I have notoiced that Hex tab of TOAD Grid Popup editor (the one that opens when you double-click on a field in Schema Browser) shows 2-byte characters when in fact the data contains only single-byte characters; the second byte displayed is always 00. For a fixed-length field, like CHAR(14 BYTE), the Hex tab shows 28 bytes - 14 bytes with real values, each followed by byte 00. I have checked by querying DUMP() of the filed, and it reports the length of field is really 14 bytes, and lists all characters in it.
My database is Oracle 11.2, with character set WE8MSWIN1252, which, I believe, cannot store 2-byte characters even if I tried.
Attached is a screenshot of the Hex tab that shows content of a CHAR(14 BYTE) field; the field contains 7 digits padded by 7 spaces, but TOAD displays 2-byte characters, and 28 bytes as the field length.
Something wrong with how TOAD displays the data in Hex tab, showing extra bytes that do not really exist?