Ham Radio on bytebang

Streaming wireless weatherstationdata via MQTT

Tue, 29 Dec 2020 09:43:56 +0100

The Problem

A lot of 433 MHz based weather stations are sending their data to their paired receiver. But how would you receive all the stations within your vincity and stream the data into the internet ?

The Solution

rtl_433 is a tool which takes samples from an attached RTL-SDR stick and decodes them. The name already suggests that it will operate in the 433 MHz frequency area where a lot of weatherstations are boradcasting their values.

Connect to Hamnet with a Ubiquity Bullet2HP

Wed, 26 Feb 2020 10:36:43 +0100

The Problem

As licensed Ham radio operator I wanted to try something new. So I climbed up the roof and mounted a TP-Link 2.4 GHz Grid antenna with splashproof connections to the inside of my house.

Now I had to configure the Bullet2HP to be able to connect to my nearest HAMNET, which is located approximately 22km away:

Connect to HAMNET with OpenWRT and a VPN

Sat, 26 Jan 2019 10:43:49 +0100

The Problem

I am a fan of ham radio operators digital backbone - the HamNet.

I wanted to be able to use it from my ’normal’ WiFi, with every device in my network. One way would be to set up a user access with a transceiver (e.g. a Ubuquity Bullet M2 HP) which is able to connect to the network and a decent antenna - but mine is currently used in another project. So i had to find another way how to do it.

Porting LuaRTOS to the TTGO LoRa32 Board

Sun, 14 Oct 2018 18:34:27 +0200

The Problem

I have bought two cheap ESP32 based IoT development boards for around 30$, because the specs looked interesting:

ESP32 based with 3D- wifi antenna
128x64 pixel OLED display
LoRa Modem

This hardware has the potential to be a very versatile IoT prototyping (and even production) platform, but there was one drawback: You have to program it in the Arduino IDE. This means: You can do almost anything with it, but whenever you want to change something in the software then you have to recompile and upload everything.

Splashproof HF connections

Wed, 23 Aug 2017 22:31:02 +0200

The Problem

Lets assume that you want to deploy your new antenna onto your roof, and the antenna (or the HF cable) has some connectors which are exposed to rain. The only type of connectors you have is something like this:

Well - if you put it into environment without protection then it is not really waterproof. And even if it would work for some time without protection, the rain will stream along the connection and finally there will be water within it.

APRS with mobilinkd and YAAC

Wed, 02 Dec 2015 11:44:40 +0100

The problem

In one of my recent articles I wrote about how to connect a simple RTL-SDR stick to xastir. Later on i decided to buy myself new shiny TNC modem which can be connected via bluetooth to various phones and tablets: The TNC2 from mobilinkd. While I stumbled upon a lot of instructions how to connect it to APRSdroid and how to receive messages with xastir in the internet, I could not find a manual how to connect it with YAAC (which is Yet Another APRS Client - written in Java).

Building a cheap FLARM basestation antenna

Tue, 26 May 2015 13:13:24 +0200

The problem

This spring I decided to build a FLARM base station with my old Raspberry Pi. The Open Glider Network is a good starting point for this purpose. The OGN is a community project. It is based on software, hardware, receivers and other contributions from individuals and the open source community. The objective of the Open Glider Network is to create and maintain a unified tracking platform for gliders and other GA aircraft. Currently OGN focuses on tracking aircraft equipped with FLARM, FLARM-compatible devices or OGN tracker. FLARM is mainly utilized in gliders, however other small aircraft (planes, helicopters, deltas or even para-gliders) are also often equipped with it, especially if operating in the areas intensively used by gliders, such as the Alps.

Locking down a Baofeng UV5R+ to disable unintentional TX

Sun, 12 Apr 2015 13:32:22 +0200

The Problem

In Austria a licensed HAM radio operator has to ensure that nobody (except other licensed HAMs) can make transmissions from their equipment. This may be a simple task if you put away your radios from your family all the time, but the Baofeng UV5R+ has a bunch of interesting features like a torch lamp (OK its just a LED on the top, but in the most cases this my be sufficient) or a built in FM-radio that can be useful in your house.

Fix the no-mic problem with the Baofeng UV5R+

Wed, 25 Mar 2015 13:08:56 +0100

The Problem

In general I am very satisfied with my Baofeng UV5R+. The performance is reasonably well (for the price) and if you are proud owner of a programming cable then you can configure it to fit your needs. However - last summer I discovered that my device suddenly stopped working. The carrier wave was there, but there was no modulation.

The Solution

After googling around I found an youtube video that shows how to fix the problem.

Changing the frequency of a HM-TRP 3DR Radio

Fri, 06 Feb 2015 14:05:28 +0100

The Problem

I recently bought a radio telemtry kit from a friend who wanted to use it for his do-it-yourself drone project. One side is connected to the computer and shows up as a serial USB port. The other side has a TTL serial interface. The main purpose of the HM-TRP from 3D Robotics is to provide a transparent serial link over the air. My buddy sold it because the plugs did not fit into the ardupilot board.

As it turned out it is a 915 MHz telemtry kit hich was bought in US and which is forbidden in the european union because it viloates the frequency regulation. In Austria the 915 MHz frequency is assigned to the GMS opertors, and it is not allowed to transmit on these frequencies. By law there would be a penalty up to a few thousand euros is somebody catches me operating this thing.

As a licensed HAM radio operator i was searching for a way how to modify this TRX to be able to operate it in the 70 cm Band.

The Solution

As it turned out both sides of the telemetry kit are using a HM-TRP 100 mW transceiver module to transmit data over the air. After an hour of analyzing the board an googling around i stumbled upon a forum post that describes how to change the operting frequency of HM-TRP 3DR Radio for Telemetry using AT Commands.

Meshed HAM Radio - High Speed Multimedia Network

Thu, 01 Jan 2015 18:19:33 +0100

Meshed networks are nothing inherently new, but i know only very few pepole that have played around with it The theory states that a meshed network uses a network topology in which each node (called a mesh node) is able to relay data for the network. In the wild there are big wireless mesh networks utilized to build up a network which is not dependent on the internet and which is used to connect multiple clients in a town - or even across towns. These networks (In Austria: funkfeuer.at and in Germany: freifunk.net) are open for everybody who is interested and willing to contribute. The only thing you have to do is to register yourself an to set up a network node.

Portable HAM radio station

Tue, 09 Dec 2014 20:16:27 +0100

My way to HAM radio

Since the age of 15 i wanted to to be a licensed HAM radio operator because radio fascinated me all the time. Unfortunately the motivation to do the exam to get the needed license was moderate because I thought had to visit a boring course and I had to learn Morse (CW) code to pass the exam. One day I stumbled across the OEVSV homepage page (= austrians ham radio association) and discovered that there was neither the need to learn cw code nor the need to visit a course to be approved to the A-class examination any more. Well at this point in time I ran out of arguments against myself and I decided to do this exam.

Receive APRS stations with rtl-str and display them with Xastir

Sun, 26 Oct 2014 13:24:53 +0100

The Automated Packet Reporting System is an ham radio based system for real time tactical digital communications of information of immediate value in the local area. This means in other words that along with messages, alerts, announcements, and bulletins, the most visible aspect of APRS is its ability to be display weather stations, alerts and objects and other map-related amateur radio volunteer activities on a map.

Well - there are services like aprs.fi which are able to display such a map within your browser, but once the internet goes down this map will also dissapear. So what are the alternatives ? … The answer is simple: Receive the aprs traffic on your own and draw them onto a offline available map. This article shows how to recieve the messages with a cheap dvbt stick, how to decode them into aprs messages and finally how to display them within Xastir (which is a program for visualizing APRS packets).

RTTY File transmission via soundcard

Sat, 11 Oct 2014 18:42:23 +0200

The Problem

If you have to transmit a file from A to B then the most common methods are to use any kind of network (wired or wireless) or a shared storage medium like an USB stick. What if everything fails and you have to transmit data from computer A to computer B then you still have an option: Transmit the data via the soundcard !

The Solution

Under Linux it is very simple to transmit data via the soundcard. The program minimodem can do exactly that: On the senders computer it converts data to a sound which is played back via the default soundcard and on the receivers computer this sound is converted back to the initial text. Here is a quick example:

406 MHz ELT Testing with rtl-sdr and Multipsk

Sun, 20 Jul 2014 19:11:51 +0200

I was asked our local glider club (ASFC Leoben) if it is possible to ensure the proper function of the new 406 MHz ELT transmitters- without the need to buy an expensive elt test device which are priced in the range of a few hundred up to a few thousand euros.

ELT Types

The old ones (121.5 MHz) could be tested by just turning on the airband radio and tuning to 121.5 MHz. Within the first 5 minutes of a full hour (xx:00 - xx:05) you can trigger the old ELTs and see if it transmits. The newer ones (406 MHz) are not as simple to test, because they consist of 2 devices in one box.