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Old 13-Mar-2019, 2:56 PM   #50
rabbit73
Retired A/V Tech
 
Join Date: Aug 2012
Location: S.E. VA
Posts: 2,536
Solid Signal's claim of a 60 degree beamwidth for the HDB91X is misleading. They are not using the conventional method of calculating beamwidth. Some people will fall for it.
Quote:
Technical Specifications
Beam width approximately 60 wide (out of 360)
https://www.solidsignal.com/pview.asp?p=hdb91x

https://www.xtremesignal.com/portfolio-item/hdb91x/





Note that Winegard also uses the -3 dB half-power points to calculate the beamwidths of the 8200U:





You can have an antenna with more gain and narrower beamwidth or an antenna with wider beamwidth and less gain, but you can't have an antenna with more gain and wider beamwidth; the two are mutually exclusive.

Additional gain comes from making the antenna more directional with a narrower beamwidth, which ignores other directions like a searchlight or spotlight. There is no free lunch.
Attached Images
File Type: jpg AD 91XG Spec Data.JPG (59.4 KB, 527 views)
File Type: jpg Winegard HD8200U gain.JPG (66.3 KB, 569 views)
File Type: jpg antenna_beamwidth_diagram_2.jpg (67.7 KB, 514 views)
File Type: jpg HDB91X Field Pattern_2.jpg (116.9 KB, 534 views)
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Last edited by rabbit73; 13-Mar-2019 at 7:08 PM.
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