P3 - WWV spectrum display
Locked
 
|
While using WWV to "fall back," I reduced the span while watching WWV
such that the VFO A marker was about half the width of the screen, and there appeared WWV's transmitted spectrum [Never did this before ... cool!]. 10 MHz WWV is about 25 over S9, I'm on AM with 3.0 KHz DSP BW. I have the stock roofing filter [2.7 KHz?] During silent periods, the carrier is there and I can see the 1 second ticks. I'm surprised when the tone is on however. Instead of a carrier and one sideband on either side, I have two sidebands on either side, equally spaced out from the carrier, like the outer ones are harmonics of the fundamental audio frequency. The inner ones are about 10 dB below the peak of the carrier, and the outer ones are about 15-20 dB below the inner ones. On QSB peaks, a 3rd set appears close to the baseline. The sidebands fade independently by perhaps 5-8 dB. The higher frequency "beep" on each minute produces a very distinct set of 5 sidebands on each side. I think I can see the BCD code modulation close in on the carrier and down near the baseline ... or maybe it's just noise and they don't do BCD code anymore. This is so pronounced that there has to be an explanation based on physics rather than something wrong with my K3/P3, but I'm wondering. WWV sounds just like the WWV I've come to know and love. 73, Fred K6DGW - Northern California Contest Club - CU in the 2012 Cal QSO Party 6-7 Oct 2012 - www.cqp.org ______________________________________________________________ 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 |
|
|
Those tones are not sine waves. They have distinct harmonic content
that makes them a little "sharp" sounding, rather than the soft sound of a pure sine wave. What you're looking at is the components that make it sound that way. 73, Guy. On Mon, Nov 7, 2011 at 7:23 PM, Fred Jensen <[hidden email]> wrote: > While using WWV to "fall back," I reduced the span while watching WWV > such that the VFO A marker was about half the width of the screen, and > there appeared WWV's transmitted spectrum [Never did this before ... > cool!]. 10 MHz WWV is about 25 over S9, I'm on AM with 3.0 KHz DSP BW. > I have the stock roofing filter [2.7 KHz?] > > During silent periods, the carrier is there and I can see the 1 second > ticks. I'm surprised when the tone is on however. Instead of a carrier > and one sideband on either side, I have two sidebands on either side, > equally spaced out from the carrier, like the outer ones are harmonics > of the fundamental audio frequency. The inner ones are about 10 dB > below the peak of the carrier, and the outer ones are about 15-20 dB > below the inner ones. On QSB peaks, a 3rd set appears close to the > baseline. The sidebands fade independently by perhaps 5-8 dB. > > The higher frequency "beep" on each minute produces a very distinct set > of 5 sidebands on each side. I think I can see the BCD code modulation > close in on the carrier and down near the baseline ... or maybe it's > just noise and they don't do BCD code anymore. > > This is so pronounced that there has to be an explanation based on > physics rather than something wrong with my K3/P3, but I'm wondering. > WWV sounds just like the WWV I've come to know and love. > > 73, > > Fred K6DGW > - Northern California Contest Club > - CU in the 2012 Cal QSO Party 6-7 Oct 2012 > - www.cqp.org > ______________________________________________________________ > 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 |
Re: P3 - WWV spectrum display
|
|
In reply to this post by k6dgw
>Those tones are not sine waves.
I wasn't so sure about this. Over the years I've never heard this mentioned, and technical references like NIST 25-67 and 668 describe the audio tones as being derived from the cesium standards, with no mention of harmonic content. So I sent an email to WWV asking if the audio tones were generated as pure sine waves or had harmonic content added intentionally. I quickly received this response: ------------------------------------------------------ Thanks for your email. The audio tones on the WWV broadcast are derived from the station frequency standard, and are pure sine waves. Detailed information on the WWV broadcast can be found in NIST publication SP432, available for download on the webpage: http://tf.nist.gov/general/pdf/1383.pdf Sincerely, Glenn Nelson National Institute of Standards and Technology Radio Stations WWV/WWVB ----------------------------------------------------- I also see the harmonics on the P3. Unless Mr. Nelson is misinformed, I suspect that it may be the "harmonics" are distortion products, either transmitter IMD or artifacts of the receiver (P3 in this case). BTW the publication he mentions is a very good read for WWV listeners. Bob NW8L >Those tones are not sine waves. They have distinct harmonic content >that makes them a little "sharp" sounding, rather than the soft sound >of a pure sine wave. What you're looking at is the components that >make it sound that way. ______________________________________________________________ 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 |
|
|
I measured the 2nd and 3rd harmonic of WWV's 600 Hz tone this morning
using an HP 8568B spectrum analyzer set at 15 MHz, 30 Hz resolution, connected to an antenna. This avoids the harmonic generation that might be found in a receiver's audio stages, for example, such as when measuring tone levels with a computer sound card connected to a receiver's line out or headphone jack. The 2nd harmonic at 1200 Hz is approximately 18 dB down from the 600 Hz sideband. The 3rd harmonic at 1800 Hz is about 30 dB down from the 600 Hz sideband. It's difficult to be precise in these measurements because all the modulation sideband fade independently to some degree and because the 1800 Hz harmonic is not too much above the noise floor at the moment. Averaging is difficult because the modulation changes frequency according to the schedule, 500 Hz, 440 Hz, 600 Hz, etc. So, yes, WWV has some distortion products. Jack K8ZOA On 11/8/2011 10:29 AM, Bob Cunnings wrote: >> Those tones are not sine waves. > I wasn't so sure about this. Over the years I've never heard this > mentioned, and technical references like NIST 25-67 and 668 describe > the audio tones as being derived from the cesium standards, with no > mention of harmonic content. So I sent an email to WWV asking if the > audio tones were generated as pure sine waves or had harmonic content > added intentionally. I quickly received this response: > ------------------------------------------------------ > Thanks for your email. > > The audio tones on the WWV broadcast are derived from the station > frequency standard, and are pure sine waves. > > Detailed information on the WWV broadcast can be found in NIST > publication SP432, available for download on the webpage: > http://tf.nist.gov/general/pdf/1383.pdf > > Sincerely, > Glenn Nelson > National Institute of Standards and Technology > Radio Stations WWV/WWVB > ----------------------------------------------------- > > I also see the harmonics on the P3. Unless Mr. Nelson is misinformed, > I suspect that it may be the "harmonics" are distortion products, > either transmitter IMD or artifacts of the receiver (P3 in this case). > BTW the publication he mentions is a very good read for WWV listeners. > > Bob NW8L > >> Those tones are not sine waves. They have distinct harmonic content >> that makes them a little "sharp" sounding, rather than the soft sound >> of a pure sine wave. What you're looking at is the components that >> make it sound that way. > ______________________________________________________________ > 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 |
|
|
I think we're barking up the wrong tree. The real travesty of WWV's signal is,
and has been for a long while, the *voice* announcements of solar conditions, weather conditions, and navigation. Have you noticed? It sounds like they use a 100-year-old microphone that has been left out in the rain for several decades, used as a chew toy by several dogs, and that served as a hammer to build several houses. 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 |
|
|
In reply to this post by Jack Smith-6
> I measured the 2nd and 3rd harmonic of WWV's 600 Hz tone this morning > using an HP 8568B spectrum analyzer set at 15 MHz, 30 Hz resolution, > > The 2nd harmonic at 1200 Hz is approximately 18 dB down from the 600 Hz > sideband. > > The 3rd harmonic at 1800 Hz is about 30 dB down from the 600 Hz sideband. Good work Jack. I don't have a P3 but I set up my K3 on cw mode, with 50 Hz bandwidth on the 20 MHz WWV signal which is running S9- 10 over here in NJ at 1-2 pm EDT. A manual spectrum analyzer. The K3 can tune to the carrier at 20.000.000 and hear a beat note, at S9+ Tune to 20.000.600 and hear the 600 Hz modulation, save it as VFO A. Tune to 20.001.200 and hear the 1200 Hz modulation, save it as VFO B. Then you can flip back and forth from VFO A to B. Right now the 600 Hz sideband is S7 and the 1200 Hz is S2. So as you say, this isn't distortion in any of our audio stages or sound cards. Rick K2XT ______________________________________________________________ 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 |
|
|
In reply to this post by alorona
They probably use a speaker phone for the recording, yuk.
You guys should grab the P3's display and post the pictures. I saw the double lines a couple of months ago, I thought they had changed their format..... Randy K7AGE ______________________________________________________________ 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 |
|
|
In reply to this post by alorona
WWV has 100 Hz data transmission and you will see the sidebands at ±100 Hz.
Jack K8ZOA On 11/8/2011 6:21 PM, Ron D'Eau Claire wrote: > I see two sidebands very close to either side of the carrier, and identical > amplitude/spacing sidebands on either side of the tones. They are at about > +/-60Hz and +/-100 Hz. I assumed that was intentional modulation since they > also appear next to the carrier. > > At least it should rule out distortion products in the tone since they > remain with the carrier when the tones are off. > > Agree with Al about the voice quality. It reminds me of an WWII vintage > carbon mike that was left in a bucket of water. That must be a feed from > some other source. The WWV time announcements from either the mainland or > Hawaii are fine. > > Ron AC7AC > > > ______________________________________________________________ > 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 |
|
|
In reply to this post by Randy Hall
Guys;
Read the information at the NIST / WWV web site. There is no microphone. The voices are all synthesized! Jack B, W6FB On Nov 8, 2011, at 3:24 PM, Randy Hall wrote: > They probably use a speaker phone for the recording, yuk. > > You guys should grab the P3's display and post the pictures. > > I saw the double lines a couple of months ago, I thought they had > changed > their format..... ______________________________________________________________ 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 |
|
|
In reply to this post by Randy Hall
On 11/8/2011 3:24 PM, Randy Hall wrote:
> You guys should grab the P3's display and post the pictures. OK. www.foothill.net/~andreaj/WWV_7KHz.bmp This is a 7KHz span with the marker on the first sideband [high side]. You can see the 2nd and 3rd harmonics, and maybe the 4th although that might just be noise. www.foothill.net/~andreaj/WWV_100Hz.bmp This is the carrier at a span on 2 KHz. The marker is at 100 Hz which is the IRIG-H subcarrier. The peak between it and the carrier comes and goes and I guess is the sideband from the time code modulation [actually, I just made that up, I really don't know] www.foothill.net/~andreaj/WWV_1KHz_beep is the 1 KHz beep at the start of each minute. The marker is at 500 Hz above the carrier. My baseline was wandering just a little when I snapped the screenshot, sorry. WWV 10 MHz was running fairly steady at 10 over S9, some QSB. On CW, with DSP at 50 Hz, I can tune to each of the sidebands and their amplitude on the S-meter relative to the carrier sort of matches the P3 display ... this is a moving target, it's hard to be exact. Explanation welcome, guesses will be added to the growing list. 73, Fred K6DGW - Northern California Contest Club - CU in the 2012 Cal QSO Party 6-7 Oct 2012 - www.cqp.org ______________________________________________________________ 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 |
|
|
On 11/8/2011 4:22 PM, Fred Jensen wrote:
> > www.foothill.net/~andreaj/WWV_1KHz_beep is the 1 KHz beep at the start > of each minute. Well, fingers don't always follow commands from HQ. Put a .bmp at the end of that URL. 73, Fred K6DGW - Northern California Contest Club - CU in the 2012 Cal QSO Party 6-7 Oct 2012 - www.cqp.org ______________________________________________________________ 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 |
|
|
In reply to this post by alorona
On 11/8/2011 3:21 PM, Ron D'Eau Claire wrote:
> The WWV time announcements from either the mainland or > Hawaii are fine. Those are, of course, high quality recorded announcements. The male voice is that of Lee Rodgers, a long-time San Francisco broadcaster at station KGO, once the west-coast flagship of ABC Radio. New owners took over recently, and Lee was laid off, always a hazard in the broadcast industry. What a shame! I have no idea whose the female voice is. --- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 From a Clearing in the Silicon Forest Beaverton (Washington County) Oregon ______________________________________________________________ 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 |
|
|
On Nov 8, 2011, at 5:21 PM, Phil Kane wrote: > On 11/8/2011 3:21 PM, Ron D'Eau Claire wrote: > >> The WWV time announcements from either the mainland or >> Hawaii are fine. > > Those are, of course, high quality recorded announcements. The male > voice is that of Lee Rodgers, a long-time San Francisco broadcaster at > station KGO, once the west-coast flagship of ABC Radio. New owners took > over recently, and Lee was laid off, always a hazard in the broadcast > industry. What a shame! I have no idea whose the female voice is. The female voice is that of Jane Barbe. http://www.oocities.org/radiojunkie3/barbe1.htm 73, Bob N7XY ______________________________________________________________ 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 |
«
Return to [P3]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |