K5NSX High Altitude Balloon - July 2026
K5NSX will be coordinating a high-altitude balloon launch. The tentative date is Saturday, July 11th.
The payloads for this launch will be:
- Primary tracker - Horus Binary v3 on 70cm
- Raspberry Pi camera - storing images to microSD while also sending preview images via 915MHz LoRa
- Secondary tracker - Horus Binary v3 on 70cm
We need two main types of assistance…either (or both) would be greatly appreciated. 1) Tracking from a home/fixed station. 1) Chasing from a mobile station during the balloon flight.
Horus Binary is a protocol specifically designed for tracking balloon payloads. To receive it requires something capable of receiving upper sideband on 70cm. This can be as simple as an RTL-SDR or it could be any ham rig or receiver and a way to get audio into a computer (internal USB or an audio interface). A few current options that you might already have:
- Quansheng UV-K5 with alternate firmware and AIOC interface
- Kenwood TH-D74A / TH-D75A
- Icom IC-705
- Yaesu FTX-1
- Yaesu FT-991(A)
- Icom IC-7100
- Icom IC-9700
There are 3 options for software to decode Horus Binary
- webhorus - browser-based decoder that can accept sound card input or directly control an RTL-SDR. This is the simplest, but also the most finnicky, option.
- Horus-GUI - Graphical application. Probably the best option if you have a home station already setup for digital modes.
- horusdemodlib - Python library for headless decoding and also running multiple decoders on a single SDR receiver. Also can integrate with Chasemapper for mapping during the chase. I’ll share some options for how to easily configure this setup on a Pi or similar machine in the next week or so.
All of these decoding options feed data to SondeHub Amateur which is where we will be tracking and coordinating the recovery efforts.
Please reach out via email or the NSX Discord if you are interested in participating in any way. I hope this will be the first of many launches like this.
73, Luke - AE5AU