Thank you to an anonymous contributor for sharing his experiences with trying to receive satellite TV beacons with his RTL-SDR. Satellite TV is typically up at 10.7 to 11.7 GHz which is far too high for an RTL-SDR to receive. So to receive these frequencies with the RTL-SDR he uses a satellite TV LNB (an LNB is essentially a downconverter and satellite dish feed), a DIY Bias T and a 90 cm dish. He writes:
Almost all television satellites have a special frequency for transmitting a beacon signal. The beacon signal is a reference signal with fixed frequency, power and [maybe] without modulation that is sent usually by satellites. One of the most important techniques used for satellite wave propagation studies is satellite beacon signal measurement. (http://eej.aut.ac.ir/article_433.html)
I used an universal LNB, DIY bias-T and a fixed 90cm dish pointed at 26 degrees East. By connecting 18 volts DC to LNB I am able to activate the 9750 Mhz local oscillator and horizontal operating mode of LNB.
Means that anything received with LNB between 10.7-11.7 GHz can be easily seen in 950-1950 MHz range, using RTL-SDR.
I used this set-up to receive the GEO satellites beacons. A list of beacon frequencies" http://frequencyplansatellites.altervista.org/Beacon-Telemetry_Europe-Africa-MiddleEast.html.
It is useful for measuring attenuation caused by heavy rain in Ku band or accurate dish positioning or even measuring frequency drift in LNB local oscillator caused by wind and temp change during a timespan.
It seems that the right signal is Eutelsat 21B and left Es'hail 1.
In picture 4 signal captured immediately after turning on LNB. but all others are captured after at least 5 hours of warming up.
MAYBE oscillator needs a stabilize time or temp change may caused the drift.
If you are interested in receiving these beacons, Daniel Estevez has also performed similar experiments with his RTL-SDR and an LNB as well, and has written about it on his blog.
Below we show some images of beacons shown in SDR# that the anonymous contributor received with his setup.