Key, Keyer, And Computer-Driven Keying; Interconnections - Yaesu FT-991A Operating Manual

Installation and Interconnections
Key, Keyer, and Computer-Driven Keying Interconnections
The FT-991A includes many features for the CW operator. These functions will be detailed in the "CW Mode Opera-
tion" section later. This 3.5 mm, 3-contact jack accepts a CW key or keyer paddles (for the built-in electronic keyer), or
the output from an external electronic keyer.
The Menu selections permit configuring the front panel KEY jack according to the device connected. For example, a
keyer paddle may be connected to the front panel KEY jack, and Menu item "012 KEYER TYPE" used to select paddle
input.
The KEY jack on the FT-991A utilize "Positive" keying voltage. Key-up voltage is approximately +3.3V DC, and key-
down current is approximately 4 mA. When connecting a key or other device to the KEY jack, use only a 3-contact
( "stereo" ) 3.5 mm phone plug; a 2-contact plug will place a short between the ring and shaft ( ground ) of the plug, result-
ing in a constant "key-down" condition in some circumstances.
KEY NC GND
Single key/Double-speed key
If the Keyer plug is removed from the jack while the FT-991A is in operation,
the FT-991A may be switched to the transmit mode.
Turn off the power of the FT-991A before connecting or disconnecting the Keyer.
F T-991 Operating Manual
KEY GND
DOT DASH COMMON
DOT DASH COMMON
Manipulator
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