6 foot dish with offset 1 meter dish type lnb

[laseradam]

Fixed 6 foot dish with offset 1 meter dish type lnb?

I was thinking about adding a Offset LNBF to my 6 foot dish. This would be in addition to the original lnb that came with the big dish. The reason I thought of this is it seem with the longer focal length of the big dish that it might be possible to add LNBF at less than 2 deg spacing and to get a stronger signal.

My questions are:
Has anyone used the small LNBF typical to 1 meter dishes on a BUD?
Has anyone tried off focus side LNBFs on a big dish?
Will the signal be able to be focused into the smaller LNBF?

My plan would be to use my big dish to receive AMC3 and IA5. I know this is greater than 2 deg spacing but that's what I might try first.

 

[SatelliteAV]

Placing a KU LNBF designed for offset dishes on a prime focus is not optimal, but you will have success. A few years ago I experimented with adding a LNBF to a C-Band Scaler ring. With the dish pointed true south, I cut a hole in the scaler to the side of the C-Band throat and slipped the LNBF scaler through, centered the LNBF with a laser level, peaked BER with the rotation and duct taped the unit into place. Had great reception. Since the LNBF was not centered, the actuator needed to be bumped slightly.

Take a look at the World's Smallest LNBF and see if this might be easily experimented with ..... drill a 40MM hole beside the existing feedhorn and slip this through ......

P.S. You would have much better results if you install a Corotor 2 with C and KU LNBs.

 

[laseradam]

Oh I forgot to say that my big dish is a fixed mount. It points at AMC3 and I have a Aspen Eagle C/KU lnb on it now. What I was trying to do was to mount another LNBF next to it to pick up another satellite. You answered part of my question as it seems that the signal will focus into a small KU LNBF.

My other question is would you be able to pick up satellites spaced closer than 4deg? It seem that a bigger diameter dish would focus the satellites farther apart at the focal point. Allowing the small LNBFs to be placed farther from the prime focal point compared to a 1 meter dish. For example, AMC4 And IA5 lnbs might be mounted 3 inches apart on a 1 meter dish but might be mounted 6 inches apart on a 2 meter dish. Or is my thinking wrong?


My other idea is that it might be possible to get satellites spaced more than 20 deg apart. The goal would be to use a Fixed position BUD with several LNDFs and cover a large part of the Clark belt without moving the dish.

 

[SatelliteAV]

Experimentation will tell you how tight of spacing that can be achieved. The diameter of the dish isn't the only factor in determining the LNBF spacing. You can't compare the LNBF spacing on another design with a different focal distance.

20 degree spacing on a fixed dish should not be a problem..... You should be able to fabricate a bracket that connects to the scaler or arms for off-setting the additional LNBFs.