Topics

3 DTV carriers on 1 frequency Channel

Paul Cianciolo
 

All,

This video was inspired by a comment from NO6B about the close relationship between carrier frequencies of DTV pilot on the same channel. Here we see that Hz relationship but also propagation of 3 carriers from 3 different transmitters on the same frequency, and the distinctly different propagation happening on each carrier. The frequency relationship does not vary, but the relative amplitudes of the carriers are subject to 3 distinct terrestrial paths. 2 hours of waterfall are compressed into just a couple minutes.

Here is the link https://youtu.be/Sbq_Ny-BbZE




PaulC
W1VLF

David Eckhardt
 

Here in the foothills of the Rockies in N. Colorado, at times I receive as many as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6 individual broadcasters painting vertical smudges - LOT'S of meteors, especially on one of the 6.  All but one carrier is detected only on densely painted meteor scatter trails.  That single one is Es and paints an intermittent solid vertical line.  In 5 or so years of monitoring this frequency with the following equipment, I have never detected less than 4 broadcasters at one time.   

Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface (decaying Upper Permian mudstone), strung E/W.  Chicken
                 laid on soil surface below dipole.
Feedline:  100-feet of new RG-58
Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside, not at antenna feed
Receiver:  Icom R7000
Frequency:  66.3095 USB
PC:  Dell laptop running SpectrumLab
Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)

Dave - WØLEV
 -


On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@...> wrote:
All,

This video was inspired by a comment from NO6B about the close relationship between carrier frequencies of DTV pilot on the same channel. Here we see that Hz relationship but also propagation of 3 carriers from 3 different transmitters on the same frequency, and the distinctly different propagation happening on each carrier. The frequency relationship does not vary, but the relative amplitudes of the carriers are subject to 3 distinct terrestrial paths. 2 hours of waterfall are compressed into just a couple minutes.

Here is the link https://youtu.be/Sbq_Ny-BbZE




PaulC
W1VLF



--
Dave - WØLEV
Just Let Darwin Work

jdow
 

Those are apparently cable TV leakage or frequency translators to fill in coverage in valleys. I'd not feel confident using their frequencies for calibration, especially if you can see four of them.

{^_^}

On 20200616 10:18:56, David Eckhardt wrote:
Here in the foothills of the Rockies in N. Colorado, at times I receive as many as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6 individual broadcasters painting vertical smudges - LOT'S of meteors, especially on one of the 6.  All but one carrier is detected only on densely painted meteor scatter trails.  That single one is Es and paints an intermittent solid vertical line. In 5 or so years of monitoring this frequency with the following equipment, I have never detected less than 4 broadcasters at one time.
Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface (decaying Upper Permian mudstone), strung E/W.  Chicken
                 laid on soil surface below dipole.
Feedline:  100-feet of new RG-58
Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside, not at antenna feed
Receiver:  Icom R7000
Frequency:  66.3095 USB
PC:  Dell laptop running SpectrumLab
Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)
Dave - WØLEV
 -
On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@... <mailto:paulc@...>> wrote:
All,
This video was inspired by a comment from NO6B about the close relationship
between carrier frequencies of DTV pilot on the same channel. Here we see
that Hz relationship but also propagation of 3 carriers from 3 different
transmitters on the same frequency, and the distinctly different propagation
happening on each carrier. The frequency relationship does not vary, but the
relative amplitudes of the carriers are subject to 3 distinct terrestrial
paths. 2 hours of waterfall are compressed into just a couple minutes.
Here is the link https://youtu.be/Sbq_Ny-BbZE
PaulC
W1VLF
--
*Dave - WØLEV*
/*Just Let Darwin Work*/

David Eckhardt
 

N. Colorado (WØLEV):  My traces are certainly not from CATV leakage as I'm well away from the cities and the closest neighbor is 1/4-mile distant.  We are very sparsely populated out here between two hog backs.  The spine of the formed valley is N/S with no cities or villages in site.  With the exception of Es, all traces support dense meteor scatter during morning hours, and reduced flux during afternoons - very typical of meteors.  At present I have 5 vertical traces painted by meteors and two discontinuous weak Es signatures.

Dave - WØLEV 


On Wed, Jun 17, 2020 at 2:16 AM jdow <jdow@...> wrote:
Those are apparently cable TV leakage or frequency translators to fill in
coverage in valleys. I'd not feel confident using their frequencies for
calibration, especially if you can see four of them.

{^_^}

On 20200616 10:18:56, David Eckhardt wrote:
> Here in the foothills of the Rockies in N. Colorado, at times I receive as many
> as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6 individual
> broadcasters painting vertical smudges - LOT'S of meteors, especially on one of
> the 6.  All but one carrier is detected only on densely painted meteor scatter
> trails.  That single one is Es and paints an intermittent solid vertical line. 
> In 5 or so years of monitoring this frequency with the following equipment, I
> have never detected less than 4 broadcasters at one time.
>
> Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface (decaying
> Upper Permian mudstone), strung E/W.  Chicken
>                   laid on soil surface below dipole.
> Feedline:  100-feet of new RG-58
> Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside, not at
> antenna feed
> Receiver:  Icom R7000
> Frequency:  66.3095 USB
> PC:  Dell laptop running SpectrumLab
> Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)
>
> Dave - WØLEV
>   -
>
> On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@...
> <mailto:paulc@...>> wrote:
>
>     All,
>
>     This video was inspired by a comment from NO6B about the close relationship
>     between carrier frequencies of DTV pilot on the same channel. Here we see
>     that Hz relationship but also propagation of 3 carriers from 3 different
>     transmitters on the same frequency, and the distinctly different propagation
>     happening on each carrier. The frequency relationship does not vary, but the
>     relative amplitudes of the carriers are subject to 3 distinct terrestrial
>     paths. 2 hours of waterfall are compressed into just a couple minutes.
>
>     Here is the link https://youtu.be/Sbq_Ny-BbZE
>
>
>
>
>     PaulC
>     W1VLF
>
>
>
> --
> *Dave - WØLEV*
> /*Just Let Darwin Work*/
>
>





--
Dave - WØLEV
Just Let Darwin Work

lyndx
 

Hi,
 
Can you help identify the signal on 60.292.20 USB in the attached video?  I am located about 15 miles east of NYC so I'm assuming this may be one of the DTV carriers. Funcube Pro+ was attached to outdoor TV antenna pointing due West. Signal strength and audio tone hasn't varied over time.
 
Thanks.
 
Lyndx
 
 
"Be patient & tough; one day this pain will be useful to you" - Ovid

jdow
 

Have you been able to figure out what the actual spacing between the signals is? If it stays constant that information can lead to knowing the frequency accuracy of the transmitters. If they are not translators (repeaters up on a hill for coverage area fill in valleys) then you are seeing the relative precision of the various stations. I could not quite read the frequency line in your video.

{^_^}

On 20200617 08:40:11, David Eckhardt wrote:
N. Colorado (WØLEV):  My traces are certainly not from CATV leakage as I'm well away from the cities and the closest neighbor is 1/4-mile distant.  We are very sparsely populated out here between two hog backs.  The spine of the formed valley is N/S with no cities or villages in site.  With the exception of Es, all traces support dense meteor scatter during morning hours, and reduced flux during afternoons - very typical of meteors.  At present I have 5 vertical traces painted by meteors and two discontinuous weak Es signatures.
Dave - WØLEV
On Wed, Jun 17, 2020 at 2:16 AM jdow <jdow@... <mailto:jdow@...>> wrote:
Those are apparently cable TV leakage or frequency translators to fill in
coverage in valleys. I'd not feel confident using their frequencies for
calibration, especially if you can see four of them.
{^_^}
On 20200616 10:18:56, David Eckhardt wrote:
> Here in the foothills of the Rockies in N. Colorado, at times I receive
as many
> as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6 individual
> broadcasters painting vertical smudges - LOT'S of meteors, especially on
one of
> the 6.  All but one carrier is detected only on densely painted meteor
scatter
> trails.  That single one is Es and paints an intermittent solid vertical
line.
> In 5 or so years of monitoring this frequency with the following
equipment, I
> have never detected less than 4 broadcasters at one time.
>
> Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface (decaying
> Upper Permian mudstone), strung E/W.  Chicken
>                   laid on soil surface below dipole.
> Feedline:  100-feet of new RG-58
> Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside, not at
> antenna feed
> Receiver:  Icom R7000
> Frequency:  66.3095 USB
> PC:  Dell laptop running SpectrumLab
> Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)
>
> Dave - WØLEV
>   -
>
> On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@...
<mailto:paulc@...>
> <mailto:paulc@... <mailto:paulc@...>>> wrote:
>
>     All,
>
>     This video was inspired by a comment from NO6B about the close
relationship
>     between carrier frequencies of DTV pilot on the same channel. Here we see
>     that Hz relationship but also propagation of 3 carriers from 3 different
>     transmitters on the same frequency, and the distinctly different
propagation
>     happening on each carrier. The frequency relationship does not vary,
but the
>     relative amplitudes of the carriers are subject to 3 distinct terrestrial
>     paths. 2 hours of waterfall are compressed into just a couple minutes.
>
>     Here is the link https://youtu.be/Sbq_Ny-BbZE
>
>
>
>
>     PaulC
>     W1VLF
>
>
>
> --
> *Dave - WØLEV*
> /*Just Let Darwin Work*/
>
>
--
*Dave - WØLEV*
/*Just Let Darwin Work*/

David Eckhardt
 

Here is a bit of data I just took from my system showing multiple broadcasters via meteor scatter.  There is some weak Es just below center which also shows overload, likely in the audio stages of the Icom R-7000.  There are also a few weak airline scatter traces which I still have yet to explain (if they are close enough to produce scatter from airliners, why don't I receive a direct signal from the transmitter?).  Local time is 1240 (MDT) so the meteor flux is greatly reduced from this morning.
image.png

Dave - WØLEV


On Wed, Jun 17, 2020 at 11:16 AM David Eckhardt via groups.io <davearea51a=gmail.com@groups.io> wrote:
N. Colorado (WØLEV):  My traces are certainly not from CATV leakage as I'm well away from the cities and the closest neighbor is 1/4-mile distant.  We are very sparsely populated out here between two hog backs.  The spine of the formed valley is N/S with no cities or villages in site.  With the exception of Es, all traces support dense meteor scatter during morning hours, and reduced flux during afternoons - very typical of meteors.  At present I have 5 vertical traces painted by meteors and two discontinuous weak Es signatures.

Dave - WØLEV 

On Wed, Jun 17, 2020 at 2:16 AM jdow <jdow@...> wrote:
Those are apparently cable TV leakage or frequency translators to fill in
coverage in valleys. I'd not feel confident using their frequencies for
calibration, especially if you can see four of them.

{^_^}

On 20200616 10:18:56, David Eckhardt wrote:
> Here in the foothills of the Rockies in N. Colorado, at times I receive as many
> as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6 individual
> broadcasters painting vertical smudges - LOT'S of meteors, especially on one of
> the 6.  All but one carrier is detected only on densely painted meteor scatter
> trails.  That single one is Es and paints an intermittent solid vertical line. 
> In 5 or so years of monitoring this frequency with the following equipment, I
> have never detected less than 4 broadcasters at one time.
>
> Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface (decaying
> Upper Permian mudstone), strung E/W.  Chicken
>                   laid on soil surface below dipole.
> Feedline:  100-feet of new RG-58
> Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside, not at
> antenna feed
> Receiver:  Icom R7000
> Frequency:  66.3095 USB
> PC:  Dell laptop running SpectrumLab
> Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)
>
> Dave - WØLEV
>   -
>
> On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@...
> <mailto:paulc@...>> wrote:
>
>     All,
>
>     This video was inspired by a comment from NO6B about the close relationship
>     between carrier frequencies of DTV pilot on the same channel. Here we see
>     that Hz relationship but also propagation of 3 carriers from 3 different
>     transmitters on the same frequency, and the distinctly different propagation
>     happening on each carrier. The frequency relationship does not vary, but the
>     relative amplitudes of the carriers are subject to 3 distinct terrestrial
>     paths. 2 hours of waterfall are compressed into just a couple minutes.
>
>     Here is the link https://youtu.be/Sbq_Ny-BbZE
>
>
>
>
>     PaulC
>     W1VLF
>
>
>
> --
> *Dave - WØLEV*
> /*Just Let Darwin Work*/
>
>





--
Dave - WØLEV
Just Let Darwin Work



--
Dave - WØLEV
Just Let Darwin Work

jdow
 

Fascinating - that spread suggests the pilots are not particularly well suited for calibration to 1ppm. 3ppm might be OK.

{o.o}

On 20200617 11:44:33, David Eckhardt wrote:
Here is a bit of data I just took from my system showing multiple broadcasters via meteor scatter.  There is some weak Es just below center which also shows overload, likely in the audio stages of the Icom R-7000.  There are also a few weak airline scatter traces which I still have yet to explain (if they are close enough to produce scatter from airliners, why don't I receive a direct signal from the transmitter?).  Local time is 1240 (MDT) so the meteor flux is greatly reduced from this morning.
image.png
Dave - WØLEV
On Wed, Jun 17, 2020 at 11:16 AM David Eckhardt via groups.io <http://groups.io> <davearea51a=gmail.com@groups.io <mailto:gmail.com@groups.io>> wrote:
N. Colorado (WØLEV):  My traces are certainly not from CATV leakage as I'm
well away from the cities and the closest neighbor is 1/4-mile distant.  We
are very sparsely populated out here between two hog backs.  The spine of
the formed valley is N/S with no cities or villages in site.  With the
exception of Es, all traces support dense meteor scatter during morning
hours, and reduced flux during afternoons - very typical of meteors.  At
present I have 5 vertical traces painted by meteors and two discontinuous
weak Es signatures.
Dave - WØLEV
On Wed, Jun 17, 2020 at 2:16 AM jdow <jdow@...
<mailto:jdow@...>> wrote:
Those are apparently cable TV leakage or frequency translators to fill in
coverage in valleys. I'd not feel confident using their frequencies for
calibration, especially if you can see four of them.
{^_^}
On 20200616 10:18:56, David Eckhardt wrote:
> Here in the foothills of the Rockies in N. Colorado, at times I
receive as many
> as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6
individual
> broadcasters painting vertical smudges - LOT'S of meteors, especially
on one of
> the 6.  All but one carrier is detected only on densely painted
meteor scatter
> trails.  That single one is Es and paints an intermittent solid
vertical line.
> In 5 or so years of monitoring this frequency with the following
equipment, I
> have never detected less than 4 broadcasters at one time.
>
> Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface
(decaying
> Upper Permian mudstone), strung E/W.  Chicken
>                   laid on soil surface below dipole.
> Feedline:  100-feet of new RG-58
> Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside,
not at
> antenna feed
> Receiver:  Icom R7000
> Frequency:  66.3095 USB
> PC:  Dell laptop running SpectrumLab
> Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)
>
> Dave - WØLEV
>   -
>
> On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@...
<mailto:paulc@...>
> <mailto:paulc@... <mailto:paulc@...>>> wrote:
>
>     All,
>
>     This video was inspired by a comment from NO6B about the close
relationship
>     between carrier frequencies of DTV pilot on the same channel.
Here we see
>     that Hz relationship but also propagation of 3 carriers from 3
different
>     transmitters on the same frequency, and the distinctly different
propagation
>     happening on each carrier. The frequency relationship does not
vary, but the
>     relative amplitudes of the carriers are subject to 3 distinct
terrestrial
>     paths. 2 hours of waterfall are compressed into just a couple
minutes.
>
>     Here is the link https://youtu.be/Sbq_Ny-BbZE
>
>
>
>
>     PaulC
>     W1VLF
>
>
>
> --
> *Dave - WØLEV*
> /*Just Let Darwin Work*/
>
>
--
*Dave - WØLEV*
/*Just Let Darwin Work*/
--
*Dave - WØLEV*
/*Just Let Darwin Work*/
66.3095 A - 17 JUNE 2020.jpg

Greg Ella
 

The "standard" pilot tone in a North American ATSC signal is 309.440559 KHz above the bottom of the channel.  However, the ATSC specification allows for other specific pilot
tone frequencies when two or more transmitters are close enough to potentially interfere with each other.  I suspect that if you watch these 3 pilot tones over the long term, you
will find that each one is stable, accurate and precise, but two of them are not "standard".  Unfortunately, I have not found an online resource which gives the pilot tone frequency
for specific transmitters.

Greg Ella
N0EMP


On Thu, Jun 18, 2020 at 9:57 AM jdow <jdow@...> wrote:
Fascinating - that spread suggests the pilots are not particularly well suited
for calibration to 1ppm. 3ppm might be OK.

{o.o}

On 20200617 11:44:33, David Eckhardt wrote:
> Here is a bit of data I just took from my system showing multiple broadcasters
> via meteor scatter.  There is some weak Es just below center which also shows
> overload, likely in the audio stages of the Icom R-7000.  There are also a few
> weak airline scatter traces which I still have yet to explain (if they are close
> enough to produce scatter from airliners, why don't I receive a direct signal
> from the transmitter?).  Local time is 1240 (MDT) so the meteor flux is greatly
> reduced from this morning.
> image.png
>
> Dave - WØLEV
>
>
> On Wed, Jun 17, 2020 at 11:16 AM David Eckhardt via groups.io <http://groups.io>
> <davearea51a=gmail.com@groups.io <mailto:gmail.com@groups.io>> wrote:
>
>     N. Colorado (WØLEV):  My traces are certainly not from CATV leakage as I'm
>     well away from the cities and the closest neighbor is 1/4-mile distant.  We
>     are very sparsely populated out here between two hog backs.  The spine of
>     the formed valley is N/S with no cities or villages in site.  With the
>     exception of Es, all traces support dense meteor scatter during morning
>     hours, and reduced flux during afternoons - very typical of meteors.  At
>     present I have 5 vertical traces painted by meteors and two discontinuous
>     weak Es signatures.
>
>     Dave - WØLEV
>
>     On Wed, Jun 17, 2020 at 2:16 AM jdow <jdow@...
>     <mailto:jdow@...>> wrote:
>
>         Those are apparently cable TV leakage or frequency translators to fill in
>         coverage in valleys. I'd not feel confident using their frequencies for
>         calibration, especially if you can see four of them.
>
>         {^_^}
>
>         On 20200616 10:18:56, David Eckhardt wrote:
>          > Here in the foothills of the Rockies in N. Colorado, at times I
>         receive as many
>          > as 6 and rarely 7 carriers on 66.310 MHz.  As I write, I have 6
>         individual
>          > broadcasters painting vertical smudges - LOT'S of meteors, especially
>         on one of
>          > the 6.  All but one carrier is detected only on densely painted
>         meteor scatter
>          > trails.  That single one is Es and paints an intermittent solid
>         vertical line.
>          > In 5 or so years of monitoring this frequency with the following
>         equipment, I
>          > have never detected less than 4 broadcasters at one time.
>          >
>          > Antenna:  Single 1/2-wavelength dipole at 10-feet off soil surface
>         (decaying
>          > Upper Permian mudstone), strung E/W.  Chicken
>          >                   laid on soil surface below dipole.
>          > Feedline:  100-feet of new RG-58
>          > Preamp:  Single narrowband J-310 followed MMIC (broadband) - inside,
>         not at
>          > antenna feed
>          > Receiver:  Icom R7000
>          > Frequency:  66.3095 USB
>          > PC:  Dell laptop running SpectrumLab
>          > Location:  40 16 36.80 N     105 13 0.16 W   (check QRZ map)
>          >
>          > Dave - WØLEV
>          >   -
>          >
>          > On Tue, Jun 16, 2020 at 1:06 AM Paul Cianciolo <paulc@...
>         <mailto:paulc@...>
>          > <mailto:paulc@... <mailto:paulc@...>>> wrote:
>          >
>          >     All,
>          >
>          >     This video was inspired by a comment from NO6B about the close
>         relationship
>          >     between carrier frequencies of DTV pilot on the same channel.
>         Here we see
>          >     that Hz relationship but also propagation of 3 carriers from 3
>         different
>          >     transmitters on the same frequency, and the distinctly different
>         propagation
>          >     happening on each carrier. The frequency relationship does not
>         vary, but the
>          >     relative amplitudes of the carriers are subject to 3 distinct
>         terrestrial
>          >     paths. 2 hours of waterfall are compressed into just a couple
>         minutes.
>          >
>          >     Here is the link https://youtu.be/Sbq_Ny-BbZE
>          >
>          >
>          >
>          >
>          >     PaulC
>          >     W1VLF
>          >
>          >
>          >
>          > --
>          > *Dave - WØLEV*
>          > /*Just Let Darwin Work*/
>          >
>          >
>
>
>
>
>
>     --
>     *Dave - WØLEV*
>     /*Just Let Darwin Work*/
>
>
>
> --
> *Dave - WØLEV*
> /*Just Let Darwin Work*/
>
>
>
> 66.3095 A - 17 JUNE 2020.jpg
>



Ray Anderson
 

Check table 8.2 in section 8.5.5.1 of the following document at atsc.org

“Recommended Practice:
Guide to the Use of the ATSC Digital Television Standard, including Corrigendum No. 1”

Alternate offset frequencies include the following: (selected for various cases where there are nearby analog and or other digital stations)

332.138 kHz ±3Hz
338.056 kHz ±1kHz

342.138 kHz ±3Hz
348.056 kHz ±1kHz

322.138 kHz ± 3 Hz
328.056 kHz ± 1 kHz

328.8436 kHz ± 10 Hz

The selection process Is pretty convoluted so you need to refer to the referenced document for details.

Ray
WB6TPU 





On Jun 19, 2020, at 10:47 AM, Greg Ella <gregella53@...> wrote:


The "standard" pilot tone in a North American ATSC signal is 309.440559 KHz above the bottom of the channel.  However, the ATSC specification allows for other specific pilot
tone frequencies when two or more transmitters are close enough to potentially interfere with each other.  I suspect that if you watch these 3 pilot tones over the long term, you
will find that each one is stable, accurate and precise, but two of them are not "standard".  Unfortunately, I have not found an online resource which gives the pilot tone frequency
for specific transmitters.

Greg Ella
N0EMP