KC1JMH

The Linux Hamtop

The Amateur Radio Laptop: Hamtop

Many amateur radio enthusiasts are running computers in their ham shacks. There are many a benefit of having a computer handy:

  • Logging QSOs and uploading the logs to the various online logging databases, to confirm contacts and win awards
  • Instant identification of new contacts on QRZ
  • Listening and exploring with SDR (Software Defined Radio)
  • Working Packet Radio with a variety of modes and their applications
  • and so much more

The Form Factor

Laptops are popular, and older ones are fairly affordable. They provide built-in battery backup, and the software and tools are portable and ready to go from the shack to a Field Day event, SOTA (hiking up a mountain to put a Summit On The Air), or in the event one feels the need to ‘bug out’.

Operating System

Due its lightweight nature on battery and resources, how it hooks into those resources, and the wealth of free tools and applications available, some of us are running a flavor or distribution of the Linux operating system. For the sake of this article, I won’t go into what flavor to choose; I’d never offer an opinion on which is the best one, there are flamewars over that. Suffice it to say, there is a distribution and desktop environment for every personal preference and need. DistroWatch lists and tracks 304 different Linux distributions, last I looked.

My personal preference is Ubuntu, a variation of the Debian Linux operating system, therefor I am writing on the challenges I have encountered with its current LTS (Long-Term Support) version: Bionic Beaver 18.04. Some of my peers run Linux Mint, which is a variation on Ubuntu. My information should be transferable to those other variants. If you’re running a variant of Arch or RedHat (like CentOS and SuSE), many of the commands and file locations are quite different, but the theory likely applicable. YMMV (your mileage may vary), as they say.

The Software
and Overcoming Its Challenges

Linux is not without its challenges. It’s a very customizable technical operating system, no matter how user friendly the interface it’s wrapped in – but it can be a fun challenge. Below, or linked from this article, you’ll find challenges that I have encountered setting up my Hamtop, and how they were overcome. Many were trivial, but they required some research, and trial and error.

OneDrive

I’ll be honest. I meant to write this article while I set up my Hamtop the first time. It crashed. Hard. I can usually unwind a self-inflicted wound, but the logical volume partitions became corrupt somehow. I had experimented with an Android application layer that required direct tie-in with the operating system’s kernel, and it got buggy.

I didn’t have a whole lot invested in the first setup. I only lost a few radio images on CHIRP, which I could download from the radios again, and a club event’s contact logs which was already exported and emailed for upload to LOTW. That said, I wasn’t going to go without backup, again. Much of what I acquired or documented on my Windows PC is on OneDrive, so I installed it on the Hamtop.

  1. Launch your Terminal
    1. Press the Windows key and type Terminal
    2. Click the icon
  2. Run: sudo apt-get install onedrive
  3. Enter your password
  4. Run: onedrive
  5. The script will produce a link, where you can browse to in order to authorize it to talk with Microsoft.
    1. CONTROL+click the link
    2. Log into your Outlook.com / hotmail.com account
    3. If you have two-factor authentication, approve it on your phone
    4. You’ll load a blank page. Copy the URL.
    5. Middle-click / click the mousewheel in the Terminal to paste the URL, and press ENTER
    6. The script will then sync all of your OneDrive documents to a OneDrive folder within your Home folder
  6. To resync changes
    1. Launch the terminal, or make a shortcut to run: onedrive
    2. Or, to continuously monitor for changes, enter: onedrive -m
      • This may be added to start-up scripts, but I haven’t researched this, yet.

Reference: https://askubuntu.com/questions/958406/how-to-setup-onedrive-in-ubuntu17-04

CHIRP: Setup, and Permission Denied

The next thing I did was to try to re-acquire my radio programming. CHIRP is available in the Ubuntu Software repository (the app store). Search for it, install it and run it.

  1. Connect the USB to Serial cable for your given radio
  2. Press ALT+D for Download (ALT+U for Upload).
  3. Set the port to: /dev/ttyUSB0
  4. Set the make and model of your radio, and click OK
  5. Receive a PERMISSION DENIED dialog box

What has happened? It turns out that standard the ‘user’ profile in Ubuntu does not have direct access to the serial interfaces, commonly or formerly used for modem connections. However, you can add your user to the group which has the permissions necessary.

  1. Launch the Terminal
  2. Run: sudo gpasswd –add ${USER} dialout
  3. Log out and back in, or just reboot
  4. Try Down/Uploading the radio config again

Reference: https://chirp.danplanet.com/projects/chirp/wiki/Connection_Issues_using_Ubuntu

SDR

Searching on the Ubuntu Software “app store” for ‘SDR’, I came across Gqrx. It turned out to be pretty easy to get going, with only a slight learning curve. This is in contrast to SDR# on Windows, where I had to use a device mapping tool to custom create a driver that links the software to the hardware – and occasionally rerun it if I change USB ports.

Setting up Gqrx with the Noolec Nano 3

  1. Plug in your SDR hardware and connect an antenna
  2. Install Gqrx and run it
  3. Upon first start, you’ll be asked to select the hardware
    • The Nano 3 is an RTL2838, a common chipset for these modified TV tuners
    • I selected “Realtek RTL2838UHIDIR SNL: 00000001 (8-digits)
    • The remainder of the settings here can remain default
  4. Press the Play button to see if you have it.
    • Hear white noise? Good!
    • Hear nothing? Go back to the settings and try to find your hardware.
    • You may have to unplug and re-seat the USB device, and rerun the application. I did a couple of times.
  5. Switch to a frequency you can transmit on low power for testing, on both a radio and the SDR
    • You can hover over the top or bottom of any number to move it up or down
      • It starts in the HF bands. If you want to move it to VHF or UHF, hover over just left of the first number, and a preceding 0 will appear that you can move up or down.
      • You can do this a second digit to the left to get into the gigahertz.
      • You’ll want to set the mode to match the radio. For my VHF handheld, I set it to Narrow FM
    • Turn up the PC volume and key up. Give your callsign to be legal
      • If you aren’t yet licensed, listening is legit. Just tune to an FM radio station and set the Mode to WFM (Stereo).
  6. Gain Control: Adjusting the noise floor
    • If you find that you have trouble hearing signals, you can crank the LNA gain, or enable AGC (Automatic Gain Control) on the Input Controls tab.

Stay Tuned

I’ll continue add sections to this article, as I continue to re-set up my Hamtop.

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