LNB modification

**Rizwan** · 02-09-2013, 09:19 AM

Can I modify the C-band LNB, Only remove its Circuit and replace it with KU-band Circuit ? So it can work as KU-band LNB ?

**satwyn** · 02-09-2013, 11:20 AM

Originally Posted by Rizwan

Can I modify the C-band LNB, Only remove its Circuit and replace it with KU-band Circuit ? So it can work as KU-band LNB ?

no never seen this done get the proper ku lnb and feed for your dish or there are chapparal corator2 available that will take both c/ku lnbs or even combined c/ku all in 1 available and no i do not know where to obtain them

**Rizwan** · 02-09-2013, 12:06 PM

Thank you for reply, I only want to try it, only want to know, what is the difference between KU and C other than its Circuit and feed shape

**satwyn** · 02-09-2013, 12:55 PM

Originally Posted by Rizwan

Thank you for reply, I only want to try it, only want to know, what is the difference between KU and C other than its Circuit and feed shape

yes the feed shape also the frequency range c-3.4ghz-4.2ghz ku 10.7ghz-12.75ghz can't see the logic in messing about with the internal workings of the lnbs when the parts you need are available and cheapish but i suppose everything is possible but a load of hastle for nothing

**Rizwan** · 02-09-2013, 01:27 PM

I agree with your argument, I have few spare KU-band LNB and also C, For your information, I have quite big Dish about 3.5 M, and using KU-band LNB and only trying fringe reception, now looking for more signals. I think big opening for LNB may permit more signals, where as my Dish is locally made and may be have not accurate focus

**unimesh7Fowner** · 02-09-2013, 04:53 PM

Originally Posted by Rizwan

I agree with your argument, I have few spare KU-band LNB and also C, For your information, I have quite big Dish about 3.5 M, and using KU-band LNB and only trying fringe reception, now looking for more signals. I think big opening for LNB may permit more signals, where as my Dish is locally made and may be have not accurate focus

You are wrong, big openings does not mean more signal ( can be more noise in) . It just like an aerial . A long car aerial does not mean more radio signals . c and Ku band are two different frequencies band so each feed horn dimension is made to tune each bandwidth. The greater the frequency the smaller the feed horn , lesser the frequency , the larger is the feedhorn.

Just like the your car aerial mobile phone aerial for car are very short compared to a FM/AM or DAB car aerial . This because the mobile phone frequency is much higher than FM/ AM or DAB

**stars** · 03-09-2013, 06:25 PM

If you want to get weak signals in the KU-Band you must have a C120 LNB for
the KU-Band and a feed horn that matches you dish F/D ratio, else can't the
LNB see the whole dish area and you will not be able to use the whole antenna surface.
primefocusvsoffsetlnb.jpg

stars