C Band Scalar dimensions

[Corrado]

I have been thinking about the scalars that are used on C band prime focus dishes since working on mine last weekend removing a bees nest.

My 10' Unimesh originally had a Chaparral feedhorn and a scalar that is 1" deep. I had a dual C-Ku LNB setup too for a time and about 10 years ago converted to a BSC621 LNBF and changed out the scalar at that time. The newer scalars only seem to be approx .5" in depth. Is there a reason for this? More efficient? Probably cheaper? Even my conical scalars I have on my 6' offset dishes have smaller inner rings after the first outermost ring.

When I swapped out to a CW1-PLL lite a few months ago I didn't bother change the mount and have posted a photo for a quick visual.

 

[Titanium]

A few years ago while selecting hardware for distribution I did quite a bit of priime focus scalar testing. Far from scientific lab testing (other than documenting), I compared several samples in the field of deep vs shallow scalar designs and found the performance to be quite similar on most readily available prime focus dishes. The shallow scalar design provided the best average performance on the typical consumer .38 to .40 FD reflectors. The deeper scalar design would provide some signal improvement when used on dishes with lower side lobe attenuation specs.

You might find information in this article of interest:
http://web.archive.org/web/20050324030215/http://astron.berkeley.edu/ral/ata3.pdf

I certainly would be interested in any other comparisons that have been done, as the cost between a shallow and deep scalar is only a few pennies (OK maybe a few dimes).