Today was spent tinkering with the FM transmitter. I swapped out my initial 150cm half wave wire antenna for a 165cm solid core half wave, fashioned a crude battery pack from two D cells some wire and duct tape. After modifying the battery pack I moved the transmitter to the loft and went and did a little range check. The modifications possibly boosted the signal by 20-30 meters. In total line of sight I think roughly 200 / 250 meters reach which isn’t too shabby. FM needs a lot more power to extend range and I think the circuits good to 12v and is currently running at around 3v will do a little more reading before I start experimenting with different power supplies and voltages, also want to check the data sheet for the transistors.