Frequently Asked Questions

To operate on the 2m band the FDM-DUO have to be unlocked in frequency (up to 165MHz). To do this disable the low pass filter with menu 2 "RX LP" and set output type to 0dBm with menu 33 "TX OUT".

With output type set to 0dBm, the output signal is issued on the RF OUT sma socket located on the rear panel. External preselectors are needed and also an amplifier if you need more than 0dBm (0dBm is 1mW).

With these settings RX antenna connector can be used for VHF antenna (with menu 31 "ANTENNAS" set to 2) and RTX/TX antenna connector can be used for HF antenna (with menu 31 "ANTENNAS" set to 1). So two antennas for reception can be connected at the same time.

Even the FDM-SW2 software must be unlocked to operate on the 2m band. Starting from version 3.50 it is enough only to disable the option Lock FDM-DUO Max. Freq. in the Settings window.

For previous versions the procedure is different and is as follows : open the file FDMSW2SwSetup.xml with a text file editor, search for UnlockDUOt label and set it to 1. For details see "Annex C - Configuration Files" of the FDM-SW2 manual available here.