Focal Distance

B

Bale

Member
My Satellite Setup
Sky+HD box (Amstrad DRX890),
Sky box (Pace 2600CI),
3.2m primefocus ,C120,
Technomate TM6900,
My Location
Larnaca, Cyprus
Hello there,

Can you please let me know what is the focal distance of a 1.8m Andersen offset dish.
Also, and correct if I am wrong is is right to say to that focal distance of an offset dish is the distance between the inner center of the dish and the feed horn.
Lastly, is the Andersen 1.8m offset dish a good combination with the Andrews feed horn and the C120.

Thanks
 
The Andersen offset 1.8m has a f/d ratio of 0.61, making focal length 1.098 metres.
This should be from the centre axis, as seen by the feed, to the front face of the feedhorn, I believe.
The Andrew offset feed works better than any other on large offset dishes such as yours.
The only problem you might have is adapting the diameter of the feed to the LNB holder on the Andersen.
On some offset dishes such as Gibertini, f/d of 0.66, the best position of the feed is as far back as it will go, exception is on Andrew dishes, where the exact point is clearly defined. In all cases, fine tuning with a meter is essential.
 
Hi Snap,

Can you let me know please if the Andrew offset feed can work on an Andersen offset 2.4m dish too?


Thanks
 
If the dish is offset, it will work. You may have to experiment on focal distance by pulling the LNB and feed back and forth.
 
I replaced today on my Andersen offset 1.8m dish the universal twin LNB 0.3dB Horn (invacom) with the Universal Quad LNB 0.3dB C120 and the Andrew offset feed , I was impressed with the results, previously I wasnt able to get the default frequency, now I can, is weak but between the hours 5.30-8.30pm is quite strong, during those times for my suprice I get channel 4 as well, also previously I had some problems with the US channel 5 plus the scifi channel(+1), now I get perfect picture for 24 hours.
I need to ask if I decide to upgrade to some point to an 2.4 Andersen offset dish, will be able to get channel 4 for 24 hours ?.

Thanks
 
Bale said:
I replaced today on my Andersen offset 1.8m dish the universal twin LNB 0.3dB Horn (invacom) with the Universal Quad LNB 0.3dB C120 and the Andrew offset feed , I was impressed with the results, previously I wasnt able to get the default frequency, now I can, is weak but between the hours 5.30-8.30pm is quite strong, during those times for my suprice I get channel 4 as well, also previously I had some problems with the US channel 5 plus the scifi channel(+1), now I get perfect picture for 24 hours.
I need to ask if I decide to upgrade to some point to an 2.4 Andersen offset dish, will be able to get channel 4 for 24 hours ?.

Thanks
Click to expand...

How is the reception on SKY Two & SKY Three?You should have a picture on these channels between 5.30pm-10.00pm..
They are weaker than Channel 4 and default transponder but they also improve at same times.
I believe 2.4 Andersen will fix Channel 4 reception for you..
I have a friend in Nicosia using a 2.4 offset and his Channel 4 is OK 24/7...
 
Bale said:
I replaced today on my Andersen offset 1.8m dish the universal twin LNB 0.3dB Horn (invacom) with the Universal Quad LNB 0.3dB C120 and the Andrew offset feed , I was impressed with the results, previously I wasnt able to get the default frequency, now I can, is weak but between the hours 5.30-8.30pm is quite strong, during those times for my suprice I get channel 4 as well, also previously I had some problems with the US channel 5 plus the scifi channel(+1), now I get perfect picture for 24 hours.
I need to ask if I decide to upgrade to some point to an 2.4 Andersen offset dish, will be able to get channel 4 for 24 hours ?.

Thanks
Click to expand...


I have fitted many Anderson 2.4m and none of them have problems with C4. You should get channel 4 with some to spare!

Nick
 
I do get sky 2 and sky 3 but with breaks-ups, but havent really checked them if there is a specific time period that can get them without problems, how about when channel 4 goes HD in December, will be in the same transporter like channel 4 now? it will be pitty if I upgrade to 2.4m and not to be able to get ch4 HD.

Thanks
 
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