Look down the throat or waveguide of the lnb and you will see two quarter wave dipoles, one for each polarity. There is not any db gain for a quarter wave dipole!
The 65 db gain refers to the line amplifier for the coax or feed line between the lnb and fta receiver. The small coax we use along with the switches and other things we put between the fta receiver and lnb have lots of loss n db.The 65 db of gain is to compensate for these items and does not represent satellite signal gain of the lnb because there is no db gain of a quarter wave dipole!
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