| FTDX1200 Operating Manual | Page 47 |
When any (or all) of the three optional units are connected, they will be automatically adjusted to center on your operating frequency.
The narrow bandwidth is especially useful on the low bands, when may strong signals are being received via NVIS propagation (Near Vertical-Incidence Signal) within a narrow bandwidth. The added protection for the RF stage is especially helpful in preventing IMD and blocking.
| FTDX1200 Operating Manual | Page 47 |