[Elecraft] KX3 IMD vs DC input, using built-in 2 TONE

[Erik Basilier]

I am testing my KX3 / KXPA100 combo, looking at TX IMD and power output
depending on the DC power supply characteristics. I am experimenting with a
N8XJK Boost Regulator (40A max) as well as an Astron linear supply adjusted
down to low voltage, simulating a run-down battery. 

 

To judge IMD I use the built-in 2 TONE, mix down sampled output to audio,
and feed into Spectrum Lab.

 

When I look at the envelope, its smallest amplitude is about 1/3 of peak.
This suggests that the 2 tones are not of equal amplitude. Has anyone else
seen this? I downloaded the laterst firmware about a week ago.

 

Thanks,

Erik K7TV