Special Joint (VK4 & VK7) Presentation Night – Optical Communications with Rex VK7MO

REAST and BVHFG Joint Presentation Night Recap – 28th August 2024

On Wednesday night, 28th August 2024, the Radio and Electronics Association of Southern Tasmania (REAST) and the Brisbane VHF Group (BVHFG) made history with their first-ever joint presentation night. This special event, featuring contributions from both clubs, brought together amateur radio enthusiasts from across Australia, with a focus on optical communications.

Presentation Highlights:

  • History of Optical Communications: Rex provided an overview of the history of LEDs and lasers in amateur radio, referencing the pioneering work documented on modulatedlight.org.
  • Detector Choices: Discussions on the pros and cons of different detectors, including red, blue, and infrared options.
  • The “Something for Nothing” Law & Line of Sight: Rex explained the physics behind line-of-sight communications and how natural and man-made obstacles affect signal propagation.
  • Building Reflection & Over-the-Horizon: Techniques to extend the range of optical communications beyond the horizon, leveraging building reflections.
  • Stanley to Mt Horror and Beyond: The remarkable 288km optical communication link from Stanley to Mt Horror, followed by Mt Horror to Cape Liptrap. Rex also shared some gripping stories from the Mt Horror bushfire and police encounters.
  • Weak Signal Communications: Demonstrations of signal decodes using Weak Signal Communicator (VK3HZ) software, showcasing the power of weak signal modes in optical comms.
  • Recent Developments: Updates on the latest in optical communication technology, including the FST4 mode, advancements in LEDs, and lens performance improvements.
  • Test Results: A summary of tests conducted from White Hills to VK7ZBX using FST4 mode, comparing equipment performance at wavelengths from 630nm to 730nm.
  • Propagation and Signal-to-Noise Ratio: An exploration of how different cloud types in Tasmania and aerosols affect signal propagation and SNR.
  • Safety Concerns: Public concerns about the use of bright red LEDs and eye safety were addressed, emphasizing the importance of responsible experimentation.

The presentation concluded with a lively Q&A session, with special thanks extended to Rex VK7MO, Richard VK7ZBX and Justin VK7TW for their contributions.

Video of the event is available at the REAST Youtube channel.

For those interested in further reading, historic research papers on optical communications experimentation in VK7 can be found on the REAST website: Optical Transmissions.

REAST Returns to the Clubrooms

Members were greeted to a friendly message on the whiteboard thanks to Paul VK7FPCL – our wonderful Clubroom’s Officer who has been ensuring that everything is wiped down between meetings and keeping us COVID -safe with supplies. A huge thank you to Paul.

Last Wednesday night was a joint welcome back to the club rooms and Presentation Night on the ICOM IC9700 Experiences and Learnings. We had about 20 people along to the presentation in person and had over 20 on the streaming channel. It was a group effort with input from Rex VK7MO, Richard VK7ZBX, Hayden VK7HH, Alan VK7KAJ and Larry VK7WLH all of whom have IC-9700s. 

A video of the presentation is available to the REAST Youtube channel – https://youtu.be/nYM5kgTF4SA.

Rex started with an outline of the IC-9700 functionality and comparison with the IC-910H. This led to whether you could effectively operate the rig out of the box. Some impressions where shared, the question of frequency stability was explored and the various GPS Locking options were explored with Rex, Alan and Hayden. Then Rex continued with 23cm operation, Digital/EME operation and Linear/Transverter operation.

Richard then took the audience through a comprehensive outline of using the IC-9700 for satellite operation including a recording taken of a contact with VK4MIR.

The presentation then moved to key configuration items that can be/need to be tweaked to improve including – Rex outlined the HM-36 Mic Mod and Hayden did a promo for his digital modes setup and firmware update videos.

https://youtu.be/rhu6fRz6Z3g

https://youtu.be/crYCBeu1yR4

Hayden then took the audience through the Remote Operating Software from ICOM – RA-BA1.

https://youtu.be/Mkhekwg0UE4

Larry finished up with a description of the WIN4ICOM software which also has remote control capability.

We then took questions from the audience and stream and retired to enjoy the clubrooms again!

Thanks to Rex VK7MO, Hayden VK7HH, Alan VK7KAJ, Richard VK7ZBX and Larry VK7WLH.

A great return to the clubrooms.

73, Justin VK7TW on behalf of the REAST Committee

VK7MO 10GHz Grid Square EME Adventures Presentation

Wow, Rex Moncur VK7MO gave us a four part illustrated presentation on his 18,000km journey on his recent 10GHz Grid Square chasing EME DxPedition. Rex traveled far and wide into VK3, VK5, VK6 and VK8.

Rex started with a short presentation on the VK6 Northern Corridor Radio Group as he was very impressed with this club and the things they get up to. Rex then moved to a tutorial on EME propagation and then moved to his grid tour and get OK1KIR up to over 100 grid squares on 10GHz EME. These grid squares were from the OH, OG and OF grid fields. There were a few interesting and frustrating things that happened along the way but Rex achieved his goal!

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