Normally there is not FSK present on this frequency, but rather some other kind of digital signal, such as Link 11. Several nights recently there has been FSK present.
The center frequency is 6947 kHz, not 6948 kHz. The tuned frequency would be about 6946 or 6945 kHz (varies depending on what you want the audio tones to be at), as you tune this signal in USB.
Without a recording I cannot tell what the signal was when you posted, however at this time it is STANAG 4481 FSK, it is KG-84c encrypted and you cannot decode it.
T!