Very strong interference when in scan mode it stops oh 469.1625 with just static
The first trick is to establish that it is a birdie and not local interference or harmonic or mixing.
If you remove the aerial and the noise is still present, then it is an internally generated signal or birdie. If the noise disappears then it is more than likely an externally generated signal, assuming that it is not a strong signal being generated by a computer or in some case digital TV or the like.
If it is a birdie and depending on the scanner you maybe able to lock it out. Otherwise it is going to be annoying. If it is a locally generated signal then moving the scanner within its environment (the shack) may help. An externally generated signal may take a bit more effort such as directional antenna, relocation of the antenna or filtering.
If it is a harmonic, then there is little that can be done, unless you can alter the IF stages of the scanner. Some can, most cannot. Again not knowing the radio involved makes it difficult to know. Mixing is a third product of two separate signal coming together to form a third. Usually a garble of voices and or data or both. Again not much that can be done, short of experimenting with aerial placement.
It is going to be an interesting exercise in RF behaviour.