Hi Alan Does the P3 also have a "peak hold" function? How does the P3 integrate with the K3 for transmit signal monitoring? How many markers can you set and are the markers smart indicating peak or average values?
I am using a Perseus with Linrad in "TX TEST" mode, its excellent. If the P3 can emulate some of Linrads TX Test mode functionality it would be a mandatory test tool for every ham station. I like the ability to monitor simultaneously average and peak signal traces in Linrad. Anything that extends the P3's functionality beyond a simple panadapter would make it an attractive option. The pricing is very close to the Perseus price. People will have to think hard and long about its purchase if the functionality is lacking and they do want to go beyond a simple panadapter John --- On Sun, 5/2/10, Alan Bloom <a...@elecraft.com> wrote: > From: Alan Bloom <a...@elecraft.com> > Subject: Re: [Elecraft] P3 Questions concerning measurement > To: "Fred Atchley" <hamkt...@att.net> > Cc: Elecraft@mailman.qth.net > Date: Sunday, May 2, 2010, 5:44 PM > Hi Fred, > > The amplitude scale on the P3 shows the signal level in dBm > at the K3's > antenna connector. As the K3 attenuator and preamp > are turned on or > off, the P3 automatically adjusts its internal gain so the > display > always reads the correct signal level. > > The reference level and scale can be adjusted from the P3 > front panel. > "Reference level" is the level in dBm at the bottom of the > display. > "Scale" is the difference in dB between the top and bottom > of the > display. So, for example, if the REF LVL is -120 dBm > and the SCALE is > 80 dB, then signal levels between -40 dBm and -120 dBm can > be seen. > > One complicating factor is that the P3 automatically > adjusts its DSP > sample rate proportional to the frequency span. As a > consequence, the > noise level drops as you narrow the span. (That works > both for thermal > noise and band noise coming in the antenna.) There is > a MENU option to > have the REF LVL change automatically as you vary the span > to keep the > noise level at the same point on the display. In this > way you always > get the best possible dynamic range. > > On my "to-do" list is to add a calibration routine, similar > to the > S-meter calibration in the K3. The signal level at > the K3's IF output > connector changes somewhat from band to band and from unit > to unit. The > accuracy should be plenty good enough for giving signal > reports on the > air, but for those who want to do more accurate > measurements it would be > nice to be able to calibrate it. Even without > calibration, the RELATIVE > amplitude accuracy is excellent, limited only by the > display resolution. > So if you tell Alex that his signal is 7 dB weaker than > Monica's, he > will have no grounds for argument. :=) > > 73, > > Alan N1AL > > > > On Sun, 2010-05-02 at 13:12 -0700, Fred Atchley wrote: > > Hi all. While waiting for the P3 I have a few > questions on setup and > > measurement. Since I have never used LP pan or similar > devices I’ll > > need some Elmering. Specifically there are two > capabilities listed in > > the Elecraft P3 page that I need help on: > > > > 1. Adjustable reference level and amplitude > range scaling > > > > 2. User calibration of the display to show > absolute signal level in > > dBm > > > > Number 1 suggests two parts. It has an “adjustable > reference level”. > > Question: WRT what reference: 0 dBm, the bottom of the > spectrum > > display baseline or some particular value? The other > part adds > > “amplitude range scaling”. Is this a separate > function or is part 2 > > the conclusion of the process? > > > > My second question concerns the use of the absolute > signal level in > > dBm. If I am assisting a Ham friend in adjusting his > signal, will this > > capability allow me to evaluate such things as his BW > and compression? > > I know that I can do that now by ear but will the P3 > give me a visual > > clue WRT onset of changes over-the-air? I have an HP > Spectrum Analyzer > > that I have used to check my own K3 on- the-bench. So > the phrase > > “over-the-air” is the big question. > > > > These questions do not pertain to the main reason I am > looking forward > > to the P3 (I.e. operating) but rather to the > “other” useful > > possibilities. I appreciate the group’s Elmering. > > > > 73, Fred, AE6IC, K3 #2241, P3 #? > > > > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
