[D66] GeoTalk 📡 : Pseudo-HAM Radio & Text Messaging — Geo-grouped by Postal Code

[René Oudeweg]

Release CHARLIE (v1.8.2)  met tkinter GUI

debian package:

https://github.com/juggao/geotalk/releases/tag/v1.8.2-charlie




On 3/7/26 22:44, René Oudeweg wrote:
> reinold at NUC1:~/Projects/geotalk$ ./charlie.sh
> 
>     ██████╗  ███████╗  ██████╗  ████████╗  █████╗  ██╗      ██╗  ██╗
>    ██╔════╝  ██╔════╝ ██╔═══██╗ ╚══██╔══╝ ██╔══██╗ ██║      ██║ ██╔╝
>    ██║  ███╗ █████╗   ██║   ██║    ██║    ███████║ ██║      █████╔╝
>    ██║   ██║ ██╔══╝   ██║   ██║    ██║    ██╔══██║ ██║      ██╔═██╗
>    ╚██████╔╝ ███████╗ ╚██████╔╝    ██║    ██║  ██║ ███████╗ ██║  ██╗
>     ╚═════╝  ╚══════╝  ╚═════╝     ╚═╝    ╚═╝  ╚═╝ ╚══════╝ ╚═╝  ╚═╝
>    📡  Geo-grouped pseudo-HAM radio & text  •  v1.3.1
>    Type /help for commands  •  #59** Venlo  •  #1***?? Amsterdam
> 
> Relay connected → 127.0.0.1:5073
>    Mode: relay unicast UDP  (multicast disabled)
> 
> Joined #5944  → relay=127.0.0.1:5073
>    Region: NL · Venlo regio
> 22:41 → BOB online (NL · Venlo regio) #5944
> 22:41 → ALICE online (NL · Venlo regio) #5944
> 22:42 → BOB online (NL · Venlo regio) #5944
> 22:42 → ALICE online (NL · Venlo regio) #5944
> CHARLIE@#5944>
> 
> 
> On 3/7/26 20:54, René Oudeweg wrote:
>> [Voila: een kersverse pseudo-HAM CLI tool dat elke postcode of 
>> postcode regio in een tekst- en audiokanaal tovert. Heeft Henk van 
>> Lingen interesse om een de relay server op tuxtown.net te installeren? 
>> Dan kunnen we texten en broadcasten over het internet zonder dure HAM 
>> radio's en de nodige licenties voor zendamateurs. :-) Dat is weer eens 
>> wat anders dan knipselkrantjes maken...
>>
>> PS: Enige Linux hack ervaring is een must.
>>
>> Nog geen GUI. Niet getest met Windows of MacOS. Dus ik neem aan dat 
>> weinigen op deze lijst hiermee overweg kunnen. Maar goed, probeer het 
>> eens zou ik zeggen.
>>
>> retour,
>>
>> René Oudeweg
>>
>> ]
>>
>>
>> -- 
>>
>> https://github.com/juggao/geotalk
>>
>> GeoTalk 📡
>>
>> Pseudo-HAM Radio & Text Messaging — Geo-grouped by Postal Code
>>
>> GeoTalk is a Linux CLI tool that turns any postal code into a radio 
>> channel. Users in the same postal zone share a UDP group; voice (PTT) 
>> and text messages are broadcast to everyone on that channel — like a 
>> local walkie-talkie net. Works on a LAN via IP multicast, or across 
>> the internet via a relay server.
>>
>> Version 1.3.1
>>
>> ## Features
>>
>> | | Feature | Details |
>> |---|---|---|
>> | 📮 | Exact postal channels | Any EU/UK postal code is a channel — 
>> `#59601`, `#
>> 1234AB`, `#SW1A` |
>> | 🔍 | Wildcard channels | `#59**` = Venlo region · `#750**` = Paris · 
>> `#1***??`
>>   = Amsterdam |
>> | 🧩 | Regex channels | `/^[0-9]{4}[A-Z]{2}$/` — full Python regex 
>> between `//`
>> |
>> | 🗺️ | Region database | 120+ EU postal prefixes resolved to human- 
>> readable regio
>> n names |
>> | 💬 | Text messaging | Instant broadcast to all channel members |
>> | 🎙️ | Push-to-Talk (PTT) | Real mic audio over UDP (16 kHz PCM) |
>> | 📻 | Multi-channel RX | Subscribe to many channels at once; all 
>> arrive in one
>> terminal |
>> | 🔎 | Channel scan | `/scan 59**` — probe a region for live users, 
>> results stre
>> am in real time |
>> | 🌐 | Relay mode | `--relay HOST` for internet use — no multicast 
>> routing neede
>> d |
>> | 🔄 | Auto-reconnect | Client reconnects to relay with exponential 
>> back-off |
>> | 🔒 | LAN mode | Pure peer-to-peer UDP multicast, zero infrastructure 
>> required
>> |
>>
>>
>> -- 
>>
>>
>> JOINING A CHANNEL
>>
>> You join a channel by typing its postal code prefixed with #:
>>
>>      #5912       join the exact channel for postcode 5912
>>      #5944AV     join the exact channel for postcode 5944AV
>>
>> Anyone else on the same LAN (or connected to the same relay) who has 
>> joined #5912 will see your messages and hear your voice.
>>
>>
>> WILDCARD CHANNELS
>>
>> You can also join a region rather than a single postcode:
>>
>>      #591*       joins the Venlo Centrum region (5910–5919, 591A–591Z)
>>      #59**       joins the entire Venlo regio (5900–5999 and more)
>>      #750**      joins all Paris postcodes
>>
>> The * matches exactly one character. The ** matches one or more. So 
>> #591* covers 5910, 5911, 5912 ... 591Z as a single subscription.
>>
>>
>> A CONCRETE EXAMPLE
>>
>> Suppose three people are running GeoTalk:
>>
>>      BOB    joined #5912
>>      ALICE  joined #5913
>>      CHARLIE joined #591*
>>
>> BOB and ALICE are on different exact channels — they cannot hear each 
>> other directly. But CHARLIE, on the wildcard #591*, is subscribed to a 
>> channel whose pattern covers both 5912 and 5913. BOB sends a message 
>> on #5912 → CHARLIE receives it. ALICE sends a message on #5913 → 
>> CHARLIE receives it too.
>>
>>
>> SCANNING FOR ACTIVE USERS
>>
>> If CHARLIE wants to discover who is active in the Venlo area before 
>> joining, he can run a scan:
>>
>>      /scan 591*
>>
>> GeoTalk expands 591* into all 36 concrete codes (5910–5919, 591A–591Z) 
>> and sends a probe to each multicast group. BOB's client receives the 
>> probe on #5912 and replies automatically. ALICE's client receives it 
>> on #5913 and replies. Within a few seconds CHARLIE sees:
>>
>>      ► #5912    BOB     NL · Venlo Centrum
>>      ► #5913    ALICE   NL · Venlo Centrum
>>
>> He can then join either channel directly, or join #591* to receive 
>> from both simultaneously.
>>
>> A broader scan works the same way:
>>
>>      /scan 59**    → probes all 5900–5999 (100 channels) plus 
>> alphanumeric variants
>>      /scan 750**   → probes all Paris postal codes
>>
>>
>> PUSH-TO-TALK
>>
>> Voice works like a walkie-talkie. Press Ctrl+T to toggle the mic on, 
>> speak, press Ctrl+T again to release. Everyone on the channel hears 
>> you in real time. Press Ctrl+Y to mute incoming audio if you only want 
>> to type.
>>
>>
>> RELAY MODE (internet use)
>>
>> For use across the internet, one person runs the relay server:
>>
>>      python3 geotalk-relay.py --port 5073
>>
>> Everyone else connects to it:
>>
>>      python3 geotalk.py --nick PA3XYZ --relay relay.example.com
>>
>> The relay routes all traffic — text, voice, and scans — between 
>> connected clients. It requires only a single UDP port (5073) open on 
>> the server.
>>
>>
>> Let me know if you have any questions.
>>
>> Best regards,
>>
>> René Oudeweg
>>
>