[Elecraft] K3S relay noise when using Rx ANT IN port

[Don Wilhelm]

Ray,

Your transmit signal is getting into your RX antenna with more energy 
than is safe for the K3S.  10 meters is not much separation unless the 
antennas are oriented so one is not in the null pattern of the other.

Using antennas that are of opposite polarization (such as a horizontal 
dipole and a vertical) may be OK for a 10 meter separation, maybe not.

There are protective devices available that will disconnect the RX 
antenna when the K3S is transmitting, and use of one of those may be the 
quickest and easiest solution.

73,
Don W3FPR

On 2/1/2020 5:21 PM, raycollins wrote:
> 
> My K3S is configured to use the RX ANT IN port for a separate Rx antenna.
> However, on SSB transmissions I can hear an internal relay operating in
> synchronism with peaks in transmit power.  I assume this is a relay in the
> receiver input protection circuit?
> 
> Is operation of the relay in this manner normal? Apart from finding the
> noise rather irritating I am concerned about the reliability of the relay
> when it is called upon to operate so many times during a QSO.
> 
> The Tx and Rx antennas are about 10 metres apart and I am transmitting 100
> Watts.
>