Having a problem with signal quality on one strong channel
 

Back in late 2001/early 2002 I installed a CM 4221 on a chimney mast about 20 feet in the air for the sole purpose of getting high definition TV over-the-air. I pretty much got all the local stations without any problems, but it seems I've always had occasional pixellation on KOMODT (38-1). Nonetheless, it was relatively inconsequential due to being a Comcast customer and getting that channel copy-free from the time they added it to their lineup.

Well, just last month Comcast in all their brilliance decided to start charging us a $10/outlet fee for all our CableCARD using devices (4X - 3 TiVos and 1 HDHomeRun Prime), and I am now strongly motivated to "cut-the-cord". In order to do that, I really want to make sure we can get all our local channels without issues.

I'm pretty happy with our reception of all the channels, but KOMODT is probably the one we watch the most, and it is also the one I have problems with. We get a consistent signal strength of 100 on HDHomerun Signal Meter, but the signal quality is normally hovering around 65-74 for just that channel while being at a 90 or higher for all the other channels.

I'm willing to put up a different antenna or move it to another location or pre-amp it (right now the only amp I have on the line is a Channel Master PCT-MA2-4P just prior to splitting it), but I'm hopeful that someone will be able to suggest what troubleshooting steps I should take and/or what different approaches might provide better results.

BTW, here's my signal map:
http://www.tvfool.com/?option=com_wr...e1c6d01e4d29b9

Also, I should add that my antenna has never been "aimed" with a compass, but kinda eye-balled at where it seems the signals are best. The neighbor to the south of us have two huge maple trees that seem to be between our antenna location and the direct it perhaps "should" be pointing, but I've tweaked it more toward the opening in the sky toward the southwest.

Thanks!

Be open to trying alternate mounting locations and elevations. Using HDHR signal quality, not strength, as the key measurement, adjust the antenna aim for best results. If the antenna has to aim at the trees, to maximize signal quality, so be it. What happens when you run this test, http://forum.tvfool.com/showthread.php?t=13646, using the HDHR tuner as the test tuner?

Signal strength at 100 units suggests that you are at risk of overload. Try removing the amplifier from the system all together.

If you can't get acceptable results with the existing antenna, consider stepping up to a Winegard HD7694P or Antennacraft HBU-33.

Well, I decided to go up on the roof and point the antenna's bowties straight at those huge maple trees to the SSW. I definitely saw a slight drop in signal strength, but the signal quality improved by about 4-5 points on the problematic channel and only dropped by 0-5 points on the other channels, leaving them still all in the 90's.

While up there, I saw I was only using about 40 of the 50 foot cable running down from the antenna and over and into the house. I had coiled and twisty-tied the excess cable, and right away suspected that to be a potential problem. At the time I didn't have a tool for customizing the length of the cable and elected to keep it all intact. I'll have to figure out the best way to deal with that because neither end of the cable is as simple to access as I'd like.

As for the amp, I actually used the signal straight from the antenna split three ways (2 TiVoHDs and a PC tuner) for many years before adding 2 HDHomerun Duals and a third TiVo (Premier). Two of these were another 50 feet from the antenna's 50-foot cable, and the extra splits and several runs total of 50 feet or so were just a little too much for the signal at the ends.

We do have a sunroom that provides a clearer view of the towers I'm trying to get, but the chimney was already there as a sturdy vertical support and permitted me to use twelve feet of mast to get the antenna nice and high. Attaching to the roof of the sunroom with a comparatively small base seemed like would lose a lot of leverage for that length of mast and I figured I might lose so 6-10 feet of elevation moving over there. I think I'll get one of my boys to help me hand-hold it in other prospective areas to see if there's a better one that's fairly simple to adequately mount to.

Thanks for the great suggestions!

In lieu of moving the antenna to a new location because of how convenient the chimney is, is there a decent chance that a double antenna with a wider pickup angle would help with signal strength and/or quality past the huge maple trees in our line of sight to the towers? One that looks tempting to try is the Solid Signal Xtreme HDB8X. Any thoughts on that?

Thanks!