Antenna 3 function notes.

101Cats includes a combo-box for each receiver to select the antenna configuration. The options available are Ant 1, Ant 2, and a third which is dependent on the configuration selected in the Operation Setting menu under ANT3 Select. Recent versions of 101Cats have included a combo-box named Antenna 3 Function, but this has omitted one supported option, TRX. This is now implemented, but subject to some controls that are described below.

The Antenna 3 socket on the FTdx101 series can be configured in several ways. These include options to connect an active receive antenna to it in order to reduce QRM/QRN. It can also be configured as a third transmit antenna. The problem with this is that if you connect an active antenna but configure the antenna 3 socket as a general purpose TX/RX socket and select it, the next time you transmit, you will push 100W of RF into the pre-amplifier of your receive antenna and almost certainly destroy it.

In order to address this, I've added a pair of configuration items to 101Cats. These are Antenna3 Permit TX and Antenna 3 Warn TX. They have been added to the configuration dialogue box. By default, they are both disabled. If Permit TX is enabled, then the TRX option in the Antenna 3 Function combo-box is enabled and you will be able to select it. This will, in turn, make the third option in the Antenna combo-boxes Ant 3. Setting the radio in this way will result in power being output on the antenna 3 socket.

If you turn on Antenna3 Permit TX, then the Antenna 3 Warn TX configuration option will be taken into account. Under these circumstances, the TRX option in Antenna 3 Function will become enabled and selecting it will enable the Ant 3 setting in the Antenna combo-box. But with the Antenna 3 Warn TX option turned on, each time you select Ant 3 as the antenna, you will be presented with a modal message box warning that this configuration could result in damaging an external receiver.