White River from north of Des Arc to just north of I-40

Paul (WA5GLS) coordinated lift gas and balloon inflation. Herbert (WA0TEY) operated the LoRa payload and ran a tracking station for LoRa and Horus Binary. Luke (AE5AU) configured the primary/secondary trackers and handled the planning.

We intended to meet at 9:00 AM CDT and launch within the hour. We had a slight delay when the original location wasn’t optimal. What appeared to be small trees on imagery were actually more mature. A lovely local couple were very helpful and offered a much better option once we explained our needs.

We transitioned to the new location where we were joined by:

• The local couple and their grandson
• Greg (friend of AE5AU) who took video and photos and assisted in wrangling AE5AU’s boys! (Huge thanks!)
• Mikey (KG5FUE) who helped with inflation
• Seth (KJ5PZP) who also helped with inflation

Other than the delay, launch went smoothly. Predictions were for a wide S curve with landing zone not far south of the launch site so we took our time packing up and some of us took a trip to get some lunch while still tracking/monitoring.

Here was the flight path:

It landed in a line of short trees / scrub brush between two farm fields. There was an elevation difference between the fields that required a bit of effort to bushwhack down to the base of the tree. Seth (KJ5PZP) took one for the team and recovered the payloads with an extension pole.

Herbert was the only one tracking the LoRa payload, but we had several others join in helping track the Horus Binary v3 payloads:

NG5P’s station in Sherwood and Herb’s station at the launch site both did a great job tracking the primary K5NSX tracker through nearly the entire flight. Longest distance goes to KE5GDB, KI5PGM, and N5COR in the DFW area. KG5FUE and KJ5PZP were able to get some practice tracking the payloads from portable stations. AE5AU-R was a full Chasemapper setup and was close by to capture the landing (and a little bit of driving afterward…whoops!)

Receiver SNR for K5NSX tracker:

Receiver SNR for AE5AU tracker:

Full telemetry links: K5NSX AE5AU WA0TEY-HAB

All images from the camera payload

Greg took some photos

and edited a video

We are starting to plan another launch for later in the summer. Watch the website and Discord for more details when it is announced.

73, Luke - AE5AU

EDIT: We will meet in Carlisle, AR at 9:00 AM CDT. Launch shortly afterward.

Talk-in / chase simplex on 146.55 MHz FM

The payloads for this launch will be:

• Primary tracker
  • K5NSX - Horus Binary v3 - 432.5 MHz
  • K5NSX-11 - APRS - 445.975 MHz ~ every minute
• Secondary tracker - Horus Binary v3 on 70cm
  • AE5AU - Horus Binary v3 - 432.6 MHz
• Raspberry Pi camera - storing images to microSD while also sending preview images via 915MHz LoRa

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

Live foxhunt log

• Fox can be heard from Baptist Hospital WLR parking lot
• The fox will be placed on Sunday…hopefully by 1PM. I will add my entry to the log linked above once it has been placed.
• It will be inside the city limits of Little Rock in a place accessible to the public. Please don’t tresspass on private property looking for it. I will give a little better detail tomorrow including a specific place from where you could start and definitely hear it.
• You will be able to drive to the fox and hopefully see the sign / scan the QR code from the car. I’m not intending to require a hike in this heat.
• The fox will be transmitting on 432.5 MHz. It will transmit the follwoing in CW in a loop that cycles about every minute: R 5 times, AE5AU, 6 second tone.
• The is FM moduled CW. You can hear it on any FM radio.

The fox for this hunt is a radiosonde that was been to near space thanks to the National Weather Service. It flew out of the North Little Rock office and I tracked it to southwest Little Rock where it landed in a tree next to the road. It has been reflashed with an open source firmware to move it from the original 400-406 MHz band to the 70cm amateur band. The firmware also gives it many other features and modes. Not bad for free (other than the time and fuel to track it down)!

73 and best of luck in the hunt! Luke - AE5AU

Live foxhunt log

• Fox can be heard from Baptist Hospital WLR parking lot
• The fox will be placed in the morning…hopefully before 8AM. I will add my entry to the log linked above once it has been placed.
• It will be inside the city limits of Little Rock in a place accessible to the public. Please don’t tresspass on private property looking for it. I will give a little better detail tomorrow including a specific place from where you could start and definitely hear it.
• You will be able to drive to the fox and hopefully see the sign / scan the QR code from the car. I’m not intending to require a hike in this heat.
• The fox will be transmitting on 432.5 MHz. It will transmit my callsign 6 times in 15 WPM CW at the top of every minute. This should give about 20-25 seconds of every minute transmitting.
• Note that this is actual CW, not CW modulated on FM. On your FM radio, it will sound like a dead carrier keying up and down. If you have a radio with an all-mode receiver, you might want to bring it. In that case, you might have to tune a little lower to hear the CW.
• If you have an SSB receiver, you might notice a hidden signal every now and then that could help you find the fox very quickly.

The fox for this hunt is a radiosonde that was been to near space thanks to the National Weather Service. It flew out of the North Little Rock office and I tracked it to Judsonia where it landed in a neighborhood next to a house. It has been reflashed with an open source firmware to move it from the original 400-406 MHz band to the 70cm amateur band. The firmware also gives it many other features and modes. Not bad for free (other than the time and fuel to track it down)!

If you are an experienced hunter, this first hunt might not be that challenging. I’m just hoping to get interest and then we can up the difficulty and variety as we go. Please let me know if you have any thoughts or suggestions.

73 and best of luck in the hunt! Luke - AE5AU

• SoftRock kits
• Peaberry variants of the SoftRock kits
• Wiki with info on getting started
• Blog about various uses of RTL-SDR dongles
• Official SDR# site
• HDSDR
• Older version of SDR# with Auto Tuner and Trunking plugins
• Unitrunker trunking decoding application
• DSD (Digital Speech Decoder)