The spike is me changing the gain, basically I switched the adaptive gain off...
I'm looking closer at the adaptive gain as the less 'pink' the better as they wouldn't implement it if it wasn't of use.
It may get switched back on..
I have a 'live' map of what I'm picking up.. the infos are uploaded to 4 sites once every 5 mins, been active since 21Nov 2016 (5 days off while we moved house)
Look at image, note between 14 to15, how light the shading is and that is when the gain dived down to 20odd so I 'lost aircraft, the deeper the blue the more planes are seen, 10-11 was the busiest today
View attachment 628974
My gain is normally 42 or 44,
I can use a script to check various gains and find me what is the best average, running it over as long as I want.