Help at 77532 zip, 20 mi east of Houston, TX

[rekit]

http://www.tvfool.com/?option=com_wr...8e035ddcef061a

Crosby, TX 77532. I'm using a new TIVO OTA and mini, with a 6 mo. old Vizio 50" LED and/or 5 -6 year old Panasonic plazma with the RCA Model #ANT3038XR.
I have minimized cable length, tried w/wo amp, tried going thru tivo/straight to tv, only one tv at a time, different tv's. Turned off LED and CFL lights. Watched for airplanes as picture goes to ****. What else can make an 85 drop to 25 strength. When I get time we're going to try raising the antenna as much as we can, aim it with the signal meter, and try any recommendations I get. I'm 40 miles from the station farm. The TVFool map says I should be able to get all desired channels with an INDOOR antenna. Maybe I have too big of an antenna?
We would be happy with just the "real" stations-2-11-13-26-39. What I've noticed is all 30 channels I get either come in great or drop out, mostly together. We are away from tall buildings, industry, just tall pine trees. Flat land. I looked for some of those little caps to terminate my unused splitter terminals, but they are hard to find. I'm going to raise the antenna a little more-it's now 4' above my one story roof ridge, and am going to try aiming it a little bit different. It's close to the 227 degrees recommended now. And I'm going to check connections, but to get an 85 strength on most stations now, I think maybe it's multipath. It does get worse at night.

[No static at all]

Antenna selection is fine.

Are all channels affected? What amp are you using? How often do you experience dropouts & how long do they last?

Bouncing signal strengths are usually an indication of multipath. If raising the antenna doesn't help, you will need to "walk" the roof to find a more favorable spot.

[ADTech]

Repaired link: http://www.tvfool.com/?option=com_wr...8e035ddcef061a

What else can make an 85 drop to 25 strength.

Usually 1) electrical interference or 2) multipath interference.

Maybe I have too big of an antenna?

Nope.

What I've noticed is all 30 channels I get either come in great or drop out, mostly together.

That means a common element is at fault. Start with a temporary coax straight from the antenna to a single set, bypassing all coax and accessories in use. You didn't mention any amplifiers, but do be clear if any are in use or not. Check the phasing lines on the antenna to make certain they are both correctly routed (not touching boom or unintended elements) and are correctly connected.

I think maybe it's multipath.

If there's nothing out in front of the antenna, it's not multi-path. Multi-path occurs when the direct signal path is blocked.

it's now 4' above my one story roof ridge, and am going to try aiming it a little bit different. It's close to the 227 degrees recommended now.

Do you have a metal roof or radiant barrier decking or foil on the underside of the roof deck? Is the antenna situated on the signal side of the house or must the signal cross the roof to get to the antenna?

Does the antenna "look" into power lines?

I looked for some of those little caps to terminate my unused splitter terminals, but they are hard to find.

Downsize the splitter to one with the correct number of outputs. What are you currently using for a splitter?

[rabbit73]

just tall pine trees.

Umm, trees can block signals.

Can you show us what the trees look like in the 227 direction? What does your antenna "see" in that direction?

If it is common to all channels, then it must be intermittent connection, intermittent interference, or intermittent interruption of signal path.

Do you have solar panels and an inverter?

ADTech's suggestion to simplify the system to isolate an intermittent connection is correct. Replace each component in the system with a known good component, until your simplified system is trouble free, even if it means substituting another antenna and ending up with a completely separate temporary independent system.

To check for interference, listen for noise on a portable radio on the AM broadcast band tuned to a vacant frequency first at the low end (540 kHz) and then at the high end (1600 kHz). If you hear noise on the AM broadcast band, there might also be noise on the TV bands. A radio that tunes the VHF aircraft band is also AM. An FM radio is not suitable for hunting noise, like power line noise.

While you are checking the signal strength on the TiVo diagnostics screen, also note the SNR and uncorrected errors readings.

[rekit]

Well, it's pretty much a wall of mature pine trees that the antenna faces. Just a regular shingle roof, no radiant barrier, solar panels, or inverter. The antenna is on the SW corner, meaning the signal does not have to cross the roof to get to the antenna. I'm sure the amp is something from radio shack, nothing fancy. No power lines for a few miles.

"I have minimized cable length, tried with and without amp, tried going thru tivo, straight to tv, only one tv at a time, different tv's. Turned off LED and CFL lights. Watched for airplanes as picture goes to ****."

I'll redo, or remove the splitters as possible. When the kids were here we went to 3 tvs so I can remove all of them now that I've run CAT 5E for the tivo and mini. This weekend I'll get with my wife and re-aim, raise the antenna, jiggle wires, and also replace a sodium vapor light near the antenna that went out. Matter of fact, I'm going to cut the power to that right now, maybe that's it. I know it gets (a lot) worse at night. Thanks for the replys!

[rabbit73]

Well, it's pretty much a wall of mature pine trees that the antenna faces.

Not good. Is there any way you can set up a temporary antenna that avoids the wall of trees?

I'm sure the amp is something from radio shack, nothing fancy.

If it's the 30 dB preamp sold by them, and you add the antenna gain, that would put your tuner in overload. But, if you still have the problem without the preamp, then it is probably something else.

Crosby, TX 77532. I'm using a new TIVO OTA and mini, with a 6 mo. old Vizio 50" LED and/or 5 -6 year old Panasonic plazma with the RCA Model #ANT3038XR.

Have you had this problem all the time with antenna reception, or did it just start? Were you using cable before?

I looked for some of those little caps to terminate my unused splitter terminals, but they are hard to find.

Lowes
Home Depot
Best Buy
http://www.radioshack.com/gold-plate...s/1501156.html
http://www.digikey.com/product-detai...473-ND/1989922
https://www.google.com/?gws_rd=ssl#q=75+ohm+terminator

[rekit]

I cut power from the sodium vapor lite near the antenna, removed the amp, (which turned out to be a Channel Master3044), no splitters anywhere. Here is some info from my tivo diagnostics-
With lite powered but off-daytime and amp on
13-1 72% 29db uncorr 0 cor 0
13-3 same
20-1 62% 25db 0 0
26-1 60% 25 db 0 0
39-1 42% 18 db 6 0

With lite power cut, no amp still daytime
13-1 72% 29db 0 0
13-3 72% 29db 18452 0
39-1 62% 25db 0 0
20-1 60% 24db 0 0
26-1 60% 24db 0 0

For some reason I failed to get the before numbers on 2-1 and 2-2 but after they are showing
2-1 67% 27db 150 million! uncorected but 0 corrected
2-2 67% 29db 100 million 0

Maybe there's a clue-the amp seemed to help some with the RS but not the signal strength much. We'll check tonite and see where this goes......I need to reconnect the amp and try to get numbers on 2-1 and 2-2.

[rekit]

Oh, we had cable since 2008, /ota since 1980 here, same house and antenna location but obviously not digital. Don't remember having much trouble before, never had to wrap the kids in foil and stand on 1 leg like the old days (I'm early 60's). Man, I don't want to go back to satellite tv-$135 mo to watch BS. BTW, I'll post this on another thread but Verizon 4G wireless internet we have-their metering is insane. We streamed 2- 45 minute episodes of Walking Dead from Amazon and it used 4 Gigs, each episode. We used to use up our 30G allowance checking email and a little Ebay stuff when we had cable (-no movies, no Netflix, etc. Makes no sense, but they swear that is so. Crappy OTA, ridiculous internet-$120 for 30G a month, and the other providers (using that term loosely) are just as bad- half Gs only good 2-5am etc. I'm gonna make myself a drink and go outside-probably best thing to do. LOL

[MikeBear]

You will NEVER see the "Corrected" error numbers change on your Tivo, if being used with an antenna. That works for cable, but it doesn't for OTA antenna. Unless they fix the firmware.

Also, 72% 29db is the highest OTA signal level a Roamio is capable of showing at present. Compare that to 100%~ anywhere else.

Anything above 40%~ should be decodable, but from what I've seen, you need a steady level around 50-55% to stay completely locked at all times. Anything 60% and above, you are really doing well.

[rabbit73]

Thanks for the background info and the signal readings. What I want to know is how long have been using OTA for digital TV? To put it another way, have you been able to receive digital OTA without these problems, and they just now started, or have you had these problems ever since you started with digital OTA?

I wanted to see what the real channels were, because those are the frequencies for the transmitted signals. Channel 13 is VHF-High, and more likely to be affected by noise, but it didn't seem to change.

2-1 KPRC NBC, real channel 35
13-1 KTRK ABC, real channel 13
20-1 KTXH MyN, real channel 19
26-1 KRIV Fox, real channel 26
39-1 KIAH CW, real channel 38
http://www.rabbitears.info/search.ph...pe=dBm&height=

There shouldn't be any difference between the sub channels like 13-1 and 13-3, because they are both part of the same transmitted signal, but there is. Maybe the intermittent problem.

Big difference in 39-1, before and after, but you changed two things at once. Looks like overload to me.

2-1 very strong after, but way too many uncorrected errors for viewing.

The CM 3044 is an old distribution amp that has a gain of 22 dB, but each of the 4 outputs is only up 8 dB which doesn't compute in today's terms. Must be a high loss split as compared to the CM 3414.

The 3044 specs say max output is 23 dBmV, which is equal to -26 dBm using a conversion factor of 49. That would mean a max input of -34 dBm, if my math is correct. Your strongest signal is -35.1 dBm before adding the antenna gain, so it could be overload.

My impression is that the CM3414 is much less likely to overload than the 3044, but why would you need a distribution amp instead of a passive 4-wqy splitter with signals that strong, unless the trees are attenuating the signals.

[rekit]

Thanks all. To answer your question, we had directv since 08, tried OTA several times in last 2 years, either to have a backup for storms or just to get ready to cut the cord, but had trouble getting 13, but other stations did ok. That's when I bought the amp I think, but it didn't help or seem to hurt. I bought a Magnavox HDD DVR for recording and it got 13 ok so I figured it was the tuner on the Panasonic TV that was the problem. This time around I changed some setting on the TV and got 13, but I tried so many things i can't recall what made it work.....doh! The tv worked very well last nite according to my wife. I recorded some late night stuff i have yet to check. And the error rates were all 0. So I'll check some more this weekend, maybe put the amp online just to see. Happy days!

[ADTech]

he CM 3044 is an old distribution amp that has a gain of 22 dB, but each of the 4 outputs is only up 8 dB which doesn't compute in today's terms. Must be a high loss split as compared to the CM 3414.

My interpretation is that it's a 30 dB amp with an integrated 4-port splitter with about 8 dB insertion loss.

so I figured it was the tuner on the Panasonic TV

Early generation tuners were much less capable of dealing with impaired signals so it might be a factor.

[Tower Guy]

If it were me I'd try completely removing both the amplifier and the power supply from the circuit.

Here's why;

Your weakest station has a 48 db NM (noise margin)
Your antenna has roughly 8 db gain
A 4 way passive splitter has about 7 db loss
100' of RG-6 feedline has roughly 6 db loss
Most TV sets have noise figures of less than 10 db
That leaves 33 db NM at the TV set. (48+8-7-6-10=33 db net noise margin.)
I doubt that there is that much loss through the trees.

Whenever the net NM exceeds 20 db, there is no justification for amplification. Over-amplification creates interference that doesn't exist without amplification. In addition, the number of stations listed on the radar report with NM values greater that 40 is 17. The more stations there are; the greater the overload potential. The exact calculations can get complicated, but here's a quick rule of thumb for equal strength stations.
2 stations = +6 db; 4 stations = +12 db; 8 stations +18 db; 16 stations + 24 db. Your situation implies that your amplifier overload potential is about 24 db greater than reception of a single station.