[Elecraft] [K3] spurious carriers in vhf

[Pierfrancesco Caci]

Hello,
playing around with the new P3 and K144XV, I've realized that I have
many carriers spaced roughly 30 kHz, which are also audible in the K3
(so probably not a bad K3-P3 coax). See the top screenshot in this image:
https://www.dropbox.com/s/t29sf9bwfpedspa/vhf-carriers.png
When I move the VFO on the K3, these carriers are modulated in
frequency, and it stops immediately as soon as I stop moving the VFO
(bottom screenshot in the linked image).
They are always on those frequencies, and definitely don't match the
"fast birdies" description in the K3 manual (they don't move if I touch
shift). If I disconnect the antenna they are reduced in level but still
there. I can sort of hear some extra noise on a different vhf radio on
the same frequencies. 
So, what am I looking at and hearing here? Is it some harmonics from the
MCU clock? 

Pf

-- 
Pierfrancesco Caci, ik5pvx