Dave,
No Sh-t Sherlock!! This was a comment a guy I used to work with would
say when someone touted something that was blatantly obvious!
I have also felt this way for a few years. I built an active hi-Z
preamp on a magnetic base with a 4' whip and drive around with a Perseus
receiver. Looking at a wide chunk of spectrum was the only way W0IVJ
and myself were able to show Century Link how much VDSL2 radiates (an
SDRPlay ws used for the VDSL2 stuff). We drove up a street with a
Century Link engineer in the back seat of the car and pointed out
exactly which houses had DSL service. Without getting out of the car we
were correct about 80% of the time and sometimes were off by one house.
Driving through a commercial or industrial area is especially
interesting as the noise floor varies easily 1000x (30dB) within a
several hundred feet.
Hope others will realize that this is an extremely good way to track
down RFI while being stealthy. A non-directional antenna will never
replace a directional one but is an additional tool.
73,
Larry, W0QE
On 8/25/2016 4:59 AM, Dave Cole wrote:
Hi,
Just thought I would share this with the collective group, because it
seems so interesting...
I took an SDRPlay, and set it to something like 2 MHZ wide, then pointed
that at the 40 meter band, and set it loose recording in graphic form,
across a very long time frame to get an overview of my RFI environment
across time. It is attached... All times are GMT, and the graph starts
at around 2:30 PM local time here in Oregon.
I expected interesting results, but got something far more fascinating,
and busy than I thought. Much structure is visible in this... Being
able to visualize huge swaths of spectrum over time is so informative.
I have been trying to get a tool for generating an RFI survey of an
area, and this seems to fit the bill well.
In the near future, I will be moving to AZ, and I think I will strap
this setup onto a laptop, put it in my car, and connect it to my mobile
antenna for Low Bands, to survey the area I am considering moving
into...
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