The downstream can be affected by heat in the main cabs with amps .In the summer you can loose 3db and in the winter gain 3 db .what also could be happening is that the network has been reset due to the maitanence that is going on .Here we visit every cab with a amp in once a year and check all forward and reverse levels 1000+ cabs done every year its like painting the forth rail bridge once you finish you start again .
