The obvious drawback is the limited data rate. Further, the frequency of transmitter and receiver must be close to identical due to the small bandwidth. Because of this there must a temperature compensated crystal oscillator (TCXO) in narrowband transceivers. The TCXO used in RC17xx series has a given accuracy in the -30/85 degree range that we utilize. The TCXO does operate functionally down to -40, but then with slightly more variance and possible degradation in sensitivity.
Last Update: August 8, 2017