[Elecraft] [K2] Receiver overload protection

[Don Wilhelm]

Matt,

Yes, I moved the decimal in the wrong direction!  Your calculation is 
correct.
If you have the K2 connected to an antenna near other antennas that is 
being used for transmit, then I would strongly recommend that you either 
disconnect the antenna from the K2 (or KX3 or any other receiver) during 
the time you are transmitting.  That could be accomplished automatically 
with relays, but if you are not doing SO2R, manual antenna switches will 
do that task just as well.

73,
Don W3FPR

On 5/2/2014 5:59 PM, Matt VK2RQ wrote:
> Thanks Don. I was chatting to a fellow KX3 owner about how the KX3 protects itself in the presence of strong RF, and he remarked that my K2 would probably do the same. When I looked into it, I was reaching similar conclusions as you, although I didn't find any information about maximum signal ratings for the mixer.
>
> BTW, 39mW corresponds to 16dBm, which is indeed huge. I calculated 0.14Vrms to be more like -4dBm (ie. an S9+69dB signal), but maybe there's a stray decimal point, or I've missed an assumption somewhere.
>
> Anyway, best thing is to take some measurements, and see if an external protection device is warranted. Thanks to Steve for the diode suggestion when using separate receive antenna.
>
>