[Hallicrafters] SX-24 Audio Question

[kirklandb at sympatico.ca]

My SX-24 schematic shows a 0.01 uf cap coming off of the plate of the audio amp tube and running out 
to the phone jack. On the two SX-24's that I've looked at, neither one have the audio jack connected this way.

One has the phone jack connected to the grid of the main audio amp, the other I am haven't traced out the wiring 
 to find out where it goes - but it doesn't go according to the schematic or the other sx-24.  This latter unit has a cap
running from the plate of the audio tube (6f6) to pin 6 of this tube (which shows as a no connect) but nothing else is 
connected to pin 6.

Just how should the phone jack be connected ?