if you believe what you read at hdtvprimer and take the data for how the cm 4228 is rated in dbd.
ch7 -1
ch8 -4
ch 9 +3
ch 10 +6
ch 11 +5
ch 12 +2
ch 13 +4
The antenna web spec for red / blue reception is 0 dbd on vhf high
so in red/ blue/purple, ch 7 and 8 should be a dog (on paper requires 0 dbd) and should work fine in yellow, green, and lt green. where the antenna web spec for vhf high is see below.
A thing of note about that gain chart...the dips are quite deep...if the measurements move side to side just a bit then ch 8 is a great
VHF Low (2-6): VHF High (7-13): UHF:
-25 dBd - 15 dBd -10 dBd (yellow)
-12 dBd -9 dBd -6 dBd (dark Green)
-2.5 dBd -2.5 dBd -2.5 dBd (light green)
-2.5 dBd 0 dBd 0 dBd (red)
-2.5 dBd 0 dBd 0 dBd (blue)
4 dBd 6 dBd 8 dBd (violet)
4 dBd 6 dBd 8 dBd (pink)
add 3db for trees
add 3 db for inside
assume all hills bock all signal
antenna web aleady adjusts for significant hills.
there are many factors involved (line of sight, power of station, heigth , etc.) and reception is not cut and dry.
It should be used as a guide to help select an antenna and not to bash the cm4228.
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