[Elecraft] KAT2

[Aaron K5ATG]

I recently installed the KAT2 in my K2. Using a 20 meter inverted V dipole,
it was working great with no problems. Then I tried it out on a end fed
antenna and it also tuned it up. Then I switched back to my Inverted V and
every time I try to tune it up I get LO P on the display. I looked it up
and this means Low Power, so I increased the power to 15 watts and I still
get the same message. I can't increase the power any more. Does anyone know
what is happening?
Thank you

Aaron Scott