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DISH SETUP: Single sat, Multi-Sat & Motorised
Re- Installing Motorised Dish
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<blockquote data-quote="Channel Hopper" data-source="post: 5893" data-attributes="member: 175144"><p>Dear 2Old</p><p></p><p>There is no correlation between the LNB and a polarisation system in a satellite system. For money saving purposes only, the domestic feed has been used to bring everything together and the end result is the Universal LNB and the dielectric plate. </p><p></p><p>Im sure you are familiar with the history of LNB technology but for the others heres a bit of education</p><p></p><p>Think back through the mists of time-</p><p></p><p>Eighteen Years ago - Ku band was a twinkling in someones eye, C band ruled with massive LNAs, separate power supplies, 1450MHz tuners, short 50 Ohm cable runs and dish sizes out of science fiction</p><p></p><p>Sixteen years ago Ku appeared. LNBs with noise figures of 2.5dB were considered state of the art. 75 Ohm cable arrives along with the first 470 MHz tuners, allowing longer runs and the F type connector. No polarisation system unless you turned the feed round on the dish. Little need as almost all satellites are one polarisation only</p><p></p><p>Fifteen years - the Mechanical polariser appeared. It was a foil accordian device that bent the signal using a crude servo. The Black Bomb appeared that gave 2dB noise figures to reduce dish size down to manageable levels of 1.8 / 2m. First motorised domestic installs under £2000 for sixteen channels (wow !)</p><p></p><p>Thirteen years ago - a split in technology </p><p></p><p>On one side - Noise figures improved with HEMT technology. Some bright spark from Racal comes up with the two wire ferrite polariser and then the dual band LNB from Sharp. 13/18 used to change bands. Chaparral mechanical three wire patented as the Polarotor.</p><p></p><p>On the other - Along came the Voltage Switching or Marconi LNB. SKY makes up plans to rule the world and capitalise on cheap outdoor equipment to remove another cost to the eventual customer. Single cable to the dish driving polarity and signal. BSB uses the single polarity for their planned satellite with circular polarisation. De polariser of PTFE inside the feed is suggested. TDF (France ) and TVSAT (Germany) are built with similar DTH/DBS specification.</p><p></p><p>Twelve years ago Sky and BSB fight with only one winner. Marconi LNB sales in one year outstrip ALL other LNB sales previously.</p><p></p><p>Ten years ago - BSKYB sells off both BSB satellties to Scandinavia for 1Million each. Sirius and Thor 1 are born and serve their respective buyers for another eight years. 2050MHz tuners make an appearance along with the full band LNB. </p><p></p><p>Eight years ago- The idea of inserting tone signals into the cable is demonstrated for purpose of switching two signals and hence two satellites from one cable. Somebody else thinks, I could use this with the 13/18 volt system for adjustment of all polarities and bands using just one cable. </p><p></p><p>Seven years - 10.60 GHz is thought of as the second Local oscillator and the Universal LNB is born. 2150 MHz tuners are brought in to give the compatibility with the LNB</p><p></p><p>Six years ago - The number of Universal LNBs sold in this year again outstrips all sales of all other types of LNB previously</p><p></p><p>And you of course know the rest.</p><p></p><p>The insertion of any depolariser dielectric is not considered in a true feed system. On all commercial systems a depolariser is a mechanical filter using segmented slots down two sides of the feed, which filter out the unwanted signal. For the other polarisation the whole feed is rotated with one component remaining static. Efficiency is maintained and the mechanical servo system is a separate drive from the indoor equipment. </p><p>I use the depolariser for both bands not through choice but through a lack of time and plumbing expertise. When its sorted, Im certain I'll add a few more low signal transponders from the ether to my viewing pleasure.</p></blockquote><p></p>
[QUOTE="Channel Hopper, post: 5893, member: 175144"] Dear 2Old There is no correlation between the LNB and a polarisation system in a satellite system. For money saving purposes only, the domestic feed has been used to bring everything together and the end result is the Universal LNB and the dielectric plate. Im sure you are familiar with the history of LNB technology but for the others heres a bit of education Think back through the mists of time- Eighteen Years ago - Ku band was a twinkling in someones eye, C band ruled with massive LNAs, separate power supplies, 1450MHz tuners, short 50 Ohm cable runs and dish sizes out of science fiction Sixteen years ago Ku appeared. LNBs with noise figures of 2.5dB were considered state of the art. 75 Ohm cable arrives along with the first 470 MHz tuners, allowing longer runs and the F type connector. No polarisation system unless you turned the feed round on the dish. Little need as almost all satellites are one polarisation only Fifteen years - the Mechanical polariser appeared. It was a foil accordian device that bent the signal using a crude servo. The Black Bomb appeared that gave 2dB noise figures to reduce dish size down to manageable levels of 1.8 / 2m. First motorised domestic installs under £2000 for sixteen channels (wow !) Thirteen years ago - a split in technology On one side - Noise figures improved with HEMT technology. Some bright spark from Racal comes up with the two wire ferrite polariser and then the dual band LNB from Sharp. 13/18 used to change bands. Chaparral mechanical three wire patented as the Polarotor. On the other - Along came the Voltage Switching or Marconi LNB. SKY makes up plans to rule the world and capitalise on cheap outdoor equipment to remove another cost to the eventual customer. Single cable to the dish driving polarity and signal. BSB uses the single polarity for their planned satellite with circular polarisation. De polariser of PTFE inside the feed is suggested. TDF (France ) and TVSAT (Germany) are built with similar DTH/DBS specification. Twelve years ago Sky and BSB fight with only one winner. Marconi LNB sales in one year outstrip ALL other LNB sales previously. Ten years ago - BSKYB sells off both BSB satellties to Scandinavia for 1Million each. Sirius and Thor 1 are born and serve their respective buyers for another eight years. 2050MHz tuners make an appearance along with the full band LNB. Eight years ago- The idea of inserting tone signals into the cable is demonstrated for purpose of switching two signals and hence two satellites from one cable. Somebody else thinks, I could use this with the 13/18 volt system for adjustment of all polarities and bands using just one cable. Seven years - 10.60 GHz is thought of as the second Local oscillator and the Universal LNB is born. 2150 MHz tuners are brought in to give the compatibility with the LNB Six years ago - The number of Universal LNBs sold in this year again outstrips all sales of all other types of LNB previously And you of course know the rest. The insertion of any depolariser dielectric is not considered in a true feed system. On all commercial systems a depolariser is a mechanical filter using segmented slots down two sides of the feed, which filter out the unwanted signal. For the other polarisation the whole feed is rotated with one component remaining static. Efficiency is maintained and the mechanical servo system is a separate drive from the indoor equipment. I use the depolariser for both bands not through choice but through a lack of time and plumbing expertise. When its sorted, Im certain I'll add a few more low signal transponders from the ether to my viewing pleasure. [/QUOTE]
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DISH SETUP: Single sat, Multi-Sat & Motorised
Re- Installing Motorised Dish
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