Recent content on rz01.org
I’ve always wanted to write a simple, custom CLI application that would let me log amateur radio contacts quickly and easily. The focus was on logging satellite contacts and the desire to avoid using a database. Instead, the log entries should be edited, deleted, or added directly in the ADIF file. So far, I’ve only used AI for translation in my personal life. At work, I use AI to automate…
I've been using MM9SQL's OscarWatch for some time now, but now that version 1.0.0 has been released, it's time to write about it. This open-source software is a satellite tracker for amateur radio operators. It has helped me finally say goodbye to SATPC32. Not that SATPC32 is bad, but for one thing, it’s a bit outdated, and for another, it unfortunately only runs on Windows. As someone who even…
Since my JS8Call station runs 24/7, but I can't always keep an eye on it, I wrote a small Python script that notifies me of incoming messages (directed text and messages) via Pushover.
I’ve always wanted to build a retro system to go alongside my regular PC, but used systems are getting more and more expensive. Then I remembered that I still had a few Raspberry Pis and a 7-inch LCD lying around. A quick search online led me to this nice 3D model: Raspberry Pi Display-Ständer. This design immediately reminded me of those iconic TV sets from the 1960s and also of various old…
Here's a quick update on my QMX+ based Remote Digital Mode Station which I now use to provide a 24/7 running JS8 station. I’ve been looking for an uninterruptible power supply (UPS) for my garden shed server rack for quite some time. I was about to buy a used rack-mountable 230V UPS when it occurred to me that I only run low-voltage devices in the rack: The switch requires 5V, the Raspberry Pi 5…
I recently fell in love with the Micro Editor and switched to it from Vim after more than 25 years. It is much more intuitive than Vim and I especially like the way how I can copy and paste text, that so many things are preconfigured like i want it, the built-in plugin manager and many more. It was super easy to pick up without reading too much documentation...
Ok, this is not really a 100% hand-crafted website but new articles and some other parts are now. Here’s the story: I used Hugo as a static site generator (SSG) for a long time and started to get bored. With Hugo, I was also much closer to the final product than, say, with WordPress, but it didn’t feel like I was personally creating the website. So I simply took the HTML code generated by Hugo as…
As a longtime UNIX/Linux/BSD enthusiast, I also greatly appreciate the motto “Do one thing well” from the UNIX philosophy. I am recently also trying to keep things simple. It’s often better to have a little of something than too much. Here’s an example of the latter: Suppose I had a handheld game console on which every game ever released for any console was available - what would happen? I’d play…
Over the past few months, things have somehow worked out so that I mainly operate in FM/SSB via satellite and only work digital modes on shortwave. For the latter, I had a Xiegu G90 in my shack, which was connected via about 30 meters of coaxial cable to my 10-meter-long vertical antenna in the garden, right behind the garden shed. It then occurred to me that I could easily work FT8 remotely -…
First of all, I want to explain how I ended up with a wristwatch in the first place. Until a few months ago, I hadn’t worn a wristwatch since I got a cell phone (about 25 years ago?). When it comes to keeping track of time, I still don’t need one - though that’s not entirely true; more on that later. In any case, I really enjoy going for walks - at least 4 to 5 km every day before I start working.…
For various reasons, I have decided to move as many services and subscriptions as possible from non-EU countries to the EU or to switch to European service providers. The reasons for this are the current global political situation and improved data protection. I don’t want to go into the first point any further for various reasons, but the second point should be immediately obvious, since the EU…
Last year, I set myself the goal of achieving the ARRL DXCC Challenge award. The ARRL describes the award as follows: "The DXCC Challenge Award is earned by working and confirming at least 1,000 DXCC band-points on any Amateur bands, 160 through 6 meters (except 60 meters)"...
As I described in a previous post, I started my IT career first as a software developer and then as a system administrator. In 2004, I had already been using computers privately for 15 years, but I was still relatively inexperienced professionally. I would not have progressed in my job as a system and database administrator if I had not also been involved with it privately. At that time, it was…
I initially wanted to write about how IRC (Internet Relay Chat) is my new old social media platform, but I'm not sure if that's even correct given the definition of social media on Wikipedia: [...] Assuming that everyone has come into contact with social media at some point, or avoids it because they know what it is, I should perhaps first explain what IRC is.
For those who know me, it's no secret that I'm a fan of the Dell Wyse 5070. This thin client with an Intel J4105 CPU, 8GB DDR4 RAM, and a 64GB SSD can often be found used in very good condition for around €50. This makes it much more versatile and cheaper than a Raspberry Pi (if you don't need the GPIO ports), which is why I already own four of them. If you don't have high demands, you can run…
I thought long and hard about whether I should switch from Hugo to another static site generator. Not that I was unhappy with Hugo, I just felt like trying something new. In the end, I realized that I don't actually need a generator to convert Markdown to HTML. Basically, it would be enough to write the pages directly in HTML. Of course, a blog also has a few dynamic components...
Introduction Shortly before I graduated from high school in 1999, my principal at the time took me aside to tell me that all my diploma would be of use for is to wipe my butt with it. While it is true that my grades were not particularly strong, this parting remark was not particularly helpful. After school, I completed my civil service (an alternative to military service) as a driver for a drug…
Working amateur radio LEO satellites reliably depends on good sources for which satellites are active and how to work them. You furthermore want to know about upcoming passes that are suitable for your station setup. You also might want to know about new satellite launches, active modes of satellites and if their transponders are active right now. Below are some useful resources I use every day:…
Introduction My kids, who are still quite young, often ask questions about space and astronomy. So I asked two friends for their opinion on which telescope I could buy for my children (and, of course, for myself). I had thought about a beginner’s telescope for around 200 euros and assumed that you couldn’t go far wrong with that. However, I was proven wrong: a very good…
On Sunday, October 12, 2025, I accidentally fulfilled a dream. I had a QSO with an astronaut in space! Around 11:30 UTC, I received a notification on my phone that the ISS was flying over Europe. I thought I’d briefly power on the radio and have in a few QSOs with other radio amateurs via the repeater onboard the ISS but as soon as I heard the ISS, I noticed something was different.
I recently upgraded my satellite ground station from eggbeaters to cross yagis. Everything seemed fine, but at first I didn’t realize I had a problem. This manifested itself in the fact that I sometimes heard myself very distorted on satellites with linear transponders and couldn’t hear anything at all on FM satellites when transmitting. Since I couldn’t find a solution myself, I…
I have recently purchased a CSN Technologies S.A.T. which is “a self contained antenna rotator and radio controller” which “natively controls Icom radios, Yaesu rotators and can interface with PSTRotator.” My main motivation for buying this device was to get rid of Windows on the Shack PC. I installed it for SatPC32, which works great, but runs on the “wrong” operating…
The CSN Technologies S.A.T. is “a self contained antenna rotator and radio controller” which “natively controls Icom radios, Yaesu rotators and can interface with PSTRotator. The S.A.T. works with any modern web browser on any device.” This device is also capable of logging contacts directly from within its web interface. These logs are stored on the S.A.T. itself which can…
After having lots of fun experimenting with eggbeaters, I decided to invest some serious money and make a huge upgrade to my LEO ground station. The result is a much more capable setup that lets me also work linear-transponder satellites (RS-44, JO-97, etc.) with much lower RF power. It also allows me to work satellites during lower elevation passes. This is the new setup: Radio: Icom IC-910H…
satpasses is a simple Python script that pulls satellite information on your favorite SATs from N2YO.com via their API to build an even simpler static HTML page listing all satellite passes over a user definable location for the next n days. Each row of the generated table has a different shade of green depending on the max elevation of the corresponding pass. A higher maximum elevation results in…
I have already experimented with 70cm/2m eggbeater antennas before with the goal to build a LEO SAT ground station. Basically, the eggbeater antennas worked, but I couldn’t find a good place to install them on my property. (Un)fortunately, the QRM situation on HF at my QTH has deteriorated so much that I can only operate on the 40m band while the other bands have become mostly unusable. So I…
I have recently posted a lot about M17, and you may be wondering what it is all about, why I am so excited about it, and how you can get involved. Let’s start with what M17 is. What is M17? M17 is a free and open-source digital radio protocol for voice and data, built by and for amateur radio operators. This means that you can communicate with other hams worldwide using an M17-capable radio…
Well you can! Took me far too long to figure out but now I am having a blast with this! There are many possibilities to achieve this but the most convenient one is to use KD0OSS’s fork of OpenRTX on a Connect Systems CS7000 M17 (PLUS), Tytera MD-380 or a Baofeng DM-1701. You can either compile it yourself or download the firmware (for the DM-1701) from my server. Ths feature will eventually…
Until now, CC1200 Hat users had to operate their M17 digital data/voice hotspot using the rpi-interface software on the command line, for example. To change this, Jim N1ADJ and I have spent the last few days developing a lightweight M17 hotspot based on the CC1200 and a Raspberry Pi. The heart of the hotspot is Jim’s m17-gateway, which he has now brought to a stable release. In the meantime,…
I assume that word has already gotten around in the ham radio community that several digital voice projects have decided to remove support for M17 from their code relatively simultaneously. This concerns, for example, WPSD, Pi-Star and MMDVM. I will not express any opinion here and will stay out of political matters. The fact is that many radio amateurs now suddenly no longer have M17…
UPDATE: The script was now updated to include Jim N1ADJ’s m17-gateway One of the ways to get QRV in the M17 digital voice mode is to use a hotspot. Many are already familiar with Pi-Star based MMDVM hotspots from other digital modes, but there is a relatively new M17 dedicated variant, the CC1200 M17 hotspot hat. Unfortunately, until now there was no easy way to install the software…
Now that I’ve built the M17 Nokia 3310 replacement board and also modded a Baofeng DM 1701 for M17, it was time to build the CC1200 Raspberry Pi hat. This small device can be plugged on the Raspberry Pi Zero’s GPIO pins and will then act as a M17 hotspot. Sourcing This time I also decided to solder myself, but with a hot plate and a stencil instead of hand soldering 0402 SMD parts…
My very first computer back then was a Commodore C64, then I switched to the Amiga 500 and later to the PC. I also had a Playstation 1 and 2 and a Game Boy Color when I was a teenager. However, I played less with the latter back then. For a few years now, I’ve been getting more and more interested in the old Ninendo handhelds and have also bought a Game Boy Advanced and Micro to go with my…
After I’ve finished building the M17 Nokia 3310 replacement board I also wanted to become more active on the M17 voice reflectors. The radio that I have modified already four years ago sadly hasn’t the best audio quality. I’ve recently learned that there is a new radio that is supported by OpenRTX and can be used for M17 which is the Baofeng DM 1701: This inexpensive radio needs…
!!! WARNING - PLEASE READ !!! Before you order anything, please read the full article. Don’t be me. Just order the assembled board from PCBWay. It’s much easier and you support the M17 project. Many of the SMD parts are tiny. REALLY tiny. I’ve now learned what 0402 means in this context. If you decide to solder it by yourself, consider also ordering a stencil and reflow solder…
Introduction This post describes how to automatically deploy your Hugo project hosted on Github to any (shared) webhost as soon as you push changes to the underlying github repository. The prerequisite for this is that the target host is accessible via SSH. I followed this good tutorial and adapted the procedure to my needs: Github actions: Deploy a Hugo website to a FTP server. Preconditions: SSH…
I’ve been typing on computer keyboards for 35 years now, mostly on ISO QWERTZ keyboards because that’s what’s standard here in Germany and it was pretty much the only keyboard available when I started tinkering with computers. In recent years I have mainly used a Ducky One TKL keyboard with MX brown switches, which I have liked very much so far. I needed another keyboard for my…
Exactly one year ago I decided to concentrate more on the QSOs itself instead of collecting QSLs to achieve certain awards. This worked nicely for a while but it turned out to become boring after a while. It looks like I have to keep changing my behaviour in order to maintain my interest in the hobby. This doesn’t just refer to the communicative aspect of the hobby, but also to the tinkering…
I recently noticed that the buttons on my Logitech MX Ergo trackball kept causing problems. To be more precise, the buttons would occasionally lose contact while I was holding them down. This led to unwanted effects when dragging and dropping as well as copying text. I therefore decided to swap the two microswitches of the left and right buttons. After the OMRON microswitches I ordered on ebay…
My main HF antenna, a 13m long vertical paired with a CG-3000 automatic antenna tuner, does a decent job on 160m to 12m but it really isn’t doing great on 10. In fact, all my previous antennas weren’t great on 10m. This is why I decided to buy a Dual Band Moxon Antenna 10m/6m from EAntenna (which has been bought by WiMo). This is what the kit looks like after unboxing the single, quite…
I think I’ve tried pretty much every amateur radio logbook software (including one for the Commodore C64) and I’m probably still not at the end of my search. Most of the time I used Wavelog. This web application, which I have running on a Proxmox server at home, actually fulfils a lot of my requirements: web-based and therefore usable on my Linux desktop, open source software, many…
In an age where information is easily available on the internet, it’s hard to imagine a time when gamers actually had to figure out everything by themselves or by sharing with (offline) friends. Back in the 90s, we didn’t have the luxury of walkthrough videos or automatic mapping; instead, we crafted our own guides, meticulously jotting down notes and sketching maps by hand. Sometimes we even went…
Inspired by M0AWS’s blog post “Easy Multi Band Vertical Antenna for HF”, I’ve converted my 40m quarter wave vertical into a 13m long random wire antenna which is tunable for 160m up to 10m. The antenna system consists of: 12 Spiderbeam HD fiberglass mast 13m of wire, the top 1m tucked into the upper most mast element Two 3D printed mounts for the mast (details here and…
Following my own new rule to only buy used computer gear whenever possible, I’ve decided to upgrade my shack by finally adding a dedicated shack PC and monitors. Being a big fan of the Dell Wyse 5070 thin client which I already use as a cheap low-power Proxmox server, I’ve bought another one for 45€ incl. shipping for the new shack PC with the following specifications: Celeron(R) J4105…
With social media there is undoubtedly the potential for addiction to likes. If you post something on X, Mastodon, Bluesky, Facebook or whatever, your post gets a certain number of likes. If you enjoy getting likes, you inevitably change your writing behaviour and post more and more content that others like instead of expressing yourself. To escape this perverse behaviour, I’m hardly active…
After the successful setup of my new cheap low-power Proxmox server, I had multiple web applications listening on a diversity of combinations of IP addresses and high ports (e.g. https://192.168.1.100:8000). Furthermore I had the issue that I needed to add security exceptions to my browsers so that they would access these apps despite their self-signed certificates. I have therefore decided to set…
After I decided to reduce hosting costs and generally bring my web applications from the cloud to my home, I needed an energy-saving server on which I could install Proxmox. After some research, I decided to buy a refurbished Dell Wyse 5070 thin client. I was able to purchase this from a commercial dealer for just under 50€ including power supply, stand and shipping. As I bought it, it had the…
I’ve recently moved away from GZDoom and picked Crispy Doom as my main Doom source port. My reasons for this are performance problems with GZDoom (believe it or not) and the desire for a more original gaming experience. Crispy Doom is a fork of Chocolate Doom (which is a modern source port aiming to be as vanilla as possible) and offers in addition to the vanilla gaming experience a few…
This page serves me to record which Doom WADs I have already played and what my verdict is on them. Having already played a few WADs, I’ve unfortunately lost track of them and would now like to take a more structured approach. It’s worth mentioning that I’m a casual player with a mediocre skill level. I started playing a few MegaWADs and was very enthusiastic at the beginning,…
This website is dedicated to amateur radio, electronic tinkering, cybersecurity, retro computing, homelab building and other (mostly technical) topics. The owner of this website and author of its content is DK1MI. Why does it exist? This blog is not intended to be read by a broad audience (with the exception of a few posts). The idea behind this site is to document my various projects, to make…