It is not enough just to read the Sacred Scriptures, we need to listen to Jesus who speaks in them: it is Jesus himself who speaks in the Scriptures, it is Jesus who speaks in them. We need to be receiving antennas that are tuned into the Word of God, in order to become broadcasting antennas! One receives and transmits. It is the Spirit of God who makes the Scriptures come alive, who makes us understand them deeply and in accord with their authentic and full meaning!
As a past electronics technician I like the antenna imagery. In this case it would be a duplex antenna being able to receive and transmit. Plus it makes sense regarding the “transmission” of faith. Then efficiency of this Gospel antenna is measure by the ratio of what is faithfully transmitted to what is received from the Church. There can be loss of efficiency due to heat since not proclaiming the truth in a charitable way generates more heat than light. With the Gospel antenna you can expect polarization as Jesus amply warned in Matthew 10. If you are not living a life of faith and then try to transmit it to others, expect transmission line losses. Expect resistance and other impedance losses.