Primestar 84E/BSC621-2 LNBF Experiment

[lumpkin666]

I just have to find dish in the 1m-1.2m range around here to do some testing. If I did, I'd order one of these conical scalars and see how well they work:
http://www.satelliteguys.us/free-ai...ost1063017.html?highlight=conical#post1063177

 

[schlever]

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?

All I have is the front portion of that assembly. I'll break out a ruler and the camera when I get a chance and post the pics.

 

[satcom1]

All I have is the front portion of that assembly. I'll break out a ruler and the camera when I get a chance and post the pics.

Thanks, but no need. What we need is a conical scallar ring that fits a standard c-band 65 mm throat. If not that then detailed dimensions of one that was commercialy made for 65 mm throat.

 

[schlever]

There are some guys on here that purchased what your looking for from a member that had them sent from a cousin over in Europe. Maybe one of them will check this post and reply.

 

[gremlin411]

the guy that got them from his cousin in Europe is "brotherhood" you might pm him see if he can help.

 

[satcom1]

Posted on another thread

Liked this article so much that I am posting it here just in case it was missed by some.

 

[satcom1]

A waste of time and resources

Check this out, Andrew has been in the Mini-BUD market for some time now.

If a big company like Andrew endorses the idea, that is coming from a professional source.


Check out the phone number they have good taste.

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Type 120 1.2M C-Band Rx Only Antenna System

The Andrew Corporation 1.2 m Type 120 Offset Antenna is a rugged commercial grade product suitable for the most demanding applications. The reflector is thermoset-molded for strength and surface accuracy. Molded into the rear of the reflector is a network of support ribs which not only strengthens the antenna, but also helps to sustain its critical parabolic shape.
The Az/El mount is constructed from heavygauge steel to provide a rigid support to the reflector. The Az/El mount secures the antenna to any 2.88" - 3.00" (73-76 mm) O.D. mast and prevents slippage in high winds. A specially formulated powder paint process offers excellent protection from weather-related corrosion.
Features

• One-piece thermoset-molded offset reflector.
• Single bolt fine elevation adjustment.
• Galvanized .75" (19 mm) O.D. feed support legs.
• Factory pre-assembled mount.
• Plated hardware for maximum corrosion resistance.
• Available with a wide variety of C-Band or Ku-Band feeds.

 

[satcom1]

76 CM Micro-BUD

Buy fabricating and fitting extensions to the prime focus Scalar Ring it is possible to increase the Signal Quality.

Using HITN-TV as a benchmark a SQ of 31-33% fluctuating level was recorded.

By adding the fabricated metal strips to the first and second rings a SQ of 41% was recorded.

 

[bloomdog]

Buy fabricating and fitting extensions to the prime focus Scalar Ring it is possible to increase the Signal Quality.

Using HITN-TV as a benchmark a SQ of 31-33% fluctuating level was recorded.

By adding the fabricated metal strips to the first and second rings a SQ of 41% was recorded.

Absolutely beautiful!! Good results too!!!
Stupid question: Did you design the extra rings to be a specific size or was this trial and error? If designed to be a specific size, PLEASE share with us your calculations and formulas.
Truely Inspiring

 

[Mr Tony]

were you able to get anything else stable besides HITN?

 

[voomvoom]

There are some guys on here that purchased what your looking for from a member that had them sent from a cousin over in Europe. Maybe one of them will check this post and reply.

I bought 2 Conical Scaler Rings from brotherhood. Info and a picture can be found in this thread:
http://www.satelliteguys.us/free-air-fta-discussion/129705-offset-scaler-ring.html

 

[DREAMFOX1]

Update


Finally got my new lnbf with 65db gain.

The PX 900A

results are GOOD

This lnb came with a one ring scalar.

 

[satcom1]

Trial and Error

Absolutely beautiful!! Good results too!!!
Stupid question: Did you design the extra rings to be a specific size or was this trial and error? If designed to be a specific size, PLEASE share with us your calculations and formulas.
Truely Inspiring

Bloomdog-

This is a very crude attempt at a conical Scalar ring. My Antenna modeling software is not sophisticated enough to generate the values needed. There are alot of currents flowing around these rings and a detailed analysis of E and M wave propogation is just guess work.

Not much can be gained from this experiment on th 76 CM Micro-BUD. It was just fun for me to do.

 

[satcom1]

Benchmark

were you able to get anything else stable besides HITN?

In my testing I have chosen HITN-TV as my bench mark. If everyone posted their results for this bench mark then we would have a level playing field. Both KU and C Band comparitive values would be good.

The reason for G23 121 is that as you know it has very strong C-Band and KU-band signals in the clear.

It is also much faster to set up on these channels when experimenting.

For example if HITN-TV produces a SQ of 45 % then I know that there are five or six other C-Band channels that I should be able to receive. But to go through the set up an scanning for each experiment is just not in my interest.

So that is all that you will see me post for findings.

 

[satcom1]

Details

I bought 2 Conical Scaler Rings from brotherhood. Info and a picture can be found in this thread:
http://www.satelliteguys.us/free-air-fta-discussion/129705-offset-scaler-ring.html

Do you still have one?

If so can you take picture with ruler next to it?

The side view picture is helpfull, I can scale steps using 65 mm throat as ruler but need inside details.

Once detailed drawing is made then it will be simple to make or have made. But there is alot of magic and art in the design of this item and using a known good example is priceless.

 

[satcom1]

Very Interesting.

Update


Finally got my new lnbf with 65db gain.

The PX 900A

results are GOOD

This lnb came with a one ring scalar.

Very interesting DREAMFOX1, it is surprising to me how much of our findings are similar.

1- the lens of the LNBF is best if slightly recessed from front of scalar ring.

2- the inner most scalar ring is very important, but so is the second.

3- there is a slight elevation for C-Band LNBF above the KU LNBF centerline. I found this on Elliptical and Offset Round dishes. Motorized.



It looks as though you can draw a straight line through those three LNBF's and that relationship may have something to do with HH-Motor and Clarke Belt tracking. If you look at a T-90 all LNB's are inline straight.





Good Work! :up

I really like your concept the best because it is so versatile.

 

[satcom1]

Request

Update


Finally got my new lnbf with 65db gain.

The PX 900A

results are GOOD

This lnb came with a one ring scalar.

It would be helpful to document what you have there.

What is needed is for you to run the motor to Zero.

Take a picture looking from the center of the dish face towards the LNBF's.

Take a picture from above the LNBF's looking straight down on them.

Take a picture directly in back of the LNBF's looking towards center of dish.

All with the motor at zero.

 

[satcom1]

DIY Conical Feedhorn C-Band

Here are the calculated results for a C-Band Conical Feedhorn with a center frequency of 5.15Ghz and a 62MM Dia. waveguide.

5150 MHZ
15dBi gain
144.2 mm Aperature Diameter
62 mm Diameter LNBF
54 mm length
Cone angel of 37.3 degrees

A paper template can be laid over copper or aluminum sheet, cut out and rolled up.
Solder or pop rivets. I used Super Glue and Painters tape to seal the seams. When the glue sets hard (12 hours) remove the painters tape.

You can download cone pattern programs that make a template on your printer.

 

[Lak7]

You could stop by your local commercial printer and ask for a couple of used or damaged plates.

 

[satcom1]

Offset Conical Feedhorn

Gustav is overhead here in Illinois so there is rainy day work to do.

I have used the previously posted construction information to fabricate a Feedhorn for testing. Shown on the Panorama Model: ER-861. The feedhorn as fabricated makes a snug fit over the LNBF. The Noise figure of the LNBF is 0.190 dB and the calculated gain of the feedhorn is 15 dBi.


Here are pictures: