Circuit to Test Servo Motor
That circuit is to test the motor servant of the parabolic antenna it is working perfectly, although a system with lnbf is much more appropriate, a lot of people they still use systems using lnb and servo motor.
Then the idea of that circuit is to help to the technician reparation of parabolic antennas when doing test of operation of the servo motor. Being detected the defect is in the polarization or in the receiver. It is enough to connect the threads to tie the equipment in the electric outlet and to select with the key S1 the type of polarization vertical or horizontal, if the servo motor is with operation ok, you will hear the characteristic noise.
List component
C1 220nF
C2 220nF
C3 470nF
D1 1N4148
IC1 NE555
R1 120k
R2 3.3k
R3 4.7k
R4 4.7k
S1 Key league turns off