DRA-52 Header / Jumper Settings:

Header - Jumper Summary:

JU1 - Selects "A" (Right) or "B" (Left) transmit audio to DIN radio connector.
JU2 - Remove this jumper to disable AllStar Link COS. 
JU3 - A = 1200 Baud, B = 9600 Baud receiver audio selection (radio dependent) 

Default Settings:

JU1 is placed in the "A" position and uses R14 to adjust the transmit 
(TX) audio level.

JU2 is removed for VARA FM or other digital mode usage.

JU3 is placed in the "B" position for wide-band (9600) operation.


Detailed explanation of these headers and jumpers:

JU1 - LEFT or RIGHT TX Audio Output:
This header selects between Left or Right transmit audio channels. 
A = Right - - B = Left.
A uses R14 to adjust TX level and B uses R16 for transmit level control.
Default is A - Right.

JU2  - AllStar Link COS logic input:
This header is used for AllStar Link and its jumper should be removed for VARA FM 
or other digital modes. This jumper can be installed to enable AllStar Link.
Default is removed or side-stepped.

JU3 - Receiver audio baud rate selection. 
This header is right behind the DIN-6 radio connector.  It's in a tight location 
and has a jumper with a (blue) handle to make repositioning a little easier.
A = 1200 Baud, B = 9600 Baud receiver audio selection (radio dependent)
Default is B - 9600 Baud.