Mayhem XLabs' Radiosonde Tracker Gives MySondy Go a Big Range Boost Using a Custom Antenna

Elkhorn, Wisconsin-based maker firm Mayhem XLabs has launched a compact gadget which turns a LILYGO TTGO development board into a dedicated tracker for radiosondes — with a tuned antenna for extended reception range.

"NOAA launches weather balloons generally twice a day from locations all over the US," Mayhem XLabs writes of the sport of radiosonde chasing. "After the balloons burst and fall to the ground you have an hour or two to find and retrieve them before their batteries die. Until the batteries die the balloons constantly transmit their location. This tracker will use the GPS coordinates transmitted by the balloon to get you to with a few feet of its location."

The tracker in question is based on a LILYGO TTGO LoRa32 433MHz development board, but with one major change: a specially-tuned antenna. "The device comes with the standard 433GHz TTGO antenna, which we find has very limited range at the ~402 to 406MHz range of most NOAA weather balloons in the US," Mayhem XLabs explains.

"So in addition to the standard antenna we provide a custom made quarter-wave monopole antenna tuned to have an SWR [Standing Wave Ratio] of less than two for frequencies around 404MHz."

The difference is stark: with the tuned antenna, the device is shown picking up a balloon launched over 132 miles away — a major increase over the range available with the more general-purpose stock antenna. An internal 18650 battery offers "a number of hours" of runtime, the company claims, and the hardware is compatible with Mirko Dalmonte's MySonde Go firmware for linking to a smartphone — though comes with a simpler open source alternative preloaded.

The tracker and tuned antenna bundle is now available on the Mayhem XLabs Tindie store at $45; MySonde Go is available on Dalmonte's website, and compatible with an off-the-shelf LILYGO TTGO LoRa32 433MHz development board, albeit without the benefit of Mayhem XLabs' custom-tuned antenna.