ICOM IC-706 Interconnection Diagram with

Optional Receive and Transmit Audio Connections.

3-Conductor 1/4”
Phone Plug
Female DB-9 Plug Optional Mix 73 CW OUT Sleeve Ring Tip
(Pin #’s Shown) or Mix 77 Ferrite To Xcvr Rear
Bead (8 Places) Panel Straight
DTR Key Jack
CW GND GND NC KEY
4 CW IN
NC = No Connection
See Note 3
CW Out
Shield 3-Conductor 1/8"
TXD Mini-Phone Plug
3 FSK IN Sleeve Ring Tip
To PC Soundcard
To Ham Shack Line Input (See
PC COM Port Note 6)
RTS GND Audio Audio

7 PTT IN To FSK/
PTT
3-Conductor 1/8"
GND
Point Mini-Phone Plug
Sleeve Ring Tip
To PC Soundcard
GND Line Output (See
5 IN GND Note 7)
See Note 4 GND Audio Audio
To FSK/
PTT
DB9
Connector
In GND
Shell Shield Point Male 13-Pin DIN Plug
(Pin #’s Shown)

See Note 3 Audio

To Xcvr
11
Audio
From Xcvr
12

To Xcvr Rear
FSK OUT 10 Panel ACC
Jack

PTT OUT 3

FSK/PTT
GND
2
See Note 4

FSK/PTT DIN
Connector
FSK/CW Interface Shield Shell

Board in Optional
Metal Enclosure See Note 3
See Note 5

Notes:
1. The connections shown above are based on available documentation but have not been verified. Please review and use your own judgment
before making any connections.
2. Make sure the transceiver RTTY settings are set for normal polarity and 170Hz shift. You may set any desirable mark frequency that is available
in both the transceiver and MMTTY or other RTTY software you are using. IMPORTANT: Make sure that both your transceiver and RTTY software
are set to the same mark frequency.
3. This connection made by mounting the board with metal standoffs or connecting the interface board mounting hole to the metal interface
enclosure. You may also ground shields directly to the metal enclosure, if desired.
4. This connection optional. You may float the shield at the interface by leaving it disconnected and insulated from the metal interface board
enclosure.
5. If the cable used with the DIN connector is shielded, you may optionally connect the shield to the DIN connector metal shell. This will ground the
shield to the transceiver chassis.
6. For receiving with external RTTY software, e.g. MMTTY, MixW, etc, receive audio must be provided to the line-level input of the PC soundcard.
It is preferable to obtain this receive audio signal from Pin 12 (AF Out) and Pin 2 (AF Ground) of the ACC jack as shown above. This receive audio
will support RTTY operation and PSK and other SSB digital modes as well.
7. Transmit audio for PSK and other SSB digital modes can be provided by connecting the line output of your PC soundcard to Pin 11 of the AAC
jack, as shown above.

Rev A – 12 Feb 2012