When the counted number reaches the predetermined maximum value, the squelch alarm signal is produced and maintained thereafter until a low level or {HEAD ~ a negative signal} is applied from {TAIL ~ the comparator} 21 to the AND gate 33 and the reset terminal R 
is applied from
When the counted number reaches the predetermined maximum value , the squelch alarm signal is produced and maintained thereafter until a low level or { HEAD ~ a negative signal } is applied from { TAIL ~ the comparator } 21 to the AND gate 33 and the reset terminal R
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH