[Elecraft] [K1] Internal Noise Bursts every 12 seconds or so

[Bob]

I just completed assembly of a 30m/20m K1 up through the point of Receiver
calibration.  Everythings has gone smoothly and all tests and alignment
steps were completed successfully.  I can hear a 1 uV signal very clearly
on both bands.

However, there appears to be some internal periodic noise.  It is very
raspy in nature and it repeats every 12 seconds.  I'm guessing it is being
generated by one of the two internal CPUs.  I hear it on battery power with
a shorting plug installed on the antenna, on any frequency and on both
bands.

Basically I hear a low level burst noise that lasts for 1/2 second, with
about a 1/2 second gap, followed by a 3 second burst, then silence for
about 8 seconds.  The entire pattern repeats every 12 seconds

While it is very low level, comparable to the 1 uV signal that I aligned
the receiver with, it seems to modulate even strong S9 signals.

Does anyone know what this noise is and how to get rid of it?

Anyway, this glitch aside, I'm very excited.

73, Bob, WB4SON