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