Question: Can't pick up the strongest channel in my location

#1
Hello everyone,

I'm usually pretty good with tech but this is killing me. I have an outdoor RCA antenna hooked up to my PC with a Hauppauge 1250. I scan real channels 2-51 and turn up tons of channels coming in clear as a bell except I get ZERO coming in from my local NBC/ABC channels (real channel 48/38). There are 3 huge towers just south of me that broadcast NBC/ABC/CBS and CBS comes in great, clear and strong. FOX comes in clear and strong and it's 24mi away and 40 degrees in a different direction!! Something isn't right here. Do these stations just go dark sometimes?

Really thankful for any advice/help. I'll try anything, I'm at the end of my troubleshooting skills.

Here is my location report from TV Fool
TV Fool

This is my antenna

Amazon.com: RCA Compact Outdoor Yagi HDTV Antenna: Electronics

I'm really just trying to have great reception for CBS/NBC/FOX for Seahawk games

PS: Go HAWKS!
 
#2
Have you tried a different tuner. Like one built into a TV. Front end overload comes to mind from too strong of signals, or even too strong of out of band signals. An FM trap might help. While FM causing problems with UHF signals is unusual it's not unheard of, but very unlikely that high in the band. 4G LTE interference is a possibility filters are available.
http://www.amazon.com/Connector-In-Line-Adapter-TV-Freeview-Interference/dp/B00MX7MM3G

Attenuators are available if the problem is overload.
Amazon.com: Parts Express In-Line Coax Cable TV Signal Attenuator 6 dB: Electronics
A simple splitter can be used as a 3 dB attenuator. If overload is the problem be prepared to start stacking attenuators. Have you tried aiming the antenna away from the tower?
Being one who works with junk of my own and sometimes other peoples I have ran across missing channel problems that are the result of bad coax connectors, a defective balun, an incorrectly assembled antenna, damaged poorly built connectors on the back of the TV,or tuner. Anyone of these problems can create high VSWR on the feedline which with digital signals can selectively wipe out one or more channels while the others look great.
House hold interference most often from Switched Mode Power Supplies is a common problem at VHF frequencies, but seldom cause problems with UHF. The noise from such power supplies can be very frequency specific.
I don't know what is causing your problem. I can only mention the possible things that come to mind.
Steve
 
#3
Steve,

Thanks for so many troubleshooting ideas, hopefully I can whittle things down a little with some more info on my end.

Firstly this is my 2nd antenna, my first was a Mohu Leaf unamped that i actually used outdoor with good but not great results. It couldn't pick up FOX (24mi away) consistently so I figured an antenna upgrade would solve it. With the Leaf I had no issues picking up NBC, CBS, or ABC so I think that would eliminate a bad tuner from the problem list.

I'll definitely try pointing the antenna away from the cluster of ABC/NBC/CBS towers to my south and try and go due west to still keep a strong signal with the weaker FOX tower. Since my antenna is directional would that effectively attenuate the signal I'm receiving from the strong 3 to the South?
 
#4
I have to ask do you know for certain which Fox signal you are receiving. One is being transmitted on real channel 22 UHF the other on real channel 13 VHF. RabbitEars.info shows that they both will channel map to 13.1. If you are not yet familiar with it welcome to the confusing world of real and virtual channels. Your TV Fool report shows your closest strongest source of a KCPQ 13.1 signal to be from a transmitter on channel 22 @ 162 degrees 5.9 miles away.
I'm not familiar with the Hauppauge 1250 or the soft ware it takes to run it. Is there some where that displays actual frequency, or real channel number. This information can be helpful when working out a reception problem even when that is not the channel you are having trouble with.
The fact that it worked using the leaf could possibly eliminate a household noise as the problem. I'd look at over load, poor connections, faulty balun. Test the leaf again while you are in a trouble shooting mode.
Steve
 
#5
When referring to FOX I am talking about the 13.1 (real 13). The other FOX is a non-HD version of the same channel and I think rabbitears.info may be incorrect since the non HD channel has always mapped to channel 22.

The Hauppauge card has a number of useful utilities and it will certainly tell me real channel/virtual channel/freq and also S/N ratio of a channel that I am tuned into
 
#6
For the sake of education and sharing I think this may be my culprit since my antenna is kind of pointing towards a tree and/or the flat side of a house. I'd be interested to hear thoughts on the issue but I'm going to hop up the ladder and point my antenna due West as best I can and see if that solves anything

Short delay multi-path - This is always caused by something directly in front of the antenna. One common cause is a tree in front of the antenna. There will be chaotically overlapped signals behind a tree. This will mainly affect UHF reception. The solution is to relocate the antenna (or cut down the tree). If the antenna stays behind the tree, you will likely see dropouts on UHF channels when the wind blows. And that’s for strong-signal areas. In weak-signal areas you will likely get no UHF reception at all behind a tree.
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EDIT: THAT TOTALLY FIXED IT! Now get all major broadcast channels in HD. Special thanks to RF Steve for helping me troubleshoot this one, you're the man!
 
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#7
While there have never been any published specifications a low gain antenna like the 751 is not likely to be extremely directional when working with signals that are as strong as what is predicted at your location.
I had to touch on the real vs virtual channel subject because it causes so much confusion, and so many of the tuners in use are designed in a way that adds to the confusion. While I've never been around one I was pretty certain that the Hauppauge provided some useful information. I think I've read posts where those feature were totally over looked by the person posting.
I'm quite well aware of the inaccuracies in all internet sources of current signal information. Including the FCC data base. A local translator owner was quick to point that out to me when he was trying to get an FCC error straightened out.
The tree and the house paints an entirely different picture. I see you've been reading HDTV Primer that's a good site some of the product information on it is getting a bit dated. I hope you've read Siting the antenna because I think your trouble shooting might need to move that direction. Signal chasing in a difficult location can require a great deal of time and patients. Antenna placement can be critical. Higher, and more antenna gain is not always the answer, but often times is. That the very low gain UHF leaf antenna found those signals is an example of that.
In your situation I don't know what will happen if you aim to the west, but I would certainly try it.
Steve
 
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