K3 S meter vs P3 S scale
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Seems to be quite a difference in the readings between the P3 showing S
scale and he S meter reading on the K3. The software in both is up to date(recently at least). The difference is quite significant with the P3 being considerably lower. Maybe I don't know how to read the two meters. On the K3 I read the mostly steady peak reading excluding the static crashes if any. On the P3 using clear frequency noise as an example, I tend to read the "average" of the noise trace. Should I be reading the peaks (disregarding static crashes)? Is there a calibration I need to do? To which and where is the procedure spelled out? Will I will need to order the new XG3? (please) TIA, de Jim KG0KP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Good Morning Jim, First, go to the Elecraft web site and verify that you have the latest version of the firmware for the K3 and P3. If you don't have it installed, install it. You do need to calibrate the P3 and the K3 S-Meters. To do this you will need an XG1, XG2 or XG3. Either will work. 1. Calibrate the K3 according to the instructions in the manual. 2. Enter the P3 menu by tapping the menu button. 3. Find the "Ref Lvl scale display mode menu item and tap the Select knob on the k3 until you see S-meter readings on the left side of the scale. 4. Find the "Calibrate amplitude level menu item. 5. Using the which ever XG version you have (You can also use a signal generator) adjust the amplitude level with the XG device set to 50 microvolts output until the signal in the P3 reads S9. Both the K3 and P3 have instructions for setting the K3 S-meter and the P3 amplitude level. Enjoy your K3 and P3. 73, Tom Amateur Radio Operator N5GE On Thu, 5 May 2011 21:59:43 -0600, "Jim Miller KG0KP" <[hidden email]> wrote: >Seems to be quite a difference in the readings between the P3 showing S >scale and he S meter reading on the K3. The software in both is up to >date(recently at least). The difference is quite significant with the P3 >being considerably lower. Maybe I don't know how to read the two meters. >On the K3 I read the mostly steady peak reading excluding the static crashes >if any. On the P3 using clear frequency noise as an example, I tend to read >the "average" of the noise trace. Should I be reading the peaks >(disregarding static crashes)? > >Is there a calibration I need to do? To which and where is the procedure >spelled out? > >Will I will need to order the new XG3? (please) > >TIA, de Jim KG0KP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Amateur Radio Operator N5GE
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In reply to this post by hf4me
On a steady carrier (i.e. from a signal generator), both the P3 and K3
should read the same. My P3 reads much lower on actual signals than the K3, it is especially noticeable on SSB signals. Calibrating on a signal generator doesn't alter the lower reading of a P3 display on SSB signals. The peak reading facility of the P3 goes some way to overcome the lower reading but has an infinite decay... if it had an adjustable decay (or better still the normal display had a peak/decay setting) then the display would be far more useful. 73 Dave, G4AON >Seems to be quite a difference in the readings between the P3 showing S >scale and he S meter reading on the K3 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by N5GE
There will also be a difference on anything but a steady state carrier unless the P3 is in 'peak' display mode. An averaged SSB signal will show a lower reading on the P3 than the S-meter, for example.
Grant/NQ5T Sent from my iPhone On May 6, 2011, at 9:45 AM, [hidden email] wrote: > > Good Morning Jim, > > First, go to the Elecraft web site and verify that you have the latest version > of the firmware for the K3 and P3. If you don't have it installed, install it. > > You do need to calibrate the P3 and the K3 S-Meters. To do this you will need > an XG1, XG2 or XG3. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by hf4me
If you have the P3's AVERAGE enabled, it can lower the peak shown on
the P3. If at the same time, you have CONFIG:SMTR PK turned ON, there will probably be a significant difference between the two indicated levels. The K3's S-Meter will hang on the peaks for a short time, maybe long enough for you to hit the next voice or signal peak (makes it artificially high). There's also a calibration for S-Meter and RF Gain shown in the OM (p51 of Rev D9). This doesn't normally need to be done because the facotry calibration is sufficient. The RF Gain calibration can be done using the K3 Utility, under the Calibration tab (...I think...). One way to be sure you are seeing signal levels as they are is to use a signal generator to put out a steady carrier (or use the ref oscillator @ 49.whatever-it-is). Since the peak and average are the same, the two readouts should be the same. I think there's a calibration for the P3's scale gain, but not sure about it since it's never been needed. You should just order the XG3 anyway. It's a heckuva great tool to have around and makes a decent QRP CW transmitter too. 73 and Good Luck! matt W6NIA On Thu, 05 May 2011 21:59:43 -0600, you wrote: >Seems to be quite a difference in the readings between the P3 showing S >scale and he S meter reading on the K3. The software in both is up to >date(recently at least). The difference is quite significant with the P3 >being considerably lower. Maybe I don't know how to read the two meters. >On the K3 I read the mostly steady peak reading excluding the static crashes >if any. On the P3 using clear frequency noise as an example, I tend to read >the "average" of the noise trace. Should I be reading the peaks >(disregarding static crashes)? > >Is there a calibration I need to do? To which and where is the procedure >spelled out? > >Will I will need to order the new XG3? (please) > >TIA, de Jim KG0KP > > >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[hidden email] > >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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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On 5/6/2011 7:52 AM, Matt Zilmer wrote:
> If you have the P3's AVERAGE enabled, it can lower the peak shown on > the P3. This is entirely normal behavior. I have my S-meter set to read peaks and use it to give signal reports, but I set the P3 to very heavily average what it sees. This smooths out the noise and makes it much easier to see signals. The peak to average ratio is typically between 6 and 10 dB. You can see this by temporarily turning on the peak hold function. I've assigned the peak function to one of the soft buttons. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by hf4me
The reason the P3 reads lower than the K3 on noise or SSB signals is
that each display point on the P3 screen covers only a small bandwidth. As explained in the manual, each display point is about 1/450 of the span. For example, if the span is 45 kHz, then each display point only covers about 100 Hz. You'd see the same effect on the K3 if you narrowed the bandwidth from 2700 Hz to 100 Hz. The S meter would read 10 * log (2700/100) = 14 dB (2-3 S units) lower. Alan N1AL On Thu, 2011-05-05 at 21:59 -0600, Jim Miller KG0KP wrote: > Seems to be quite a difference in the readings between the P3 showing S > scale and he S meter reading on the K3. The software in both is up to > date(recently at least). The difference is quite significant with the P3 > being considerably lower. Maybe I don't know how to read the two meters. > On the K3 I read the mostly steady peak reading excluding the static crashes > if any. On the P3 using clear frequency noise as an example, I tend to read > the "average" of the noise trace. Should I be reading the peaks > (disregarding static crashes)? > > Is there a calibration I need to do? To which and where is the procedure > spelled out? > > Will I will need to order the new XG3? (please) > > TIA, de Jim KG0KP > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Jim Brown-10
When an SSB signal is "S9", that means that the total power in the ≈ 3 kHz
bandwidth, added up, is equal to S9. The voice power is spread out across 3 kHz of bandwidth and has to be integrated, or summed, in that bandwidth before comparing to an S-meter reading. Therefore, the amplitude of any point inside the SSB signal, as seen on a panadaptor, will always seem less than actual. Noise, being a broadband signal, also acts the same way. You have to know the receiver bandwidth to properly integrate all of the power inside that bandwidth to come up with a meaningful average power number to compare to an S-meter. A CW signal, on the other hand, exists at only one frequency (ignoring noise and keying sidebands). The amplitude of a CW signal on the P3 should be close to a calibrated S-meter. In the case of the P3, "close" means within a few dB. There is nothing wrong with your setup. Enjoy it in good health. R, Al W6LX ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Alan Bloom
THANKS everybody. Some very good definitions. I didn't think anything was
really broken and sisn't really believe it was out of calibration either but jsut did not understand wht appearant difference. Good to know that all is well. Thanke es 73, de Jim KG0KP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I need coffee!! 73, de Jim KG0KP
----- Original Message ----- From: "Jim Miller KG0KP" <[hidden email]> To: "Elecraft Reflector" <[hidden email]> Sent: Friday, May 06, 2011 4:45 PM Subject: Re: [Elecraft] K3 S meter vs P3 S scale > THANKS everybody. Some very good definitions. I didn't think anything > was > really broken and sisn't really believe it was out of calibration either > but > jsut did not understand wht appearant difference. Good to know that all > is > well. > > Thanke es 73, de Jim KG0KP > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Alan Bloom
Alan,
Thank you for this, I have been wondering whether my P3 required calibration. I am not sure if this is mentioned in the manual but if not it should be. The P3 is a new product and some of us are still learning. The forum once again proves valuable. 73 Doug EI2CN -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Alan Bloom Sent: 06 May 2011 23:00 To: Jim Miller KG0KP Cc: Elecraft Reflector Subject: Re: [Elecraft] K3 S meter vs P3 S scale The reason the P3 reads lower than the K3 on noise or SSB signals is that each display point on the P3 screen covers only a small bandwidth. As explained in the manual, each display point is about 1/450 of the span. For example, if the span is 45 kHz, then each display point only covers about 100 Hz. You'd see the same effect on the K3 if you narrowed the bandwidth from 2700 Hz to 100 Hz. The S meter would read 10 * log (2700/100) = 14 dB (2-3 S units) lower. Alan N1AL On Thu, 2011-05-05 at 21:59 -0600, Jim Miller KG0KP wrote: > Seems to be quite a difference in the readings between the P3 showing S > scale and he S meter reading on the K3. The software in both is up to > date(recently at least). The difference is quite significant with the P3 > being considerably lower. Maybe I don't know how to read the two meters. > On the K3 I read the mostly steady peak reading excluding the static crashes > if any. On the P3 using clear frequency noise as an example, I tend to read > the "average" of the noise trace. Should I be reading the peaks > (disregarding static crashes)? > > Is there a calibration I need to do? To which and where is the procedure > spelled out? > > Will I will need to order the new XG3? (please) > > TIA, de Jim KG0KP > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Hi Doug,
On Sat, 2011-05-07 at 17:10 +0100, Doug Turnbull wrote: > Alan, > Thank you for this, I have been wondering whether my P3 required > calibration. I am not sure if this is mentioned in the manual but if not > it should be. There's a section in the manual titled, "How to Set Up and Interpret the P3 Display" that covers that and a number of other issues. Panadapters and other types of spectrum analyzers are new to many operators so that section was written to address some of the questions that come up. 73, Alan N1AL > The P3 is a new product and some of us are still learning. > The forum once again proves valuable. > > 73 Doug EI2CN > > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of Alan Bloom > Sent: 06 May 2011 23:00 > To: Jim Miller KG0KP > Cc: Elecraft Reflector > Subject: Re: [Elecraft] K3 S meter vs P3 S scale > > The reason the P3 reads lower than the K3 on noise or SSB signals is > that each display point on the P3 screen covers only a small bandwidth. > As explained in the manual, each display point is about 1/450 of the > span. For example, if the span is 45 kHz, then each display point only > covers about 100 Hz. > > You'd see the same effect on the K3 if you narrowed the bandwidth from > 2700 Hz to 100 Hz. The S meter would read 10 * log (2700/100) = 14 dB > (2-3 S units) lower. > > Alan N1AL > > > On Thu, 2011-05-05 at 21:59 -0600, Jim Miller KG0KP wrote: > > Seems to be quite a difference in the readings between the P3 showing S > > scale and he S meter reading on the K3. The software in both is up to > > date(recently at least). The difference is quite significant with the P3 > > being considerably lower. Maybe I don't know how to read the two meters. > > On the K3 I read the mostly steady peak reading excluding the static > crashes > > if any. On the P3 using clear frequency noise as an example, I tend to > read > > the "average" of the noise trace. Should I be reading the peaks > > (disregarding static crashes)? > > > > Is there a calibration I need to do? To which and where is the procedure > > spelled out? > > > > Will I will need to order the new XG3? (please) > > > > TIA, de Jim KG0KP > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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