25 Nov
2015
25 Nov
'15
3:21 a.m.
El 24/11/15 a las 23:20, Joe escribió:
what are the three hills about?
That's just noise from the passband of AO-7 transponder. It's stronger in three spots, one on the middle of the passband and two near the edges. These spots are quite strong, in fact comparable to some of the stations. If you look closely, you can also see that these spots get frequency modulated with the strong transmissions.
This is one of those things that it's quite difficult to see on a traditional receiver but it's quite apparent on an SDR waterfall.
73,
Dani M0HXM/EA4GPZ.