On Mon,9/26/2016 12:29 AM, Hare, Ed W1RFI wrote:
<Does the searcher have an open mind?>
I can't begin to say how important this is.
YES, YES, YES!
One of the greatest "mind opening" tools is a spectrum display of the
noise. Here's my take on it. (And as I learn more stuff, I will add to
it.) That's more of the open mind.
http://k9yc.com/KillingReceiveNoise.pdf
But also check out the really neat stuff that NK7Z has been doing with
an SDRPlay ($130) that goes up to 2 GHz.
http://nk7z.net/sdr-for-rfi-survey-p1/
Dave uses the SDRPlay with HDSDR software running on his PC to capture
24 hours of noise on multiple bands. The resulting data, graphically
presented, show him the relationships between noise on multiple
frequencies, whether the noise is electronically generated or is power
line noise, when it starts and stops through the day, whether it's
frequency stable (a microprocessor clock) or unstable (a SMPS or a
variable speed drive motor control).
This is REALLY valuable information -- it identifies the generic type of
noise so you have some idea of what you're looking for, and knowing that
type, know how to SEARCH for it.
Also, ALWAYS assume that you could be hearing more than one noise
source. You might have a bad insulator on a power pole AND a battery
charger in yours (or your neighbor's) garage. I'm estimating that the
average home has at least 30 electronic noise sources of varying
severity. Again, spectrum analysis helps.
73, Jim K9YC
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