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[Elecraft] [Elecraft-K3] Interesting P3 Anomaly

Al N1AL
 

Yes, what you're seeing is IF leakage, not the RF signal.  The level level is uncontrolled and depends on the isolation of the PIN diode switches, etc.

Yes, you can see it by transmitting, with the RS-232 cable that normally goes between the K3 and the P3 temporarily disconnected.

Because it is the IF signal, it doesn't show distortion caused by the transmitter PA.  Still, it does display the frequency response of the transmitted signal, which can be useful when setting up the TX equalizer.

Alan N1AL

On 3/15/20 8:09 PM, David Box wrote:
Don't know what you mean "doesn't represent your transmitted signal" It is leakage of your signal at the IF, I see it with my SDR that is tied to the P3 IF out and it looks exactly like the signal I see on a spectrum analyzer using a coupler.
de Dave K5MWR


On March 15, 2020 8:11:07 PM CDT, Brian K0DTJ <huntinhmb@...> wrote:
As I recall, if you disconnect the RS232 thru the P3 to the K3 it the
P3 will display your spectrum since it doesn't know to mute during TX.
Someone from Elecraft said it was due to "leakage" and is at IF so
doesn't represent your transmitted signal. Seems like you found a
software way to do this. :-)