Given the CAA Conspicuity Rebate, I decided to buy the transponder early (very early!) as it’ll save £250 on the purchase price.

After some research and thought, I decided that I’d be going for the Garmin G3X Touch as the basis of my avionics, so either the GTX 35R or 45R would be a good, remove transponder, as panel space is likely to be at a premium.

I’d like G-RETH’s avionics to be the best they can be (within reason!), and so ADS-B both in and out would be good - which means the GTX 45R. This means I’ll be able to see other aircraft (ADS-B In), and also transmit my position and autopilot/flight director intentions to other aircraft too (ADS-B Out).