Ham Radio Portable Station
William McKeehan
William McKeehan
January 12, 2022

Ham Radio Portable Station

Portable Station in use at Winter Field Day 2021

Ham Radio Portable Station

Over the last year, I've been working on a portable station that I would be able to use to setup at a temporary location. The station that I used to work digital at Winter Field Day is the result of that work and I'm pretty happy with the current setup.

The base of the station is an Icom IC-7100. This radio covers HF as well as 6M, 2M and 70cm. It has a built-in sound card which makes it perfect for digital modes such as JS8Call and the modes used by FLDigi. A single USB cable connects the radio to the computer.

While the antenna that I was bringing should work without a tuner, I have a tuner as part of my station. The tuner that I'm using the MFJ-939i. This tuner tunes most antennas very quickly. It is about the same size as the radio, so it sits well on top of the radio. It works with the 7100, so that makes using it very easy.

Speaking of antenna, I am using the "IMD-109-Go Anywhere Antenna" antenna from TN07 Engineering. This antenna is operates on 3.5 - 55 MHz; SWR ≤ 2:1 no antenna tuner required. Our test in the field showed it to have an SWR of < 3:1 everywhere and it seemed to be resonant on 160M. If you're looking for a stealthy HF antenna, this is a good one to look at because it uses a virtually invisible insulated antenna wire. You can read more about it on their website.

The computer that I use for digital operations is the Raspberry Pi 3 Model B. I have been a Unix system administrator since I was 18, so working with the Linux based Raspberry Pi OS (previously called Raspbian) is very natural for me. I start with Raspberry Pi OS Lite, then build up with just the software that I need to avoid things that are useless to me. If you're just getting started with a Raspberry Pi, I'd recommend using the "Raspberry Pi OS with desktop and recommended software" option. Anyway, starting with Lite, I add the PIXEL desktop (the same that you would get with "Raspberry Pi OS with desktop"). Then I start adding Ham related software:

  • fldigi (flrig, fldigi, flamp, and flmsg)
  • JS8Call my current favorite data mode
  • pat for WinLink
  • voacapl for determining the best WinLink stations to connect to

The Raspberry Pi is connected to a 12.3 Inch Touchscreen Portable Monitor.

The keyboard that I use with the Raspberry Pi is a small Bluetooth keyboard: Rii i8+ Mini Bluetooth Keyboard with Touchpad; this keyboard is very compact and for the limited typing that I had to do with the Pi, it worked very well. I also carry a small travel mouse (similar to the Verbatim Mini Travel Optical Mouse) because I prefer a mouse to a track pad.

If you are looking to get started with using a Raspberry Pi for Ham Radio, I recommend the video series by KM4ACK available on YouTube.

The power for everything in the box comes from a 20Ah LiFePO4 battery: BLF-1220A - 20Ah LiFePO4 Battery.

That battery alone would not run this station for too long, so I use a small 15A power supply, the MFJ-4115, to feed the battery. While I like the compact size of this power supply, I would not recommend it due to the fact that it's loud (the fan mostly-which runs constantly).

To keep an eye on the power from the battery, I've got a High Precision Power Analyzer Watt Meter in line between the battery and everything else.

All of this equipment is stuffed into a large black protective case from Harbor Freight (specifically, the APACHE 3800 Weatherproof Protective Case, Large, Black). Nothing is "mounted" to the box, it's all friction fit - the display is attached to the lid using Velcro.

The build is not the cleanest "Go-Box" that you'll see. I'd like to take some more time to clean up the wiring, reducing the length of wires where I can and a few other clean-up items. Ideally, I'd like to add a small 2M radio in here that I could use for voice and/or APRS (you all know how much I love APRS and how useful I believe it to be). Currently, I don't think there's enough room for that, but if I eliminate some of the bulky wiring that I have in the box, I may be able to get it done. If anyone has a recommendation on a very compact 2M radio that has output power of 25 watts or more, I'd love to hear about it. I may also drill a hole or two in the side of the box for coax and power connections - eliminating the need to drape the cables over the edge of the box. But for its first trip into the real world, I'm pretty happy with this setup.

Feel free to ask me any questions that you have about the box; I'd be happy to answer them.

Winter Field Day QSO Map
Map of contacts made during Winter Field Day 2021

Map of contacts made during Winter Field Day 2021