[Elecraft] Interesting observations after installing antenna switch

[Joe Subich, W4TV]

Download (or look at) the schematic for the switch/controller.
It has 3.3V zener diodes across each of the BCD inputs.  The
K3/K3S has pull-up resistors to *5 V* on each of the BCD
outputs.

The switch is not allowing the inputs to the KPA500 to reach
the 5V necessary to resister as "High" thus the input is
always 0000 (or 60 Meters).

I suggest you contact the designer/manufacturer of your switch
and ask him what hi will do to fix his defective product (since
he claims compatibility with Elecraft).

73,

    ... Joe, W4TV

On 8/29/2023 3:37 PM, W3FPR wrote:
> Ken,
> 
> Check the voltage/current ratings on the band data lines for both the 
> amp and your antenna switch.
> It sounds like they may not be compatible.  60 meters is encoded as 
> "0000", so if the voltage is not high enough (perhaps due to 
> insufficient current), it will show 60 meters.
> 
> 73,
> Don W3FPR
> 
> On 8/29/2023 3:25 PM, ken.kj9b at gmail.com wrote:
>> Hi Ray.  Either I was unclear in my description, or it was mis-read.  
>> According to the display of the amplifier, it is ALWAYS set for the 60 
>> meter band, regardless of what band I am actually operating.
>>