If you are very aggressive attaching the antenna to the base, I believe some have broken the connection inside of the base where it is soldered.
Most household devices , like phones and such will be on low to mid channels.
I set my internet Wi-Fi on 11.
I use channel 9 for the Legacy.
Also, if you are using different batteries than the originals, be sure you have ones with a mah rating of close to 2500 mah to help the radio have enough oomphf.