Troubleshooting signal

[Poormountaineer]

In an effort to provide as much info as possible, this will likely be a long post.
My current set up is rooftop antenna (picture below) 30 ft off ground, connected via a short 300 ohm wire to my preamp which is a Philips SWS2083W/17 Outdoor 28dB Antenna Amplifier (bought and installed in 2009). From there I am using RG6 to go into the house where it goes into a splitter and the power supply for the preamp. From the splitter it goes to two TV's, one using a RCA converter box and one using a built in tuner (Zenith Z50PV220 TV).

As a side note, I had to move the antenna to the roof because my house has steel siding on it.

The Zenith tv was recently purchased to replace another TV that died that had a built in tuner . We hadn't had any issues with reception until recently. The issue is intermittent and is obviously caused by weather at times, but even so the TV using the converter box seems to have less issues, although we only turn that one on when the new tv is having issues to compare picture.
Stations (real, not virtual) I have received and would like to receive:
35, 22, 20, 45, 43, 38, 32, 12 (this was quite reliable, but neither tv receives it currently) Any other stations from the northwest would also be welcome. I linked my tvfool report below.

What I have tried:
Disconnecting the preamp - lose all signal, at least no stations can be tuned.
Removed splitter
Used converter box to check signal strength at both TV locations with and without splitter installed, signal strength at both TV locations is within 1% of each other.
I checked all connections to make sure they are tight.
Check cable for damage, and removed some slightly damaged cable.
Tried slowly rotating the antenna, only to move it back to original position.
I took the back cover off my preamp power source it smelled of hot electronics, but as I said above without it, I get no signal so it must be working at least a little.


1. Does anyone know if the converter boxes typically have better tuners than the ones built into TV's? Are they able to handle more noise than built in tuners? It seems like ours outperforms both of the tvs we have had with built in tuners.
2. My antenna is old and came with the house when I purchased the house 7 years ago, any idea what gain I could expect to be getting from it? I realize it is not ideal and could use replacing, so suggestions on that would be appreciated. I am currently considering a DB8 or a channel master 3671 (although I am somewhat concerned about it being directional since I don't have a rotor.)
3. I realize I bought a cheapo preamp 3 years ago, I was experimenting and didn't want to spend to much, so is what I am experiencing my preamp possibly going bad and sending more than its fair share of noise down the line? Is there a way to check its performance with a multimeter?
4. I know this is a distinct possibility, does it sound like I have a bad tuner in my new tv? Or is this what I would experience when I have too much amplification of my tv signal?
5. Do cell phone towers cause any major interference? My antenna is currently pointed about 3 degrees away from one and I can easily see it when standing on my roof next to the antenna.
6. If I were to get a rotor and a CM 3671, any idea if I might pull in any of the stations from the northeast (I would love to get 16 so I could have another option for football in the fall, I have picked this channel up in the past, but mainly because of atmospheric conditions)

I think those are my only questions, so please let me know if you need more detail.


http://download.p4c.philips.com/file...17_dfu_aen.pdf

http://www.tvfool.com/?option=com_wr...0b86d0616efbed

[Electron]

The antenna in the picture looks like a VHF only antenna. Most of the Tv stations/channels are UHF at your location. Install a Winegard HD7698P antenna with a Winegard AP8700 preamp aimed at about 305 degree magnetic compass. Here is how to aim antennas , http://www.kyes.com/antenna/pointing/pointing.html. Here are some places to buy antennas and etc. , http://www.winegarddirect.com , http://www.solidsignal.com , http://www.amazon.com

[GroundUrMast]

KDSM, real channel 16 is simply too far away to expect reliable reception. At about 117 miles, it's well below the horizon. You might get lucky at times and see it if the atmosphere reflects the signal favorably... a phenomena you and I have no control over.

[Electron]

The tvfool radar list of digital tv channels shows the Real Digital Channels that are being received and the Virtual channels. The Virtual channel in most cases is the Legacy analog channel number that the Tv station had before the switch to digital.

[Poormountaineer]

Thanks for the replies. After I had posted last night I continued to do more research and figured my issue was more about how good a signal my antenna was able to pull in rather than anything else.

It makes sense to me now that the antenna I currently have is a VHF only antenna, but it definitely gives me some UHF gain as without it I am dead in the water. So I am still curious if you have any idea how much UHF gain it would provide, hard to find any info on it since I have no idea what it is. Really just curious so I can compare it to other antennas.

In your experience how wide of an angle does the HD7698P have for reception? Seems like since I am currently getting fairly good reception with a VHF antenna, this one might be a little overkill, but then it probably would keep me from having any future issues.
Thanks.

[Poormountaineer]

One other question while I am thinking about it, my current antenna is pointed to about 270-280 degrees and that is the only way I can pick up all the channels I listed in my original post, is that because of the antenna I am using or because I am picking up reflected signal?

[GroundUrMast]

A rough guess-ti-mate of the UHF gain would be between a few dB positive and as much as 10 dB negative. Expect the net gain to vary across the UHF band also. The positive NM figures shown in your TVFool report suggest that an antenna with negative net gain could successfully receive several signals, which seems consistent with the experience you're reporting.

The beam-width of the HD7698P is (over the majority of its bandwidth) about 40° (+ and - 20° from center). Aiming west or NW is consistent with your TVFR. Suggested aim point is just that, a suggestion and/or a starting point from which to fine tune the final aim.

I would expect you to see significantly better signal quality if you opted to replace your old antenna with the suggested Winegard. The AP8700 amplifier is also a good option, the Antennas Direct PA-18 is another very good choice, it's noise figure is a bit better.

[Poormountaineer]

So now a question about noise from the amplifier. My current amplifier claims a noise value of 4 dB, the AP 8700 claims a value of 2.8 dB for noise and the PA-18 claims 1.8 dB. Assuming these are all accurate and all of the amps are operating as designed, is the 2.2 dB significant? I have read that a 1-3 dB difference in antenna gain is not significant, so I didn't know if that was the same for noise or not.
Thanks.

[GroundUrMast]

2.2 dB is only significant if you are on the ragged edge... usually seeing a reliable picture, just not 100% of the time.

Installation of a UHF capable antenna will be the most significant improvement for your situation.

[Poormountaineer]

Thanks for the reply. I ordered the antenna today, but plan on trying my current preamp with the new antenna, I know it isn't ideal, but if it works for a little longer I can spend the money on a new preamp later.

[Electron]

The HD7698P antenna is big high gain antenna. Try installing the antenna with no preamp. Looking at Current Plus Pending Applications Included Digital Channels , I expect that you will receive down to KUON-DT 12 PBS and likley down to KYNE-DT 17 PBS.

[Poormountaineer]

Electron, thanks for the latest reply. I had a similar thought after installing the antenna last night. In your experience, when a preamp goes bad, does the noise it produces typically increase? The mast mount of my current preamp didn't look like it weathered too well and I still have more pixilization of the picture than I was used to before having signal issues. I am able to pull in more channels but they aren't as good as I had previously experienced yet. I don't blame the antenna, I actually think it is proving it is an upgrade, but I am thinking the preamp is causing more problems now than it is solving.

[Electron]

Yes when the preamp fails the electronic noise that circuits of the preamp generate in a normal operation , those circuits will become much more noisy. Electronic noise when you hear it with your ears is a hissing rushing sound the more of the noise there is the more you can not hear what you trying to hear. It is the same with with electronic tv reception , more noise masks , covers the signal that you are receiving.

[Electron]

Check all coax connections , look inside the connectors on the ends of the coax for corrosion. Also look inside the connectors to see if the foil shied and shied wires of the coax is pushed in toward the center wire of the coax , if is , then push foil shied and shield wires away from the center wire with the point of a knife or small flat blade screw driver. If water has entered in to the coax then put the coax in the trash.

[Poormountaineer]

I took out the preamp today. I had already checked all connections and they looked good. I have replaced some of the coax ends with new ones so that I could put rubber boots over them to protect them from the weathers. So without the preamp I am getting a much more reliable signal. I have about 75-100 ft. of coax between the antenna and the tv with a coupler for grounding and a wall plate coupler. With the preamp I was able to pick up real channels 33 and 17, but without it I cannot get these reliably. The preamp was boosting those channels signals to overcome the loss in my coax but it appears it was also the source of my pixiliaztion issues. 33 and 17 are the same as 35 and 12 respectively so I will not be installing a preamp at this point. If I ever need to split my signal I may get a distribution amp instead of putting up a preamp again, but at this point I am very happy with my signal. Thanks for the suggestions and help.

[Electron]

Yes the PBS stations are all part of main tv stations and repeater networks. http://en.wikipedia.org/wiki/Iowa_Public_Television , http://en.wikipedia.org/wiki/Nebrask...communications. There will most likley be enough signal strength for 2 tv's with a simple common 2 way splitter. If KUON-DT 12 PBS is a little if'y being split 2 ways then install a Channel Master CM3412 2 way distribution amp. For 3 or 4 tv's install a CM3414 4 way distribution amp. http://www.channelmasterstore.com. Put 75 ohm terminators on any unused out put ports of the distribution amp. . If silicone grease is put in the boots , but not in the connectors , the silicone grease will keep water from collecting in the boot and corroding the connection.

[Electron]

Typically the big screen big brand tv's such as Samsung , Sony , LG , Panasonic , have the latest and best digital tv tuners. Vizio and other lesser brands tend to cut corners. Channel Master converters are very good.

[Electron]

Cell phone towers can cause interference with tv reception and what is called WiFi hot spots can cause interference , many cell phones now days are wifi hot spot devices. However typically but not always it is not the cell phone tower or wifi hotspots fault. It is digital tv's tuners fault , a lack of adaquate filtering.