(5)AFT电压作为自动搜台过程中自动记忆的根据。所以确定AFT电路是否存在故障,可以在副载波恢复电路正常的情况下,在自动搜台过程中看看搜到信号时有没有节目号增加。有节目号增加,说明AFT电路正常:无节目号增加,说明AFT电路有故障。进一步确定AFT电路是否存在故障,也可以在自动搜台过程中看看搜到信号时TMP87PS38N(13)脚、TB1238④脚电压是 (5) AFT voltage as the basis for automatic memory search automatically found. So to determine whether there is a fault AFT circuit, you can subcarrier recovery circuit in the normal circumstances, in the process of automatic search to see if there is no program number to find the signal increases. A program number increases, indicating AFT circuit is normal: no program number increases, indicating AFT circuit is faulty. Further determine whether there is a fault AFT circuit can also be found in the process of automatic search found signal TMP87PS38N (13) feet, TB1238 pin voltage is