I should clarify - the DB4 antenna I installed is ChannelMaster 4221 (bought at local Frys) -- does anyone know if it is cutting off VHF band @ the Balun?
I am receiving KNTV (NBC, Ch 12 210MHz) just fine - no pixellation etc.
Searching online for VHF Hi testing for CM4221/DB4, i found
http://m4antenna.eastmasonvilleweath...Data/Data.html
The plot (scroll down to the last one) shows -15 dB for 4221 @ 180MHz. Dont know if its due to the design OR the balun cutting off lower frequencies. tvfool shows Noise margin @ 53 dB so it seems like I should still be ok with the following approx losses:
cable run (RG6 x 150 ft) attenuation = 5 dB
Connectors (3) excess loss = 3 dB
Antenna Gain (negative) = -15
Effective NM at tv = 53 - 15 - 5 - 3 = 30dB
unaccounted for: balun loss @ 180MHz and unless it is set up to filter out VHF and attenuates the signal another 20-30 dB ???
suggestions ?