[Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery

[Wayne Burdick]

Hi all,

If you're powering the KX3 and a KXPA100 from the same large 12-V battery, and you've had a problem with the KX3 dropping power from QRO levels to 5 W, please contact me directly. I have an experimental firmware fix for this.

This only applies if:

- the KX3 is connected to the amp via the special control cable

- MENU:PA MODE set to ON

- the power control is set higher than 10 W

In this case (with the amp in-line), there was a bug where a drop in supply voltage to 11.0 V or lower would kick the KX3+amp into QRP mode (with the amp bypassed). 

A key-down drop below 11 V is not unusual with a moderately depleted 12-V battery running a QRO station. With the new firmware, the user can continue to use the amp anyway, at some appropriate power level. Of course you shouldn't try to get the full 100 W output in this case. For example, if the voltage is in the 11-V range on key-down, I recommend not using more than about 40-50 W. At 10 V (which isn't even safe to us with some 12-V batteries), you're better off using QRP levels and setting PA MODE = OFF to conserve battery power. 

73,
Wayne
N6KR