How do I install a 40mm LNBF on a Prodelin 8 foot offset dish?

Discussion in 'Free To Air (FTA) Discussion' started by miguelaqui, Dec 29, 2017.

  1. miguelaqui

    miguelaqui Topic Starter SatelliteGuys Pro

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    I bought an 8 foot offset 2.4 dish from Satellitedish.com I tried to get a receive-only, but he could not seem to get one in , so he sold me this send/receive, 1.8, for a discounted price.

    Now , I have an issue with figuring out where the focal point on the dish would be. Since the bracket that it comes with is made for the send/receive LNB, the 40mm LNBF does not fit, not even when I broke the plastic off the LNBF.

    Even when I was able to get a signal, it was not really any better than my Channel Master 1.8 antenna. My assumption is that the Channel Master, which is receive-only, had a bracket perfect for the 40mm LNBF.

    I received a holder, which is not really made for the type of LNBF I am using. I contacted General Dynamics Prodelin directly, and was told that they did not make an LNBF bracket for that type of antenna.

    The seller told me to just look where the one that it came with was pointed, and then figure out a way to get my LNBF pointed there.

    If anyone has dealt with Prodelin antennas and using an LNBF with them, please let me know.

    I can get a signal using the front bracket with a zip tie on the LNBF. I tried putting the rear, wide, bracket up front , and wrapping the LNBF in tape to put it in the middle of the bracket. I have tried moving the locations of the brackets, but no setup seems to give me a much better signal than I can get with the Channel Master 1.8 antenna.

    My only conclusions are that either the Channel Master does so well because it is a 1.6, or I simply am not putting the LNBF at the true focal point with the corresponding elevation of the antenna.

    I have included images of the bracket. I included a pic of the LNB that cam with the dish, just in case it might help figure out what I need to do.

    Thanks to all in advance!


    IMG_20171229_133011578.jpg
     

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  3. RimaNTSS

    RimaNTSS SatelliteGuys Pro

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    On my picture I circled in yellow what you have to do. IMG_20140718_155259 (Medium).jpg
    Do you know what is an offset angle of your antenna? Knowing that would help you a lot to properly install LNBF.
     
  4. miguelaqui

    miguelaqui Topic Starter SatelliteGuys Pro

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    17.35 is the offset angle.
     
  5. Magic Static

    Magic Static FTA Geek
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  6. RimaNTSS

    RimaNTSS SatelliteGuys Pro

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    Of course, if you install properly universal LNBF to your antenna you will get good reception. All universal LNBFs have designed for antennas with F/D ratio about 0.6 , but your antenna has F/D ~0.9, so performance of the system might not be so good as it could be if already advised feedhorn and flange LNB are used.
    My 1.8m Prodelin has F/D=0.6, I've tried several LNBFs on it and also original feedhorn with customized LNB attached. Results were satisfactory enough :)
     

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  7. beavs2112

    beavs2112 Addicted to Legal FTA
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    It seems very odd that the dealer couldn't get a RX only model cause GD Satcom make a few versions in the 2.4m size.

    Anyway I would use the front bracket with the big feedhorn using a modern C120 lnb bolted to it. They are sometimes called flange lnbs. I have a GD satcom 1.8 so I have been doing some digging around the net recently.

    There are some of the old C120 flange lnbs kicking around but they are 20 year old technology. they were made by Eagle Aspen I think for the small Primestar dishes but they should bolt onto your big feedhorn. I'm not sure if Impakt is still in business selling satellite stuff but if they are these are fairly reasonably priced http://www.impaktproducts.com/Eagle-Aspen-270-Ku-Band-Dual-Output-Linear-LNBF-ON-SALE-p-16619.html.

    I would go with much newer technology though and get an Inverto lnb. please note that the Invertos are made for the European market foremost and are a universal freq 10.7 - 12.7 lnb not a standard North American freq. 11.7-12.2. They will work here but you need to figure out how to setup your receiver to access the correct freq band used here in North America. they have two LO frequencies

    There are these on ebay USA Inverto Black Pro C120 Quad LNB | eBay but they are a Quattro output not a quad as in the description. If the Quattro is overkill for you try the twin version below.

    you could get one from ebay UK that's a dual Inverto Black Pro C120 Twin LNB | eBay
    have not purchased from ebay overseas recently so buyer beware obviously.

    ps beautiful dish btw

    Kevin
     
  8. Magic Static

    Magic Static FTA Geek
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    Quattro LNBs need a multi-switch to operate. Quads can serve 1 ~ 4 receivers or a multi-switch.
     
  9. beavs2112

    beavs2112 Addicted to Legal FTA
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    I respectfully disagree MS. Quattros can be used here in NA if you use a dual tuner RCVR and only use 2 ports on the LNB. They don't NEED a multiswitch to operate .... just if you want to access all 4 ports you need a switch. But the OP is here in NA so he probably isn't ever going to use the low band ports anyway.
     
  10. Titanium

    Titanium AI6US
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    So how would you use a Quattro without a switch? Dual tuner STB - One tuner only have horizontal polarity and the other tuner only vertical? If so, I would use a multi-switch so each tuner could have both polarities.
     
  11. Magic Static

    Magic Static FTA Geek
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    I knew if I said that somebody would disagree. Yeah you can use a lot of stuff the in a way it wasn't designed for. But a quattro is designed to be used with a switch.
     
  12. beavs2112

    beavs2112 Addicted to Legal FTA
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    Correct - one tuner vertical other tuner horizontal
     



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