[MurrayW]

I'll preface this by saying I know I have the right to put my antenna on top of my roof and there are probably better antennas, but I want to work with what I have and if I do put the antenna on top of my roof, to make it as unobtrusive as possible.


Right now I'm using the RS double bow-tie antenna with the 300 - 75 ohm modification in my attic to get the few local stations that are broadcasting digitally in Austin. I get occasional dropouts from the NBC station and do not get the FOX station at all (broadcasting at very low power). A few others in my general area have been able to get the FOX station. All the stations are broadcasting from the same tower area, so that makes it easier on pointing the antenna.


I bought a Channel Master 4221 (4 bow-tie UHF antenna) in the hopes that I will be able to improve the signal strength on the CBS station and pull in the FOX station. Before I go up in my attic or possibly up on my roof, I have a few questions.


1. If I do put it on my roof, I'd like to mount it on my chimney but not have it extend above the peak of my roof (it's more hidden this way -- the way that I want to keep it). In order to aim it toward the transmission towers, the line of sight will be blocked by my roof. Does this mean that the signal needs to travel through my attic and then back out the roof to get to my antenna - if so, would I have higher strength putting the antenna inside the attic (it would only have 1 layer of roofing material to penetrate rather than 2).


2. If I diplex the OTA signal from my antenna with the cable from DirecTV dish, and then separate them prior to entering the STB should I expect any significant signal degradation on either the satellite signal or OTA signal?


thanks,


Murray

 

[Ratman]

1. IMO it would probably be worse than in the attic shooting through one roof. But... you never know. It depends on a lot of variables that no one can answer definitively. All you can do is try and set up a temporary rig and see what you get. Obviously, try the attic first. If you get good reception, leave it there.


2. You should be fine.

 

[MurrayW]

Thanks ratman...that's what I thought also. I knew that no one would have a definite answer, just looking for opinions.

MurrayW

 

[woodworm]

Murray,


As to #2, I am doing just that with my RS bowtie through Trunkline multiswitch and it does great. Depending on your stb you may not need to split the signal back out at all. This is the case with my Tos DST3000. Please keep us posted as to how you make out if you mount the CM in the attich. I am thinking of doing that along with a rotor so I can dial in some of the marginal stations in my area. I currently have my RS in the attich and optimized positionally for CBS for that SEC game each week.

 

[BarryO]

You could also try mounting it high on a wall, on a side of the house facing the transmitters. You can mount the screen right up against a wall, and even paint the screen the same color as the house.

 

[mangriotis]

One note on #2:


I had my signal diplexed because I had only one line to my living room. However, in Chicago CBS-DT is channel 3 (VHF) and I was getting serious interference using diplexing... when I ran a separate line this problem cleared up completely.


Whenever possible, independent coax cables are always better...