[Milsurplus] BC-AO-229 questions

[John Franke]

The BC-AO-229 TRF receiver has a few oddities when compared to many of the other BC-229 series receivers. I am looking for schematics and possible descriptions of two. The first is the "DFI" jack on the lower right-hand corner of the front panel. I assume DFI stood for "direction finding indicator" and was possibly used when the the receiver was coupled to a DU-2 loop antenna. Maybe the DFI was just a AGC signal strength meter. The second involves a switch on the left-hand side of the front panel below the single antenna post and is labeled "A-L." I was thinking it was used in conjunction with the DFI. I am guessing the antenna post was connected to the DU-2 when doing direction finding and the switch changed the antenna matching for the receiver frontend. And, in the A position the receive matching network was what one would expect with a normal BC-229 setup. 
If anyone can provide schematics or other information to help clarify, I would be grateful for the assistance. 

John WA4WDL