Jouni OH3CUFMar 13, 2025

I have been testing CATS.radio protocol today, setting up SDR-iGate and flashing RS41ng. Promising results!

Good reason to go pick some RS41 radiosondes, free CATS.radio transmitter inside :)

#catsradio #cats.radio #rs41 #rs41ng #radiosonde #amateurradio #radioamateur

n3tcat 🐈 🇨🇦Aug 28, 2024
CATS I-Gate boards are back in stock! (And my wrists are sore from snapping off PCB edges)

https://www.tindie.com/products/hamcats/cats-i-gate-board/

#hamCATS #CATSradio
CATS I-Gate Board by CATS on Tindie

70 cm CATS I-Gate board, for use on a Raspberry Pi

Tindie
VK2TTY he/himMay 14, 2024
I mostly ponder APRS, and mostly ponder non-tracking use cases. My SDR-on-a-Pi gateway doesn’t pick anything up. If I gave it a decent antenna, it still wouldn’t, because there’s no traffic. I intend to try CQSRVR, ANSRVR, and something like APRFID but with different media providing the data bytes. Also, on #CatsRadio. @ve3qbz @HopelessDemigod @xssfox @stephen
n3tcat 🐈 🇨🇦Mar 25, 2024
CATS, in the palm of your hand! Spent this weekend writing a GUI library that I can use to develop the rest of the software. Just the textbox alone took hours - so many edge-cases and I had to rewrite a lot of stuff. Definitely has some rough edges I still need to fix.

There are other issues - the screen refresh rate is slower than I'd like - but not bad for a bit of free time this weekend. #hamCATS #CATSradio
Show threadVK2TTY he/himMar 12, 2024
All that said, I wonder if the #CATSradio community might prove the concept sooner? It sounds like their kind of fun.
n3tcat 🐈 🇨🇦Mar 7, 2024
Got CATS running on a DFM-17 radiosonde. Still needs some work, mainly cleanup, but the hard stuff is done! The packets are generated entirely in software - no hard-coding shenanigans!

#hamradio #hamCATS #CATSradio
n3tcat 🐈 🇨🇦Feb 4, 2024
https://peertube.scd31.com/w/7Gk2j6Kp36od83fRjRT4gK

I've been working on a handheld CATS transceiver, called the CATS Companion. My LCD screen died, so while I wait for a new one, I spent the weekend designing a case for it! #hamCATS #CATSradio
CATS Companion

PeerTube
n3tcat 🐈 🇨🇦Jan 31, 2024
For those following CATS, I've written an RX I-Gate that receives packets from an RTL-SDR and forwards them to FELINET.

It uses the codec2 FSK demodulator, and does soft-bit decoding under the hood so it should be operating close to the theoretical limit of what's possible.

I do still prefer a "real" I-Gate (that is, one that can transmit), but in a pinch, an RX I-Gate is certainly better than nothing!

https://gitlab.scd31.com/cats/sdr-igate

#hamCATS #CATSradio
CATS / SDR I-Gate · GitLab

GitLab Community Edition

GitLab
Show threadVK2TTY he/himJan 26, 2024

@IU5FHO At their 1.1GHz frequency for omni-directional use, their QFH is 50mm wide and high, which is about as squat as my usual calculator likes. https://jcoppens.com/ant/qfh/calc.en.php

Scaled for CATS’ 430.5MHz the antenna would be 130mm (5”) or so wide and high. It'll vary a bit depending on your wire size and design.

If it checks out in a simulator, maybe you could wrap 740mm (2.5’) of wire up and down around a small bucket, solder some joints, and have an antenna? @F1RAD #CatsRadio #AntennaDesign

Quadrifilar helicoidal antenna - Javascript on-line calculator

Description of the construction of a quadrifilar helicoidal antenna. This model is for meteorological satellites, but a calculator is provided to adapt measure to other frequencies. Construction is cheap, and materials are easily available.

Show threadVK2TTY he/himJan 26, 2024

@IU5FHO it depends on whether their QFH antenna design suits your CATS use cases?

Rosette Maria Bichara et al’s design strikes a compromise between radio performance and mechanical stability in two patterns. If you only need one pattern eg. fixed deployment for ground-to-ground use, you only need one shape. You could optimise that shape for radio performance and perhaps cost.

That said, perhaps it can be scaled for 70cm use, sure! @F1RAD #CatsRadio #AntennaDesign