The MBARS Annual Construction Competition has been running since 1991 and is designed to encourage members to experiment in construction. All members are eligible to vote on the evening of the competition after entrants have shown and discussed their entries.
The competition is designed to take into account the experience of the constructor balanced against their entry.
The annual MBARS competition took place on Tuesday 20th February 2018 with four entries:
- Luke Lewis 2E0LJL entered a high-altitude balloon payload with GSM module, LoRa transceiver and GPS receiver with active antenna.
- Kevin Hodgkins 2E0KHR entered his build of the m0nka mcHF rev 0.7 QRP SDR Transceiver including a custom designed and machined case.
- Stewart Baker G3RXQ entered a home-built 40m QRP transceiver with custom circuit and SMT internals on home-manufactured PCBs in a novel PCB-based case.
- Bob Wilkinson G3VVT showed several pieces of test equipment, home built out of necessity and cost.
A members vote resulted in Luke Lewis winning – he was presented with the cup by the club secretary Mark.
The payload consists of an Arduino Nano, GSM transceiver, SD card module, LoRa transceiver and Neo 6m GPS receiver with active 3v3 antenna, all soldered to a protoboard. Using a 17.3cm quarter wave monopole with a 4 radial groundplane, a bandwidth of 62.5KHz, 10mw TX power and LoRa’s Chirp Spread Spectrum modulation on the 70cm ISM band a string of telemetry has a range of a few hundred kilometres. The telemetry string will include parsed NMEA data, altitude, heading, speed and internal/external temperature from a 18B20 and TMP36GT9Z sensor. The receiver will compute the received telemetry and upon calculating a 16bit checksum will upload to the online Habhub for easy access and tracking throughout the flight. The payload will experience violent turbulence, temperatures as low as -40°C and minimal heat dissipation from the high altitude environment of only a few percent atmosphere. Lift will be provided from a high altitude weather balloon with an inline parachute which will self deploy once the balloon expands to its maximum width of approximately 8 meters around 100,000ft (35km) and burst! Permission is of course required from the CAA before deployment. For further information please refer to Dave Akerman’s (M0RPI) website, his efforts and extensive documentation has made this project possible for myself and many others.