[Elecraft] KPA500/KAT500 paired with AL-1500?

[john at kk9a.com]

How do you control which amp's relay engages during TX? 

John KK9A

From: Mark E. Musick

I do this with my Alpha 9500. But differently than K9YC.
I use the two antenna ports on the K3 and an Alpha Delta 2 position switch.
Antenna one on the K3 goes to the KPA500 input. Antenna 2 on the K3 goes to
the 9500 input.
The output of the KPA500 goes to position one on the Alpha Delta switch. The
output of the 9500 goes to position two of the Alpha Delta switch. The
common of the Alpha Delta switch goes to the antenna switch. 
When I want the KPA500 the K3 is on ANT1 and the Alpha Delta switch is on
position one.
When I want the 9500 the K3 is on ANT2 and the Alpha Delta switch is on
position two.
Since the K3 remembers power by band and antenna, when I'm on the KPA500
regardless of band it has the correct power setting to give me 500 Watts or
200 Watts on 30 meters. When I'm on the 9500 the K3 has the correct drive
power for the 9500 for that band.
That is how I do it and it works for me.

Mark, WB9CIF