Hi Hiram,
I use my Elecraft KX2 as a QRP exciter to operate on 5346.5 kHz USB with my Elecraft KPA1500 set to Band 5; staying well within the permissible 100W PEP ERP limit.? The built-in ATU of my KPA1500 even provides VSWR matching for my experimental 60M antenna.
I certainly wouldn't want to pair my LA-1K with the Elecraft KX2 in like manner for reasons cited in my posts here
/g/la1k/topic/99360701#1316 under the topic of FCC ID: 2ANZ2-LA-1K.
73,
Ray
KJ5MI