My understanding:
TDZE = touch down zone elevation (ICAO Doc 8400). The Jeppesen's reference to "landing surface" probably means "not necessarilly runway for all the times" i.e. heliport.
L/OM Savoy 356. Two things there, not to be confused. a) Outer Marker for the ILS facility: should produce lights and sounds in the cockpit through the reciever. Marker beacons have their own distinct (and same) frequiencies. b) The co-located Locator is in fact an NDB to be received with ADF. Whatever the "no voice" means I do not know, but assume it could be the lack of morse ident of the Locator(ndb). There is no reason why the OM should be affected at all, as these are two separate installations.
The point isyou cannot navigate towards an OM / MM / IM, you will only get the signal when passing over it. Hence the commonly used idea to put an (ndb) Locator into the same position.