[hpsdr] Steady Waterfall

[Ben Witvliet]

Hello all,

 

I use the PowerSDR waterfall display a lot, as it proves very usefull for
finding weak DX signals in a quiet band. The waterfall gives a very good
overview. And "memory" of short transmissions that have happened on other
frequencies, so that you can check each of them one by one. To find that
rare DX you still need, of course :-)

 

(1) Just like Maximo, I would much prefer the waterfall to be steady, and
not to skip around when I click-tune my receive frequency. It messes up the
waterfall, and makes it difficult to find the signals back you previously
spotted. You then have to wait for new transmissions to find those signals
again. I tried Maximo's "work-around" solution, but that is far from ideal.
I cannot click on the signals to tune to them, for example. So if someday,
someone would update the waterfall, could this be changed, maybe....?
Please? :-)

 

(2) To get maximum sensitivity and best indication of weak signals, I set
the (Setup - Display - Waterfall) LowLevel just below the noise level. I
then set the HighLevel some 25 or 30 dB higher when the band is quiet. Weak
signals are then showing up very clearly, and even short transmission are
caught straight away.

I found that adjusting the LowLevel is needed quite often, depending on the
time of day, the band and the antenna used. And the HighLevel must be
adjusted also to get best results. A band full of strong signals requires
other settings than a very quiet band. 

 

Would it be an idea to set the Lowlevel automatically to the average noise
level within the full receiver bandwidth (200 kHz)? The Waterfall-HighLevel
could than be replaced by Waterfall-DR (Dynamic Range). Dr would be the
present ´HighLevel´ minus ´LowLevel.  DR could be set automatically also,
calculated from the strongest signals within full bandwidth or manually.
Setting it manually to 30 dB would result in the DX setting I described
above. If helpful I would be happy to devise a suitable formula for this.

 

Kindest regards,

Ben PA5BW

 

 

> Date: Sun, 24 Apr 2011 19:18:15 +0000

> From: Maximo EA1DDO_HK1DX <ea1ddo at hotmail.com>

> Subject: [hpsdr] Steady Waterfall

> Message-ID: <BAY148-w30E2B9B4B801C9DB90A2AE95970 at phx.gbl>

> 

> Hi,

> 

> Just a quick question about PowerSDR and waterfall use.

> 

> Is there any way to move the "demodulation area" instead to move the
spectrum?

> I mean, when you click over a signal, the view centers itself. I would
like to lock the spectrum and move the Rx area.

> 

> It is important when you want to use the waterfall. Everytime you chose a
signal, the spectrum moves centering the signal and the waterfall gets >
unuseful. The dial?s mark is always centered. Is there any option to move
the dial along a locked spectrum?

> 

> Thank you and Happy Easter.

> 

> 73, Maximo - EA1DDO

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