[ICOM] IC-746 PRO Keying

[Larry L. Hinton]

Hey all.

I understand the confusion. The Instruction Manual (A-6085H-1US-2) states: 

a. Iambic Key paddle: Use a 6.35(d) mm (1/4") STEREO plug and connect to the
[ELEC-KEY] jack located on the front of the radio.
b. Straight Key: Use a 6.35(d) mm (1/4") MONO plug and connect key to the
back of the radio.
c. External Keyer: Use a 6.35(d) mm (1/4") MONO plug and connect to the back
of the radio.
d. Computer Keying: Use a 6.35(d) mm (1/4") MONO plug and connect to the
back of the radio.

HOWEVER, the wiring diagram for the straight key (diagrammed to the [KEY]
jack on the back panel) shows a "STEREO" plug with the tip as (+) and the
sleeve as (-).

I found the service manual and took a look at the keyer [KEY] jack for the
back panel. It actually makes no difference which plug is used as long as
the (+) is tip and the (-) is on the sleeve. According to the schematic, the
ring is not connected unless someone has modified the unit so shorting the
tip and ring in this jack is not an issue.

Larry
K7YBZ

>> IIRC (I'm away from home), the straight key is supposed to use the TIP
and SLEEVE of the key jack. The 2-circuit plug in 
>> the 3-way jack would continuously ground both TIP and RING contacts.