[Amps] Clipperton L on 10 m

[Yuri Onipko]

Gentlemen,
where can I find the information on how to modify Clipperton L amplifier for
10 M? I'm testing one for a friend, everything works fine, except on 10 m
there is no output and SWR on a radio is sky high. I don't have schematics
or manual but I suspect there should be a matching section installed on the
input of the amp?
Any information will be greatly appreciated.

Yuri  VE3DZ