Ku scalar ring?

[jogon64]

Is there such a thing as a Ku scalar ring?

I´m using a c band scalar ring for my 1.5m offset mini bud and it helps a lot for bringing in some signals though not all of of them I know.

The thing is Amc5 is pretty low in my location (northern Mexico) and I was wondering if such thing existed and if it would help me on this sat since this signal is usually pretty low for me on my 30" no matter how much I tweak my dish.

Any thoughts?

 

[Anole]

The scalar ring is built into the LNBF
And if a 30" dish doesn't do it, ... well I hate to state the obvious, but ...

get a bigger dish ! - - :up

 

[jogon64]

I understand "the obvious" perfectly well about "bigger is better"

But turns out I got a hold for free of several 30" offset with universal lnbs from sky.
Amc2/5 has a very strong demand down here, but the dish is a bit small. Remember, I already got them (and free! ) so I dont want them to go to waste. A lot of people down here would be interested in this sat.

I recall some time ago I read about someone building a cband scalar ring from scratch which was bigger (better?) than the blue one I got on ebay for my 1.5m minibud. Would bigger is better apply for ku band also?

I don´t know exactly how a scalar ring works but if it "amplifies" or catches more signal wouldn´t something like this help the built in scalar on the lnb?

Thanks.

 

[Anole]

The height and width and spacing of the rings is related to the frequency it's used on.
So, a C-band scalar may do something, but not what a proper Ku scalar would do for Ku reception.

Its purpose is to keep the LNB from receiving unwanted noise.
On C-band, where the scalar is easily adjustable, it helps the LNB 'see' just the dish and nothing off to the side of the dish.
(if the feed sticks too far through the scalar, then it sees off the edge of the dish)
Also, you want to see all the dish, not just the middle or any other small portion.
(if the feed were recessed too far back into the scalar, only the central part of the dish would be 'seen')
Look up F/D for a better understanding.

BUD dishes have F/D from 0.28 (?) to maybe 0.40 or so.
And the scalar needs to be adjusted accordingly.

Ku dishes/LNBFs are generally set to about 0.7 F/D and aren't generally adjustable.

 

[jogon64]

Its purpose is to keep the LNB from receiving unwanted noise.

Ok. I get it.

So perhaps I should check if neighboring sats are interfering.

I´m aiming for 11904H 2170 @79w. If there were an adjacent signal how far away or near to this frec and sr should I be worried about? I mean like 11889H 13025 @83w? Is this near enough to be of concern? Cause then a larger scalar just might be able to help some.

Is my thinking correct?

 

[Anole]

It's the dish size (the width, actually) that determines how succeptable you are to signals from nearby satellites.
The scalar just makes sure your LNB gets signal from the entire surface of the dish, no more, no less.

Was just talking with PwrSurge, and he suggested a lower noise LNBF.
Likewise, a Standard instead of a wide band Universal, might be helpful.
If you have one, I'd try it.
As to recommending any to buy... well, I couldn't guarantee they'd solve your problem.

 

[jogon64]

Thanks anole for all your explaining. I think I´m understanding lnbs and scalars a little bit more.

So then a lartger scalar doesn´t help much. My free 30"s won´t cut it either.

What I still don´t understand is why this signal is great between 6pm and 11am. And starts to degrade at noon every single day of the week.

Thanks.

 

[Hermitman]

That could be a "heat of the day" issue.

 

[Auric]

I understand "the obvious" perfectly well about "bigger is better"

But turns out I got a hold for free of several 30" offset with universal lnbs from sky.
Amc2/5 has a very strong demand down here, but the dish is a bit small. Remember, I already got them (and free! ) so I dont want them to go to waste. A lot of people down here would be interested in this sat.

I recall some time ago I read about someone building a cband scalar ring from scratch which was bigger (better?) than the blue one I got on ebay for my 1.5m minibud. Would bigger is better apply for ku band also?

I don´t know exactly how a scalar ring works but if it "amplifies" or catches more signal wouldn´t something like this help the built in scalar on the lnb?

Thanks.

Some Ku dishes have what's known as feedhorn flange...You see those on commercial Tx Rx dishes. What they do I don't know(LOL)
But here's a pic of one
Skyware Global Type 123 Antenna Ku-Band Tx/Rx Antenna Class II

 

[jogon64]

That could be a "heat of the day" issue.

What is this and how can you overcome it?

We`ve been having 100+ for the last month or so, but his has happened even last winter where we got highs of 60f.

Also, even at 9pm we`re still at around 95f and the signal at this hour is booming at 70%.

Auric, that picture is what I had in mind, but like you I don`t know how it works and following Anole`s enlightment I`m not sure it would help.

Thanks all.

 

[Panavision]

A feedhorn flange is useful if you're transmitting. These feedhorns are usually attached to a length of waveguide or directly to a BUC (amplifier) through an OMT (Orthomode Transducer). Take a look at the dishes at the gas station. You'd just need an LNB that has a flange (not an LNBF).