What can I say...I'm retired and between trips away, I get bored.
Here's a small project I did recently. After relocating my GME antenna from the bullbar to the top of the canopy (2012 Chev Silverado, with 6" lift), it soon became apparent that despite having a sprung-base, it was fouling and creating large BANGS when I drove under my carport etc.
So, having a complete on-board air system (comprising an Endless Air compressor and a re-purposed 9kg LPG bottle), I decided I could make the activation of the fold-down antenna air-operated. The air ram and distribution block are activated when I turn the UHF on at a master switch in the cab.
The video shows it in operation. It might help somebody else who wants to lay the UHF down without having to get out every time. https://www.youtube.com/watch?v=Pog9id5JPzk&ab_channel=BillRoach