[Collins] 75A-4 S-meter question

[Mac McCullough]

Hello all..  I have a 75A-4 mid 3k s/n ..   on the back terminal strip, it looks like a supplemental plate has been added  that looks like this

  S METER   STANDBY
     +     -          1      2
     o----o         o     o     


the 2 terminals + - are jumpered together  and nothing is connected to terminals numbered 1 and 2  

Have I just missed this on earlier 75a-4 sets I have owned ??  or is this something different..  all answers appreciated  , thanx  mac/mc


Located 46 miles due North of the Alamo, and 121 miles due South of the Western White House.   see my website at  www.collinsandharrisradios.com