[Elecraft] P3 Questions

[pastormg2 at verizon.net]

I am condidering a purchase of a P3 with my k3. Do I understand correctly that I would need an additional power supply for the P3?  Or would I be able to connect it to the power jack on back of the k3 for power?  If I need an addiitonal power supply that's going to make the equipment jammed packed.  But I also read on the reflector that the power jack on the back of the K3 doesn't have sufficient amps to run the K3.  Any advise would be greatly appreciated.  Mark KB3Z