Kenwood TM-261A - Manual (Page 12)

ACCESSORY CONNECTIONS
■ External Speaker
If you plan to use an external speaker, choose a
speaker with an impedance of 8 Q. The external
speaker jack accepts a 3.5 mm diameter mono
(2-conductor) plug. Recommended speakers include
the SP-50B and SP-41.
To communicate in the voice modes, plug a 600 Q
microphone equipped with an 8-pin modular connector
into the modular socket on the Front Panel of the
transceiver. Press firmly on the plug until the locking tab
clicks.