Bias for transistor 168 is provided by current via {HEAD ~ return resistor} 174 coupled between {TAIL ~ the base} thereof and the voltage source A 
coupled between
Bias for transistor 168 is provided by current via { HEAD ~ return resistor } 174 coupled between { TAIL ~ the base } thereof and the voltage source A
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH