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

[Erik Basilier]

One more question:

Assuming that the 2 tones are about 2:3 in amplitude ratio, can anyone say
how that would be expected to affect the 3rd order IMD figures?

 

From: Erik Basilier [mailto:ebasilier at cox.net] 
Sent: Sunday, June 12, 2016 2:53 PM
To: 'Elecraft at mailman.qth.net' <Elecraft at mailman.qth.net>
Subject: KX3 IMD vs DC input, using built-in 2 TONE

 

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