Primestar 84E/BSC621-2 LNBF Experiment

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Telling photo

This picture shows something very important that I had missed before. DREAMFOX1 has his C-Band LNBF aimed at the center of the dish, rather then side mount straight forward. I had missed that before.

Also ths is not the Scalar ring that comes with the Panorama ER-861, it appears to have much deeper Scalar contours.
 

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The scalar ring was from a previous lnbf that had a 65db gain.

It died when it filled up with water due to days of unusual hard rain in Los Angeles.

I noticed that the first ring is very important for reception.

Also that the Scalar ring needs to be at the very edge of the lnbf to get good results.

Added foil to rebuild the first ring near the lnbf.

Got rid of the inline amp due to problems it was causing.
(Reducing voltage to my motor resulting in sudden stops).
 

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Yes and so...

Lnbf is 23 1/2 inches away from dish.

Dish is...

34 1/2 wide

36 1/2 tall

Now I see that you are measuring to the inside of the stiffner ring that DigiWav puts on their dish. That explains the dimensions.

My observation is that the dish design should be very strong and not allow "Oil can" flexure.

The more I study your project the more I like it.
 
Modified Satellite Dish

Satcom1
How wide is your primestar dish?
and
I wonder is it possible to add more reflector to a current dish?

Oh man, you are reading my mind!

The Primesar dish measures 1 meter by 0.7 meter. Roughly 40 inches wide.

It might be possible to increase dish surface area by adding a collar to the dish. This would be highly experimental and require alot of calculations or even more trial and error. Aluminum mesh or window screen could be easy and cheap to use. Duct tape it in place. If you get a shape that improves reception marine two part epoxy would stiffen it up. This would change the length of the dish arm for the new f/d.



In my terrestrial microwave network we use something called a precision dish. It is kinda like a 55 gallon drum cut in half and the bottom banged concave like a steel drum from Jamaica.

Sometimes there are 4 & 6 Ghz. Multi-path signals that create interference just like neighbor satellites. This design greatly reduces those signals and improves SQ.

If you make a precision satellite dish by adding a cylinder to it you should see an improvement in signal. Remember that the cylinder would tilt up 24 degrees or what ever your dish offset is. The more you lengthen it the greater selectivety you will get, the better the SQ. To a point of no return.
 

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Yes a Hybrid for sure.

Almost like a fused mesh and solid dish.

A hybrid?


Yes, That would be a very interesting project for sure.

You have an advantage being on the roof, your neighbors can see what your doing.

On the issue of the line amp, are you using RG-11 coax? If not that would make an improvement for your long run.
 
Round Offset Dish Scalar Ring

Round Offset Dish Scalar Ring

The Scalar ring for subject dish will have a top Scalar area reduced in depth to match the overhang of the dish.

The bottom portion will be reduced in depth but not as much as the top and the two sides will come in towards the dish most.

Think of it as a light source at the center of the LNBF throat and you are trying to illuminate just the surface of the dish without overspill beyond the dish. Likewise you want to illuminate all the way out to the edges.

DREAMFOX1, you can try to build this up with cardboard covered with aluminum foil, one ring at a time while you observe SQ.

This might be an improvement in SQ more easily obtained then changing dish surface area.
 

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Metalizing Paint

Check out Aluthane aluminum paint


On one of my Cellular Sites on a water tower, when they painted the tank with Aluminum paint, they also painted the Cell Site antenna fiberglass covers.
We lost the service immediately.

Another approach would be Copper Leaf available through craft stores.
 
Hang Ten on your dish

No just plain RG6 coax.

I wonder if a dish reflector could be made out of foam like a surfboard?

Then sprayed with a metalic paint.


Sounds like something that could work. The epoxy paint mentioned above will coat the foam and protect it. This would be a super light weight dish. :D
 
C-Band on 76 CM Winegard

You can get a few of the stronger C-Band channels if you experiment.

Signal Qality of 33% on HITN-TV AC3

I use HITN-TV as a benchmark.
 

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Offset Dish Conical Scalar Ring

Here are some close ups of the Invacom SNH-031 Scalar ring that they state is designed for Round Offset Dish. :D

:usa
 

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Round Offset Dish Scalar Ring

The Scalar ring for subject dish will have a top Scalar area reduced in depth to match the overhang of the dish.

The bottom portion will be reduced in depth but not as much as the top and the two sides will come in towards the dish most.

Think of it as a light source at the center of the LNBF throat and you are trying to illuminate just the surface of the dish without overspill beyond the dish. Likewise you want to illuminate all the way out to the edges.

DREAMFOX1, you can try to build this up with cardboard covered with aluminum foil, one ring at a time while you observe SQ.

This might be an improvement in SQ more easily obtained then changing dish surface area.

Very intresting indeed.

So the inner rings should be lower than the outer rings in a oval pattern?

That explains why I get great reception from G11 and bad signals from satmex6.
 
C-Band Conical Scalar Ring

I googled Scalar rings in Europe/UK and found that they buy from Andrew/Channel Master products. Many use Conical Scalar Rings but they are for KU-Band.

I did find one company in Europe that sell C-Band Conical Scalar Rings.

no need for oval pattern to start, these are plain conical.
 

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Here are some close ups of the Invacom SNH-031 Scalar ring that they state is designed for Round Offset Dish. :D

:usa

I have one of these, but mine is from Prodelin. I have not had a chance to even try it.

It is rather heavy, I would say about 2 or 3 pounds.
 
I have one of these, but mine is from Prodelin. I have not had a chance to even try it.

It is rather heavy, I would say about 2 or 3 pounds.


So, you have a C-Band Conical Scalar Ring?

Could you post a straight on picture with a ruler across the face and a side view with a ruler?


Is this it?



P1_RxTxFEEDS_2.jpg
 
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