TM721A.6

Subject: KENWOOD TM-721A TIME OUT, FREQ, & X BAND MODIFICATIONS,

To operate the TM-721A in the repeater cross-band mode, chip resistor
R121 on the control unit (X53-3130-XX) (B/3) must be removed.  The
following modification will detail how to access the resistor.

1.  Disconnect the power supply and antenna from the transciever.
2.  Remove the top and bottom covers (12 screws).  Do not damage the
    speaker wires when removing the top cover.
3.  Remove the silver colored screws from the front panel chassis (2
    on each side, 1 on top and 1 on the bottom).
4.  Carefully pull the front panel away from the body of the trans-
    ciever (DO NOT disconnect any cables).
5.  Locate chip (surface mount) resistor R121 on the control unit in-
    side the front panel.  Unsolder and remove the resistor.

        NOTE:  There was an illustration with my instructions that
        showed the location of the resistor specifically.  In order
        to acurately perform this mod I HIGHLY recommend you purchase
        the service manual for this product.  It has illustrations
        that show the resistors location.  Surface mount chips are
        extremely difficult to work with and near impossible to
        replace without surface mount rework equipment.  This is my
        warning and disclaimer to you.

        NOTE:  Read the time-out timer paragraph before you perform
        step 6.

6.  Reassemble the transciever by reversing steps 1 - 4.

TIME-OUT TIMER

The TM721A provides a built-in 3 minute time-out timer.  This automatic-
ally places the transciever in the recieve mode after 3 minutes of
continous transmit.  This function can be defeated by removing resistor
R122 on the control unit inside the front panel.