Scalar ring positioning with a one meter mini-BUD

[cracklincrotch]

I don't know if this should really be in the C-Band group or this one but if it gets moved I presume Ice thought it should be.

This past weekend I set up my Winegard 1M with a C-Band LNB on Galaxy 16.

I have a Panorama 13K LNB on it now. Figured that I should keep it on the cheap until I can prove anything. I proved I can get some C-Band with it. From reading the experiences of others that have tried mini-buds with any success, I now have a BSC421 LNB coming.

But my question has to do with the scalar ring positioning, in general. On the side of the LNB is a scale that if I've done my research has to do with the focal depth of the dish. Right now, although the LNB only has a scale up to 42 I have the scalar ring set at a position that would be at 46. My Birdog shows a S/N on 3845 H of 5.1dB. Best I could get on this transponder. 3904 H gives me 8.9dB.

The Winegard DS-3101 has a f/d of 0.59. So, should I set the scalar ring at the imaginary 60 ring (the Panorama only goes up to 42) on the LNB and peak from there? Or should I put it where it allows me to get the best signal?

 

[Cadsulfide]

Drive for max signal Q, the real bottom line. If you have a slow day, measure the diameter, the depth and calculate the focus. I have a BSC421 on a 10' CM and am pleased with it. Are you going to motorize?

 

[Anole]

In one of the recent "C-band on a Ku dish" threads, someone posted this link.
It shows a C-band LNBf with a flat scalar, and again with a conical.
The signal levels speak for themselves.
Increase is about 22%.

I tried to extract more info from the site and found it a dead end.
Maybe the pictures will give you a starting place.
Document your improvement, and let us know.

There were old threads (here) with posts of similar gains, but finding them right now might take some searching.

 

[Dale_Gribble]

What I found out with C-band on the 1 meter primestar the BSC-421 scalar rings seemed to work the best when they were flush the end. And the front of the scalar rings had to be a few inches closer to the dish than the original KU lnbf. Maybe this is because the 2 little antennas inside the BSC-421 are near the back of the LNBF? The KU LNB was about 28 inches from the dish, and the BSC-421 worked best when it was about 24-25 inches away, which puts those antennas pretty close to the original 28 inches.

 

[cracklincrotch]

Guess it's just trial and error and go with what works. That's an okay answer.

 

[Anole]

What gets confusing, is if you mount your C-band LNB by the scalar.
Regardless which scalar you use, the focal point of the dish is at the same point.
And so the LNBf should be at the same point.

If you were to mount the LNBf itself, and find the focal point, the adding the scalar should improve your quality (reduce noise).