[Elecraft] LP Pan versus P3 Panadapters

[Alan Bloom]

Hi Larry,

It depends on the span.  Unlike some other panadapters, the P3
automatically reduces the sample rate as you narrow the span, which
improves the sensitivity.

For example, I have my HP8656B signal generator set to 3640 kHz with the
amplitude as low as it will go (-127 dBm).  The K3 has the preamp off,
the attenuator on, and default CW shift and width.  Under those
conditions I can just barely hear the carrier.  It's weak enough that if
it were a modulated CW signal I don't think I could copy it.

However the carrier is clearly visible on the waterfall if I set the P3
span to 2 kHz.  As I increase the span the signal gradually gets harder
and harder to see.  Above about 30 kHz or so the signal disappears into
the noise.

So that's the trick.  Narrow the span to make those signals pop out of
the noise.

73,

Alan N1AL


On Tue, 2010-09-14 at 06:03 -0700, Larry K1UO wrote:
> Bill,
> 
>    I can tell you that just last night, on 160 meters, I copied 2 very weak
> stations perfectly Q5 that did not show on the P3 waterfall.  Now, Its
> entirely possible its my adjustment skills but I dont think so.  Yes..the K3
> IF Mod was factory installed.     This has happened more than once.  For
> some reason I was expecting the P3 to show these very weak signals better
> than I could find them myself while tuning but no amount of adjustment so
> far will do this.  I may be expecting too much?
> Just so you know what anothers experience has been so far.
> 73
> 
> 
> 
> 
>   I too would like to see details of the improvement over LPan etc. I am a
> long time user of SDR/computer panadapters for use in detecting very weak
> signals at UHF/VHF/microwave. I use a Softrock on the K3 IF port since I got
> my K3 a year ago.  I have yet to see one report regarding weak sig detection
> with the P3 after many requests to the initial testers of the P3. ANYONE out
> there looking for weak weak sigs with a P3??
> 
> 73  Bill K0AWU  EN37ed
> 
>