Federation Commander

The latest version of (as opposed to the hydran attack version) Direct fire defense has added 'offensive jamming' of enemy ships, however it still puts this as a sub catgeory of direct fire defense.

Direct fire defense says;"A given ship cannot get a shift of two by using two channels"

Which begs the question; if I use a sensor on one of my ships (5S4a), and a sensor on the enemey ship who fires at my ship (5S4c), I have used 2 channels, but as they are on different ships do I get cumulative +2, or am I still under the above quote that my given ship can't benefit from the use of 2 channels in 1 impulse even though they were used on different ships to benefit the 1 target ship.

[edit] - Supplemental question:

Plasma defense says the use occurs during the ADD portion of defensive fire. Does this mean that the 25% reduction occurs then, or only that you declare the use then, and calculate the 25% reduction at the point of applying damage (which may be after phasers have reduced the plasma). e.g a Pl-F hits for 20. If I do 25% during ADD part of the phase then the plasma loses 5 and phasers may reduce it another 10 to 5 left. Or do I fire phasers reducing it to 10, then calculate 25% and end up taking 8.

(these both came up last night during a game)

First question:
No, you may not use two different channels in different modes to get a combined shift of two. The prohibition is part of the base rule (5S4), so regardless of the mode used (in 5S4a, 5S4b, or 5S4c), the prohibition applies.

Second question:
The reduction applies immediately. So, if you pay the energy and use the channel, the 25% reduction is immediate at that point. Any subsequent phaser fire will then apply to the remaining warhead.