There are a lot of possibilities here.
1. As was mentioned, you need to make sure the antenna is properly tuned and the radio is happy. This is probably your number one most common problem. Along those lines, make sure that the coax and connector are all intact. Seemingly small problems can be big issues.
2. Make sure the radio is intact. The connectors on the radio can fail internally and may need repaired.
3. For receive, you need to have a minimal amount of noise as possible. If every time you turn your radio on, and the S meter is pegged, you may have a noise issue. That can mean that a much stronger signal is needed for you to hear them.
4. Make sure there is nothing extra in the line of the coax. Meters, amps, splitters, etc. You need to make sure your basic setup (radio and antenna) are functional.
5. How is the radio wired electrically. I have seen some extremely odd problems manifest themselves from low or very high voltages. Crappy transmit audio is the most common.
WM
