I noticed something interesting the other day with my setup.
I have two receivers connected to two dishes. One controls my Ku dish and the other controls the C band dish. To enable the Ku receiver to also see what the C band receiver is on I connected the C receiver IF loopthrough to one port of the DiseqC switch on the Ku receiver.
With the C receiver powered and hence signal from the C band dish on the IF loop output I did a blind scan on the Ku receiver of the Ku side, in my case G11/Ku using the entire bandwidth of a universal LNB in the faint hope that some of the low band Ku was active.
I was almost fooled into thinking I'd found a feed at 10860MHz on G11 when a transponder showed up there in the scan. The symbol rate was a familiar number (16180) and the channel names were also familiar (PAL Japanese, NTSC Japanese, PAL English.....). Since I spend a lot of time on Pas9/C I quickly figured out that I was seeing the strongest transponder from the C band side passing through the inactive port on my switch (received quality much lower though).
A quick calculation confirmed it.
5150 (C band L.O.) - 4040 (transponder freq.) = 1110 MHz I.F. frequency
9750 (Ku low universal L.O.) + 1110 = 10860 MHz perceived frequency
It also appeared on both polarities but for some reason did not appear in the scan of the high side of the universal LNB.
So if you have connected your dishes and receivers like mine just be aware of what you might see.
I have two receivers connected to two dishes. One controls my Ku dish and the other controls the C band dish. To enable the Ku receiver to also see what the C band receiver is on I connected the C receiver IF loopthrough to one port of the DiseqC switch on the Ku receiver.
With the C receiver powered and hence signal from the C band dish on the IF loop output I did a blind scan on the Ku receiver of the Ku side, in my case G11/Ku using the entire bandwidth of a universal LNB in the faint hope that some of the low band Ku was active.
I was almost fooled into thinking I'd found a feed at 10860MHz on G11 when a transponder showed up there in the scan. The symbol rate was a familiar number (16180) and the channel names were also familiar (PAL Japanese, NTSC Japanese, PAL English.....). Since I spend a lot of time on Pas9/C I quickly figured out that I was seeing the strongest transponder from the C band side passing through the inactive port on my switch (received quality much lower though).
A quick calculation confirmed it.
5150 (C band L.O.) - 4040 (transponder freq.) = 1110 MHz I.F. frequency
9750 (Ku low universal L.O.) + 1110 = 10860 MHz perceived frequency
It also appeared on both polarities but for some reason did not appear in the scan of the high side of the universal LNB.
So if you have connected your dishes and receivers like mine just be aware of what you might see.
