Best LNB and Bracket for HughesNet 90cm Dish

[TxSatPatriot]

Looking though all the threads and just wondering if there is any updated information on setting up a 90cm HughesNet dish for FTA and is it worth experimenting with? I have been messing with satellite dishes for 10+ years and was given this dish by a neighbor and I figured I couldn't turn it down because of it's nice size!!! I have also attached a photo of the dish I have for reference but the one I have does not have the original LNB on it. Any recommendations on a good FTA LNB and bracket that I can make work on this would be greatly appreciated since I have been out of the FTA loop for a few years and things seem to change every few years...

 

[MattFL]

I can’t speak for the HughesNet dish (although I am keeping an eye out for a trash-pile pickup), but I can tell you about my directv dish conversion. I used an lnb bracket like this. I first measured and made note of the position of the actual directv lnb placement, and I lined up my FTA Ku lnb so the placement was the same (held the new lnb bracket in place with a c clamp). Once I dialed in a satellite and tweaked the lnb placement, I drilled my hole and permanently mounted my new lnb bracket. Works like a charm. I think the most important part is to make sure the HughesNet lnb head and the new FTA lnb head are in the same position and pointed to the same place on the reflector.

 

[TxSatPatriot]

I can’t speak for the HughesNet dish (although I am keeping an eye out for a trash-pile pickup), but I can tell you about my directv dish conversion. I used an lnb bracket like this. I first measured and made note of the position of the actual directv lnb placement, and I lined up my FTA Ku lnb so the placement was the same (held the new lnb bracket in place with a c clamp). Once I dialed in a satellite and tweaked the lnb placement, I drilled my hole and permanently mounted my new lnb bracket. Works like a charm. I think the most important part is to make sure the HughesNet lnb head and the new FTA lnb head are in the same position and pointed to the same place on the reflector.

Thanks for the reply!!! The problem I have is that I don't have the HughesNet LNB to reference, just photos I have found on the internet... from what I can tell by roughly eyeballing what I have and what I have seen is that the center / focal point of the dish appears to be in the vicinity of the center bolt that attaches the reflector to dish framework. If anyone could verify this that would be much appreciated!!!
Also, where can I get a bracket like that, it looks very solid... and what LNB would you recommend???

 

[a33]

from what I can tell by roughly eyeballing what I have and what I have seen is that the center / focal point of the dish appears to be in the vicinity of the center bolt that attaches the reflector to dish framework.

That would then (maybe) be the aiming point for the LNB.
The focal point is where the LNB feedhorn must be; it is much more important to get that location right, than the aiming point!

Is a hughesnet dish for single LNB, or meant for multifeed?
In the first case, the focal distance and location of the focal point can be calculated rather simply.
In the second case, it's much more difficult.

But maybe some others can give you LNB position of this dish from their own dishes. That would be easiest...!

Greetz,
A33

 

[TxSatPatriot]

That would then (maybe) be the aiming point for the LNB.
The focal point is where the LNB feedhorn must be; it is much more important to get that location right, than the aiming point!

Is a hughesnet dish for single LNB, or meant for multifeed?
In the first case, the focal distance and location of the focal point can be calculated rather simply.
In the second case, it's much more difficult.

But maybe some others can give you LNB position of this dish from their own dishes. That would be easiest...!

Greetz,
A33

I'm assuming this dish is for a single LNB set up but couldn't you add multiple LNB's with a bracket and correct skew?

And yes, if I aim the LNB at that center bolt that should be a good starting point and then I would just have to figure the distance from the dish for the focal point. I do have an idea of where the LNB should be located from photos I have but would like to calculate the exact location instead of guessing... please let me know how I can do that, I think I have seen a formula but do elaborate!!!

 

[RimaNTSS]

where can I get a bracket like that, it looks very solid... and what LNB would you recommend???

Install something like that, then you will have full flexibility adjusting LNB. And when you find out where is the focal point of the antenna, you will be able to adjust LNB in such a way that it's phase center is co-located with the antenna's focal point.

 

[a33]

but would like to calculate the exact location instead of guessing... please let me know how I can do that, I think I have seen a formula but do elaborate!!!

Four measures are needed for a paraboloid dish; measuring procedure is here: Measuring and calculating zone-1 and zone-2 dish
or also here: OTHER - Question about LNB position
Depths should be measured with a precision of half a millimeter, if possible.

The equation to calculate with is in the second post here (and in the article in the first post): Just Sharing This - Calculation of the focal length of an offset satellite dish antenna, Revisited
When you give me the 4 input measurements, though, I can let my calculator calculate for you.

NB Some do this by the 'water method', described by paul wade and by john legon. I prefer the dry measuments..

This method is for pure paraboloid dishes, as designed for single LNB reception.
Multifeed dishes are designed parabolical tn the vertical sense, but circular in the horizontal sense. That means that paraboloidal maths doesn't work for them.
That is their design; however you can or cannot use multiple LNBs or both, if you want.

Greetz,
A33

 

[TxSatPatriot]

Install something like that, then you will have full flexibility adjusting LNB. And when you find out where is the focal point of the antenna, you will be able to adjust LNB in such a way that it's phase center is co-located with the antenna's focal point. View attachment 160713View attachment 160714

That is awesome and would definitely give infinite adjustments to figure out the sweet spot for the LNB... but I would assume I wouldn't find that just sitting on a shelf, but could definitely be made out of some angle bracket that I have laying around! Did you buy this or make it, I don't want to get too crazy investing in this experimental project if you know what I mean! LOL

Thanks for the great info and idea!!!

*** BTW, what LNB should I be looking for that will be decent quality??? ***

 

[RimaNTSS]

Did you buy this or make it, I don't want to get too crazy investing in this experimental project if you know what I mean!

I've made it after seeing your problem. Actually, it is more or less common issue when LNB should be installed and adjusted on a round feedarm (usually it is around 1" in diameter).

BTW, what LNB should I be looking for that will be decent quality???

Start from any universal LNB.

 

[MattFL]

I pass this dish on the way home from work every day. It’s just off the road so I grabbed these pictures for you. Hope they help! It looks like the aiming point is directly at the center of the dish.

 

[TxSatPatriot]

I pass this dish on the way home from work every day. It’s just off the road so I grabbed these pictures for you. Hope they help! It looks like the aiming point is directly at the center of the dish.

Thanks brother... that is so awesome!!! That is the exact same arm and bracket that I have! So it looked to you too that the LNB is pointed straight at the center of the dish which from what I can tell is the top center bolt for the reflector?

 

[MattFL]

Thanks brother... that is so awesome!!! That is the exact same arm and bracket that I have! So it looked to you too that the LNB is pointed straight at the center of the dish which from what I can tell is the top center bolt for the reflector?

Yes, right at the center

 

[polgyver]

This method is for pure paraboloid dishes, as designed for single LNB reception.
Multifeed dishes are designed parabolical tn the vertical sense, but circular in the horizontal sense.

With due respect, I am not sure if single reflector dishes can be designed as multifeed.
True multifeed dish was Wave Frontier, size 55 cm or bigger, 90 cm, its TWO reflectors were not paraboloid. Designed allegedly by North Korean engineers co-operating with Russian engineers.
I believe all single reflector dishes are paraboloidal with SINGLE focal point. Yes, paraboloid contains parabolas vertically, and cicles horizontally, as per definition - Paraboloid of Rotation.
Sidecar LNBF's are placed on the left or right of privileged central LNBF, and they receive less signal as there is so-called COMA associated with position not exactly in the focal spot.
Please correct me, if I am mistaken.
cheers,
polgyver

 

[RimaNTSS]

Designed allegedly by North Korean engineers co-operating with Russian engineers.

Yes, first T55 was introduced March 2003 (20 years ago). But not North Korean specialists, but from South Korea. Production was organized in Taiwan.

Please correct me, if I am mistaken.

There are several true multifocus (single mirror) antennas, for example Swedish SMW-OA-1600 or Equatorial. I have both of them, great dishes IMHO. They are part of toroidal shape though.

 

[polgyver]

I am curious how these 2 dishes reflect and focus Sun light, using small mirrors placed on them.
Do they produce 2, or more light circles - separated as to illuminate more LNBS's? Or, they provide
just an elongated, say, 4" to 8" (10 to 20 cm) long strip of reflected light, 1" or 2 cm high?
This would mean the reflected energy would be dissipated on larger area, resulting in lower "Q".
For years, I try to popularize checking the geometry and locating the focal spot of dishes just using small mirrors, and am disappointed that it is not commonly used.
Maybe it deserves to be included in "sticky" posts?
2 string method is not always possible, as a dish can be cut out of Mother Paraboloid not by plane, but by other, elongated shape.
Filling dish with water and taking measurements is not easy.
Even dry measurements are cumbersome, as well as following calculations.
Small mirrors are cheap and available in craft stores or on Amazon, the same about 2-sided thin glue tape.
Small mirrors CAN reveal much more than traditional checking methods, see my post from 8 years ago:

Satellite OASIS folding dish not ready for FTA yet...

For a long time wanted to have portable Ku dish set, to show to my friends the specifics of my hobby, when visiting them. Maybe, even converting some of them to this hobby. The e-bay offer was rather affordable. Import charges and Pitney-Bowes brokerage added to expenses (Gee, what happened to...

www.satelliteguys.us

regards,
polgyver

 

[polgyver]

Thank you, RimaNTSS for valuable info, today I learned a lot...
I took a screenshot from the link you provided, and now I am a believer, yes,
the SMW-OA - 1600 can illuminate a long strip of possible 9 LNBS's, because, it is L-O-N-G ! more than 5', like 1.6 m ! And tall, almost 4' (1.1m). With such HUGE surface, it can afford "losses" of large focal strip. See photo below:

 

[a33]

The (big!) Simulsat dishes are also excellent examples of multifeed/toroidal dishes.
Also the Visiosat/Cahors (Big) BiSat and T85 dishes are multifeed dishes, not necessarily in the exact billboard form.

I've seen discussions whether they can all be called toroidal: some say the billboard form is essential, others say the horizontal circular shape is enough to call it toroidal....

After RimaNNTS had his Equatorial, I studied the form of the toroidal a bit. I came to the conclusion that it has two design choices for the circular form:
a. the radius of the circular mirror (r ~~ 2 f, and in fact they choose not to use the exact r==2f (f of the parabola), as to stay overall closer to the proportions of the vertical parabolic shape).
b. the angle of the circle axis in relation to the symmetry axis of the vertical parabolical shape (not necessarily perpendicular!).

As you mostly do not know what design choices were made, I would now measure these dishes only from the vertical parabolical shape: multiple depth measures along the vertical center of the dish, and calculate from there.
(I've derived three equations for that, but I've not put them in a spreadsheet yet.)
By doing depth measures also along the horizontal center of the dish and some calculations on those, you could assess how much that differs from the parabolic specs of the vertical parabolic shape.


The paraboloidal dishes (parabolical both horizontally and vertically) are perfect for rays from infinity along the symmetry axis. For rays with an offset angle to the symmetry axis, abberation occurs.

Spherical dishes (circular both horizontally and vertically) are perfect for rays at any angle; but for rays from infinity, abberation occurs.

Greetz,
A33

Edited

 

[a33]

For years, I try to popularize checking the geometry and locating the focal spot of dishes just using small mirrors, and am disappointed that it is not commonly used.
Maybe it deserves to be included in "sticky" posts?
2 string method is not always possible, as a dish can be cut out of Mother Paraboloid not by plane, but by other, elongated shape.
Filling dish with water and taking measurements is not easy.
Even dry measurements are cumbersome, as well as following calculations.
Small mirrors are cheap and available in craft stores or on Amazon, the same about 2-sided thin glue tape.
Small mirrors CAN reveal much more than traditional checking methods,

I too am wondering that many people don't seem to want to check their dishes: string test (for flatfaced dishes), offset angle, and focal length.
It looks like they find the effort too much hassle, and take their dish setup for granted?
I checked my Triax TD115, and the LNB position was not congruent with the measurements. (Alas I took no before- readings of the reception, so I cannot say if/how much improvement was reached after I repositioned the LNB...)

(Exact LNB aiming direction however I find not very important; G-spot, or deepest point? After a recent dialogue with a moonbouncer, I am now more and more inclined to the latter!)


Your way with mirrors is practically inspiring! I've never put it to practice, though.
I've invested more in developing calculation methods. (E.g. here: Calculating focal length of a PrimeFocus dish that has a hole in the middle

By the way, the filling with water method is not per se needed for non-flat dishes. There is an equation using four (not too difficult) input measurements, as I referred to in post #7 above.

Greetz,
A33

 

[RimaNTSS]

Speaking about water-test. There is one I made on Equatorial dish. As far as I remember, it took about 10 liters of water.

 

[a33]

Speaking about water-test. There is one I made on Equatorial dish. As far as I remember, it took about 10 liters of water.

Correction: 31 liters!
(Good that you didn't use wine... )

See: Oude Equatorial antenne

Greetz,
A33