Best LNB holder for offset dish

[RimaNTSS]

I am very eager to start some new threads this evening . And question here would be:
What is, in your opinion, best LNB holder for any offset satellite dish? We can start from the description, without any concreate or concrete examples.

 

[blademedia]

Same way as ive made this for a prime focus dish, make new arms to suit,

 

[RimaNTSS]

I was speaking about an offset dish. But, in principal, theoretical description of the "best LNB-holder" could also be applied to PFA. Anyway, this practical example of the feed-holder is little bit step too far, cuz we did not finish with theory.

 

[blademedia]

I was speaking about O/S dish ive made lots like this in the past for O/S dish, the theory is, it adjust in every way so it will hit the focal point

 

[RimaNTSS]

Agree with that. Perfect LNB holder is that holder which holds LNB in such a way that LNB's Phase center is co-located with antenna's Focal point and points LNB in the detection of the proper aiming point on the surface of the dish. The "perfect" holder should be made of durable material, should be light as much as possible and should not make lots of distortion to the signal, ideally it should be made out of plastic or non-magnetic material. So, is there any possibility to create really universal LNB holder for any offset dish?

 

[blademedia]

Making it to small causes problems when installing C band, the arms need bending in such away there not interrupting with scalar

If you want to be critical arms can be made to a wavelength and become nearly invisible,

I always make the ring so its slightly smaller than a scalar, it works just the same with o/s dish with modified arms .

 

[RimaNTSS]

But, again, this is not about an offset dish! And is not about using minimum needed magnetic materials, which could be negatively impact overall performance of the system. That is also seems to be overcomplicated and, therefore unnecessarily more expensive. Used galvanized materials have not long weather-endurance characteristics. Amount of used independent parts is too great to be called "perfect" holder. That is IMHO.

 

[william-1]

The Gibertini cast aluminium takes a lot of beating.

 

[blademedia]

But, again, this is not about an offset dish! And is not about using minimum needed magnetic materials, which could be negatively impact overall performance of the system. That is also seems to be overcomplicated and, therefore unnecessarily more expensive. Used galvanized materials have not long weather-endurance characteristics. Amount of used independent parts is too great to be called "perfect" holder. That is IMHO.

Sorry I must have misread the thread title

 

[RimaNTSS]

The Gibertini cast aluminium takes a lot of beating.

Perhaps it is good holder.... for Gibertini dishes. But, is that is universal for for any offset dish, as I was asking in my first post? I do not think so!

 

[Archive-8]

I like the type that fit my iss 1m dish, it will also fit the gibertini 1.25 & 1.5 dishes.

Had to google to find some pictures, these are the best I can find at the moment.

 

[RimaNTSS]

I like the type that fit my iss 1m dish, it will also fit the gibertini 1.25 & 1.5 dishes.

It looks nice. But..... Will it hold any LNB (C-band, Ku-band. Ka-band) in such away that LNB's Phase center is co-located with the Focal point of any offset dish? I doubt that! Will it point the LNB in proper direction to hit the proper point on the surface of the dish? Probably not!

 

[Ghostleader]

I like the type that fit my iss 1m dish, it will also fit the gibertini 1.25 & 1.5 dishes.

Had to google to find some pictures, these are the best I can find at the moment.

View attachment 104901 View attachment 104902

Takes a $ly/Freesat Zone 2 into new purposes of multi LNB goodness also [emoji4] [emoji106]

 

[Channel Hopper]

For a truly accurate, centred feed design the best place to start would be with an optical Gregorian design, then work back to a radio telescope of similar dimensions.

The focus point is kept rigid to the primary reflector and tuned to the 'optics' of the secondary.

 

[Channel Hopper]

The feed type of these structures is aligned using turret rotation around a central point.

 

[Channel Hopper]

unlike optical designs the feeds for radio can be rotated in a sleeve for optimum depolarising to the required source.

 

[sonnetpete]

For a truly accurate, centred feed design the best place to start would be with an optical Gregorian design, then work back to a radio telescope of similar dimensions.

The focus point is kept rigid to the primary reflector and tuned to the 'optics' of the secondary.

Nice view of your back garden CH...

 

[RimaNTSS]

Back to topic. So, IMHO, the best LNB holder for an offset satellite dish looks like that. It can be installed on any satellite dish, it is non-magnetic, does not rust, light enough (about 80 grams, but if 6mm rod is used could weight even less). It can hold LNB in any position and allows to point it to any place on the surface of the dish. Depending on the clamp used, it can hold C-band, Ku-band and Ka-band LNB.

 

[william-1]

Lnb holder in stainless steel adjust to suit any offset dish.

 

[Lazarus]

Ingenious!