I run two Elecraft W2 watt meters in the shack for 4 TX paths: 2m-440 mobile, 2m transverter on my Flex, 70cm transverter on my Flex, and one dedicated to my 6m Loop. It’s a beautifully accurate instrument, but the front panel display is somewhat course in the data it displays. The Elecraft W2 Utility continues to function well but the Display software they distribute is somewhat outdated to say the least. I really just wanted a more accurate meter for 2m-440, but there are not a lot of options and I already had the W2. So I decided to build some more modern software with a little help from Claude (Anthropic’s AI), which did the heavy lifting on the code while I steered with the ham-radio and hardware knowledge.
The result is W2 Monitor: a clean, dark-themed desktop app that talks straight to one or more W2 meters and gives you a big, readable, real-time display. It’s free and open source (GPLv3).
What it does
- Live readout — forward power, SWR, reflected power, return loss, and peak-hold, with bar graphs and green/amber/red SWR color coding.
- Multiple W2 meters at once — each meter runs on its own background thread, and the display auto-focuses whichever meter you’re transmitting through. A Detect button finds connected meters automatically.
- Full W2 control from the app — switch sensor, auto/manual range, Avg/PEP, peak-hold LED, and a Search button that tells the W2 to follow whichever of its two samplers has RF.
- A transmit-timeout timer — set your TOT whatever you like and the timer goes solid yellow 30 seconds before, then flashes red at timeout while it keeps counting. It’s completely silent, so nothing goes out over the air.
- A resizable, self-remembering UI — scale it, toggle rows on and off, and it restores your window position and preferences every launch.
A little about the engineering
The app is written in PowerShell with a WinForms interface — no install, no admin rights, nothing written to your system outside of the app folder or, if you want it, a desktop icon. The key design decision was putting each meter’s serial communication on its own background process so the interface never stutters, even while it’s polling hardware several times a second. It speaks the W2’s simple ASCII serial protocol (9600 8N1) directly, the same commands the old utility used, just wrapped in something that feels like it belongs on a modern desktop.
Working with an AI on this was genuinely productive. I described what I wanted as an operator; it wrote and iterated the code; and — importantly — it pushed back on a couple of my ideas. When I asked for a Smith chart, it correctly pointed out that the W2 is a scalar meter (magnitude only, no phase), so a Smith chart wouldn’t show anything the SWR number didn’t already. We shelved it for a future project using a vector-capable meter.
Free and open source
W2 Monitor is released under the GNU GPLv3 — free to use, study, share, and modify. If you run a W2, I’d love for you to try it, and bug reports and suggestions are very welcome.
It’s a beta — in active use here at the station, but not yet broadly field-tested, so consider it a work in progress.
What’s next
I just finished building a second W2, so the multi-meter side is about to get a real workout. And the frequency-tracking and antenna-analysis ideas we were prototyping are moving to a separate project built around a TelePost LP-100A vector watt meter — where phase and impedance data will let us do the Smith chart and SWR-vs-frequency plots properly.
More to come. If you build one of these or have a W2 and want to kick the tires, drop me a line.
73,
Dave – AB0R