Conical scaler

sanpat

SatelliteGuys Family
Original poster
Feb 25, 2023
60
15
Rockport Tx.
Going to set up a 6 ft pronelin dish for c band for a friend, is a conical scaler needed for offset dish or would a prime focus scaler suffice ?
 
Of course, conical scalar is needed for LNB when used on offset dish. Flat scalar when the same LNB is installed on PFA. If flat scalar is used on an offset dish than it will overilluminate ( see much more than entire dish surface). Is not this the case you meant by saying word "otherwise"? In contrary , if conical scalar is used of PFA then it will underilluminate the dish (will not see entire dish surface). OK, I am not native English speaker, but that is my understanding of the issue.
 
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Scalars are designed to properly illuminate a reflector. An OEM scalar matched by the manufacturer for the band and model would be the best option.

A scalar is simply a mechanical choke designed to match a given frequency for a specific Focal Diameter Ratio (F/D) and reflector shape (round, oval, etc.). It has little to do with a reflector being prime focus or offset.

The Prodelin 1183/1184 model reflectors , both spec a 0.6 F/D and are round (not elliptical or oval), so an off-the-shelf conical scalar should be used as they typically are optimized for this 0.5 - 0.7 F/D range. A flat scalar typically is optimized for a F/D ratio of 0.3 - 0.5 and would over illuminate the Prodelin 1183/1184 model reflector (see beyond the reflector's surface) allowing ground noise and terrestrial interference to directly enter the feed.
 
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