Prime focus Ku ONLY LNB

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hotsat9
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Prime focus Ku ONLY LNB

Postby hotsat9 » Sun Jan 28, 2018 7:20 pm

Can anyone recommend a Ku ONLY LNB for a prime focus dish? I would like to run some Ku tests comparing the signal strength differences of a 6ft mesh prime focus vs a .96m offset Ku dish.

Im curious if some frequencys will do better on one dish or another.

Also curious if one dish will respond better than the other in hot signal areas. Also curious if one dish will respond better than the other in fringe signal areas.

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owhite47
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Re: Prime focus Ku ONLY LNB

Postby owhite47 » Mon Jan 29, 2018 9:23 pm

I would supect that the mesh would degrade you signal so that you wouldn't see any improvement at all........Just a guess

STRETCH
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Re: Prime focus Ku ONLY LNB

Postby STRETCH » Tue Jan 30, 2018 3:44 pm

You could try a INVERTO ULTRA SINGLE BLACK, the dia. is only 40mm, you may have to mod your dish for this LNB to fit.

DEN

Cornhusker
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Re: Prime focus Ku ONLY LNB

Postby Cornhusker » Tue Jan 30, 2018 11:05 pm

What is the f/d of your prime focus dish? Most offset lnbs are usually made to illuminate an offset with a f/d ratio of .6.

Cornhusker
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Re: Prime focus Ku ONLY LNB

Postby Cornhusker » Wed Jan 31, 2018 3:42 pm

http://www.linkboxusa.com/pf7900u.htm Here is a lnf made for a prime focus reflector.

hotsat9
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Re: Prime focus Ku ONLY LNB

Postby hotsat9 » Fri Feb 02, 2018 10:50 pm

My prime focus is 71" wide x 24" deep

Ill see if I can get my hands on a linkbox LNB

Satman43
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Re: Prime focus Ku ONLY LNB

Postby Satman43 » Sat Feb 24, 2018 6:41 am

hotsat9 wrote:My prime focus is 71" wide x 24" deep

Ill see if I can get my hands on a linkbox LNB
have you come to any conclusions yet?? I have ran similar tests on a c/ku setup on a 10' big dish vs an offset small dish and a prime focus small dish

oscar2873
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Re: Prime focus Ku ONLY LNB

Postby oscar2873 » Wed Apr 04, 2018 1:18 am

If you need a standard ku lnbf for prime focus you can buy the GEOSATpro SL1P SINGLE STANDARD 10750 with 60db gain and 0.6 noise figure, if you need a universal ku lnbf for prime focus recommended the Golden Interstar GI-209P with 60db gain and 0.2 noise figure or the MTI AP8-TFT with conversion gain: 65dB and noise figure: 0.1 , all three you can buy in ebay.

Regards

mos
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Re: Prime focus Ku ONLY LNB

Postby mos » Mon Apr 30, 2018 4:22 am

can you line the back of a big mesh dish with aluminum foil will that help bounce a better ku into lnb?
V8 Golden / V8 Nova

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iq180
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Re: Prime focus Ku ONLY LNB

Postby iq180 » Mon Apr 30, 2018 1:17 pm

mos wrote:can you line the back of a big mesh dish with aluminum foil will that help bounce a better ku into lnb?


You can take out the mesh and replace it with sheet metal, I have done it and it works great, remember to paint it with flat black or flat gray paint before you put your LNB on it, if you don't paint it you will kill your LNB just as soon as the sun hits it.

mos
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Re: Prime focus Ku ONLY LNB

Postby mos » Wed May 02, 2018 5:31 am

yes thanks i have an idea now i will try it also is there a difference with the focal point distance of ku lnb compared to c lnb? i have 8 feet dish.
V8 Golden / V8 Nova

Wilis13
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Re: Prime focus Ku ONLY LNB

Postby Wilis13 » Tue May 15, 2018 2:02 am

I have a mesh dish and it works great with both c band and ku. I use the same focal distance. If your dish is well aligned you should be able to scan ku.

Jim
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Re: Prime focus Ku ONLY LNB

Postby Jim » Tue May 15, 2018 9:44 pm

mos wrote:yes thanks i have an idea now i will try it also is there a difference with the focal point distance of ku lnb compared to c lnb? i have 8 feet dish.


The focal point for your particular dish is the focal point no matter if it's C or Ku. I have a 10' Mesh dish that gets excellent C/Ku. The distance is calculated http://www.satsig.net/focal-length-parabolic-dish.htm

Jim
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Re: Prime focus Ku ONLY LNB

Postby Jim » Tue May 15, 2018 9:48 pm

Jim wrote:
mos wrote:yes thanks i have an idea now i will try it also is there a difference with the focal point distance of ku lnb compared to c lnb? i have 8 feet dish.


The focal point for your particular dish is the focal point no matter if it's C or Ku. I have a 10' Mesh dish that gets excellent C/Ku. The distance is calculated http://www.satsig.net/focal-length-parabolic-dish.htm
. If you know th the brand of your dish this chart will help too! http://www.bigdish.info/mainten/lfocal.html

melvinfta
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Re: Prime focus Ku ONLY LNB

Postby melvinfta » Wed Jun 06, 2018 12:49 am

Please let us know if that worked?

kroll
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Re: Prime focus Ku ONLY LNB

Postby kroll » Wed Jun 06, 2018 4:00 pm

owhite47 wrote:I would supect that the mesh would degrade you signal so that you wouldn't see any improvement at all........Just a guess

Completamente de acuerdo contigo,el ancho de banda de la frecuencia en KU requiere que el plato sea de lamina y no de malla para que funcione en esa banda,si es malla pierde ganacia cuanto mayor sea el diametro de las perforaciones de dicha malla,saludos
10 foot prime focus c band dish w/36 actuator pansat ap-3000 positioner at full arc & freesat V7

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Feralkiwi
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Re: Prime focus Ku ONLY LNB

Postby Feralkiwi » Wed Jun 06, 2018 10:24 pm

Some mesh dishes with flat sheet that is punched with small holes is spec'ed or said to be Ku / c band.
This sheet has a smooth surface.
IMG_6813.JPG
IMG_6813.JPG (112.06 KiB) Viewed 1243 times

As I went to photo my dish I find my turkeys on my highest dish.
One jumped off before I took the pic.
IMG_6812.JPG
IMG_6812.JPG (57.35 KiB) Viewed 1243 times


Owen
Dishes; 5x3m, 2.4m, 2.1m, 1.8m and 4.1m, 10+ ku, 2 movers, USARLS. Skybox F5, F5s, V6, V8. Openbox V8 Combo, Pro, Freesat V8 Golden, Nova, GTC, Super and Angle (Sample). Freesat V7HDs, Combo and V7s. Sats 100.5E to 177W. I'm a Sat hobbyist who helps out.

highswr
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Re: Prime focus Ku ONLY LNB

Postby highswr » Sat Jun 16, 2018 9:37 pm

Nice "bird" what transponders does it have? My wild turkeys never get on the dish, thank goodness.

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Marsat
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Re: Prime focus Ku ONLY LNB

Postby Marsat » Tue Jun 19, 2018 7:19 am

Feralkiwi wrote:Some mesh dishes with flat sheet that is punched with small holes is spec'ed or said to be Ku / c band.
This sheet has a smooth surface.
IMG_6813.JPG
As I went to photo my dish I find my turkeys on my highest dish.
One jumped off before I took the pic.
IMG_6812.JPG

Owen


lol

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Marsat
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Location: Miami

Re: Prime focus Ku ONLY LNB

Postby Marsat » Tue Jun 19, 2018 7:24 am

I do have installed a Universal LNB in a 2.4m along with 2 for C band

It does work however I do not see much of signal improvement due the signal here mostly is over 85%. BUt..... I do see the difference when it rains

On 76cm I lost the satellite.
1.2 m almost lost
2,4 some flickering

I havent tried one for Prime Focus, still. I like to hear about those PLL LNB Downconverters though

zoricua1981
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Joined: Thu Jan 11, 2018 11:15 pm

Re: Prime focus Ku ONLY LNB

Postby zoricua1981 » Sun Jul 08, 2018 12:23 am

thanks for the info
i bought a c/ku lnb and i was never able to get ku to work properly maybe 2 or 3 channels on 87w but that was about it


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