MattL wrote:Don’t forget those charts are ground station reception, not air to air.
This is a very good point, the ground station antenna is 9dB giving an 8X power improvement in terms of reception.
Most receivers are either 2 or 3 dB, giving much less
Not sure what gain or directional performance the MIFA antenna in SE2 gives, perhaps @Cub could comment ?
russp wrote:That's 'Brilliant' except directly to the front where it's most needed where the coverage seems to be less than a mile or about 15 seconds warning at normal GA speeds. ? That diagram would seem to indicate that you should ideally be looking to find an alternate better position?
It does appear to have power reduction along the axis of the PCB plane as seen from your diagram which would be the axis when suckered to the side window ?
Have seen this in a number of diagrams an apparent bias left to right, and loss front to rear
For comparison, here is a flarm device which of course is only 25mW, but also received by a 9dB ground based antenna, I am pretty sure this is one of the RAF Aircraft, and I would be pretty certain it is fitted with an external antenna (anyone have information), I think this shows an effective and achievable omnidirectional pattern