[R-390] R-390a modified IF sub-chassis

[Larry H]

This mod does require a panel mod.  The original BFO switch needs to be changed to a 2 pole 2 position in order to switch the audio.  This looks pretty clear to me on the schematic Gary supplied.  This is the same technique used by Lee's original mod.  So, this IF unit will not work in another R-390A with out the associated wiring and switch change.

Regards, Larry