[Elecraft] Using Elecraft KPA-1500 for 2 radios

[Jim Brown]

On 3/17/2019 1:26 PM, Charlie Wirth wrote:
> Other than disconnecting the send and control cables from the 1500 that go to the Flex and plugging in the same cables from the 7700 is there any other way to have both sets of cables connected to the amplifier safely?

Several thoughts. First, both of Elecraft's power amps nearly 
instantaneously detect the frequency of the drive signal, no there is no 
need for the rig to send band information to the amp. Second, ALC should 
never be used to set TX power -- that should always be done by setting 
the output power of the rig.

The only necessary connections are the "amp key" line that puts the amp 
in transmit mode and the coax between the rig and the amp input. 
Switching the coax is easy with a SPDT coax switch or relay.

Most of the rigs I've owned use a short on the key line to key the amp. 
If both of yours do that, you can probably connect them in parallel to 
the Key input of the power amp using an RCA Y-cable. I've done that for 
years to switch my K3 between my KPA500 and a 1500w tube amp (for many 
years a Ten Tec Titan, now an 87A).

73, Jim K9YC