[Elecraft] Harmonics from K3

2011-10-27 Thread PKA
I have been measuring the level of harmonic spurious from my K3 #3674 and came up with some interesting results. I measured with the K3 connected to a dummy load and to my antennas (loop for 80-40-30 and 17m dipole for higher bands, both antennas fed by 450 ohm feeder and Elecraft 4:1

Re: [Elecraft] Harmonics from K3

2011-10-27 Thread Jack Smith
Poul-Erik: You have an implicit assumption that the spectrum analyzer to transmit antenna has a flat response with respect to frequency. That's unlikely to be the case. Another assumption is that the spectrum analyzer antenna is in the far field of the antenna. This is also unlikely to be the

Re: [Elecraft] Harmonics from K3

2011-10-27 Thread Dave Johnson
I used a RohdeSchwarz FSH8 portable Spectrum Analyzer using a short wire in the input connector center pin to pick up the signal from the antennas Using such a wire pick up will exaggerate the higher frequencies and not give a flat response. You need to use a resistive tap or power attenuator in

Re: [Elecraft] Harmonics from K3

2011-10-27 Thread Robert Friess
Hello Poul-Erik, If your K3 is putting out 100 watts, it is very unlikely that it is generating the harmonics that you are measuring, especially in the case of the even harmonics. Your measured results may be due to some non-linear element in the near field such as a corroded or loose connection

Re: [Elecraft] Harmonics from K3

2011-10-27 Thread PKA
: Elecraft@mailman.qth.net Emne: Re: [Elecraft] Harmonics from K3 Poul-Erik: You have an implicit assumption that the spectrum analyzer to transmit antenna has a flat response with respect to frequency. That's unlikely to be the case. Another assumption is that the spectrum analyzer antenna