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Discussion Starter · #1 ·
After reading numerous thread here I took the plunge and got an HD set.


I have strange multi-path problem with the local CBS channel here. I recently went from an indoor RS antenna to an outdoor highly directional RS UHF Yagi. I now get all the local channel at 100 signal strength by pointing the antenna southwest(I don't need to rotate it) The CBS signal fluctuates from 6 to 100 during the day but stays stable at 93 during prime-time.


I live in Rancho Penasquitos I have a Hughes E86 and the antenna is a RS 15-2169 mounted outside about 9 feet up. What is the best way to get rid of this? I wouldn't mind so much but CBS carries the Chargers games so I have to have this channel.
 

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Are you absolutely sure you don't have to rotate your antenna?


Remember that the U.S.A. system of digital TV broadcast transmission, called "8-VSB," requires a signal pretty much free of multipath. The newer tuners are better in this regard, but not perfect.


A signal strength meter tells you about only one parameter of reception. Somehow the industry has to deal with the problem of having insufficient clues about a lack of a useable signal.


Try this experiment: Tune to channel 35, an analog low-power TV station from UCSD on Mt. Soledad. Optimize your antenna for this signal. Don't worry if it's snowy, but make sure it has ZERO multipath (ghosting).


Now tune to digital channel 8-1 (UHF 55 from Mt. Soledad). You should get a strong, steady picture.


The Radio Shack antennas are known to be poor performers on the upper UHF channels. You may need to trade up to a Winegard PR-4400 from Western Radio Electronics in Kearny Mesa. Appreciate that it's cheaper than cable, and you may be able to use it to receive all San Diego stations without multipath or a rotator.


Good luck!
 

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Quote:
Originally posted by [email protected]
You may need to trade up to a Winegard PR-4400 from Western Radio Electronics in Kearny Mesa. Appreciate that it's cheaper than cable, and you may be able to use it to receive all San Diego stations without multipath or a rotator.


Good luck!
I went into Western Radio Electronics a few weeks ago looking for an antenna. The first guy I spoke with looked at me like I had a horn growing out of my forehead. Another guy knew what I was talking about but said they had none in stock. He said they were planning to carry them but had no idea when they'd be in. I didn't get a very good feeling that it would be anytime soon.


Here in Escondido I'm getting a strong signal (max'd on the signal meter of the MyHD card I have) on all but one channel -- KGTV. I know KFMB and KGTV are supposed to be broadcasting from the same location but KFMB comes in much stronger. I rarely get dropouts on KGTV so it's good enough for now. I'm using a Winegard 8800 with no rotor. I played with the orientation until I got a pretty good signal from all the local station and then locked it down.
 

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Discussion Starter · #4 ·
Thanks Gary!!! I was hoping I wouldn't have to change antennas as the one I have is really quite small and is perfect to move into my attic. I'll give the Winegard a shot.
 

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I think there's a Mexican tv station in Tijuana that also broadcasts on ch. 25. The *only* digital channel I cannot receive is CBS/25.1 and that's only when I point my rooftop antenna to the southeast (towards the hilltop with NBC, Fox, etc.). If I point it anywhere else, I get CBS fine -- of course, I'm in Pacific Beach at the foot of Mt. Soledad with ABC and CBS just 2 miles above me!

- Tony
 

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Quote:
Originally posted by sdsalsero
I think there's a Mexican tv station in Tijuana that also broadcasts on ch. 25. The *only* digital channel I cannot receive is CBS/25.1 and that's only when I point my rooftop antenna to the southeast (towards the hilltop with NBC, Fox, etc.). If I point it anywhere else, I get CBS fine -- of course, I'm in Pacific Beach at the foot of Mt. Soledad with ABC and CBS just 2 miles above me!

- Tony
Um, 25 is KGTV which is ABC. CBS is KFMB which is on channel 55.


But that might very well explain my difficulties with KGTV. Since I'm trying to point in a general direction to get all the channels without a rotor, I might be getting a strong signal from the station further south that's trashing my reception of 25/KGTV.
 

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There's no other channel 25 outlet in range of your antenna. The problems you describe are likely caused by multipath. When you are that near the transmission site, you are likely to get strong signals bouncing off all kinds of surfaces.


Also, if you have a preamp in line, it can be readily overloaded and create conditions which make good digital reception impossible.


I tell everyone with reception problems to tune in to channel 35, UCSD-TV's low power station atop Mt. Soledad. If you get any multipath (ghosting) whatsoever on this analog station, you may have difficulties getting consistent reception of 25 (10-1) and 55 (8-1). Use the station to aim your antenna.


A signal strength indicator on your tuner reveals very little about reception of DTV in your neighborhood.
 

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I spoke with Jim at Western Radio Electronics and he states that they now stock Winegard PR-4400.


I'm guessing that your experience with them, hoxford, was a day or two after I had requested that they stock the antenna and recommended them to viewers. They may not have gotten the word around to their staff by the time you contacted them.


This antenna is also available at Willy's Electronics in National City.


I've had good experiences at both places but can't vouch for their knowledge or stock or your mood when you visit. Your mileage may vary, yada, yada....
 

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Discussion Starter · #9 ·
Gary,


I went and picked up the antenna that you recommended. I can very strong signals from all the stations but I now have ssome really strange problems.


NBC has a signal strength of 93 but when I watch it its a blocky mess. ABC will come in equally strong but it will have intermitant dropouts where I will lose picture completely. CBS comes in strong but it is quite picky about the orientation of the antenna.


I would appreciate any suggestions.


Thanks in advance
 

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Multipath kills DTV. There's no way to check this with the current crop of set-top boxes (STBs), but you can preview multipath (aka "ghosting") with analog signals.


Pick an analog station at each location to preview multipath, making sure that you have the antenna precisely pointed to each of the three sites. Use K35DG (UCSD-TV), channel 35, for Mt. Soledad; KNSD 39 or KPBS 15 for Mt. San Miguel; XHAS-TV 33 for Mt. San Antonio. With the antenna pointed at each site, you should receive zero multipath.


If you have multipath, answer these questions:
  • Do you use a rotator to precisely orient the antenna?
  • Is your antenna mounted high enough to have line-of-sight to each of the transmission sites?
  • Do you have a good quality, weatherproof balun at the antenna to transform its 300-ohm impedance to 75-ohms?
  • Do you use a high quality RG-6/U cable (never RG-59/U!)?
  • Are the connectors properly attached and crimped?


Hope this helps!
 
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