[Elecraft] [K2] KAT100 odd behavior cured by reset of KPA100?

[Don Wilhelm]

Bill,

That makes sense to me.  With KPA100 U6 removed, the KPA100 is not able 
to control power properly.  Turning the PA off in the menu restores the 
KAT100 to proper operation with the base K2.

73,
Son W3FPR
On 8/14/2012 1:37 PM, Bill Coleman wrote:
> OK, I had a failure of U6 EL5146C on my KPA100, which caused me to lose the RS-232 port, since the 5 V to power the MAX 232 chip was no longer present.
>
> Once I figured this out, I was troubleshooting the rig on the bench, and I was having trouble with the KAT100. My observations:
>
> * The KAT100 would not turn on immediately with the K2/100. It would take several seconds for it's lights to come on after the K2/100 powered on. A check of Q1 and Q2 revealed that they were working as expected.
>
> * Once on, the KAT100 would not respond to K2/100 control changes. Swinging the power control from low to high power would sometimes, but not always cause the KAT100 to change from low to high power and vice versa.
>
> * When activating the Tune or Ant1/2 functions, the K2/100 would respond with "not inst". Which is weird.
>
> * Looking at the primary K2/100 Menu showed the ATU selection showing "--". Pressing the display button resulted in "PA Ant1"
>
> Trying to diagnose this further, I ended up going to the K2/100 Menu for the PA and turned the PA off. After this, the KAT100 responded properly to all commands, and the ATU menu showed the menu items.
>
> Turning the PA menu back on and everything works. Weird.
>
>