Awhile ago Rulhof ZS4RM informed me that he is busy building an AllStar Portable / Mobile Node which he will be using whenever the need arises.
Now what on earth is a Portable / Mobile AllStar Node?
A
DIY mobile AllStar node is a custom-built, portable device that uses a low-power computer, a radio interface, and amateur radio equipment to connect to the global AllStarLink network via the internet (often a mobile hotspot). This setup allows amateur radio operators to
communicate with thousands of other nodes and repeaters worldwide using
their handheld or mobile radios, essentially acting as a personal
gateway or "hotspot". The
"DIY" aspect means the operator assembles the components themselves,
which is a common and cost-effective approach within the ham radio
community, as opposed to buying a pre-built commercial unit.
Key Components:
A typical DIY mobile AllStar node requires the following main components:
- A Computing Device: A small, low-power computer, most commonly a Raspberry Pi (Pi 3 or Pi 4 are popular choices). It runs a Linux-based operating system with the AllStarLink software, often a pre-configured image like HamVoIP.
- A Radio/Audio Interface: A small circuit board or device that connects the computer's USB port (via a C-Media CM108/CM119 sound IC) to the radio's audio input/output and Push-to-Talk (PTT) lines. Pre-made interfaces like the DMK URIx or Masters Communications DRA boards are available, or advanced users can build their own from scratch.
- A Node Radio: A simple, often inexpensive, UHF or VHF radio (e.g., a Baofeng UV-5R or similar) dedicated to the node. This radio receives signals from your personal handheld radio and transmits audio back from the network.
- Power Source: For a mobile setup, a portable battery bank or a buck converter for a vehicle's power system is used.
- Internet Connection: The node needs internet access, which can be provided by Wi-Fi or by tethering to a mobile phone hotspot.
Functionality:
The setup works by:
- Receiving an FM signal from your handheld radio on a specific frequency.
- Converting the audio to digital data via the sound interface and the Raspberry Pi.
- Transmitting that digital data over the internet to other AllStar nodes.
- Receiving internet audio from other nodes.
- Converting the digital audio back to an FM signal for transmission to your handheld radio.
This
allows for seamless communication over vast distances, bridging the gap
between local RF (Radio Frequency) coverage and the global internet
network.
Building Your Own:
To build a DIY node, you would typically follow these general steps:
- Register for an AllStar node number on the AllStarLink website.
- Gather the necessary hardware components.
- Install the AllStar software (like HamVoIP) onto the Raspberry Pi's SD card.
- Wire the radio to the interface board (if necessary).
- Configure the software settings, including audio levels and network parameters, often using a program like PuTTY for remote access.
- Test the node using the "Parrot mode" feature.
There are many online guides and YouTube tutorials available to walk users through the process.
Information regarding the ZS4RM AllStar Portable / Mobile Node:
Call Sign: ZS4RM
Frequency: 433.4125 Mhz
CTCSS: 100 Hz
Node Number: 647031
Location: Bloemfontein
Site: Bayswater
Affiliation: Hammies Free State (ZS4ZU)
The "inauguration" of the node took place during the recent holiday season when Rulhof visited Shelly Beach in Kwazulu Natal. He use the node regularly while mobile and even portable when he visited the beach. The node is functioning well and is definitely a great asset when going mobile or portable. Congratulations on constructing a useful and effective node, Rulhof. It is clear from the videos that you enjoy the node to the full.
Images: Click on images for larger view.
Videos:
