Problem receiving CBS (Seattle)

[woody]

So I recently found out about digital OTA TV and decided to give it a try. Based on the good reviews, I bought an RCA ANT751, with the idea of installing it in the attic space above my garage. (For various reasons, I don't want to put it on the roof.)

Here is my signal analysis:
http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3dcc49eef3382a90

I'm able to get most of the green-shaded channels in at least some antenna locations. The strongest, most reliable signals are the three that are farthest away: KCPQ, KBTC and KTBW. My problem is that I am unable to get KIRO (CBS) and KONG at all, no matter where I put the antenna. They sometimes show up on channel scans, so there must be some detectable signal, but when I click on them, I just get snow (unlike other channels, where I see a black screen and the message 'Poor signal quality' or 'Channel not available' if the signal is too weak). The weird thing is, when I switch to KIRO, I can sometimes see a faint image of it through the snow, like an analog broadcast. But the TV signal meter shows 0%.

Any idea why I can get KOMO and KING, but not KONG and KIRO? They all come from the same location, on Queen Anne Hill. If I could get the latter two channels reliably, I could get rid of the cable. Would a pre-amp possibly solve the problem?

Geographically, I'm at a relatively high point in my neighborhood, but the end of my street in the direction of the Seattle towers slopes upward slightly.

Any help would be appreciated.

[GroundUrMast]

The ANT-751 should be a good choice for your location.

I would have tried in the attic also. But the reality for many folks is, the attic may not be a workable reception site. This can be true for a variety of reasons, but generally, the reflective properties of the roof and building materials are to blame. That you're receiving some frequencies is not a guaranty that you will receive all frequencies.

Re. Amplifiers: Reliable reception is not simply a matter of signal strength, rather it's more a matter of signal quality. An amplifier is not able to correct signal quality problems, it's purpose is to overcome signal loss in the cable and splitter connected to the output of the amplifier. Think of it this way, If there is a little bit of mud at the bottom of a shallow hole in the ground, would installing a high pressure pump deliver clean water to the tap? Obviously not. The answer to the problem no doubt lies in digging deeper to access clean water. Only with a supply of clean water would you then consider the need for a pump.

Can you try the antenna outdoors as a test? If you still have trouble outside, with the antenna connected to only one TV (no splitters or amplifiers during the test), then consider adding an FM trap. The FM stations on Cougar Mt. to the NE of you location may be causing trouble with some channels. http://www.radioshack.com/product/index.jsp?productId=10939219

Several questions;

How many TVs are connected to the ANT-751?

Is there a splitter? If so, how many output ports does it have and are there unused ports on the splitter?

How many feet of coax from the antenna to the TV?

Are there splices or any questionable connections? Any used cable or parts that may have had water intrusion?

Is there any chance cable service and antenna signals are sharing the same coax? (If so, you risk causing harmful interference to licensed radio services. Never mix cable and OTA signals in the same coax.)

Is the tuner set to scan for 'antenna' or 'air' rather than 'cable'?

[woody]

Thanks for the response.

To answer your questions:
I did try the antenna outside, at ground level, but the results were no better.
The antenna is only connected to one TV, with no splitter. I used a 50-foot-long cable (brand new), and later connected another 25-foot cable to that, but it didn't seem to affect the reception. The coax is completely separate from the coax used for the cable TV. And yes, I scanned for 'antenna', not 'cable'.

I hadn't considered using an FM trap. I read that those are only needed for amplified antennas, which I don't have. But for just $5, it might be worth a try. I'm very close to Cougar Mountain.

[GroundUrMast]

...
I hadn't considered using an FM trap. I read that those are only needed for amplified antennas, which I don't have. But for just $5, it might be worth a try. I'm very close to Cougar Mountain.

The tuner in your TV has one or more amplifiers. Regardless, at $5 and some gas, it's the cheapest 'next step'.

Have you tried other TVs in place of the first?

[woody]

No, I don't have any other TVs.