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Biswajit.HD
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@Mazhar : You can ask Vikram, Om prakash or Vinay for solution... :huh
M@zh@R said:
66cm dish will not lock C-band signals at all.
You need a 90cm dish with a Conical Scalar Ring or a 120cm dish to receive the C-band signals with lockable signal quality.
Sahara Samay 4020 tp is strong on Asiasat3S.
RE: Equipment pics :6ft C Band Multi LNB Dish Set up
What is importance of scalar ring? When scalar ring need?
Thanks.
I know types of Lnbf of DVB - S. But what difference between C band dish antenna & Ku band dish antenna? I dont understand really there is any such kind of difference like that except it's size & lnbf type?
If an user use 90 cm dish for catching KU band signals from a satellite, he can use same dish replacing / adding C band lnb for catching c band channels then why they printed on box it is C & Ku band dish antenna?
If there any matter which make difference like that please give information please.
Thanks.
Vinay said:
What is importance of scalar ring? When scalar ring need?
Thanks.
biswajit.HD said:Here are the exclusive pics of all the equipments for my 6ft (180 cm) C band Dish Set up, which i brought from Pune, Maharashtra :
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I know types of Lnbf of DVB - S. But what difference between C band dish antenna & Ku band dish antenna? I dont understand really there is any such kind of difference like that except it's size & lnbf type?
If an user use 90 cm dish for catching KU band signals from a satellite, he can use same dish replacing / adding C band lnb for catching c band channels then why they printed on box it is C & Ku band dish antenna?
If there any matter which make difference like that please give information please.
Thanks.
RE: Equipment pics :6ft C Band Multi LNB Dish Set up
Rare thing / problem maybe of open sky. If u installed ur antenna under roof / balcony / slab which is straight up side of antenna maybe problem to catch signals. I m talking about Ku band channels cause dish size is 66 cm.
M@zh@R said:
Rare thing / problem maybe of open sky. If u installed ur antenna under roof / balcony / slab which is straight up side of antenna maybe problem to catch signals. I m talking about Ku band channels cause dish size is 66 cm.
Biswajit.HD
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RE: Equipment pics :6ft C Band Multi LNB Dish Set up
In all feedhorns the scaler rings reject thermal noise (kelvin), TI, etc from beyond the edges of the dish. Also normal feedhorns such as (Chaparral) the scaler rings act as a choke plate to cut off noise and out of focus energy being picked up by the feedhorn throat. In a dual mode hybrid feed (ADL) the moding chambers take this out of focus energy, puts it back in phase to be used as good signal. This is why a properly set up ADL (dual mode hybrid feed) such as a RP1-C will out perform a Chaparral.
The most common type of feedhorn manufactured today is called a scalar feedhorn. This type of feed has a large circular plate with a series of three or four concentric rings attached to its surface. The scalar rings conduct the incoming signal from the outer edges of the focal cloud to the large waveguide opening located at feed center. The scalar feedhorn primarily sees or illuminates the inner portion of the antenna's surface area, while attenuating the signal contribution from the outer portion of the dish by 8 to 22 dB, depending on whether the dish is deep or shallow in its construction.
Molecular motion within the Earth itself generates random noise which permeates the entire electromagnetic spectrum used for the transmission of satellite signals. This random noise is many times stronger than the satellite signals reaching any location. The attenuation or illumination taper provided by the feed sharply reduces the reception of the Earth noise which lies just beyond the antenna's rim. The outer area of the antenna's surface therefore acts more as an Earth shield for the feedhorn than as a contributor to the overall signal gain of the receiving antenna.
In all feedhorns the scaler rings reject thermal noise (kelvin), TI, etc from beyond the edges of the dish. Also normal feedhorns such as (Chaparral) the scaler rings act as a choke plate to cut off noise and out of focus energy being picked up by the feedhorn throat. In a dual mode hybrid feed (ADL) the moding chambers take this out of focus energy, puts it back in phase to be used as good signal. This is why a properly set up ADL (dual mode hybrid feed) such as a RP1-C will out perform a Chaparral.
The most common type of feedhorn manufactured today is called a scalar feedhorn. This type of feed has a large circular plate with a series of three or four concentric rings attached to its surface. The scalar rings conduct the incoming signal from the outer edges of the focal cloud to the large waveguide opening located at feed center. The scalar feedhorn primarily sees or illuminates the inner portion of the antenna's surface area, while attenuating the signal contribution from the outer portion of the dish by 8 to 22 dB, depending on whether the dish is deep or shallow in its construction.
Molecular motion within the Earth itself generates random noise which permeates the entire electromagnetic spectrum used for the transmission of satellite signals. This random noise is many times stronger than the satellite signals reaching any location. The attenuation or illumination taper provided by the feed sharply reduces the reception of the Earth noise which lies just beyond the antenna's rim. The outer area of the antenna's surface therefore acts more as an Earth shield for the feedhorn than as a contributor to the overall signal gain of the receiving antenna.
Biswajit.HD
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RE: Equipment pics :6ft C Band Multi LNB Dish Set up
@max : C band antennae is generally used for catching up low frequency signals on C band transmission, which needs a large dish as compared to Ku band high frequency small dth dishes. Although C band can be tried on a 90 cm dish, but the c band lnbf needs conical scalar ring. For more details on conical scalr ring you can search our satellite section.
As regards to the dish i brought its a C and Ku band dish, which can serve multipurpose for both C and Ku band reception. i mean you can use Ku band lnbs also to recieve ku band signals on this dish apart from traditional C band lnbf used on this dish...
@max : C band antennae is generally used for catching up low frequency signals on C band transmission, which needs a large dish as compared to Ku band high frequency small dth dishes. Although C band can be tried on a 90 cm dish, but the c band lnbf needs conical scalar ring. For more details on conical scalr ring you can search our satellite section.
As regards to the dish i brought its a C and Ku band dish, which can serve multipurpose for both C and Ku band reception. i mean you can use Ku band lnbs also to recieve ku band signals on this dish apart from traditional C band lnbf used on this dish...
hyaRE: Equipment pics :6ft C Band Multi LNB Dish Set up
I got difference of additional thing of scalar ring. Suppose if user have 240 cm Ku band solid panel dish antenna. Can the dish give same quality for C band channels like same size C band dish (180 cm) can ggive?
Thanks.
biswajit.HD said:
I got difference of additional thing of scalar ring. Suppose if user have 240 cm Ku band solid panel dish antenna. Can the dish give same quality for C band channels like same size C band dish (180 cm) can ggive?
Thanks.
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RE: Equipment pics :6ft C Band Multi LNB Dish Set up
Max bhai,
its but obvious thing that big pan dish will gives u more signal then small one... it also affect by the focal ( prime focus or offset focus)
see there is nothing to do with C & Ku band if you are getting good signal of any band you can spot that beam with any LNB but yes signal quality is depend upon dish size,focal, EIRP ( Equivalent isotropically radiated power) of the transponder of viable satellite.the more power full the transponder is, i mean higher value of EIRP so the more signal quality you will receive unlike weak one, less the EIRP then higher dish size require & the higher EIRP require small dishes...
Ku band signal with high frequency are mostly broadcasted with specific beam like regional, spot, specific country beam for specific targeted services to audiences hence normally it requires small dishes (30,45, 60, 90 or 120 cms. dishes) because signal are concentrated...
C band signal with low frequencies are mostly broadcasted with large continent as it covers most visible part of the visible earth hence more coverage less signal area of outer ring of foot print.... sometime its possible that if your geo area is showing lower EIRP then you need to use higher size dish....
You can check EIRP values of each transponder of satellite on www.lyngsat.com, www.tracksat.com
Max said:
Max bhai,
its but obvious thing that big pan dish will gives u more signal then small one... it also affect by the focal ( prime focus or offset focus)
see there is nothing to do with C & Ku band if you are getting good signal of any band you can spot that beam with any LNB but yes signal quality is depend upon dish size,focal, EIRP ( Equivalent isotropically radiated power) of the transponder of viable satellite.the more power full the transponder is, i mean higher value of EIRP so the more signal quality you will receive unlike weak one, less the EIRP then higher dish size require & the higher EIRP require small dishes...
Ku band signal with high frequency are mostly broadcasted with specific beam like regional, spot, specific country beam for specific targeted services to audiences hence normally it requires small dishes (30,45, 60, 90 or 120 cms. dishes) because signal are concentrated...
C band signal with low frequencies are mostly broadcasted with large continent as it covers most visible part of the visible earth hence more coverage less signal area of outer ring of foot print.... sometime its possible that if your geo area is showing lower EIRP then you need to use higher size dish....
You can check EIRP values of each transponder of satellite on www.lyngsat.com, www.tracksat.com
