APRSDroid and dual port Direwolf
In my mobile setup, I want to run a Direwolf instance with two ports (VHF and HF) on an Orange Pi Zero. APRSDroid is used to monitor both ports and send messages through them. Since …
Building a VHF / LoRa APRS Bridge
In this article I will expose how I built a VHF (1200bps AX25 APRS) to UHF LoRa APRS Bridge without going through APRS-IS (Internet). This is work in progress, feel free to comment and come …
Building Xastir from sources
Most of Linux distributions have Xastir in their repositories , yet most of the time it is not the latest version or it is seriously outdated. Let’s see how we can build the latest version …
Simple audio streaming server using socat
I was suspecting a receive issue on our club’s mountain top APRS digipeater. To spare me the 1 hour drive to listen to the radio’s audio I came up with the idea to remotely stream …
Modding the Kenwood TM-271 for voice alert
I have been using the TM-271 for my mobile APRS operation for over 18 Months now. Here is a quick article on how you can enable the radio for APRS Voice Alert. It is all …
We do not give a f*ck about your repeater!
Here is a provocative/clickbait headline, and it is on purpose. Today I want to rant about APRS sysops abusing objetcs. Usually I try to keep the content here technical, but now is the time for …
Direwolf: add pre-emphasis to your AFSK signal
Direwolf is very capable software TNC, yet it is not yet possible to add twist between the high and low tone e.g if you want to feed 1200bps to the 9600bps flat audio input of …
Setting optimal receive level for the Tinytrak 4
Recently I got myself a Kenwood TM-271 and wanted to give it a go on APRS with the TT4. This turned out to be more complex than expected.
Start Direwolf at Boot, the SystemD way
The ways to start Direwolf at boot, as provided in the manual, are quite archaic and hacky. Let’s see how we can do this in a more modern way using systemd.
Doing APRS Voice Alert with CRT 2M / Anytone AT-588
After trying and failing at getting a working APRS set-up with voice alert here is my last try with a CRT 2M Radio, a rebranded Anytone AT588.
Putting a 3.3V HC-05 module in the Tinytrak 4
If you followed my previous adventures with the Tinytrak 4 and Bluetooth you may know that I used HC05 modules which where RS232 levels capable. I bought these years ago and, as of today, they …
HC-06 and Tinytrak : Fail
A couple of month ago I Bluetooth enabled my second Tinytrak 4 using a HC-06 module. It turned out this failed after a few weeks and the HC-06 is not usable for APRS.
Retevis RT98 for APRS, review 8 weeks after
After almost 8 weeks of using this little radio for my mobile APRS operations I thought it’s a good time to provide some feedback. I must admit I have mixed feelings about this radio…
Analog vs. Digital APRS
I keep on reading about “Digital APRS” vs “Analog APRS”. Youtube and social media are full of these words. This is utterly wrong. Whenever I hear “Analog APRS” I’m going mental: “Analog APRS” simply does …
Bluetooth and TinyTrak 4, episode 2
I got myself a second TinyTrak 4 and wanted to Bluetooth enable it like I did for my first one. I went a different route using a different module and wiring it another way.
What is APRS Voice Alert ?
Ever got frustrated of not being able to contact a passing by station you just saw on APRS? APRS can also work as a nearby station radar and help you out with that.
Using the Retevis RT98 for APRS with voice alert
My TYT THD9000 started to exhibit some strange behavior, after transmitting it sometimes needs half a second to switch back to receive. So I was in the market for a new APRS radio and came …
Putting Bluetooth into the Tinytrak 4
Byonics provides a Bluetooth add-on for the Tinytrak 4. While I love the TT4 I am not a huge fan of their TT4BT Bluetooth solution. It consists of a board with 2 DB9, no case …
APRS.fi is not APRS-IS
There is a widespread belief that aprs.fi is the internet backbone of the APRS network. It is not uncommon to read posts on social networks saying “I am connecting to aprs.fi with aprsdroid” or “I …
APRS with Tinytrak 4 and TYT TH-9000D
After a couple of frustrations (here and here) I have finally managed to get my TYT TH-9000D running quite well with my Tinytrak 4. After a few weeks using it I must say I am …
And so I wanted to use a TYT TH-9000D for APRS …
I was in the market for another radio for my mobile APRS operations. After reading various articles (here and here) about the ability to add a D-SUB9 connector with all relevant signals for that matter. …
