[TenTec] Argosy 525 with amp?

[John Farler]

I want to try my Argosy 525 with an external amplifier for a little
more power.

Looking at the detailed block diagram on the back of the pull-out
in the manual, it a T/R relay assembly 80853 going to the center
RCA jack of the 3 spare jacks on the back of the rig.

There is no such assembly listed in the manual, and no diagram
of such an assembly, as far as I can tell.  I vaguely recall there
might have been an accessory to use here with a built in relay,
or some way to add one.

Obviously, if it was an add-on option there's not chance of finding
one.  But I wonder if someone has the information, and call give
me a circuit for adding one?  I haven't had the rig apart, but that
is the next step.

Can someone help with the circuitry to add the Amplifier relay?

Thanks,
73,
John Farler
K4AVX