We have extensively searched for periodic signals in the area of the soft gamma-ray repeater SGR 1900+14 , at 430 and 1410 MHz with the Arecibo telescope .
Our observations did not reveal the 5.16-s periodicity reported for the magnetar down to a 430-MHz flux density limit of 150 \mu Jy .
During the search we discovered a 226-ms radio pulsar , PSR J1907+0918 .
The period derivative implies the characteristic age for this pulsar is only 38 kyr .
Independent evidence in support of this apparent youth are the unusually high degree of circular polarization and its relatively flat radio spectrum .
The close proximity of PSR J1907+0918 to SGR 1900+14 suggests that they may have evolved from a massive binary system .
Regardless of this possibility , it is presently not clear to us that SGR 1900+14 is associated with the supernova remnant G42.8+0.6 .