What I have is a DirecTV Alaska Hawaii Ka/Ku Low Noise Amplifier/Blockdownconverter/Feed which was purpose made to work with a 1.2m offset reflector mfgd. by the same Co.
I need to modify it to work with a 2.4m offset reflector with a different f/D ratio.
I wrote to Eagle/PBI, the mfgrs., but have not received a reply, so I thought I'd just copy/paste the letter and see what
folks here think.
~~~~~~~~~~~~~~~~~~~~~~
I have successfully used your DirecTV Alaska/Hawaii Ka/Ku LNBF on a variety of reflectors (Prodelin 1.2 and 1.8m) with satisfactory results, and now I need to fit it to an Andrews 2.4m reflector.
Appx. 4 years ago, I installed Ku LNBs at 101/110/119 (DirecTV) on this antenna. It was boresighted on 110 and I used a spectrum analyzer to find the focal points of 101/119 and attached those LNBs to a bracket I fabricated that was bent to the correct "tilt" angle which worked great.
Now that the Ka birds are being used, I need another solution in order to get HD into this SportsBar and there is a dearth of solutions available, especially with the requirement of switch outputs to be used with a SWM 16.
I estimate the new focal points for 99/103 to be around 2.6 inches from the 101, but I'll locate these empirically, exactly.
What I was planning on doing was to use a fine-kerf hacksaw and separating the Ka feeds down to 1/2 in. from the flange which screws to the LNB, then cutting them off.
Some Dremel tool grinding, etc. if needed to get both ends round.
Now all I need is a method to "extend" the end of the Ka feed in order to get the RF EM field into the remaining 1/2 in. tube of the feed attached to the LNB input.<grin>
Affix a WR-42 flange to both ends and use flexible waveguide? Bent copper tubing?
[snip]
~~~~~~~~~~~~~~~~~~~~~~~~~
Both the Ka and Ku feeds are 4 1/32" from throat to LNB opening.
Ka is from 18.3-18.8GHz and from 19.7-20.2GHz. Ku is from 12.2 to 12.7GHz and is Circular Polarized as is (I believe) Ka.
Many thanks to anyone who takes the time to look at the pics and comment here.
--Michael
PHTO0005 | Flickr - Photo Sharing!
I need to modify it to work with a 2.4m offset reflector with a different f/D ratio.
I wrote to Eagle/PBI, the mfgrs., but have not received a reply, so I thought I'd just copy/paste the letter and see what
folks here think.
~~~~~~~~~~~~~~~~~~~~~~
I have successfully used your DirecTV Alaska/Hawaii Ka/Ku LNBF on a variety of reflectors (Prodelin 1.2 and 1.8m) with satisfactory results, and now I need to fit it to an Andrews 2.4m reflector.
Appx. 4 years ago, I installed Ku LNBs at 101/110/119 (DirecTV) on this antenna. It was boresighted on 110 and I used a spectrum analyzer to find the focal points of 101/119 and attached those LNBs to a bracket I fabricated that was bent to the correct "tilt" angle which worked great.
Now that the Ka birds are being used, I need another solution in order to get HD into this SportsBar and there is a dearth of solutions available, especially with the requirement of switch outputs to be used with a SWM 16.
I estimate the new focal points for 99/103 to be around 2.6 inches from the 101, but I'll locate these empirically, exactly.
What I was planning on doing was to use a fine-kerf hacksaw and separating the Ka feeds down to 1/2 in. from the flange which screws to the LNB, then cutting them off.
Some Dremel tool grinding, etc. if needed to get both ends round.
Now all I need is a method to "extend" the end of the Ka feed in order to get the RF EM field into the remaining 1/2 in. tube of the feed attached to the LNB input.<grin>
Affix a WR-42 flange to both ends and use flexible waveguide? Bent copper tubing?
[snip]
~~~~~~~~~~~~~~~~~~~~~~~~~
Both the Ka and Ku feeds are 4 1/32" from throat to LNB opening.
Ka is from 18.3-18.8GHz and from 19.7-20.2GHz. Ku is from 12.2 to 12.7GHz and is Circular Polarized as is (I believe) Ka.
Many thanks to anyone who takes the time to look at the pics and comment here.
--Michael
PHTO0005 | Flickr - Photo Sharing!
