[Drake] R4B antenna connector

[John King]

I have acquired a Drake R4B receiver and it is different from all my other 
Drakes in that it has a BNC connctor on the rear of the chassis which is labeled 
"ANT" and next to the antenna connector  is another BNC connector with the label 
"spare" .

Did any of the R4B receivers come from the factory with two BNC connectors on 
the rear of the chassis in those positions?

Is it possible that the RCA phono jacks were replaced by someone with BNC 
connectors? Would the holes in the apron of the chassis have had to have been 
enlarged to install the BNC connectors? If that was the case, it would probably 
be best to leave the connectors as they are/ Your input, please. Thanks and 73, 
John, K5PGW