Internal Antenna Tuner - Kenwood TS-990S Instruction Manual

receiver and the sub band receiver. This will result in a
sensitivity reduction of approximately 3 dB with a noise
level rise by 3 dB.
To prevent the sensitivity reduction, turn OFF the sub band
receiver or connect an antenna different from that for the
main band.
RX ANTENNA
You can select an antenna to be dedicated for reception.
To operate the transceiver with an antenna dedicated for
reception, such as an HF low band Beverage antenna or
a directional loop antenna, you must connect the antenna
to the RX IN connector on the rear panel. You can insert a
homemade or commercially available BPF, trap filter, etc.
between the RN IN connector and the RX OUT connector.
1 Press [RX ANT].
Each key press toggles the antenna for the selected
operating band between active and inactive.
While active, "RX" appears on the main screen.
If the same antenna (ANT1 to ANT4) is configured for the
main band and sub band, the RX antenna for the deselected
band is also changed. RX ANT settings, if any, made for non-
operating bands will be disabled when the RX ANT settings
are made for the target operating band, provided that the
antenna for the main band is different from that for the sub
band.
DRIVE OUTPUT (DRV)
The frequency ranges that can be output from the
Drive (DRV) jack are 135 kHz (135.700 kHz to
137.799 kHz) and the 1.9 to 50 MHz amateur bands.
The output level is approximately 1 mW (0 dBm).
1 Press [DRV].
• The "DRIVE" LED lights green.
• If the transmit signal is sent from the DRV connector,
no signal can be transmitted from the ANT1 to ANT4
connectors.
Contents Index
• Following the configuration in Advanced Menus 11 (Linear
Amplifier Control (HF Band)) and 12 (Linear Amplifier
Control (50 MHz Band)), +12 V is sent from pin 7 (RL) of
the REMOTE connector.
• The PWR meter is inactive while transmitting from the DRV
connector. The automatic level control (ALC) circuit will
operate if the ALC voltage input from external equipment
is applied to the ALC pin of the REMOTE connector. In
that case, the ALC meter will indicate the operating status.
The DRV output level will be in control only if the ALC
voltage input is applied. Therefore, the output level will be
determined according to the MIC input or the CAR control
setting. Furthermore, you can turn the [PWR] control to
reduce the output.
Note:
◆ Be sure that the connection for use with the drive output is in place,
as described above.

INTERNAL ANTENNA TUNER

As explained in "ANTENNA INSTALLATION AND
CONNECTION", you will have the best performance when
matching the impedance of the coaxial cable with the
antenna. {page 1-1}
To adjust the impedance between the antenna and the
transceiver, use an external antenna tuner or the internal
antenna tuner.
SECURING THE MATCHING TO THE ANTENNA
1 Select the transmit frequency.
2 Press [ANT] (F) to select the antenna.
• Ensure that "ANT 2" has been selected if the internal
antenna tuner will be used and if the external antenna has
been connected to the ANT1 connector.
• If the external antenna has been connected to the ANT1
connector, the internal antenna tuner cannot be used with
"ANT1" selected.
3 Press and hold [AT/TUNE] to tune.
• The transceiver is placed in CW mode, and tuning begins.
The transmit power will be "10 W", the SWR meter will be
selected as the transmit meter.
• After the tuning has completed, the blinking ">T" lights.
While the antenna tuner is enabled during the reception,
the blinking "R>" also lights.
• To stop tuning, press [AT/TUNE] again.
• If the Standing Wave Ratio of the antenna is extremely
high, such as 10:1 or higher, a Morse code "SWR" alert
sounds and the internal antenna tuner turns off.
• Adjust the antenna system to lower the Standing Wave
Ratio before tuning again.
BASIC OPERATIONS 4
4-21