| Author |
Message |
bill simard
Guest
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 Posted:
Tue Dec 14, 2004 5:37 am Post subject:
How do local stations send their signals? |
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I was wondering how all the local stations from around the country get their
signal to DTV & Dish ?
I know that radio stations use G11 on the L-band to send AC3 audio to their
remote transmitter sites. Do TV stations also use this? If I had an L-band
LNB could I use a FTA reciever to pick up these freq?
What frequency range is the L-band ?
Thanks for the help |
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scambron
Guest
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| Posted:
Tue Dec 14, 2004 7:07 am Post subject:
Re: How do local stations send their signals? |
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On Tue, 14 Dec 2004 00:37:02 GMT, "bill simard" <simard@nycap.rr.com>
wrote:
| Quote: | I was wondering how all the local stations from around the country get their
signal to DTV & Dish ?
I know that radio stations use G11 on the L-band to send AC3 audio to their
remote transmitter sites. Do TV stations also use this? If I had an L-band
LNB could I use a FTA reciever to pick up these freq?
What frequency range is the L-band ?
Thanks for the help
There are many way to do this |
Set up terrestrial antenna(s) for the local station and a high dollar
TV receiver(s) with Audio(s) and Video out puts (no picture tube).
Then you take the Audio(s) / Video and feed them in to an analog to
digital converter..
All the locals are then Multiplexed in to a larger data stream, DS-3
Meg bit / seconds, OC-3 [3 DS-3s], or OC-12 [12 DS-3s]).
Who Pays for this? DirecTV and/or Dish-Net in the end…
Or the locals could get together and pay for satellite space and other
equipment to put the Multiplexed data on a satellite as a conditional
access DVB stream.
Or a local could sample the input to the TV transmitter, feed the
Audio(s) / Video in to an analog to digital converter and feed the out
put to a DS-3..
The amount of compression of the Analog to Digital conversion will
determine the quality of the signal that the
up-link station (DirecTV Dish-Net…) will up link.
Garbage IN, Garbage OUT
I am sure that if I missed any thing, some one will point it out!
S Cambron |
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kryppy
Guest
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| Posted:
Tue Dec 14, 2004 6:39 pm Post subject:
Re: How do local stations send their signals? |
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On Tue, 14 Dec 2004 02:07:33 GMT, scambron@chesapeake.net (scambron)
wrote:
| Quote: | On Tue, 14 Dec 2004 00:37:02 GMT, "bill simard" <simard@nycap.rr.com
wrote:
I was wondering how all the local stations from around the country get their
signal to DTV & Dish ?
I know that radio stations use G11 on the L-band to send AC3 audio to their
remote transmitter sites. Do TV stations also use this? If I had an L-band
LNB could I use a FTA reciever to pick up these freq?
What frequency range is the L-band ?
Thanks for the help
There are many way to do this
Set up terrestrial antenna(s) for the local station and a high dollar
TV receiver(s) with Audio(s) and Video out puts (no picture tube).
Then you take the Audio(s) / Video and feed them in to an analog to
digital converter..
All the locals are then Multiplexed in to a larger data stream, DS-3
Meg bit / seconds, OC-3 [3 DS-3s], or OC-12 [12 DS-3s]).
Who Pays for this? DirecTV and/or Dish-Net in the end…
Or the locals could get together and pay for satellite space and other
equipment to put the Multiplexed data on a satellite as a conditional
access DVB stream.
Or a local could sample the input to the TV transmitter, feed the
Audio(s) / Video in to an analog to digital converter and feed the out
put to a DS-3..
The amount of compression of the Analog to Digital conversion will
determine the quality of the signal that the
up-link station (DirecTV Dish-Net…) will up link.
Garbage IN, Garbage OUT
I am sure that if I missed any thing, some one will point it out!
|
You could have pointed out the "L" band vs "C/KU" band thing. :)
http://ourworld.compuserve.com/homepages/pjmarsh/inmarsat.htm |
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AMRChiefEng
Guest
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| Posted:
Tue Dec 14, 2004 8:13 pm Post subject:
Re: How do local stations send their signals? |
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bill simard wrote:
| Quote: | I know that radio stations use G11 on the L-band to send AC3 audio to
their remote transmitter sites. (snip , snip) . . .
|
They do? I'm chief engineer of three radio stations and this is the
first I've ever heard of using L-band satellites for a studio-
transmitter link (STL). All of our station use either leased telco
lines or terrestrial microwave (950 MHz). Larger networks use C or Ku
band satellite. |
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scambron
Guest
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| Posted:
Wed Dec 15, 2004 7:21 am Post subject:
Re: How do local stations send their signals? |
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On Tue, 14 Dec 2004 10:13:50 -0500, AMRChiefEng <AMRChiefEng@msn.net>
wrote:
| Quote: | bill simard wrote:
I know that radio stations use G11 on the L-band to send AC3 audio to
their remote transmitter sites. (snip , snip) . . .
They do? I'm chief engineer of three radio stations and this is the
first I've ever heard of using L-band satellites for a studio-
transmitter link (STL). All of our station use either leased telco
lines or terrestrial microwave (950 MHz). Larger networks use C or Ku
band satellite.
|
The only L-BAND satellite that I know of is AMSC-1
American Mobile Satellite Corporation / Motient Corporation
http://www.motient.com/
AMSC-1
NSSDC ID:1995-019A
Launch Date/Time: 1995-04-07 at 23:47:00 UTC
On-orbit Dry Mass: 2700 kg
AMSC-1 was a communications satellite launched from Cape Canaveral
aboard an Atlas 2A rocket for the America Mobile Satellite
Corporation. It was placed in a geostationary orbit at 101.1 deg W. It
had the capability to support 2000 radio channels in L-band. The
footprint covered the entire continental US and Canada, as well as
Alaska, Hawaii, Puerto Rico, the Virgin Islands, and 200 miles of US
and Canadian coastal waters. It was the first satellite to use Hughes'
springback antennas, flexible 17-foot-by-22-foot ovals made of
graphite.
http://science.msfc.nasa.gov/RealTime/JTrack/3d/JTrack3D.html
S Cambron |
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thesatguy
Guest
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| Posted:
Wed Dec 15, 2004 9:25 am Post subject:
Re: How do local stations send their signals? |
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They use VyVx fiber optic network.
"bill simard" <simard@nycap.rr.com> wrote in message
news:OAqvd.61907$AL5.57170@twister.nyroc.rr.com...
| Quote: | I was wondering how all the local stations from around the country get
their signal to DTV & Dish ?
I know that radio stations use G11 on the L-band to send AC3 audio to
their remote transmitter sites. Do TV stations also use this? If I had an
L-band LNB could I use a FTA reciever to pick up these freq?
What frequency range is the L-band ?
Thanks for the help
|
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bill simard
Guest
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| Posted:
Thu Dec 16, 2004 1:28 pm Post subject:
Re: How do local stations send their signals? |
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I worked at a station that had 12 remote transmitters and we had a Ku uplink
dish that was pointed at G11, and they tell me
they were using L-band. I'm not sure how the whole L-band thing works.
They tell me L-band is an IF of the Ku.
Maybe you can explain in more detail. Is the L-band actually in the Ku
transmission ? or is it a whole different band below C-band? Thanks
Bill
"AMRChiefEng" <AMRChiefEng@msn.net> wrote in message
news:cpn01c$a1o$1@newsfeed.cv.nrao.edu...
| Quote: | bill simard wrote:
I know that radio stations use G11 on the L-band to send AC3 audio to
their remote transmitter sites. (snip , snip) . . .
They do? I'm chief engineer of three radio stations and this is the first
I've ever heard of using L-band satellites for a studio- transmitter link
(STL). All of our station use either leased telco lines or terrestrial
microwave (950 MHz). Larger networks use C or Ku band satellite.
|
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scambron
Guest
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| Posted:
Thu Dec 16, 2004 7:41 pm Post subject:
Re: How do local stations send their signals? |
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VLF (Very Low Frequency) 0 ~ 30,000 Hz
LF (Low Frequency) 30,000 Hz (30 KHz) ~ 300,0000 Hz (300 KHz)
MF (Medium Frequency) 300 KHz ~ 3,000 KHz
HF (Hi Frequency) 3 MHz ~ 30 MHz
VHF (Vary Hi Frequency) 30 MHz ~ 300 MHz
UHF (Ultra Hi Frequency) 300 MHz ~ 3,000 MHz (3 GHz)
L-Band 950 MHz ~ 1500 MHz (aprox)
SHF (Super Hi Frequency) 3 GHz ~ 30 GHz
C-Band 3 GHz ~ 6 GHz Satellite
X-Band 7 GHz ~ 10 GHz Military Satellite
Ku-Band 10 GHz ~ 15 GHz Satellite
EHF (Extremely Hi Frequency) 30 GHz ~ 300 GHz
L-Band is the IF (Intermediate frequency) for most satellite
receivers.
The LNB (Low noise Block Downconverter) at the antenna receives the
satellite signal (C-Band or Ku-Band) and converts it to L-Band (IF)
frequency.
The COAX cable that pass L-Band Frequencies cost less the cable that
will pass C-Band and Ku-Band frequencies.
The only TRUE receiver and transmit L-Band Satellites that I can think
of are AMSC-1 (101.1 Degres West) and InMarSat Constellation.
http://science.msfc.nasa.gov/RealTime/JTrack/3d/JTrack3D.html
S Cambron
On Thu, 16 Dec 2004 08:28:21 GMT, "bill simard" <simard@nycap.rr.com>
wrote:
| Quote: | I worked at a station that had 12 remote transmitters and we had a Ku uplink
dish that was pointed at G11, and they tell me
they were using L-band. I'm not sure how the whole L-band thing works.
They tell me L-band is an IF of the Ku.
Maybe you can explain in more detail. Is the L-band actually in the Ku
transmission ? or is it a whole different band below C-band? Thanks
Bill
"AMRChiefEng" <AMRChiefEng@msn.net> wrote in message
news:cpn01c$a1o$1@newsfeed.cv.nrao.edu...
bill simard wrote:
I know that radio stations use G11 on the L-band to send AC3 audio to
their remote transmitter sites. (snip , snip) . . .
They do? I'm chief engineer of three radio stations and this is the first
I've ever heard of using L-band satellites for a studio- transmitter link
(STL). All of our station use either leased telco lines or terrestrial
microwave (950 MHz). Larger networks use C or Ku band satellite.
|
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Rompinhell
Guest
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| Posted:
Thu Dec 16, 2004 8:21 pm Post subject:
Re: How do local stations send their signals? |
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bill simard wrote:
| Quote: | I worked at a station that had 12 remote transmitters and we had a Ku
uplink dish that was pointed at G11, and they tell me
they were using L-band. I'm not sure how the whole L-band thing works.
They tell me L-band is an IF of the Ku.
Maybe you can explain in more detail. Is the L-band actually in the Ku
transmission ? or is it a whole different band below C-band? Thanks
|
L band is the output of the lnb, for the sake of simplicity.
http://www.jneuhaus.com/fccindex/l_band.html |
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Crazy George
Guest
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| Posted:
Fri Dec 17, 2004 8:49 am Post subject:
Re: How do local stations send their signals? |
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Among other errors in the replies, the method of obtaining the programming is incorrect. The stations provide a video
and audio stream before it is sent to the local transmitter. Probably in parallel with the local cable feed. I do not
know if the station digitizes it, or if he satellite service does that. I suspect the latter. Proof of this occurs
quite often when the local station transmitter goes distorted or off the air, while the satellite carried programming
continues uninterrupted.
--
Crazy George
Remove N O and S P A M imbedded in return address
"bill simard" <simard@nycap.rr.com> wrote in message news:OAqvd.61907$AL5.57170@twister.nyroc.rr.com...
| Quote: | I was wondering how all the local stations from around the country get their
signal to DTV & Dish ?
I know that radio stations use G11 on the L-band to send AC3 audio to their
remote transmitter sites. Do TV stations also use this? If I had an L-band
LNB could I use a FTA reciever to pick up these freq?
What frequency range is the L-band ?
Thanks for the help
|
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| Back to top |
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bill simard
Guest
|
| Posted:
Fri Dec 17, 2004 9:23 am Post subject:
Re: How do local stations send their signals? 70Mhz IF loop |
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There is a loop out and back into the satellite receiver that is labeled
70Mhz
There are SCPC signals carried in the 50Mhz-90Mhz band coming from this
70Mhz output.
Where in the C-band or Ku band do these frequencies come from ?
Normal audio on the satellite channels is between 5Mhz-9Mhz. Is the 70Mhz
range also imbedded in the satellite channels?
Thanks again
"scambron" <scambron@chesapeake.net> wrote in message
news:41c19b2a.2542796@NEWS.CHESAPEAKE.NET...
| Quote: | VLF (Very Low Frequency) 0 ~ 30,000 Hz
LF (Low Frequency) 30,000 Hz (30 KHz) ~ 300,0000 Hz (300 KHz)
MF (Medium Frequency) 300 KHz ~ 3,000 KHz
HF (Hi Frequency) 3 MHz ~ 30 MHz
VHF (Vary Hi Frequency) 30 MHz ~ 300 MHz
UHF (Ultra Hi Frequency) 300 MHz ~ 3,000 MHz (3 GHz)
L-Band 950 MHz ~ 1500 MHz (aprox)
SHF (Super Hi Frequency) 3 GHz ~ 30 GHz
C-Band 3 GHz ~ 6 GHz Satellite
X-Band 7 GHz ~ 10 GHz Military Satellite
Ku-Band 10 GHz ~ 15 GHz Satellite
EHF (Extremely Hi Frequency) 30 GHz ~ 300 GHz
L-Band is the IF (Intermediate frequency) for most satellite
receivers.
The LNB (Low noise Block Downconverter) at the antenna receives the
satellite signal (C-Band or Ku-Band) and converts it to L-Band (IF)
frequency.
The COAX cable that pass L-Band Frequencies cost less the cable that
will pass C-Band and Ku-Band frequencies.
The only TRUE receiver and transmit L-Band Satellites that I can think
of are AMSC-1 (101.1 Degres West) and InMarSat Constellation.
http://science.msfc.nasa.gov/RealTime/JTrack/3d/JTrack3D.html
S Cambron
On Thu, 16 Dec 2004 08:28:21 GMT, "bill simard" <simard@nycap.rr.com
wrote:
I worked at a station that had 12 remote transmitters and we had a Ku
uplink
dish that was pointed at G11, and they tell me
they were using L-band. I'm not sure how the whole L-band thing works.
They tell me L-band is an IF of the Ku.
Maybe you can explain in more detail. Is the L-band actually in the Ku
transmission ? or is it a whole different band below C-band? Thanks
Bill
"AMRChiefEng" <AMRChiefEng@msn.net> wrote in message
news:cpn01c$a1o$1@newsfeed.cv.nrao.edu...
bill simard wrote:
I know that radio stations use G11 on the L-band to send AC3 audio to
their remote transmitter sites. (snip , snip) . . .
They do? I'm chief engineer of three radio stations and this is the
first
I've ever heard of using L-band satellites for a studio- transmitter
link
(STL). All of our station use either leased telco lines or terrestrial
microwave (950 MHz). Larger networks use C or Ku band satellite.
|
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Gary J. Tait
Guest
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| Posted:
Fri Dec 17, 2004 10:09 pm Post subject:
Re: How do local stations send their signals? 70Mhz IF loop |
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|
On Fri, 17 Dec 2004 04:23:20 GMT, "bill simard" <simard@nycap.rr.com>
wrote:
| Quote: | There is a loop out and back into the satellite receiver that is labeled
70Mhz
There are SCPC signals carried in the 50Mhz-90Mhz band coming from this
70Mhz output.
Where in the C-band or Ku band do these frequencies come from ?
Normal audio on the satellite channels is between 5Mhz-9Mhz. Is the 70Mhz
range also imbedded in the satellite channels?
|
Essentially, this is what happens:
The C-band satellite transmits 3.7 to 4.2 Ghz (ku 11.7 to 12.2 Ghz).
The LNB downconverts that to 1450 to 950 Mhz.
The tuner converts a ~40 Mhz range down to that 50-90 Mhz
An old school LNA/downconvertor system directly converts the C-band to
70 Mhz.
For a normal analog channel, the audio subcarriers (5-8 Mhz) are
combined with the video (0 to 4.5 Mhz), and are FM modulated on an RF
carrier, which eventually is centered on 70 Mhz on the tuner output.
FM2 (FM Squared), puts subcarriers where the video would be (0 to 4.5
Mhz)
SCPC audio puts individual carriers on the C-band (or Ku) for each
audio channel. The tuner would download the group of carriers to the
50-90 Mhz range.
For most of the systems though, chances are there is a modulator of
some sort that modulates those channels on some sort of IF, which is
converted to the uplink frequency somewhat close to the uplink dish or
feed assembly.. |
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Bill R.
Guest
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| Posted:
Fri Feb 25, 2005 2:32 am Post subject:
Re: How do local stations send their signals? |
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Actually, it varies by station. Where I work, DirecTV takes our signal OFF
THE AIR -- if our transmitter goes down, the signal to DirecTV is lost ...
and within minutes, we get a call from them asking what happened. Other
stations in this market provide them with a fiber feed, which is preferable,
but not always possible.
"Crazy George" <muNnscOh@attSglPobaAl.nMet> wrote in message
news:41c25c61_4@news1.prserv.net...
| Quote: | Among other errors in the replies, the method of obtaining the programming
is incorrect. The stations provide a video
and audio stream before it is sent to the local transmitter. Probably in
parallel with the local cable feed. I do not
know if the station digitizes it, or if he satellite service does that. I
suspect the latter. Proof of this occurs
quite often when the local station transmitter goes distorted or off the
air, while the satellite carried programming
continues uninterrupted. |
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