VP959, two points:
1. To fly in controlled airspace (where it most certainly is allowed to fly), the paramotor in question needs a transponder. Might be a daft thing to do if ATS where you fly wouldn't allow it in anyway ... But most people in the world do not fly in the UK...
2. The point of my post was that if a paramotor can fit it, so can anything else. Not sure exactly what transponder he uses, but it's not the same type of ancient, power hungry kit you'd find in an average 70's vintage PA28.
Seems to me having or not having a transponder is a cost issue complicated by British aviation regulations, not a practical issue of power and weight...
Firstly, this thread came about because of an accident in British airspace, so my comments (like the majority here) referred to UK rules and regulations.
Secondly, ALL transponders have to have a peak power output of around a couple of hundred watts in order to do what they have to - NATS have made it clear that upgrading the sensitivity of SSR to allow low power transponders to have an effective range won't happen. My health and safety concerns remain.
The cost issue is real and one of relative importance to those who take up this form of budget flying.
Jeremy