Requesting Reception Help

kdub · 2-Jan-2015, 12:47 PM

Greetings! As one of my new year's resolutions this year I am looking to finally get my reception issues cleaned up around the house. Over a year ago we got rid of satellite (directTV) and switched over to a internet streaming & OTA setup. The setup works ok... unless it gets windy or cloudy or it is a Tuesday. Then we get some issues on certain channels. I would like to present my current setup and see if there are any suggestions for improving the current setup.

First the signal analysis:
http://www.tvfool.com/?option=com_wr...2c154d6da38fb0
The only stations that are of concern are really the top 5 of this chart (channels 49, 51, 47, 26, 11). They "should" be LOS, but in the ~16-17 miles between the house and the transmitters there are some hills and other terrain.

The setup:
So back when making the switch I researched antennas and ended up purchasing an Antennas Direct ClearStream4. This is currently mounted in my attic on a south facing wall pointed as close as possible to a 155-160 degree bearing. The wall construction is fairly standard plywood sheathing, tyvek and vinyl siding. The house sits down in a depression (there is a creek behind the house) and there is a large patch of woods directly south of the house. The antenna sits probably ~15 feet off the ground.

From the antenna I have probably about a 75' cable run to a splitter. I do not know the make/model of the splitter. The splitter has runs to 3 televisions, however, I would like to get that up to 6 locations if possible. A quick note - the house was built in 2011. As part of the construction I wired the house for comms during the construction. I ran a bundle of RG6 Coax (for TV), cat5 (for phone/backup internet), and cat6 (for internet) to each bedroom and common area. The runs from the central splitter to the wall outlets vary from ~20 feet to ~75 feet. I have a feeling that the length of the runs causes some issues as some channels that have trouble on some TVs work good on others.

I also tried to help the solution many months ago by purchasing an amplifier:
http://www.amazon.com/gp/product/B001DFZ5EW
As I could not seem to get any better reception with this in place it is not currently connected.

My issues are:
Some of the televisions have issues on one or two of the channels, especially if it is windy or stormy. These happen to be the channels that carry NFL games which makes it very frustrating when trying to watch a game. Ideally a permanent solution would also allow the signal to be split out to 6 end points so that I could cover every location in the house.

Any suggestions/ideas are very much appreciated. Thanks for the help!

Tim · 2-Jan-2015, 3:47 PM

You have a very good signal report for the 5 stations you are interested in. To isolate where the problem is, I would suggest installing a TV at the end of the 75' cable from the antenna without using a splitter:
1. If you are now getting a great picture on that TV, then you will probably need to replace your splitter with a distribution amplifier.
2. If you are still getting a problem picture then you may need to look at getting that antenna out of the attic and out in the open.

timgr · 2-Jan-2015, 4:25 PM

Attic installations are always dicey.

My advice would be - if you aren't happy with performance - move the antenna to the roof. At attic height, you might be aiming through trees, and multipath through the trees will get worse if it's wet or windy. You have lots of signal to work with, and all the stations of interest are closely grouped. The C4 is a fine antenna, and you could add the dipole kit to get WHAS... but you might not need it in free air.

You could try moving the antenna around in the attic. But that's just looking for a chance improvement - no guarantee anything will change.

Sounds like your problem is signal quality at that location, not signal strength. Take a look at this link http://www.hdtvprimer.com/antennas/siting.html to get an idea of what's going on with diffraction, ground reflection and trees.

kdub · 2-Jan-2015, 4:39 PM

Thanks Tim and timgr for the replies.

A few notes to add:

I have connected a TV directly at the point of the splitter and had very good reception, however, as I mentioned in my initial post, sometimes the reception on all of the TVs is pretty good so what I haven't done here is to wait until a time when the main tvs are having issues with a certain channel and then go down and try the direct connect tv test. There is a chance for some weather to move in this weekend and if I notice the connection issues I will try and perform this testing and report on the results.

A signal amplifier was mentioned. An 8 channel distribution amp would also allow me to wire up the remaining rooms pretty easily. Are there any recommended units to look for or will a basic unit like this work?
http://www.amazon.com/Channel-Master.../dp/B002M1EPL0

As far as the external mounting for the antenna, that is a possibility. About 10 linear feet away from the attic mount location on the outside of the house is the old directv dish still mounted with a coax line running from it into the basement where the junction is. That would be the location for where I would mount the antenna outside, and I would probably use the same mount and just remove the dish and rig up the antenna to the dish mount.

Also - one more note, it was mentioned to rig up a dipole kit for the WHAS signal - I am assuming that this is due to it being a VHF signal. The interesting thing is that I have never noticed any issues with that station. The two that I have noticed issues with are the WDRB and WLKY stations (both UHF). Not sure if this adds much to this conversation but thought I would mention it anyways.

kdub · 2-Jan-2015, 4:43 PM

One quick additional note - the antenna in the current location in the attic is already as high as I can get it, moving it outdoors will not really net me any additional height for obstruction clearance unless I look to put up some sort of tower for the antenna to sit on. The only real gain I will get in moving it outside is to avoid any attic interference and be able to better point it more directly towards the signals. (at least, that is my assumption of the gains I would get - if I am missing something I would be glad to hear it!)

timgr · 2-Jan-2015, 9:02 PM

Quote:

Originally Posted by kdub

...
Also - one more note, it was mentioned to rig up a dipole kit for the WHAS signal - I am assuming that this is due to it being a VHF signal. The interesting thing is that I have never noticed any issues with that station. The two that I have noticed issues with are the WDRB and WLKY stations (both UHF). Not sure if this adds much to this conversation but thought I would mention it anyways.

Yes -

I think that supports the idea that you have a signal quality issue, not a signal strength issue.

A UHF antenna will not be deaf to VHF, but because it's not designed to be resonant at those frequencies, it will be significantly less sensitive then at its target frequencies. If you have lots of signal in the air, the lower sensitivity won't matter, and the VHF signal will be above the threshold for reception.

timgr · 2-Jan-2015, 9:06 PM

Quote:

Originally Posted by kdub

One quick additional note - the antenna in the current location in the attic is already as high as I can get it, moving it outdoors will not really net me any additional height for obstruction clearance unless I look to put up some sort of tower for the antenna to sit on. The only real gain I will get in moving it outside is to avoid any attic interference and be able to better point it more directly towards the signals. (at least, that is my assumption of the gains I would get - if I am missing something I would be glad to hear it!)

Well, going outside the attic you will gain signal strength on the direct LOS path to the stations. Again, it's hard to predict what will happen... you could also gain strength in the multipath directions and see no change. However, I'd expect that increasing the strength of the LOS path would be the most likely path to improvement.

Tim · 2-Jan-2015, 9:16 PM

The Channel Master is a good distribution amp. Be sure to put a 75 ohm terminator on any unused ports.

By the way, you can buy 10 ft lengths of galvanized electrical conduit at your local home supply store. They are great for antenna masts and would get you up a bit higher than your sat dish mount. Use a size of conduit that would fit either inside or over the sat dish pole and drill a hole through both to bolt it in place.

ADTech · 3-Jan-2015, 12:46 AM

Your problem is your depressed location and the trees, compounded by the attic placement of the antenna. Unless you can solve those issues, your reception will probably never be 99% reliable.