02 Antenna Switching Circuit; Signaling Paths; Using The Same Antenna Connector For The Main Band And The Sub Band - Kenwood TS-990S In-Depth Manual

02 ANTENNA SWITCHING CIRCUIT

Signaling Paths

The TS‑990S has 4 antenna connectors, ANT1 to ANT4, and the RX IN and RX OUT connectors that can be used for a
reception‑dedicated antenna input or an external filter connection.
There is more than one path from the antennas to the receiving circuits, and these paths can be changed according to
the configuration. The paths from the antennas to the receiving circuits can be specified for each reception band in the
main band and the sub band. The antenna terminals that are not specified are connected to GND.

Using the Same Antenna Connector for the Main Band and the Sub Band

ANT 1 ANT 2
AT
FINAL
Fig. 1
When the antenna specified for the sub band is the same as that configured for the main band, signals are routed as
illustrated in the figure "Signaling Paths with ANT1 for the Main Band and ANT1 for Sub Band". The signals received by
the antenna are split nearly equal to the main band and the sub band, by a splitter. In this case, the readouts of the S
meter with the gain corrected in the reception path are processed to be the same readouts that are indicated when no
receive signal is split by the splitter.
2
ANT 3 ANT 4
RX (OUT)
Signaling Paths with ANT1 for the Main Band and ANT1 for the Sub Band
BPF, etc.
RX (IN)
Each Relay is in the
Off state (inactive).
Splitter
3 dB loss
MAIN
SUB