Focal Distance

Bale

Member
Joined
Aug 4, 2007
Messages
33
Reaction score
1
Points
8
Age
57
Location
Larnaca, Cyprus
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
 

dxsat

Regular Member
Joined
Jun 22, 2005
Messages
745
Reaction score
70
Points
28
Age
69
Website
skyinmadrid.com
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
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.
 

Bale

Member
Joined
Aug 4, 2007
Messages
33
Reaction score
1
Points
8
Age
57
Location
Larnaca, Cyprus
My Satellite Setup
Sky+HD box (Amstrad DRX890),
Sky box (Pace 2600CI),
3.2m primefocus ,C120,
Technomate TM6900,
My Location
Larnaca, Cyprus
Hi Snap,

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


Thanks
 

dxsat

Regular Member
Joined
Jun 22, 2005
Messages
745
Reaction score
70
Points
28
Age
69
Website
skyinmadrid.com
My Satellite Setup
Snap's setup: (In Spain) Humax HDR, Prodelin 1.8m dish + Invacom QDF-031 + CM feed, (In UK) CallFlow VDSL + EE 4G, Sky Q, YouView HD, Mac OSX, iOS
My Location
UK: Tonbridge, Kent. Spain: Madrid.
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.
 

Bale

Member
Joined
Aug 4, 2007
Messages
33
Reaction score
1
Points
8
Age
57
Location
Larnaca, Cyprus
My Satellite Setup
Sky+HD box (Amstrad DRX890),
Sky box (Pace 2600CI),
3.2m primefocus ,C120,
Technomate TM6900,
My Location
Larnaca, Cyprus
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
 

iceman

Regular Member
Joined
Apr 3, 2003
Messages
744
Reaction score
3
Points
18
Age
63
My Satellite Setup
3.0m Motorised Channel Master + 4 fixed dish Amstrad_DRX890C
DM7020s,DM800se
UNOHM EP314 PROMAX TV Explorer
My Location
Kyrenia - NORTH CYPRUS
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

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...
 

bignick

Specialist Contributor
Joined
Feb 13, 2005
Messages
336
Reaction score
0
Points
16
Age
56
My Satellite Setup
Back in the UK and missing Cyprus!!!
My Location
Aylesbury
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


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
 

Bale

Member
Joined
Aug 4, 2007
Messages
33
Reaction score
1
Points
8
Age
57
Location
Larnaca, Cyprus
My Satellite Setup
Sky+HD box (Amstrad DRX890),
Sky box (Pace 2600CI),
3.2m primefocus ,C120,
Technomate TM6900,
My Location
Larnaca, Cyprus
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
 
Top