[Eliot Ness]

but I do not know what you mean by a "Ten turn Link".

I think Chas is talking about ten turns of solid hook-up wire coiled into a two inch loop.  One end connected to signal generator out and one end to signal generator ground.  Use it to couple the output of the signal generator into the radio.
   

Though the alignment method of signal input is possibly a direct connection to a grid.  I suggest using a ten turn link made of solid hookup wire into a 2" diameter hank, even five turns will work. Connect this link to the hot and shield from the RF generator. Plug the generator into an outlet not common to the radio as well. This more completely isolates the RF generator from the radio so only injection point is the link which can be brought near the grid of the mixer. I do not think that will greatly improve the "booming" audio issue in of itself but may help to redefine the peaks of the IF more correctly.