(As is Vince’s usual, this article has a bunch of links – click on as many as you wish for the full experience)
Before I go too far into this topic, I wish to first offer hearty congratulations to Thomas Witherspoon for having one thousand posts on QRPer.com! Woo-Hoo!
Do you pack a Radio Field First Aid kit?
On my recent trip to VE3-land I had a few opportunities to practice set-up with my gear–away from the safe place that is my truck–to ensure I’d brought everything for my trip to Hamvention and activations along the way. I did forget an audio cable, however a visit to a local dollar store solved that problem inexpensively.
So, unless you pack two of everything -because two is one and one is none– you should expect that something’s going to fail or break along the way. What you never know is when or how that’s going to happen. I wouldn’t be writing this story if it had not happened to me before.
This time it was on a Sunday outing to VE-1512, the McLaughlin Bay Reserve Wildlife Area in Oshawa Ontario and far away from the comforts of my shop at home. Tucked away not far off of the 401 Highway, this nature reserve is a calm and peaceful oasis just minutes from urban life. I saw kayakers, hikers and trail runners during my visit.
Setting up my Comet HFJ-350M, I added the jumper cable to set the antenna for 20m and then I started to push the antenna down into the ground onto the stake. And that’s when my hand slipped and I broke the jumper cable connector, busted off in the hole.
I built this BCI filter specifically to pair with the Xiegu G106 transceiver. Why? Because the G106 is prone to overload if you’re anywhere near an AM broadcaster.
The last time I visited Fort Dobbs State Historic Site (K-6839), a local AM broadcaster bled through the audio of the G106. I was able to complete the activation without any issues at all–in fact, it was a very successful activation (read the report here).
Still, I did feel that the receiver was a bit less sensitive due to the broadcaster overwhelming the front end of the radio.
That Friday, I wanted to pair my Xiegu G106 with the new in-line BCI filter to see if that might mitigate the interference I experienced before.
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.
Many thanks to Adam (BD6CR) who shares the following guest post about his latest project:
From Open Source Project ADX to Kit ADX-S
by Adam (BD6CR)
BD6CR @ CRKits.COM
Original Design: WB2CBA
Modification and Kitting: BD6CR
I knew Barb, WB2CBA from his uSDX design a few years ago and I introduced both DL2MAN and his designs in my blog. So, when I came across the ADX – Arduino Digital Xcvr a few months ago, I immediately ordered both the ADX (through hole) and the ADX UNO (surface mount) PCB samples.
I started building the ADX UNO and put it in a dental floss case and made a few contacts on park bench. However, the soldering is too much for my eyesight. So, I turned back to the ADX because I don’t need to solder any SMD parts, since both the M328P and SI5351 are module based. I could build the project in 3 hours and it worked the first time.
However, I felt unsatisfied with the strong BCI since the CD2003 radio receiver chip was connected as a direct conversion receiver. JE1RAV mentioned in his QP-7C modification project that he tried JA9TTT’s idea to build a superhet SSB receiver with the TA2003 or CD2003, so I tried and it worked very well. I have decided to name the new circuit as ADX-S, where S stands for Superhet.
I shared the great news with Barb and he encouraged me to carry the flag to make it a kit, since my design D4D was his first digital radio and he loved it.
My hardware modification can be outlined in this schematic. I have added an FL1, PFB455JR ceramic filter by Murata and a C25 coupling capacitor from CLK2 of SI5351 module. The RX audio comes from pin 11 instead of pin 4.
What is it about winter that engages my inner kit-builder–?
I go through this cycle every year: when outdoor temps plummet, I fire up the soldering iron and start building kits that have been sitting on the shelf for the previous three seasons.
I used to think that I built more kits in the winter because I spent more time indoors, but that’s not actually true. Reality is, I probably spend more time outdoors in the winter than I do in the other seasons…save fall, perhaps.
I actually have a QCX+ transceiver kit that a kind reader generously donated to me (thanks again, OM!). I can’t wait to dig into this particular build, but I’m forcing myself to wait.
Until I finish building and installing my Murphy Bench (check out this HRWB podcast episode where we take a deep-dive) I don’t have a dedicated space for a good multi-day transceiver kit. At present, I have to take over the dining room table and as you might imagine, the others in my family aren’t incredibly pleased with a semi-permanent workbench in the middle of the house.
I’m making my Murphy Bench a priority and dangling the QCX+ as a reward for completing the build. Wish me luck!
I’m curious: Do you find that you also do more kit-building during certain seasons? What kits or other projects are on your horizon?Please comment!
I try to start each year by doing a POTA or SOTA activation on New Year’s Day.
POTA actually issues a certificate for completing an activation on New Year’s Day so there are typically loads of activators and hunters working the bands. It’s an ideal time to play radio.
This year, we had a number of family activities on New Year’s Day, but I made a little time to fit in an activation during the late afternoon at my most accessible spot on the Blue Ridge Parkway: the Southern Highland Folk Art Center.
As with my last activation, I suspected I would be operating in the dark, so I brought my LED lantern along for the ride.
Although not intentional, this New Year activation had a lot of new-to-me stuff involved!
New VK3IL Pressure Paddle
The prior evening–on New Year’s Eve–while my wife and daughters were watching a classic movie movie marathon, I used the time to heat up the soldering iron and work through a few kits and projects that had been sitting on my desk.
Quanity of 1: Three conductor wire with a (typically) 3.5mm plug (note that I had one of these in my junk drawer)
Keep in mind: the components are surface-mount. If you’re not used to working with SMD components (ahem…that would be me) I suggest buying a few spares of each in case you lose or damage one or more during the build.
It also helps to cover the finished board in heat shrink not only to protect the board and make it easier to grip, but most importantly (if you’re me) hide your electrically-sound yet unsightly surface mount soldering job.
The build might have taken me 20 minutes.
New FT-817ND Narrow CW Filter
Some time ago, I purchased a second FT-817ND with the idea of doing full-duplex satellite work. I later realized I could be taking the second FT-817ND out to the field more often if I simply had another narrow CW filter installed, so I built one.
This New Year’s Day activation was actually the first time I’d taken this particular FT-817ND and its new narrow filter out to the field!
New Armoloq TPA-817 Pack Frame
Earlier this year, I also decided that I wanted to outfit my 2nd Yaesu FT-817ND with an Armoloq TPA-817 pack frame. The idea was to experiment with building a rapid-deployment field kit around it.
In early November, I happened up a new waterproof case called the Evergreen 56. As with Pelican cases, it’s waterproof and also made in the USA. Like Nanuk cases (that are also waterproof and made in Canada) Evergreen cases have a built-in locking mechanism to keep the latch from accidentally opening during transport.
I thought the price for the Evergreen 56 at $28 US was fair and in-line with the Pelican 1060 and Nanuk 903 which are similar in size. I grabbed one made of a clear material with one radio in mind: my QCX-Mini!
There are a number of color options available for this Evergreen case, but I like the clear polycarbonate one because it makes it so much easier to see what’s inside (for a quick gear check) but also to confirm that no one part of the kit is being pressed too hard inside the case after the lid is sealed.
After receiving the Evergreen 56, I was very pleased with the quality–again, on par with what I would expect from Pelican or Nanuk. It is incredibly solid and the seal is watertight. The Twist Lock Latch (see above) is easy to operate and the case comes with two “keys” for adjusting the inner lock.
The Evergreen case has a soft egg crate-like rubber boot interior as opposed to the pick foam material you’d typically find in a water tight case. The case also has a hammock-like rubbery webbing on the inside of the lid that can be used to organize smaller contents (I knew instantly I’d use this to hold the antenna!).
The QCX-Mini fits in the Evergreen case perfectly–this was no surprise–but I was eager to see if my other station components could also fit. Note that I didn’t buy anything specifically to be used in this case; I used components I already owned. I could minimize the contents even further if I used a smaller battery, antenna, and key. Here are the components of the first version of the QCX-Mini Field Kit: Continue reading Testing a new QCX-Mini Field Kit built in an Evergreen 56 Watertight case→
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’ve just learned that my buddy Mark (N6MTS) at Halibut Electronics has just kitted up a new batch of his CMCC Test Rigs and is now accepting orders. I know that some of the experimenters in our community might appreciate this brilliant bit of gear that Mark originally designed as a piece of test gear for his own workbench.
I asked Mark to shed a little light on this kit and exactly what it does:
A Common Mode Current Choke, aka a 1:1 Current Balun, is a common (pardon the pun) device in a ham shack. They can be used: at the Antenna feed point to prevent dangerous unbalanced return currents on the outside of the feedline, at the Radio’s antenna port to minimize RF noise picked up on the feedline, on DC or AC power cables and other interconnect cables to minimize RF pick-up in the shack, etc.
Most RF test equipment, such as a (Nano)VNA, measures the Differential Mode of a system, that is, the balanced currents that flow on the INSIDE of a coax cable. This is great for measuring things like: the frequency response of a filter, the complex impedance (or SWR) of an antenna, or the loss of a length of coax.
It cannot measure the Common Mode of a system, that is, the unbalanced current that flows on the OUTSIDE of a coax cable. This means it cannot (directly) measure a Common Mode Current Choke.
The Halibut Electronics Common Mode Current Choke Test Rig converts the Differential Mode signal generated by the VNA into a Common Mode signal, and places it on the outside of the shield of a coax system. This allows the VNA to directly measure how effective the choke is at choking common mode RF currents. Once you can directly measure a device, you can measure the real world effect of changes you make, and optimize the device for your specific use case. As opposed to relying on calculations and predictions of ideal conditions in free space.
The Common Mode Current Choke Test Rig is a kit that requires some assembly, using a soldering iron and Philips head screw driver.