hi, I have regular analog cable tv and internet and I want to split it 7-8 times to really long cable runs so I assume I need a signal amplifier. The signal is currently already split twice and running across the whole house and it's not exactly crystal clear, but I checked where the cable enters the house and it's perfect there, so I guess that's the best place to put the amp. First off, is it possible to amplify the signal too much? or does the tv know what the maximum amplitude is? would it hurt to amplify more than the 3.5db that each split removes? Also, whats this bidirectional stuff? do I have to worry about an amp not being bidirectional? I went to radioshack and I saw a few models. In particular, i was wondering about one that didn't have a power plug and was promising 12-15 DB gain. how would these things work without external power?