I have a small GSM Modem whose internal antenna sucks. I bought a small external antenna that boosted the signal a little, however I want to boost it more. Would using a typical high frequency audio amplifier that is connected to a satellite antenna boost the signal?
Would using a typical high frequency audio amplifier that is connected to a satellite antenna boost the signal?
No, absolutely not. In fact it would make things worse.
An audio amplifier has absolutely no capability at the (near/-) microwave frequencies used by GSM. Quite likely it will function as a very effective attenuator and block almost all of the signal that a plain coaxial antenna cable would have let through.
Further, GSM is a bidirectional communication scheme, so an amplifier would need to have coordination or subband-specific behavior with the transmit/receiver behavior of the base radio. Further, cellularized networks depend on the base station commanding the mobile device's power output to a level which will achieve communication, but not interfere with frequency re-use in other cells.
Such a device is not only going to be ineffective, if it were effective, it would probably not be legal.