Just doesn't make sense

[islanddawg]

Ok, so based on my report (http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d46ae36eb212c68) it seems like I should easily receive all the OTA channels in my area.

My problem is that I get great reception on all the channels except for ABC (25.1) and FOX (30.1). The reception on these 2 channels is very spotty especially at night. It just doesn't make sense to me with the stations all being the same distance away in the same direction with a similar signal strength.

a little about by setup: I am not sure the specifics, but I have an antenna mounted in my attic with a cable that runs directly to my TV (no splitters, amps etc..) I haven't been up there in a while so I don't know the brand but I do know with very little tweeking in either direction I can get ABC or FOX perfectly, but never both...

Any thoughts??? Thanks

[teleview]

The antenna in the attic looks the most like what antenna picture.

http://www.kyes.com/antenna/pointing.html.

[GroundUrMast]

Teleview is correct, it will be helpful to know what type antenna you're using. Even if we don't know the brand or model, an accurate description will help us understand if it supports both UHF and VHF reception, which you need.

Can you describe the materials used in your roof and attic construction? Are there heating/cooling ducts or other metal near the antenna?

Have you considered 'testing' the reception with an antenna outside?

[islanddawg]

It looks like this one:
http://www.kyes.com/antenna/pointing/pointuhfpanel.jpg

I believe it supports both uhf and vhf. The attic is wood frame and the roof has asphalt shingles. The antenna is located near a lot of HVAC duct work...

I did test it outside before mounting in the attic and from what I remember the reception was great on all channels, however I didn't test it long enough to notice any fluctuations. Just holding and pointing in the correct direction I was able to get great reception so I assumed that once it was elevated in the attic and mounted using a compass for direction there wouldn't be any problems.

Thanks for the help.

[GroundUrMast]

Wood frame and asphalt shingles are usually the least troublesome materials... But radiant barrier and insulating materials containing any type of metal, including metalized film can form barriers to OTA signals.

Any metal HVAC ducts and those made of plastic with wire or other metal supporting parts are going to reflect OTA signals and detune the antenna if they are within a few feet. The situation is worse when the metal is in front of the antenna, but even to the side or behind you can expect a negative interaction with the antenna.

A few panel antennas offer some support of H-VHF reception (the Channel Master CM-4228HD is an example), but the majority should be considered UHF only.

Given that you had success outside, clear of the HVAC ducts and other impairments created by the attic & roof construction, I would suggest you 'test' again... An outdoor install beats an attic install just about every time.

If you are committed to the attic install for whatever reason, you'll need to locate the antenna so that no metal is in front of it, including vent pipes, gas appliance flues, ducts, insulating products, etc.

Finally, you may need to add a H-VHF antenna or, replace the UHF only with a combination UHF/H-VHF antenna.

[teleview]

If reception issues/problems are not resolvable by adjusting aim and location in the attic.

Then install the antenna above the peak of the roof in such a manner that the roof and building are not impeding and blocking reception in the directions of , South and North West.

Aim the antenna at about , 190 degree magnetic compass direction.

Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html.

A Winegard DS3000 , J pole type antenna mount will work Ok with the antenna.

[islanddawg]

Thanks for the responses. I think I am starting to make some progress now. I got in the attic this morning to confirm the type of antenna I have and adjust the aim.

This is the antenna I have: http://www.antennasdirect.com/store/ClearStream-4-Ultra-Long-Range-Outdoor-DTV-Antenna.html

After looking this up online it looks like it is UHF only... This would explain why I can't receive RF channels 7 and 10 in my area, correct??? The signal meter on my tv indicates full green bars for all channels except RF 7 which gets no reception and RF 10 which gets really bad reception.

can you recommend a UHF/VHF antenna for attic mount and my area. I may even be able to use a set top antenna?? I get really great reception in this area and don't think the attic/building materials is the problem.

Thanks!

[GroundUrMast]

If you have room in the attic, the Antennacraft Y10713 is not overkill. The shorter Y5713 would be fine outside in the clear and may be OK in the attic.

You'll also need a UVSJ to combine the UHF and VHF signals into a single coax.

http://www.antennacraft.net/Antennas/AntennasVHF.html
http://www.solidsignal.com/pview.asp?p=uvsj&d=pico-macom-uvsj-uhf-vhf-band-separator%2Fcombiner-for-antenna-%28uvsj%29

[islanddawg]

Would adding a separate h-vhf antenna as you have suggested, be a better option than replacing my current one with a combo UHF/vhf like this one?

http://www.antennasdirect.com/store/ClearStream-2V-UHF-VHF-Long-Range-Indoor-Outdoor-DTV-Antenna.html

I don't mind going for the combo but they sell the antenna above at my local Walmart and would be easy for me to purchase and just replace my current one..

Thanks for the suggestions

[GroundUrMast]

If you mount the C2V outdoors, I think it would do fairly well. In the attic, I doubt it has enough VHF gain to get the job done. YMMV

I'm thinking, you're doing well as far as UHF performance is concerned. So why start over... just add the VHF capability you need.

If you want to replace the existing antenna... In the attic, a Winegard HD7698P would be an example of a UHF/H-VHF combo that I would suggest.

[islanddawg]

I think you are right. I am going to add in the vhf antenna. I will let you know how it turns out. Your assistance is very much aooretiated.