One other option is to use a T-9090 II or Yamaha T-85 when DX signals arrive from similar great circle bearings to the local transmitter site.

It is very important problem to achieve adjacent channel duplex in radio communication, that result in to eliminate the large signal blocking interference from local transmitter in reciever.

The author's main work is the development of the lo (local oscillator) in DTV transmitter, it is one of the important research projects planned by Shanghai Mingzhu Company.