[Hallicrafters] SX-71 Question

[Bill McCourt - WF1L]

Hi,
 
Maybe this a question you've responded to before but, is there a circuit to mute the SX-71 when it's used with a transmitter?
 
Is it just a matter of replacing the existing Octal jumper plug on the chassis backplane with an external pair of wires to a set of external contacts on a DOW-KEY TR relay like my Hammarlund?  Didn't see any reference to a Transceiving arrangement in the manual.
 
Bill - WF1L