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.
Hazel decided to accompany me on this activation.
Actually, she’d join me on each of my activations if I could allow that!
She’s particularly fond of the BRP site I chose–the Folk Art Center–because of the abundance of squirrels running around. Poor thing, though: a leash prevents her from chasing them. It’s more like squirrel TV for her. 🙂
Other than squirrels, we pretty much had the whole place to ourselves (mainly because it was a very rainy day).
In the activation video (see below) I demonstrate how to put the MTR-4B V2 into “straight key mode” so that the LCD display will show not only the SWR but power output as well. The MTR-4B must be in straight key mode to show the SWR.
Next, we tune the ZM-2–again, it’s all in the video, but you can also read a quick tutorial on tuning the ZM-2 in this post.
Time to hop on the air!
- LnR Precision Mountain Topper MTR-4B
- Emtech ZM-2
- tufteIn EFRW QRP Antenna Long Wire
- Key cable: Cable Matters 2-Pack Gold-Plated Retractable Aux Cable – 2.5 Feet
- CW Morse Outdoor Double Paddle With Steel Base
- GoRuck Bullet Ruck
- Bioenno 3 aH (9V) LiFePo Battery (Model BLF-0903W)
- Ham Radio Workbench DC Distribution Panel Model HRWB101
- Mini Arborist throw line kit: Tom Bihn Small Travel Tray, Marlow KF1050 Excel 2mm Throwline, and Weaver 8 or 10oz weight
- Tom Bihn Large Travel Tray
- Rite In The Rain Weatherproof Cover/Pouch (affiliate link)
- GraphGear 0.9mm 1000 Automatic Drafting Pencil (affiliate link)
- Rite In The Rain Notepad (affiliate link)
- Camera: OSMO Action Camera with Joby tripod (affiliate links)
- Sony ICD-FX312 Digital Recorder ($20 thrift store find)
On The Air
I worked three more stations on 20 meters, then moved to the 40 meter band (QSY) which required re-tuning the ZM-2.
40 meters was very healthy! I worked an additional 22 stations in exactly 22 minutes!
Here are my paper logs:
And, of course, since I used my pricier Rite in the Rain notepad, the rain held off during the entire activation! Never fails!
Here’s what this activation looks like when plotted out on a QSO Map. Really impressed looking at this knowing I was only running 4-ish watts!
Here’s my real-time, real-life video of the entire activation. As with all of my videos, I don’t edit out any parts of the on-air activation time. In addition, I have monetization turned off on YouTube, although that doesn’t stop them from inserting ads before and after my videos.
Going to miss the the MTR-4B V2…
That said, I’m going to miss it.
I’m super tempted to buy an MTR-4B and I may some day. In fact, the kind reader who sent this to me also donated half the amount of a new MTR-4B so that I could grab one (or any other radio) should I choose. (Yes, I told you he was generous!)
I have an MTR-3B and I absolutely love it (I named it “Tuppence” in case you’re wondering!).
Because I have the MTR-3B, I haven’t felt the urge to buy a 4B mainly because I so rarely use 80M in the field. Then again, I do like the MTR-4B upgrades (SWR and PO meter for sure).
Time will certainly tell!
I will be posting my full MTR-4B review in the coming days–update: click here to read it–a review that was originally published in the November 2022 issue of The Spectrum Monitor magazine.
Thank you for joining me on this activation!
I hope you enjoyed the field report and my activation videos as much as I enjoyed creating them.
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.
As I mentioned before, the Patreon platform connected to Vimeo make it possible for me to share videos that are not only 100% ad-free, but also downloadable for offline viewing. The Vimeo account also serves as a third backup for my video files.
Thank you so very much!
Cheers & 72,