[Elecraft] K2/100 and KPA100 SWR bridges

[Ron]

Hi ,
      I would have to say that the K2/100, coupled with the KAT00 is 
probably one of the few radios I know of that have two SWR bridges in 
series/parallel. How do they work together?
The VRFDET of both is joined together via pin 7 of J3 between the ATU and 
the KPA100 and ultimately end up on pin 2 of the main MCU on the control 
board. Ok, that detects power levels I believe, but what happens if either 
SWR bridge stops functioning?
The VFWD and VREFL lines from each SWR bridge both go to their respective 
MCU's on the boards they are derived from, and one can only assume they 
dissapear as a signal back to the main MCU again via the Aux Bus ???   But 
if they do and are in parallel, once again, how do they work? I imagine 
there is some programming magic applied here somewhere.
I can also see that removing the SWR bridge when you plugged a KPA100 in 
would be virtually impossible, but one of the big NO NO's in Ham Radio is 
putting your SWR bridge before the ATU, so how does Elecraft get away with 
this one?
I seem to remember the KAT2 can be used in series with outboard amps and the 
like, but I also seem to remember they were "removed" by software...as such. 
Perhaps this applies to what I am asking about, but I think not 
....especially after having diodes shorted in the KPA100 and KAT100 
seperately and both times the K2 was affected the same way.( ok.... I forget 
to remove my antennas when lighting is around)
Just curious, and thought it might realign the Reflector with radio problems 
rather than horticulture? [G]
Cheers.......Ron ZL1TW