Beats me
It may be for an unused function in an institutional set etc. Had a LOT
of these apart to resolder or repair & dont remember it. You could see
where it can reach with a little slack. Also look at the Sams
& see if the tuner has any unaccounted connectors & where they go.
If me I would try the set. BUT dont blame me if it brews up !!
IIRC the chassis has pin connectors but no edge connectors UNLESS
they are on small sub-pcb's.
Maybe Johnct will pipe in. He has better grasp of RCA than me
73 Zeno
LFOD !