Amplifier with Yaesu question
 

I have a Yaesu FT-767 coupled to an Ameritron AL-811. The cables, power
cords, etc. are all hooked according to instructions, but the amp, while
powered on, will not "kick" in.
The manual that came with the 767 (I bought this rig new) says only that
the TX GND phono jack is connected across contacts of a special
transmit/receiverelay in the FT-767GX, which are closed circuit during
transmission, and open circuit during reception. "Note: Internal switch
s2002 (on the rf unit) must be set to the ON position when the phono jack is
used.

What the manual fails to show is just where this switch is! Yeah, I know. It
is on the RF unit.

Can anybody shed some light on this? Thanks in advance.