Darn annoying reception problem

[middleofnowhere]

Been awhile since I've been here.

Anywayz, I've been having this problem with just one channel ever since I got this antenna last year.

One channel, PBS on real channel 33 digital 22.1-2-3, is VERY intermittent in being received. It will come in for no more than 10minutes, than blank out again and not come back sometimes for days on end.

What makes no sense here, is that it doesn't obey any known law of energy that I know of. It's as if the energy builds up in the antenna then is discharged when the TV is on or some weird stuff like that. The transmitter comes from the same EXACT (same tower) location as 3 other channels that work like perfection 100% of the time. There is no co-channel interference, as I have 1) a directional antenna 2) No stations within a receivable distance (150Miles) that could even have a chance of interfering.

Could this be the TV tuner? I have a set-top converter box that I was going to use with my old TV before it died, should I try that even if it means tearing the TV cable bundle apart?

There is also a smidge of the top of a tree that could possibly be in the way; should I trim it? And the antenna isn't totally perfect; it's tilted up at about a 2-4° angle.

[GroundUrMast]

I went back and looked at your thread from 2011... http://forum.tvfool.com/showthread.php?t=13015

The C290 was not panned and openly ridiculed, but larger antennas were suggested.

We failed to respond to your information regarding the connectors you reported using to splice cable together. If I understand correctly, you had used single conductor 'butt-splice' connectors rather than the coaxial 'F-type'. Using the wrong type of connector can produce some odd trouble, including failure of some channels while others seem to make it from one end of the cable to the other. Taped connection are notorious for absorbing and holding water... once there is water in the coax it needs to be replaced.

Have you replaced spliced sections of coax with a single piece of coax, free of any splices?

Have you performed this test: http://forum.tvfool.com/showthread.php?t=13646 ? If so, what are the results?

[StephanieS]

Hi MiddleofNowhere,

I wasn't involved in your prior thread, however I understand your frustration with the PBS signal.

GroundUrMast gives you appropriate advice concerning your coax. Think of your situation as a rain gutter with leaks and clogs. The some water is going to spill out before it gets to the drainage system. The TV signals coming down your coax are similar in that you disrupt the seamless flow of energy down your lead and possibly allow for things to "leak" our and potentially in as well interfering with the signals in the coax. You want to give the signals your antenna is receiving every chance to make it in the best shape possible to your receiver.

The suggestion of replacing the existing coax with an unkinked and unharshly bent run would be a great first step.

Looking at your TVfool plot, I agree that a more robust antenna would've served you better. The CBS affiliate ought to be received with the existing 290 without much fuss. The PBS though at -82.5 dbm strength is getting down to that area where the signals can become affected by atmospheric variances and drop out. These are very weak and require for reliability a "big gun," if you will. Even more so for the ABC affiliate.

The positive, you won't have to do much work for NBC as you are served by green shaded K06NS-D with that programming, leaving real channel 13 a non-important channel.

I could recommend a "go big" set up that would integrate 2 antennas, one at the magnetic 210 heading for NBC, PBS and ABC, while the other being high-VHF only orientated to magnetic 243 for CBS. In the end, it's what you want to do.

My suggestion fix your coax, get a new line in place then test.

We can discuss those results when you get there.

I would expect the C290 would not be the antenna to try for PBS and the ABC affiliates. It's a good antenna, you are just asking a bit more than what it is rated at. It is a fringe antenna, PBS and ABC are deep fringe.

A low cost improvement might be to stick a RCA TVPRAMP1R preamp on it once you get a new coax system in.

Cheers.

[middleofnowhere]

1) The coax setup I mentioned in my old post was so I could drag it around the yard. Right now I'm using a 80ft run of the coax that the satellite company put it. Pretty sure it's OK; it's been sealed.
2) I was going to go with the extreme option, the C490, but I had limitations of what I could actually fit in my car without bungee straps, what would fit in my wallet and the strength of my pole was questionable before I replaced it.
3) I don't know where that channel 6 comes from, but I can't get it. 13 is actually the strongest channel I get....
Currently I receive: 10 (CBS, pretty amazing it magically appeared one day) 13 (2.1, the first channel I received during tuning), 31.1 (ABC, again it works fine) and a smidge of analog channels 41 and 44, which I could care less about except that all the football games are on them.

NOTE: There also has been some coordinate confusion between my GPS and Google Earth. They keep showing different coordinates that are about 20 miles apart. Should I use GPS coords or Google Earth coords? They give two totally different reports.

[ADTech]

Use the online TV Maps function in "Satellite" view to place your virtual antenna right on your rooftop.

Google's geo-coding of street addresses leaves a lot to be desired for accuracy.

[middleofnowhere]

I used the map, and the google earth coords put me MILES off.

After moving it manually, it actually shows ABC being weaker than PBS, but PBS refuses to come in. Annoying!

I might just need to get the c490. Groundurmast, I'll do that test if I can get a 50ft section of BRAND NEW coax as I don't really trust any of the stuff I have.

[ADTech]

Use the interactive map tool as I said, enter the estimated height of the antenna, run a new plot, then post the link to that plot unless it's identical to the old one.

If we don't have an analysis based on a precise location, then any interpretations will be based off faulty data and the old expression of "garbage in, garbage out" applies. It's up to you to prevent that by not having a "garbage" plot.

[middleofnowhere]

Updated (and dismal) report: http://www.tvfool.com/?option=com_wr...5b945527ad961d

Still shows ABC as being weaker than PBS!

Sidethought: On a transmitter information site I remember seeing, PBS had a much higher bandwidth of data transmitted (in the range of 18-20Mbps or something) and a relatively lower ERP than the other stations. Could this be a factor in the required receiving strength?

[GroundUrMast]

The report you just posted leads me to suggest using the combination of an Antennas Direct 91XG + Antennacraft Y10713 + RCA TVPRAMP1R. (The 'big guns').

PBS may be operating at lower power levels, but the ATSC standard has them operating at the same gross data rate as all other digital stations in North America, 19.39 Mb/s. They can allocate portions of that bandwidth to various program streams, so when transmitting multiple programs, no one program will have access to all the available bandwidth. Transmitted power levels may affect your reception, the transmitted data rate is not a factor though.

[middleofnowhere]

Wow. 2 antenna setup. Never thought that was needed :-\
I'm hesitant to spring for a double-antenna as it would be 'unsightly' to the neighbor, who I might add complains about my dog 24/7.
At this point would a C490 from Radioshack work? http://www.radioshack.com/product/in...ductId=3767303

I would kind of like to avoid too much load on my pole, it's not the best in the world. I will of course look into the preamp. Might not be such a bad idea with my cable run and a possible plan for a 2way splitter however unlikely.

Interesting occurrence: Flipping my antenna around in vain hopes, I pointed it at a local mountain, 90° from where it was being transmitted, and received 2.1! apparently it was being reflected minutely by the bulk of the mountain.

[GroundUrMast]

The reports posted in 2011 and your current one are quite different. The signal from real channel 6 is not going to be received based on the signal level and noise issues in the low VHF band... and it's a duplicate of KOTI. This translates to, 'no need for an all channel antenna'.

A single UHF/H-VHF such as the Winegard HD7698P or Antennacraft HBU-55 (or maybe the HBU-44) could be substituted for the 'big guns'.

[middleofnowhere]

Well in 2011 not only was I much more of a noob, I was using Google Earth coords that were literally miles off.

I'll probably spring for the Wineguard when I do go for it as Wineguard seems to have that 'air of quality' that comes with a proven product. Antennacraft is probably just as good, but Wineguard it is. I was mainly just looking at the C490 because it's easy to grab at the local Radioshack.

+=>
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This why am Very Direct and to the Point.

Only use the Tvfool mapping.

Go to the Tvfool home page and click on >>Start MAPS<<.

Enter the Exact Address.

If the exact address does not work.

Then enter only the zip code.

And then move the pointer to your location.

If the zip code does not work , then enter some address or another zip code and move pointer to your exact location.

25 feet above ground is a reference antenna height that provides a good idea of what is receivable.

Make and post the Tvfool radar plot and channel list.

Making additional radar plots at higher antenna heights of 40 and 60 feet a ove ground is often requested.

[GroundUrMast]

Originally Posted by middleofnowhere

Well in 2011 not only was I much more of a noob, I was using Google Earth coords that were literally miles off.

...

Hey, I've 'been there, done that' too, in various ways.

[middleofnowhere]

Originally Posted by GroundUrMast

Hey, I've 'been there, done that' too, in various ways.

Haven't we all...

[ADTech]

Yep, we all have....

Well, that TVFool plot explains why KFTS is so poorly received. There is a 5600' ridge line dead in your signal path about 12 miles away. That, combined with the measly 9600 watts of transmitter power from the station, means that very little signal power will diffract over that ridge and will be available at your general location.

This is a case where patience and the right mix of equipment are your two best tools. You will need a very high gain, very high gain UHF antenna plus a very low noise pre-amplifier to improve your odds. You can keep your existing combo antenna for its VHF capabilities. You will also need to select a prime antenna mounting location that is absolutely clear of physical obstructions, usually trees. Be prepared to 1) try various heights and locations for the UHF antenna and 2) adapt the antenna location with the seasons as the diffraction of the signals over the ridge line will be affected by the weather and ground conditions up there. You may find that the signals are different in the summer when there are thermal updrafts vs wintertime when the ridge is covered by snow.

I don't see any mention that you have a pre-amplifier, but one should be mandatory in this location. If you must run a very long coax from the UHF antenna back to the rest of the system, I'd recommend a high gain (25-30 dB), low noise (< 2 dB) preamp just for the UHF antenna. Your VHF could use a good boost, too, but that can probably be addressed separately.

You might want to see post 11 in this thread to gain more insight into receiving "diffracted" signals. http://forum.tvfool.com/showthread.php?t=14081

Anyway, the 91XG or the DB8e would be suggested for the UHF antenna. The pre-amp selection is up in the air as we don't yet know if the UHF and VHF antennas will be on the same mast or if they must be separated, perhaps by a wide distance.

[middleofnowhere]

Un Milagro!!!

Cranked up the pole another 4 feet, PBS is now perfect in the whole sense of the word. Amazing how such a small distance can make such a difference!

Anyway, that's all the channels I need except for fox, which the superbowl is on and it's analog. 'Niners lost anyway, so I don't care. Maybe that translator will go digital sometime soon :-\