TNC2.13 
(4)  Put the 1" long sleeving over each end of the 1 kohm resistor. Make a 
     hook  in  one end and loop around the lead of the new  1.5  kohm  R34 
     nearest  to the battery (the end that goes to the  LED).  Solder  the 
     other end to U14 pin 8. That's it!
 
The  way  this circuit modification works is as follows:  when you are  in 
receive,  the LE^@?is being driven by +5V thru R34 and a high output  level 
from  the  gate at U14 pin 8,  resulting in normal  brilliance.  When  you 
transmit,  U14 pin ^@ goes low, resulting in lower current thru the LED.
IF you wish to reverse the sense of the LED (dim on receive, bright on xmit), 
take the U14 end of the 1 kohm resistor to pin 9 instead of to pin 8
     improve the heat conduction from the 7805 to the aluminum cabinet:
     a. Drill  a small hole (to clear the 4-40 or 6-32 screw in step b.) in 
        the  bottom of the case to line up with the mounting screw for  the 
        7805  regulator.  this should be 1.32" from the front lip  of   the 
        case and 0.55" from the side of the case.
CONTINUED IN FILE TNC2.8