On 2/26/2021 7:31 AM, John Kaufmann via Topband wrote:
>
When dealing with narrowband
> coherent signals, this can really make very weak signals become
> visible on the display
That's exactly what I said in my first post.
> when they are virtually invisible in a larger measurement
> bandwidth.
Hi Rick,
This next piece of info is not really related, but here is another data
point for folks since you mentioned using an AM radio with built in bar
antenna tuned to 1710 KHz to track down powerline noise. I just checked
the sensitivity of my portable flag versus built in bar antenna on a
Hi Jim,
From the P3 manual:/
/
/"The dsPIC further processes the signal for presentation on the
480x272-pixel color TFT LCD display. The "circuitry" shown inside
the processor box in the block diagram is actually implemented as
software routines. The FFT is the fast Fourier
On 2/26/2021 7:31 AM, John Kaufmann via Topband wrote:
I think there may be some semantic confusion over the term "averaging" and
how averaging affects noise when making spectral measurements, so let me
clarify what I mean. My comments are specific to the P3 but are fairly
Averaging is a
ebruary 25, 2021 10:39 PM
To: topband@contesting.com
Subject: Re: Topband: FW: The WD8DSB mini-flag antenna (LONG!)
On 2/25/2021 5:16 PM, John Kaufmann via Topband wrote:
> The P3 averages power, not amplitude, so using longer averaging times just
> smooths the display and doesn't reduce rando
Hi Jim and gang,
I would like to make one minor correction and then add some more info. On
my SDR receiver I should have said I increased averaging from 1 to 10 in my
previous post (not 2 to 10) and this really made the noise floor drop and
smooth out and this really helped expose the signal of
Hi Jim,
It’s funny that you brought up this topic as yesterday when I was doing
comparisons of the signal I could hear on my 160 meter vertical TX antenna
versus my portable flag, I increased the averaging value on my portable SDR
receiver connected to my portable flag and the signal that was
On 2/25/2021 5:16 PM, John Kaufmann via Topband wrote:
The P3 averages power, not amplitude, so using longer averaging times just
smooths the display and doesn't reduce random noise.
It has nothing to do with power. Last I looked, the P3 is reading and
displaying the instantaneous voltage in
, 2021 8:03 PM
To: topband@contesting.com
Subject: Re: Topband: FW: The WD8DSB mini-flag antenna (LONG!)
On 2/25/2021 2:29 PM, John Kaufmann via Topband wrote:
> The P3 noise measurement bandwidth was about 100 Hz in my measurements.
I hope that everyone realizes that setting a high va
On 2/25/2021 2:29 PM, John Kaufmann via Topband wrote:
The P3 noise measurement bandwidth was about 100 Hz in my measurements.
I hope that everyone realizes that setting a high value for averaging
cancels non-correlated noise in spectrum displays, including the
waterfall, greatly increasing
ssage-
From: Topband [mailto:topband-bounces+john.kaufmann=verizon@contesting.com]
On Behalf Of Lee STRAHAN
Sent: Thursday, February 25, 2021 4:46 PM
To: topband@contesting.com
Subject: Topband: FW: The WD8DSB mini-flag antenna (LONG!)
Hi John,
What did you use as the P3 bandwidth for
Hi John,
What did you use as the P3 bandwidth for your noise measurement? And
conversion to 1Hz equivalent.
The P3 has its own bandwidth and is not affected by setting the receiver
bandwidth.
Lee K7TJR OR
(Note: what follows is a long, technical discussion about noise and “small”
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