[Elecraft] KPA-500 band data input

[Don Wilhelm]

Brian,

The open BCD lines should signal 60 meters to the KPA500.  See the band 
data chart in the K3 manual.

The normal way the KPA500 works (with the K3) when you press a band 
button on the KPA500, it communicates that information to the K3 over 
the AUXBUS - the KPA500 does not receive information from the K3 over 
the AUXBUS, information flows only from the KPA500 to the K3.

Then the KPA500 waits until the K3 switches bands and presents data on 
its BCD outputs - at that time, the KPA500 switches to the same band as 
the K3.

Are you breaking the K3 to KPA500 BCD outputs with your antenna 
switching hardware?  Ideally I would think the antenna switching would 
only listen in on the K3 BCD outputs and react accordingly, but you may 
have implemented something more complex.

73,
Don W3FPR

On 1/5/2013 8:34 AM, Brian Alsop wrote:
> Question: What "band" is selected when the Radio=BCD and the inputs 
> are open?
>
> It appears to revert to RF sensing.
>
> The situation is this.  Antenna switching stuff automatically echos 
> the band BCD data to the KPA-500.  The exception is if one manually 
> selects an antenna.  In that case power to the auto mode PIC is turned 
> off and one gets whatever the PIC outputs are with no supplied Vss.
>
> 73 de Brian/K3KO