Log in
Register
Menu
Log in
Register
Home
What's new
Latest activity
Authors
Forums
New posts
Search forums
What's new
New posts
Latest activity
Members
Current visitors
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Satellite TV receivers & systems support forums
DISH SETUP: Single sat, Multi-Sat & Motorised
C-Band Reception, UK and Europe
C-Band in the uk any one useing it
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Huevos" data-source="post: 744883" data-attributes="member: 301161"><p>Digital uses phase shift keying, but apart from that the properties of the two are pretty much the same.</p><p></p><p>On a conventional satellite (not SES Astra) H polarisation is parallel with the equator directly below it and V polarisation is perpendicular. A properly set up polar mount follows this closely but there is a very minor error in skew caused by the aerial being located topocentrically, rather than geocentrically.</p><p></p><p>In theory the LNB skew is irrelevant with regard to circularly polarised signals, and any discrepancies you do see will be due to imperfections in the transmitting and receiving aerials, rather than the skew. I've tried playing with the LNB skew on several satellites with circular polarisation but don't see any signal improvement at all. In the end I just align my LNB for best H/V skew so I could just whip the plate out when not on a circular polarised satellite.</p><p></p><p>Personally I'm for the easy life so if I were setting up a big prime focus dish for C-band I'd go for a pair of dual polarisation LNBs (one linear, and one circular) and fit them to a <a href="http://www.satellites.co.uk/forums/picture-members-setups-general-satellite-installations/145445-work-progress-gibertini-1-5m-3.html#post978613" target="_blank">siamesed scalar ring</a>. Percentage cross section and offset go down with dish size so the bigger the dish the better with this set up.</p><p></p><p>As for my own experience with C-band LNBs I'm using Zinwell's which I didn't buy for the K value, but just because they were what my supplier had, and at 12€ each they were well within budget. I'm only using a 1.5m dish with them but am <a href="http://www.satellites.co.uk/forums/picture-members-setups-general-satellite-installations/145445-work-progress-gibertini-1-5m-3.html#post978613" target="_blank">catching a fair range of channels</a> from 57ºE through to 58ºW and limited any further by my local horizon.</p></blockquote><p></p>
[QUOTE="Huevos, post: 744883, member: 301161"] Digital uses phase shift keying, but apart from that the properties of the two are pretty much the same. On a conventional satellite (not SES Astra) H polarisation is parallel with the equator directly below it and V polarisation is perpendicular. A properly set up polar mount follows this closely but there is a very minor error in skew caused by the aerial being located topocentrically, rather than geocentrically. In theory the LNB skew is irrelevant with regard to circularly polarised signals, and any discrepancies you do see will be due to imperfections in the transmitting and receiving aerials, rather than the skew. I've tried playing with the LNB skew on several satellites with circular polarisation but don't see any signal improvement at all. In the end I just align my LNB for best H/V skew so I could just whip the plate out when not on a circular polarised satellite. Personally I'm for the easy life so if I were setting up a big prime focus dish for C-band I'd go for a pair of dual polarisation LNBs (one linear, and one circular) and fit them to a [URL="http://www.satellites.co.uk/forums/picture-members-setups-general-satellite-installations/145445-work-progress-gibertini-1-5m-3.html#post978613"]siamesed scalar ring[/URL]. Percentage cross section and offset go down with dish size so the bigger the dish the better with this set up. As for my own experience with C-band LNBs I'm using Zinwell's which I didn't buy for the K value, but just because they were what my supplier had, and at 12€ each they were well within budget. I'm only using a 1.5m dish with them but am [URL="http://www.satellites.co.uk/forums/picture-members-setups-general-satellite-installations/145445-work-progress-gibertini-1-5m-3.html#post978613"]catching a fair range of channels[/URL] from 57ºE through to 58ºW and limited any further by my local horizon. [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Satellite TV receivers & systems support forums
DISH SETUP: Single sat, Multi-Sat & Motorised
C-Band Reception, UK and Europe
C-Band in the uk any one useing it
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top