[TenTec] How dioes one modify a crystal flter?

[Craig Roberts]

Gurus,

I have a spare 2.4 KHz SSB crystal filter for my Argosy II and would 
like to narrow its bandwidth to 1.8 KHz (or thereabouts).  Has anyone 
done this?  How? (I'm guessing I could order crystals from Ten Tec).

Thanks and 73,

Craig
W3CRR