Phones Jack; Keypad Jack - Kenwood TS-990S In-Depth Manual

08 TERMINAL

PHONES Jack

The TS‑990S can accept a set of stereo headphones. There is an internal headphone‑dedicated amplifier available to
provide stable output even with high‑impedance headphones.
Also, the main band/sub band output mixing ratio can be configured in Menu 1‑07 "Headphones Mixing Balance", and the
left/right output reversing can be configured in Menu 1‑08 "Headphones Left/Right Reverse". In Menu 1‑07, the audio output
mixing ratio can be configured from 10 steps allowing you the comfortable and natural sound even for long‑term operation.

KEYPAD Jack

A maximum of four functions can be assigned to the PF key located on the TS‑990S front panel. Connecting a keypad to
the KEYPAD jack on the rear panel allows you to assign a maximum of eight functions to the keys of the keypad.
For example, if the message memory function has been assigned to the PF key, a voice message, CW message, FSK message,
and PSK message can be transmitted with a single press, for instance during a contest when quick operation is effective.
To make your own keypad, refer to the following circuit diagram.
Note:
◆ The circuit diagram merely shows a principle scheme. Before using a self‑made keypad, make sure it does not cause any
malfunction due to RF wave or noise interference. Adding bypass capacitors, inductors, and/or ferrite cores to the keypad
circuit may lower the possibility of malfunction.
◆ Internally, the terminal voltage is pulled up to 3.3 V, and the voltage obtained by voltage‑division with the resistance
connected to the terminal is read by the CPU through an A/D converter to detect which key is pressed.
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Fig. 132 PHONES Jack
Fig. 133 KEYPAD Jack
Φ3.5 mm plug
EXTP2
EXTP1
GND
Fig. 134 Example of a KEYPAD
R1
PF1
1.5kΩ
R2
PF2
1.5kΩ
R3
PF3
2.2kΩ
R4
PF4
4.7kΩ
Circuit
R5
PF5
1.5kΩ
R6
PF6
1.5kΩ
R7
PF7
2.2kΩ
R8
PF8
4.7kΩ