communications with locomotives or other railroad vehicles and equipment over one or more rf channels with reference now to fig2 there is shown a locomotive or other railway vehicle occupying a block of track the railway vehicle is equipped with an onboard receiving and processing unit to receive the coded electrical signals from code transceivers 6 via the track 1 in addition when a block of track or series of blocks is occupied the track code pulses 9 10 are unable to reach the neighboring transceivers because of the shunting action of the axles 11 of the vehicle the onboard train control unit on the railway vehicle may be equipped with a cab signal receiver and pickup coils 12 these pickup coils can be laminated core multi turn coils placed above and perpendicular to each rail and connected in series but wound or connected in opposite directions the coils 12 are inductively magnetically coupled to the rails so as to respond additively when out of phase sinusoidal magnetic fields are present in each rail and respond destructively when a common mode magnetic field intercepts both of the coil cores such pickup coils are well known by those versed in the art similar receiver coils may be used to receive.