[RFI] Noise - where do I start?

[Jim Brown]

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