First time installer in Durham, NC

[NotAnEngineer]

I’m new at installing TV antennas (and at most “do-it-yourself” electronics) and would appreciate some help/advice. Here are my TV signal analysis results from TV Fool:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d8e0361cd787b03
Short version, I want more channels, and I’m debating between buying a pre-amplifier or getting a bigger antenna.

I’m in a one story house in Durham, NC, surrounded by a lot of tall trees (much taller than the house) planted closely together, and 30 miles away from some of the towers of the signals I want to pick up. I went from an indoor Mohu Leaf 30 in my living room to an RCA ANT751R in my attic (50 ft RG6 coax), but it didn’t give me any more channels (I’m getting 4 channels plus the substations). If you look at my report, I’m getting PBS (25), Univision (38), ABC (11), and NBC (17), but I also really want to pick up CW (27), CBS (48), and Fox (49). The thing that I find especially puzzling is that I can pick up NBC but not Fox or CW, because on the map they look like they are all three originating from the same location about 30 miles away.

Any help/advice (including criticism) would be greatly appreciated. That being said, I want to avoid mounting the antenna on the roof instead of in the attic because a) I’m renting and planning to move by summer 2016, and b) it seems a lot more complicated safety-wise, and I don’t want to screw it up. As I mentioned before, I’m looking at pre-amplifiers (perhaps high gain because of interference in the attic and from the trees?) or buying a bigger antenna. Thoughts/comments?

[Tower Guy]

I’m looking at pre-amplifiers (perhaps high gain because of interference in the attic and from the trees?) or buying a bigger antenna. Thoughts/comments?

Try a modest gain preamp. The TVPRAMP-1R is cheap, but you may need to futz with the FM trap and combined switches.

The preamp will overcome the loss in the 50' of coax and help compensate for a higher noise figure of the TV set. Otherwise, different locations in the attic may work better.

[rabbit73]

I’m in a one story house in Durham, NC, surrounded by a lot of tall trees (much taller than the house) planted closely together,The trees are your biggest problem. Even if the antenna was outside, the trees would still be a problem. See attachment 1.

I see a lot of trees in your area. See attachment 2.

When the signals filter through the trees, it creates a multipath problem.

http://forum.tvfool.com/attachment.php?attachmentid=1716&d=1445196601

http://forum.tvfool.com/attachment.php?attachmentid=1717&d=1445196636

The thing that I find especially puzzling is that I can pick up NBC but not Fox or CW, because on the map they look like they are all three originating from the same location about 30 miles away.They are coming from the same direction, but the transmitting antennas are not at the same height, and the channels are different, which creates different field patterns because the wavelengths are different.

You have some strong local FM signals that might interfere with TV reception. You should insert an FM filter in the coax line or use the FM trap in a preamp. See attachment 5.
http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-FM-88-/33-341

[NotAnEngineer]

Thanks TowerGuy and rabbit73. I'll give the pre-amp and FM-trap a shot (the TVPRAMP-1R as recommended), and fiddle with location. I wasn't aware of the level of interference I'm likely facing from FM stations. rabbit73, I really appreciate the insight on what might be causing the problem - I have a science background and it goes a long way towards satisfying my curiosity.