More on the evil plot of RF noise...

[W2VW]

Good read

When I was in business, some of what I did was to trace interferences to TV reception.  Over the 45+ years of this work I found everything from soup to nuts causing interference of all sorts.

No all was noise, a lot of RF type problems.

I found that about half of the noise problems were from power lines and the same amount from problems inside buildings.

Tracing noise from power lines had its own set of problems.  If you call the power company, then would check for noise at the location of the complaint.  Very often the noise source was nowhere near that address.  It could be a half a mile from the complaining customer.

I had my own method for locating power line noise and never failed to correctly locate it.  Even when the power company disagreed.

Noise that would have shown up in an analog TV picture doesn't bother a DTV picture.  Although, I'm sure if the noise was close enough and strong enough it could interfer with DTV reception.

Fred

Noise that would show up on an analog tv picture does not show up on a digital tv picture but it most certainly can and does lower SNR. This is one of the problems with some DTV stations going back to VHF.

Dave, you're right.  What I was trying to say was that analog TV would show even low level noise.  Noise at that level or really any level doesn't show up in the DTV picture as it was seen on an analog picture.  Of course, noise on the signal lowers the SNR and could cause the DTV to not work at all.

Fred

PS. My wife is complaining again that CH 4 has been off the air early AM.  She is missing her programs.  I'm taking the heat over this.  I told her that I'll pass along the complaint to the proper personnel.

Tell the little woman you have the problem all fixed for now.

Next time point toward West Orange.

[KA2DZT]

Rob,

FB on trying a big TV antenna.

If your TV stations are only on UHF and high band VHF try using one of Winegard's HB VHF/UHF antennas.  These antennas are easier to install higher as they don't have the larger low band VHF elements.  These antennas work well.  The series is HD-769x, use the largest model.  If you add the preamp, use a Winegard.  They make two U/V models, one having about 20dB gain and the other about 30dB gain.  Don't use the preamps that fit into the plastic box that is affixed to these antennas.  The preamps to use are separate units that you U-bolt to the mast.  Don't cascade multiple amps as this can create more problems that can be hard to detect,  only use one preamp.

Once you add the preamp near the antenna there is no need to use hardline, just use some good RG-6.  You may want to put the preamp lower on the mast to make it easier to reach standing on the roof.  With your problems with reception you should put a rotor on the antenna,  being in a valley you'll need to play with direction.

Fred

[KA3EKH]

More weird DTV fun facts! Sometimes antenna gain is a bad thing, if you have an antenna that’s very directive that may cause more problems than it solves. You can set the antenna for one station but unless the others are where that one is you won't see them. Having the antenna on a rotor can be an issue. The TV has to build a virtual channel table and has to have a good signal acquired from each station in the channel table. You can crank on your antenna but if the channel is not in your table you won't see it unless you directly enter the channel number and also keep in mind that it takes a second or two for the decoder to start working so with a real directive antenna you may pass the peak. Where I live I am lucky being all the local stations are roughly the same heading from my QTH so I have a little UHF corner reflector mounted on top of the tower but being a engineer I did use a spectrum analyzer to peak it. Most demods have a signal level meter incorporated in them that will allow you to peak the antenna. On the subject of demods also beware old first and second generation HDTV equipment. The older HDTV stuff did not have the newer chip sets. First generation chip sets only allowed a limited number of channel configurations and today some broadcasters are doing things like mixed 720/720 as opposed to the older 1080/480 splits and the oldest chipsets will not decode this. Second generation chip sets included an improved fading- ghost algorithm that will allow the decoder to work in multipath where the first two generations before this just stopped decoding when you had a small amount of multipath. The good news is that everything I have seen in the last four or five years has had the latest chip set and none of these issues. The little "welfare" government subsidized decoder has a great chip set and works well also if you ever see any of the "US Digital" decoders that wall mart was selling they will decode anything regardless of PIDs or channel configuration but they do lock occasionally.  Took me a while to buy into the 8VSB way of life but I am a big believer in it today, excellent quality, more channels, smaller easy to work on transmitters and less power required  not to mention will never have to think about differential phase and gain again!, but I do miss old dual 30 kW IOT Comark. The analog transmitters required skill and technique to operate where the digital has one button for on and off.

[K5UJ]

Okay Fred and Ray thanks, I will try moving the antenna around.  I got the one you recommended Fred, the biggest channel 7 on up Winegard they make, can't remember the model no. but it is the 14 foot long job with around 70 elements that lists for around $179 but I got mine from Summit Source for around $120.