c. Test procedure 48. If the lower portion of the keying circuit is
bad (zero ohms between pins C and A J5) further divide the lower keying
circuit by disconnecting the CX-13062/U from the KY-57 AUDIO jack (Figure
Remeasure continuity between pins C and A J5 (TP1).
If the meter now indicates zero ohms, the CX-4723, J-3513, or CX-
13062/U are the possible bad items.
If the meter now indicates infinite ohms, the KY-57, CX-13061/U,
or J-3513 is bad.
RT keying, continuous keying (lower loop).