transferring file in binary mode

Hi, we are using OPenSSH version of "3.7.1p1" for remote execution between unix and windows. here we are using SFTP for transferring files from windows to unix box. But the files which gets transferred to unix side contains junk characters as there is no provision of binary transmission in sftp. can anyone help us in this regard as how to eradicate the junk char while transmission of files. Regards, Kishore