P3 spurious signals


farrerfolks <farrerfolks@...>
 

I have been playing with the P3 now for a week and while in the band segment I generally use, it has been excellent. However, While I had the K3 and P3 on, I disconnected the antenna to reroute it and notice alot of signals on the display. Not just a couple but dozens from 160 meters well past 80 meters. And three kinds,

1. A series of mixing products that crisscross the display as you tune the K3. This is like a picket fence in the 3 to 4 MHz range.
2. Very noisy carriers that are fixed frequency in the same range.
3. A slowly downward drifting signal starting at approx 3960 KHz that pulsed and had approx 240 modulation components in the sideband. Sounds like a display refresh. All can be heard on the K3 as you tune through the band.

These signals are in the range of -105 dbm level. With no antenna the noise floor is -140 dbm. When connecting the antenna, the noise floor is around -125 dbm. Interesting, that the signals do not change when the K3 preamp or ATT is selected. When you select one of the signals on the K3 and turn off the P3, they go away. Disconnecting the RS232 or the RF cable does not make them go away on the display.

I would like to know if this is something generic to the P3 or that I have a problem with my unit.

Mel, K6KBE

Join Elecraft-K3@groups.io to automatically receive all group messages.