OTA Reception

[Tivoman44]

I am in test mode of an antenna in case the economy forces me to go strictly OTA.  I have a wineguard SS-3000 amplified antenna.  I live in Tosa, in a second story apartment, and have the antenna on top of a book shelf pointing toward the towers, what I get is generally speaking great reception, a coax is hooked to the back of the TV, and almost always the signal level shows all bars. What is frustrating is that the picture on almost all channels seems to pixelate up quite a bit, not sure if it is due to traffic or not.  I'll just be watching TV, it'll pixelate up, and it happens fairly frequently, not just say once or twice during a half hour show, I would say upward of 10 to 15 times.

[budda]

With a digital signal it can be too strong which drowns out the signal and causes drop outs and digitizing. You need a Attenuator. Also caused by multi-path issues.Two signals to close and cancel each other out.  Also could be a bad cable but I would guess you have tried that. Good luck.

[ddeerrff]

Good luck.  8VSB is very sensitive to multipath, and you are probably getting reflections from all over the place.  Best bet is a highly directional antenna. Generally you want it pointed directly at the transmitter, but sometime you can get better results by pointing the antenna into one of the reflections.

Too bad we didn't adopt COFDM.

[ArgMeMatey]

8VSB is very sensitive to multipath, and you are probably getting reflections from all over the place.  Best bet is a highly directional antenna.

I would try to get as directional as possible as well.  I had good signal levels but lots of dropouts.  Moved up to a better antenna and added a very sophisticated Reynolds reflector (aka aluminum foil) which seems to have mostly eliminated problems with passing autos and other multipath for me.  

Can't find it at the moment but somewhere online there's a step-by-step showing the installation of an antenna inside a metal trash can.  It might be tough to replicate that in an apartment, however.

[Will]

Start with the simple stuff.  Try unplugging the power on the antenna -- as mentioned, you likely need an attenuated signal.  An amplified antenna doesn't help in that case.  

I'm in Tosa too, and had some antenna issues at my place.  I couldn't get anything to work short of an antenna in the attic.  Six blocks away, my folks can get great signal with a pair of rabbit ears -- go figure.  They tried an amplified antenna, and it would cause pixellation too.  Unplugged, it works like a charm.  

Did you try just rabbit ears?

Good luck.

[Tivoman44]

Thank you all for the help.  I will try unplugging the amplifier first.  Also I have been meaning to try different cables.  I need to try using shorter cables that I have from TWC (I have been told that the coax cables with a blue color mark are the best).  I have a long one currently bought at Home Depot and noticed a small kink in it, so that doesn't help.  

Also I went onto amazon and typed in Attenuator, came up with this example

http://www.amazon.com/-Line-Coax-Cable-Signal-Attenuator/dp/B0002ZPIT6/ref=sr_1_1?ie=UTF8&qid=1310470679&sr=8-1

That almost looks like an adaptor where you connect one end of the coax to the attenuator, and then into your unit (like the Tivo).

The funny thing to is we currently don't have cable in our bedroom, using an old tube TV with a digistream converter, basic vhf/uhf rabbit ears.  On a brief occasion, it pixelates up, but hardly ever, works well, very high signal.  

I like to think I know a lot about electronics, but as always thank you for everyones help.

[Tivoman44]

Wow, unplugging the amp has helped a ton, the signal is still high but it almost never breaks up.  The only other problem though is that I noticed that METV seems to have a lower signal along with CW18.  While I don't care much about METV, I like CW.  What is the issue with CW18, are they still going through their testing and how much power they broadcast on?  Also for the record I rescanned the TV after I unplugged it.  

I guess I'll be watching the All star game OTA.  I have never understood why I can hear OTA tv better, with cable I always have to turn the TV way up

[Tivoman44]

ArgMeMatey, quick question, would you suggest I place tin foil over the plastic part of my antenna?  http://www.amazon.com/Winegard-SS-3000-Amplified-Indoor-Antenna/dp/B001DFZ5II/ref=sr_1_1?ie=UTF8&qid=1310603500&sr=8-1  here is a picture

[ArgMeMatey]

ArgMeMatey, quick question, would you suggest I place tin foil over the plastic part of my antenna?  http://www.amazon.com/Winegard-SS-3000-Amplified-Indoor-Antenna/dp/B001DFZ5II/ref=sr_1_1?ie=UTF8&qid=1310603500&sr=8-1  here is a picture

Typically you would put the foil behind the antenna, relative to the transmitter.  The garbage can approach restricts the antenna from receiving signals from the back and sides, depending on the depth of the can.  

Winegard mentions "Scatter Plane Technology To Receive Indoor Direct and Reflected Signals" which might indicate that the antenna's characteristics are not ideal for multipath and strong reflections.  The SS3000 front-to-back ratio in the UHF band is rated 7.5 dB.    http://www.winegarddirect.com/ss-3000/winegard-ss-3000-antenna.asp

I have a DigiTenna DUV-S which has a front-to-back ratio of about 13 dB in the UHF band.  http://digitenna.com/SpecSheets.pdf
Expensive, and there are probably far cheaper alternatives, but it works very well for me.

[Tivoman44]

Got my 3 Attenuators, two Fam 6 and one Fam 10, not sure how many I needed.  With my Wineguard antenna, their is a coax cable coming out of the antenna that cannot be removed.  It came with what looks like a two way splitter, but on end is is where you connect the cable  that is connected to the antenna, then on one of the outputs you connect another coax to the power plug and plug it in, on the other you connect another coax that would then go into a tivo, back of a TV, etc.  I don't understand how many Attenuator's to use, and if just one,would I connect it to the coax that connects to the power plug, or to the cable that connects to the TV/Tivo, etc?

Also never quite understood the difference between the Fam 6 or Fam 10, guess I should have researched that more before buying, but was very cheap online.

[Nels Harvey]

Also never quite understood the difference between the Fam 6 or Fam 10, guess I should have researched that more before buying, but was very cheap online.

Try the attenuator right on the antenna input of your TV.  Run a scan, make sure all of your channels are seen, and see if that solves your problem.  If you don't have enough attenuation, add another one.  It's all trial and error.  If your problem is due to too strong a signal, some combination ought to work.  I do wish you well!

[ddeerrff]

Also never quite understood the difference between the Fam 6 or Fam 10,

Most likely that would indicate a 6 dB and a 10 dB attenuator.  Decibel is a logarithmic  power ratio;  3 dB = 1/2 power, 6 dB = 1/4 power, 10 dB = 1/10 power.  So if you add two 6 dB and one 10 dB attenuator in-line, you have reduced the power coming from the antenna by a factor of 160.

[WPXE ION]

If you need different attenuators there is a place on good Hope Rd. called Ness Electronics. They will have any atteunator you need, 3dB, 6dB, etc. They also sell a varitey of antennas and the staff can recommend one for you. Dont be intimidated by the sign on the door that says wholesale ONLY!!! Or something along that route. They sell to anyone. A sale is a sale.

If I remember some parts of Tosa are down in a valley. If you live in one of these areas that might affect your signal. Being in Tosa you should be getting a strong enough signal from all stations, just have to remember the multipath issues.

If you want to PM me with your address I can come in to the neighborhood and take a look at the signals on an analyzer and post what I find. Doesnt have to be exact address just close so I can do a signal analysis.

Keep us posted.

[Tivoman44]

Thank you all again for all your help.  I think I am near done with my experiment.  I finally switched out that coax cable for some high quality one's that I had lying around from TWC, connected 3 together using two female-female connectors, and placed one 6 rated attenuator to the tivo and plugged the amplifier back in.  It has very quick pixelations every now and then, but so far works, may add my other 6 rated attenuator, but seems to work.  

Also WPXE Ion, I sent you a PM the other night.  I was curious what you would do to measure the strength in the neighborhood.  Don't worry about having to respond right away though, not urgent.

[techboy]

FAM 3 equals 3db attenuation / 1/2 original signal level.
FAM 6 equals 6db attenuation / 1/4 original signal level.
FAM 10 equals 10db attenuation / 1/10 original signal.  It's a log scale.