the new firmware to thoroughly test in the field. I replaced the TR-35 chip myself.

I tested the new functionality in the shack and on a dummy load.

As with most built-in CW message recorders, you’ll need to set the CW speed to a comfortable setting before recording. During the recording process, you need to send accurately spaced characters, else, for example, the software might interpret the “AN” in your callsign as a “P.”

The first time I set memory 1 to “CQ POTA DE K4SWL” it took three tries to get it right. When I set the second memory to “BK TU 73 DE K4SWL” I recorded it in one go.

Recording message memories on the TR-35 is at least as easy as directly recording a message on my KX2 or KX3. I’m pleased.

In the field

Last week, I took the upgraded TR-35 to the field and used the message memory keying during my activation.

It worked beautifully.

John sorted out a clever way to initiate playback without having to make any hardware additions to the radio:

  • To play a message memory, simply tap the AUX switch down and then hit the left side of your paddle to send message #1 or the right side to send message #2.
  • Recording messages works the same way, but instead of a short press of the AUX switch, you initiate a long press.

Even this early version of the upgrade worked well.

Field report and video coming soon!

I’m going to push the field report from last week to the front of the line because I know many of you will be curious to see how it plays in the field. Hopefully, I can post this by Monday (April 25).

My Penntek TR-35 Review

FYI: My full review of the TR-35 will be in the May 2022 issue of The Spectrum Monitor magazine.

Morse Code, News, QRP Radios

The Yaesu FT-817/FT-818 and narrow filter availability

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IMPORTANT UPDATE:

After this article was originally posted, I discovered a very easy way to assemble your own narrow CW filter. Click on this link to read a post that describes, in detail, how you too can build a replacement Collins narrow CW filter for the FT-817/818 series radios (plus other similar Yaesu models). 

What follows is the original article:

So I’m a big fan of the Yaesu FT-817/818 series radios. This general coverage QRP radio has had a longer market run than any other transceiver I can think of and for good reason.

While the 817/818 lacks some of the advanced features of more modern field rigs and have no internal tuner, it makes up for it by:

  • sporting multi-mode HF, VHF, and UHF coverage,
  • having two selectable antenna options (a front panel BNC and back panel SO-239),
  • being incredible durable/rugged,
  • featuring excellent QSK (albeit with a bit of relay clicking…which I actually like),
  • and  generally being very affordable (prices typically from $400 used to $650 new).

In addition, they tend to hold up well with time.

For the price? I feel like you get a lot of radio with the FT-817/818.

This is the reason why I often recommend the FT-817ND and FT-818ND if it sounds like a good match for the operator.

One gotcha though…

I’m starting to realize that there is one downside to this rig especially if you’re primarily a CW operator: optional narrow filter availability. Continue reading The Yaesu FT-817/FT-818 and narrow filter availability →

Field Radio Kits, Guest Posts, News, Portable, QRP Radios

The Elecraft KX2 version of Scott’s chest plate/manpack

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Many thanks to Scott (KA9P) who writes:

As a follow-up to my previous post: this chest pack is still a bit of a work in progress but has been tested and works as is. I didn’t want the non-IC-705 owners to feel left out 🙂

The Condor MCR-3 chest plate can be used with a Condor T & T pouch (30 bucks) for most QRP rigs with a KX format.

The Condor T & T pouch is a frequently reviewed favorite of hikers and hunters – YouTube videos abound. The key feature is the way the pouch opens from a chest plate, or just straps, to form a tray. I expect you could modify other clamshell pouches of other sizes with an adjustable cord to do the same thing. I haven’t seen other pouches built to do this, yet.

The “tray” section contains a number of MOLLE loops as well as some loop material. This makes it easy to fashion your own radio attachment system. I have been using some hook material fastened to the back of KX2 for now, but am working on something that locks in, rather than tempt fate. Continue reading The Elecraft KX2 version of Scott’s chest plate/manpack →

Field Reports, Kits, Morse Code, New Products, News, Portable, POTA, QRP, QRP Radios, Reviews

Video: Taking the new (tr)uSDX QRP transceiver on a CW POTA activation!

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As I mentioned in a post published three days ago, I’m now the proud owner of a (tr)uSDX QRP transceiver.

The (tr)uSDX has been a much-anticipated QRP transceiver for those of us who love playing radio in the field.

What’s not to love? It sports:

  • Up to 5 watts output power
  • CW, SSB, FM, and AM modes
  • A built-in microphone
  • Five bands: 80, 60, 40, 30, and 20 meters
  • A super compact and lightweight form factor
  • An open-source hardware and software design
  • Super low current consumption in receive
  • A super low price of roughly $89 US in kit form and $143 US factory assembled (via AliExpress, but there are numerous other group buys and retailers)

Frankly speaking, this sort of feature set in such an affordable package is truly a game-changer. Back when I was first licensed in 1997, I could have never imagined a day when a general coverage QRP transceiver could be purchased for under $150 US. The price is almost unbelievable.

My initial impressions

On Wednesday, March 30, 2022, I took the (tr)uSDX to the field to attempt a Parks On The Air (POTA) activation. I had only taken delivery of the (tr)uSDX about 15 hours beforehand and had only had it powered up for a total of 30 minutes the previous day. Most of that time, in fact, was checking the power output at various voltage settings into a dummy load. I did make one totally random SSB POTA contact shortly after hooking the radio up to my QTH antenna.

I knew that taking the (tr)uSDX to the field and making an activation video might not be the best idea having had so little time to play with the radio and get to know it in advance, but then again, I was simply too eager to see how it might perform.  That and I always believe there’s value in sharing first experiences with a radio. Continue reading Video: Taking the new (tr)uSDX QRP transceiver on a CW POTA activation! →

Morse Code, New Products, News, Portable, QRP, QRP Radios, Reviews

The (tr)uSDX QRP transceiver: My initial impressions after a CW POTA activation

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I mentioned in a previous post that I placed an order for a (tr)uSDX kit with roWaves in February. My order was placed for a third production run kit and I assumed I would receive it sometime in March 2022.

Later that month, I discovered that DL2MAN announced AliExpress would sell both kits and fully-assembled versions of the (tr)uSDX. I used the link from DL2MAN’s website and ordered a fully-assembled unit.

My thinking was that I would receive the kit first, build it, then test the performance by comparing it with the factory-assembled unit. These units are so dang affordable I felt like I could splurge for both.

roWaves order on hold

I recently discovered that my (tr)uSDX kit had been placed on hold due to issues that popped up in the first and second kit group buys via roWaves.

Evidently–and someone can correct me if I’m wrong here–the first and second production runs kits had a component issue that equated to lower output power. In addition, Josh (KI6NAZ), reports that the early group orders had no boot loaded and the MCU was DOA.

I’ll patiently wait for roWaves to sort this out. I’m not in a huge hurry at this point because, frankly, my available time to build a kit has come and gone. The next few months, I’ve a lot of plans, travels, and projects to work through.

Fully-assembled (tr)uSDX

Much to my surprise, the assembled (tr)uSDX arrived Monday and I picked it up when I was at home on Tuesday of this week.

I was only home one night, but managed to do some quick testing.

I soldered Anderson Powerpole connectors on the supplied power cable pigtails. Next, I hooked the (tr)uSDX up to my variable power supply and a dummy load.

A quick test showed that I was getting about 3 watts of output power with about 13-13.2 volts, 3.25 watts at 13.8 volts, and 2 watts of power with 9-10 volts. This is lower than the expected 5 watts of output power @ 13.8 volts. The current consumption in receive however was about 60 mA even at 9 volts. That’s slightly below the published specs.

I honestly had no time that evening to play radio, but I took a moment to hook up the (tr)uSDX to my skyloop antenna just to check the audio quality in SSB.

As luck would have it, the first station I heard on 40 meters was a POTA activator in Ohio. He was calling CQ, so I couldn’t help but reply. I pressed the PTT button on the (tr)uSDX, spoke into the internal mic,  and he came back immediately with a 5×8 report. My meter was showing a max of 2 watts output power–the heavy lifting, of course, was done by the antenna.

This gave me a very good initial impression!

(tr)uSDX POTA Activation

The following morning, after running a few errands and carting my kids to some appointments, I left the QTH for a couple nights of travel.

I just couldn’t help but pack the (tr)uSDX and attempt a park activation en route. My goal was to see if it had enough positive receiver characteristics to be a proper POTA/SOTA portable rig–the feature set is comprehensive for a $135 radio.

I stopped by South Mountains State Park and paired the (tr)uSDX to an EFHW my buddy Steve (MW0SAW) kindly built and sent me. [Steve–I’m loving this antenna! Thanks again, OM!]

I made a video of the entire activation and will soon post the field report. I’ll push this video to the front of the line, but with my internet bandwidth, it might still be a few days before I can post it. Because of this, I thought I’d go ahead and share some of my experience with the (tr)uSDX in case you’ve been thinking of purchasing one.

(tr)uSDX pros

This little radio design has a lot going for it.

The chassis is very compact–perhaps the size of two Altoids tins stacked on top of each other. The encoder does protrude–in fact, it’s nearly as deep as the radio chassis. It’s not that the encoder is particularly tall, it’s just that the (tr)uSDX is so wee.

The radio has all of the CW adjustments you’d typically find in a compact field transceiver and even sports QSK (there’s also a semi QSK setting) with no relay noise. I assume it uses PIN diode switching.

(tr)uSDX Cons

Unfortunately, I did find a few negatives. The reviewer in me automatically gives the (tr)uSDX wide berth and a lot of forgiveness: we’re talking about a $135 transceiver here. I don’t think anyone is under the impression this would be a stellar performer.

In my opinion, the biggest negative is the (tr)uSDX audio. This little rig has a very high noise floor–perhaps S5 or S6.

The internal speaker is very modest and mine is incapable of producing audio at a level that is workable in the field where there are ambient noises like wind, water, conversations, birds, etc. The audio sounds decent when working a strong station, but weak stations are extremely hard to hear. If you turn up the volume on my unit beyond level 14, the audio simply squeals. I need to tinker with the volume control more.

Since the audio was so weak, I hooked up my Sony digital audio recorder to the (tr)uSDX headphone jack and made a separate audio recording for the upcoming activation video.

The headphone audio is louder, but there’s also a lot of noise in the audio amplification chain–again placing the (tr)uSDX noise floor around S5 or S6.

I was fully expecting the (tr)uSDX receiver to overload and it does. The variable filter helps and narrowing it makes the audio sound more pleasant in CW, but it doesn’t stop adjacent signals from bleeding through. Honestly, though? I could live with this and just use the filter between my ears if the audio was simply cleaner.

I also discovered that my unit needs alignment: the frequency display is off by 1.6 kHz in CW mode on 40 meters. I’ve put this on my to-do list–after all, this is a project radio meant for hands-on tweaking. I’m good with that.

One final point and minor quibble: the OLED display is very difficult to read outdoors. It’s superb indoors, but outside any sunlight or reflection simply wipes it out. To read the display I had to cover it with my hand.

The activation was a success: I worked 11 stations in 20 minutes or less, but I’m sure there were weaker signals out there I missed because they were simply buried in the (tr)uSDX’s noise floor.

I liked the (tr)uSDX keying, and I love the form factor, but I’m not sure I’ll ever use this radio again–configured as it is now–during an activation. For casual contacts, it could still be fun.

A little (tr)uSDX grace

I mean…$135 right?!?

The (tr)uSDX is an open source project and truly pushes the boundaries of what one can achieve for $135–again, even much less for the kit version. Frankly, I’m in absolute awe that any transceiver can be made below the $150 price point; especially a multiband, multimode transceiver.

The (tr)uSDX is an experimenter’s radio and I plan to dig into this little unit and see if there’s anything I can do to lower that noise floor. My hope is that the CPU or display may simply need better grounding or isolation. My time is limited at the moment, but I will open into this radio in the next few weeks.

In fact, eventually completing the kit build will give me an opportunity to explore the components and connections in much better detail.

I do know that my unit also seems to have the power output issue that some of the roWaves kits have. I can’t achieve anything better than 3.25 or 3.5 watts output at 13.8 volts. It should be about 5 watts at 13.8 V.

I would welcome your suggestions especially if you’ve built the (tr)uSDX kit or if you’ve put your assembled (tr)uSDX on the air and found that it had much better audio characteristics.

Announcements, QRP, QRP Radios

New Beta Elecraft KX2 and KX3 Firmware

4 Comments

Many thanks to Tony (AE0KW) and Eric (WD8RIF) who note that Elecraft has released new a Beta firmware for the KX3 and KX3 that extends the time before the radio drops to 5W in CW mode:

  • The KX2 release extends CW operating time at 10 W by allowing the supply or battery voltage to go as long as 9.0 V before dropping to 5 W.
  • The KX3 release has the same CW power improvement, as well as a fix to the TX inhibit function of the ACC2 jack.

Details: https://elecraft-kx.groups.io/g/main/message/71950

Antenna Tuners, Articles, Field Radio Kits, Grab And Go, Kits, News, Portable, QRP, QRP Radios

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

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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 →