Key Jack; On/Off Switch; Phones Jack - Yaesu FT-991 Operating Manual

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ON/OFF Switch

Press and hold in this switch for one second to turn
the transceiver on. Similarly, press and hold in this
switch for one second to turn the transceiver off.
Connect the FT-991 transceiver to a commercial-
m
ly available DC power supply. Turn the DC sup-
ply on to place the transceiver in standby mode.
The transceiver must be in standby mode to turn
it on using the ON/OFF switch. For details on
how to connect a commercially available DC
power supply, see page 13.
Press the ON/OFF switch briefly while the pow-
m
er is on, the receiver audio from the speaker will
be muted for about 3 seconds (Mute function).

KEY Jack

Connect a telegraph key or electronic keyer paddle
to use for CW mode operation.
KEY NC GND
When connecting a single straight key
DOT DASH COMMON
When connecting an electronic keyer paddle
Page 18
c
ontrols
KEY GND
DOT DASH COMMON
& s
witches
5
9
m When connecting a key or other device to the
KEY jack, use only a 3-contact ("stereo") 1/4"
phone plug; a 2-contact plug will place a short
between the ring and the (grounded) shaft of the
plug, resulting in a constant "key-down" condi-
tion.
Key-up voltage is +3.3 V, and key-down current
m
is about 4 mA.
n :
ote
A 2-contact plug cannot be used in this jack.

PHONES Jack

Connect headphones to this ϕ3.5 standard stereo
jack.
Inserting a headphone plug into this jack will de-
m
activate the internal and external speakers.
n :
ote
When wearing headphones, we recommend that you
turn the AF Gain levels down to their lowest settings
before turning power on, to minimize the impact on
your hearing caused by audio "pops" during switch-on.
MIC Jack
This 8-pin jack accepts input from a microphone uti-
lizing a traditional YAESU HF transceiver pinout.
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F T-991 O
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DOWN
UP
+5V
MIC GND
MIC
PTT
GND
FAST
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peraTing anual