Hi Mike, I am only testing various functions with my Hamshield so no real
opinion about aprs.
I have measured the current consumption.
My Hamshield is modified with "power led" and "TX-led" so my numbers
are a little bit higher than standard.
With HandyTalkie sketch RX with SqueclhOn 82 mA and transmitting 330 mA.
Output was 0.1 W.
Using my Bird 43, Fluke 77 and
Power source was 9 volts from big Daiwa PS .
/ 73 Tommy