Well, is that 330 Ohms into the base of the 2N2222 and 4.7uF caps up and down?  if so that seems like a lot of capacitance, and not much current limiting into the base. Certainly not 4.7pF that's not enough to do anything except limit GHz rf. Speaking of rf, a few ferrite beads might be a good idea, they make tiny ferrite SMD parts now and that would go a long way to preventing some issues seen with rf at high level emi sites.    I presume JP1 and JP2 will be co-located so a jumper can bypass the inverter stage if necessary? I will buy one when it available!  W6MTF On Thursday, December 17, 2015 1:20 PM, Steven Donegan <donegan@donegan.org> wrote: Attached is a circuit design that covers breaking out the URI-X pins, supporting the EEPROM, a COS generator for radios which do not have one OR you don't want to hack the radio. What else might be useful on this board design? When it is 'done' I will have boards made and folks can buy them if desired. And Merry Christmas/Happy New Years BTW - please critique/validate the design. Steven Donegan KK6IVC General Class FCC License PP-ASEL Silver State Car #86 www.sscc.us _______________________________________________ App_rpt-users mailing list App_rpt-users@ohnosec.org http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users To unsubscribe from this list please visit http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-usersand scroll down to the bottom of the page. Enter your email address and press the "Unsubscribe or edit options button" You do not need a password to unsubscribe, you can do it via email confirmation. If you have trouble unsubscribing, please send a message to the list detailing the problem.