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Old 24-Jan-2017, 2:00 PM   #5
dragons021
Junior Member
 
Join Date: Nov 2012
Posts: 15
Quote:
Originally Posted by ADTech View Post
A "perfect" reflector would increase forward gain by 3 dB (doubling of power) while the reception off the rear would be zero. Think of how a perfect planar mirror behind a perfectly omnidirectional light source would behave.

In a real antenna like the C4, the reflector adds around 2.5 dB to the forward gain while reducing reception off the back by 10-20 dB, depending on frequency and angle. I have a plot on my office computer that illustrates this, I'll add it to this post later this morning. I have another plot that illustrates what happens when the reflector is removed, I'll see if I can find that and also add it.

I frequently recommend that the reflectors be removed from our UHF antennas where the signals are from opposite directions. Usually works well as long as the small decrease in forward gain or undesired reflections don't rear their heads.

I haven't looked at the Televes yet, so I cannot comment about it. I will point out that, if you use separate UHF and VHF antennas, you will need either a combining device (UVSJ) or amp with that feature built-in.

Winegard has a published specification sheet that includes plots (almost impossible to read with a linear voltage, not logarithmic power scale) that illustrate the patterns including either F/B or F/R information. I don't know if you can find it on Winegard's site any more, but I do know it's on Solid Signal's site. BTW, that antenna is really big, be prepared for it's size.

I always recommend installing antennas where it's expected to be the most reliable, not necessarily where it happens to be convenient. It's pretty frustrating trying to make a convenient but lousy signal location work and customers hate to hear me tell them to move the doggone antenna if they want it to work, they just want it to work regardless of where it's put.

Best of luck!
Thanks, I'll have him test different locations to see if different masts make sense. The size is a bit of a concern to me, especially if I need to mount it 10' above the roof.
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