I received an answer from Octagon, the Whispy-Series do not use a PLL and are obsolet. From my point of view such PLL-LNBs can be used even with a horn. If there is some waveguide after removing the horn to carry the transmit antenna, it will work. Probably there is some trouble with the original clamps so make a new one. Especially the the plug of the transmit cable collides with the clamp. Use SMA instead of N. If the PLL is not too far away from 9750 MHz leave the crystal untouched. Check the real frequency of the PSK-Beacon and tell the the difference to the Console . It will lock and be stable.