Sonic KSE-310 - Page 175

Ⅲ-IV-3
(2) Switching the logics
EXTERNAL SYNC signal input can be switched between the negative logic and
positive logic, which can be set at JP5 on the IF46B circuit board in the PRC-63
Type Computing Unit.
Fig. 4-2 IF46B circuit board silk-screen drawing and JP5
Table 4-3 Table of EXTERNAL SYNC signal input level switching
JP5
Logic
1-2 short
Negative logic (default setting)
2-3 short
Positive logic