MF beacons

[skylark]

According to AP1136 the first medium frequency beacons were set up at the end of 1940. They were arranged in groups of three and for security reasons only one of each group would transmit at the same time. However "splasher" beacons were also medium frequency, but are not mentined in A)1136, which was supposed to be a history of aircraft radio devices during the war. I suspect the former were used to obtain fixes and the latter primarily for homing, and were more normal, but they might have been the same thing. Of course splashers were much used by the U.S. Eight Air Force. I would be very grateful if anyone can anyone provide me with any information on the difference between the two?
Trevor (Skylark)