Cat/CI-V versus Band control for linear amplifiers
There are two methods for your linear amplifier to obtain operating frequency information from your transceiver automatically. Some transceivers support only one method, while with others there may be a choice of using either. If so, you can use the information here to choose which you prefer. You will then need to buy the corresponding Cat/CI-V or Band control cable as they are wired differently.
The amplifier is able to determine the exact frequency that the transceiver is tuned to. It then automatically switches to the correct band and if amplifier has an ATU fitted, recalls the appropriate ATU setting from memory.
Pro - The ATU in the amplifier is able to more accurately match the antenna before you transmit.
Con - May make it difficult or impossible to control the transceiver from your computer e.g. for logging software.
The amplifier is able to determine the amateur band that the transceiver is set to. It then automatically switches to the correct band.
Pro - Doesn't use your Cat/CI-V connection so you can use this to control your transceiver from your PC e.g. for logging software.
Con - The ATU in the amplifier can only coarse tune the antenna when switching bands and can only determine the exact operating frequency when you begin transmitting.