[TenTec] Omni 6 Plus Audio Filter

[Ken Koval <kakoval@cox.net>]

I just obtained a very nice Omni 6 Plus and was surprised to find an 
Inrad 756 filter installed.  Is there an easy way to find if the 
previous owner also installed the Inrad Audio Filter Mod which they sell 
for $15?  I have no problem buying the mod from Inrad, but do not want 
to do so if one is already installed.  Thanks.
K9PGC