Culture Wars

[donjm27]

I'm deprived of cartoons and opera because I'm suddenly having problems receiving both FOX and PBS from a nearby tower. I've been in the same house for 22 years, and while I've had to work out some bugs in the transition to digital, this is a new situation. I'm able to receive both VHF and UHF channels from much farther away (9,13 and 16- nearly 40 miles to the south, but 7 and 14, which are broadcast from the same tower, less than six miles to the north, suddenly elude me. The have different problems: FOX will display a pretty solid picture with my antennas (more on them later) pointed in almost any direction, but the sound breaks up every few seconds. My TV's pretty crude signal strength indicator swings wildly from 8/10 to 0 bars. Channel 7 PBS also comes in well with almost any orientation, but exhibits a couple seconds of pixelization or a creepy sort of solarized effect during cuts between shots in the program. It shows a solid 8 bars of signal- it doesn't fluctuate. Only FOX (14) shows an unstable signal.

For years, I got by with a modest UHF Radio Shack antenna in my attic, on a rotating mast. Over the past few weeks, I've added a ClearStream 5 to the same mast, which is still there. I also rented a nice VHF/UHF antenna from a local pro to do some testing but got the same results. I built a bowtie antenna just for kicks, which got me nowhere, of course. Thinking I might have too strong a signal, I bought a little set top antenna and got the same bad sound from FOX (although I forgot to check the pic on PBS). I've hooked up all of these antennas with various lengths of known good coax, and carried them to various spots in my attic, up and down the stairs and outside, to no avail. I've installed and removed an inline attenuator and FM trap. I had a little amp for years, but it's currently out of the picture (so to speak) I've performed a pretty thorough search and unplug mission to rule out interference from in my house. I've brought an old analog TV from school and connected it to my old converter box with the same audio result for FOX (but forgot to check PBS again!).

So right now, I have the UHF and ClearStream stacked on a mast in my attic, pointed the same direction. I have composition shingles, and painted wood siding. There's no insulation between the rafters, and only blown insulation between the ceiling joists. A run of coax of about 40 feet, straight into my pretty new Samsung TV. There are no trees nearby, although I'd guess that the neighbor's house, which is higher than my antenna is placed, is about 5 degrees out of my LOS to the tower.

Again, 7 and 14 are stations I've gotten for years, before and after the digital transition. This is a sudden change. My DIY pride is pretty bruised, so I hope someone out there has some clever ideas for me. Thanks in advance for your help. Here's the link to the results from the signal analysis tool.

http://www.tvfool.com/option=com_wra...574712a3e3b9c0

[John Candle]

The link is not working. And is also interesting that you left out any hint of where your location might be , like tv station call letters.

[donjm27]

Thanks for the heads-up John, and sorry for the snag. Here's another report, which I assume includes my location:

http://www.tvfool.com/?option=com_wr...5747518c92e883

I also neglected to mention that the best reception for Ch14 FOX seems to be through the back of my antenna- when it's pointed at around 190 degrees.

The callsigns of the problematic local stations are KOAC (real Ch7) and K14Gw, real channel 14), both on a tower about 6 miles from home. I'm successfully getting the Eugene stations: KVAL (13), KEZI (9) and KMTR (17), and that's really all I want. Looks like I have the option of getting PBS from K26AY (48) to my east, but Fox KLSR (31) is just out of range for my current setup. Thanks.

[dkreichen1968]

For the PBS problem, I'd call the station. It sounds like digital artifacts from over compressing the signal on their end. Did they add channels, or otherwise modify the signal recently?

For the FOX problem, it sounds like multi-path. Has anything changed in your neighborhood or in your house? (New Construction, moved appliances, etc.) Did you have any of these problems before adding the C5? Did you use a UVSJ (UHF, VHF, Splitter, Joiner) to connect the C5 to the UHF antenna? If not, that may be your problem.

[GroundUrMast]

'How are you combining the two antennas?' is an excellent question. A UVSJ would be the better choice over a reversed two-way splitter. Fluctuating signal strength indication on CH-14 suggests multipath which can change with the season, the weather and construction of buildings near and far. Multipath symptoms can also be caused by damaged coax, connectors and poor combining technique.

All amplifier components (power supply and antenna unit) are completely removed, disconnected, yes?

KLSR 'should' be not be difficult to receive. In fact, you should easily see stations down into the yellow section of your report. The attic construction may be attenuating and/or reflecting signals far more than you realize. You say you have tried the antenna outside, which antenna, how high and what aim point(s)?

[ADTech]

The C5 was shipped with a UVSJ, hopefully he's using it per instructions.

Any chance of identifying that Radio Shack antenna?

[John Candle]

By typing call signs in to the google search box to find out more information about the stations , I see that KOAC-DT 7 PBS is a sister station of KEPB-DT 29 PBS and K14GW-D 14 Fox is a repeater for KSLR-DT 31 Fox. Both KEPB and KSLR are LOS = Line Of Sight at your location and easly received at your location. I am evaluating the rest of your information , you are all twisted up. I will be back with more information

[John Candle]

You need to read and understand about , REAL Digital Broadcast Tv Channels , Virtual Digital Broadcast Tv Channels , Analog Broadcast Tv Channels , Here is how to point Tv antennas , http://forum.tvfool.com/showthread.php?t=695 , http://www.kyes.com/antenna/pointing/pointing.html .

[John Candle]

I recommend pointing the the UHF antenna at about 120 degree magnetic compass and adj. for best reception of the UHF stations at 88 and 153 degree magnetic compass. I recommend pointing the C5 at about 141 degree magnetic compass for best reception of the VHF High channels. Use the UVSJ = UHF-VHF-Separator-Joiner to connect the two antennas. Remove all preamplifiers , amplifiers , splitters and etc. and connect direct to one 1 tv. Due a channel search scan with the Tv with no antenna connected, this should clear most of the channels out of the tuner so the Tv can start fresh with a new scan when the antenna is connected.

[John Candle]

What type and kind is the radio shack uhf antenna?? How many Tv's are connected when all of the Tv's are connected??

[donjm27]

This is a wealth of information, everyone. I'll try to consolidate your questions for the sake of efficiency.

- The Radio Shack UHF antenna is too old for me to identify, but each of its arms is about 30 inches long. It's been inside its whole life, so it's in new condition and used to do a good job of bringing in both UHF and VHS stations, both here in Corvallis and in Eugene, back in the analog days and up till recently. I don't think the tuner in my digital Samsung TV is as good as the one in my old Zenith converter box, but both currently have the same problems with the transmitters up on the hill.

- I only have one TV, and the amp is disconnected and put away.
- I've tested my system with several lengths of known good coax (one was tested by an installer just before I rented it), and they all perform the same as the one attached to my house.
- My local channel reception problems predate the purchase of the C5, so I don't think it's an issue.
- The C5 is joined to the Radio Shack UHF using the provided connector. It has inputs for UHF, VHF and a combined output.
- John, I like your idea of getting the UHF stations at 88 and 153 degrees, but since those are both analog stations, I'll keep chipping away at the ones up on the hill (I work practically at the base of them, so they taunt me daily), and use those as my backup. I'll do the clean scan routine that you describe.
- I also think I should be able to get to FOX in Eugene (KLSR- 31), and if I scan with the antenna oriented just so, it gets entered on my list. But it's only one bar on my sorry excuse for a meter, and can't be counted on. A solution for everything might be to get PBS from KEPB- 29 (per John's idea) and reliably reach KLSR with a small UHF antenna under my southeast eave, aimed halfway between those stations. I confess to being too vain and lazy to take the obvious route and put the mast on the roof.
- I agree that the building materials in the attic are a problem, but the sudden onset of this makes me think there's something else happening.
- I'm also unaware of anything else happening in the neighborhood, although my engineer friend up the street did once boast that he could probably sterilize speeding drivers with a microwave transmitter he keeps around for fun. And while he built a Faraday cage in his basement, I don't think he wrapped my house in chicken wire while I was on vacation. I may take off a piece of siding, to be sure.
- Good idea, dkreichen1968, I'll give KOAC a call and see what's up with the weird artifacts.
-GroundUrMast, I'll carry my little test TV and antenna over to the neighbor's to check for a multipath issue in my attic. My narrow attic doesn't let me give me much wiggle room, and happiness may be just a few steps away.

Really, everyone- thanks for the feedback and suggestions. It's amazing that this expertise is out there through your generosity. I'll keep you posted, once I have time to explore a bit more.

[GroundUrMast]

Another idea popped to mind... I have seen translators transmit a solid signal in terms of the RF you receive while the link to the translator is taking hits.

Garbage in = garbage out.

K14GW may or may not have such a problem though the bouncing signal level makes me think the trouble is local to your area (multipath). A call to their engineering staff may be in order.

30" elements sound quite long for a UHF antenna. Can you post a photo of it?

[John Candle]

Sounds like you are still twisted up. I agree with GUM , 30 inch metal receiving elements is to long for a UHF only antenna. What antenna does the antenna look the most like in these pictures , http://www.kyes.com/antenna/pointing/pointing.html. And it is interesting that you are so intent on receiving 7 and 14 to the north when the same channels are KEPB 29 and KSLR 31 to the south east.

[donjm27]

John, I'm not sure why I wrote "two arms," but this is the antenna I have, or very close to it: It's the center spar that's around 30" long, but that may be a mild overstatement.

http://www.radioshack.com/product/in...ductId=2103088

I mentioned that I built a Gray-Hoverman that produced pretty much the same results as the Radio Shack until this recent, mysterious change in quality on 14. Whether that speaks to the quality of RS products or my construction skills, who can say? (I'm not proud). The Combo antenna I rented from a local installer also showed the same symptoms on 7 and 14 but performed well on every other channel that I watch. I didn't notice what it was, but it had the approximate appearance of the Winegard HD 7694P. A pretty conventional looking design that was about feet long.

I'm not exactly obsessed with getting the local channels on the hill (7 and 14), but FOX 31 in Eugene isn't reliable under certain conditions with my setup. I was just hoping for a free solution, like discovering that there's a thick layer of moss on my roof. And I've only spent a few minutes looking at PBS 29, so I can't be certain of it, either. (I can find out though, and will). Channels 9, 13 and 16 from Eugene all are solid, so I seem to have a FOX-only conflict in both directions. Do you think it's because I voted for Obama?

But John, I'm warming to the idea of turning my back to the local signals from the north, since I have a pretty clear shot down the valley to Eugene. Then, I have a couple of tall trees about 20 feet from my house in that direction, and the house across the street is three stories high, but I think it's west of my path.

So I'll wait for your assessment of my RS UHF rig and maybe ask for a recommendation on a small UHF antenna for my eave, just about a 20 foot run from my TV. Or maybe there's a better choice for an attic UHF. The C5 is impressive, with the exception of 7, on the hill, so I think it's a keeper. Thanks, all. I appreciate your great help.

[GroundUrMast]

The UHF antenna you referred to is a good choice. The CS5 is a good choice to cover the high-VHF. The combination of those two antennas correctly installed on the roof should be able to deliver all the stations on your report down to the bottom of the yellow section -- in the direction aimed provided co-channel or adjacent channel interference is not present.

I would be looking into tripods, gable and chimney mounts.

[donjm27]

Thanks, GUM. Getting out of the attic would certainly improve my chances. I think I'll borrow a mast this weekend and look around for a good spot to locate the RS UHF for Eugene stations.

For the record, I drove north on my street this morning and noticed a pretty pronounced amount of static on the radio station I was tuned to, just as I passed a pole-mounted transformer a couple of houses away. I backed up and did a drive by a few more times and got the same result. My route is the same heading as the stations that are suddenly giving me problems, so the transformer is my wild guess of the day. I'll ask my RF tech friend to bring a meter down and poke around for noise there. If he finds anything, I'll call the utility, but I doubt Pacific Power cares much that I only hear 2 out of every 3 wisecracks Bart Simpson makes on Sunday nights. Still, it would be nice to have an explanation for the wild swings in the signal from FOX-14.

But John makes the good point that everything I want is available to the south, so with the right setup, I may be able to avoid rotating my antennas much at all.

Thanks! Don