On 4/10/13 1:44 PM, Jack Brindle wrote:
Maybe.
Putting a major noise source (micro controller with lots of high-speed clocks)
right at the single most important quiet area might not be that good of an
idea. Adding chokes and bypass caps to knock down the noise can only go so far.
I'd rather not have the noise generator at the antenna in any case.
Which brings up the question, what kind of birdies and noise does the Green
Heron and similar devices add?
It's not all that tough. The things don't radiate all that much, and
putting them in a decent box with appropriate feed throughs works pretty
well.
I'm running the Velleman relay board into a RCS-8V and sending RS232 to
a LDG antenna tuner. The computer and relay board is in a regular sheet
metal aluminum box with a SMA feed through for the WiFi antenna. The
relay control lines and the RS232 are both run through a filtered D sub
connector that I happened to have, but realistically, the filter isn't
all that great down low.
I think the saving grace is that the CPU clock frequency is 16 MHz, so
most of the noise is well above the HF band, and in any case, none of
the harmonics fall in ham bands. ANd for my newer work, I'm using
Teensy3 computers (smaller than Arduino, faster, and cheaper) which have
a 50 MHz clock.
Granted, I'm in a suburban residential area with a fairly high hash
level overall.
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