Hallicrafters Dd1 Communication Receiver Instructions

The A and B balance control consists, as Indicated by the schematic, of two controls on one 
shaft. In order to obtain most satisfactory diversity reception it has been determined that the 
gain of each receiver section should be relatively the same. 
Where the signal input to the two receivers is unequal as shown by a lower average reading on 
either A or B diversity meter it will be necessary to reduce the gain on the side getting the 
greater signal. This is accomplished by turning the A or B balance...

REJECTER THEORY AND OPERATION  
The Infinite Adjacent channel Rejecter enables the operator of the Model DD1 Receiver to 
cope with Interference more capably than ever before. The Frequency at which rejection 
occurs is indicated by the position of the pointer in reference to the calibrated scale. This 
control varies the amount of bucking capacitive coupling between the coils in the I.F. 
transformers from 3 KC to 18 KC. Rejection is accomplished by so arranging the Inductive 
and capacitive coupling in...