Amplifier gain problem

Discussion in 'Homework Help' started by craigi73, Oct 20, 2009.

  1. craigi73

    Thread Starter New Member

    Oct 6, 2009
    On a basic P.A system, at a particular amplifier setting, the system will howl if 1% of the output power is fed back to the microphone. Estimate the power gain of the P.A. amplifier in decibels.

    I was using Gf = G/1 + GH and convert to dB using 10 log x.

    No other figures/details given. Can anyone help?
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    I think you are on the right track....

    By using
    to define the onset of instability
    where G is the power gain magnitude setting and H=.01 [the 1% condition]

    Find G and GdB=10log(|G|)