Hi Mak, thanks for reply. The problems occur when we go and try and make the polarity control unit remote controlled. I have a fully working manual unit here in the shack and is 100% fine. However the remote unit I built use's relays to add in extra lengths of 50ohm coax as a delay line (a 1/4 wave on the -45degree yagi, and a 1/2wavelength on the +45degree yagi.) This system I have seen used by very many operators and also some comercial units, however with just the 2 delay lines the LHCP will never really be LHCP, it needs an extra set of relays to switch in the other 1/4wave delay line. I was just wondering if anyone else had seen this or have I just misunderstood the circuit somehow. Any thoughts would be appreaciated. regards Gus M0IKB