How to Stop 15.1 Interfering with 14.1

[otaer]

UHF 15.1 is 2.5 miles from my house and is my strongest station.
UHF 14.1 and 34.1 transmit from the same location, 47 miles from my house, and 14.1 has a higher power output.

Strangely, I get 34.1 great on my new LG TV, but 14.1 does not come in. Using a strong pre-amp makes no difference; 34.1 comes in stronger and 15.1 will pixilate or drop out.

Obviously it seems, 15.1 is interfering with 14.1, how can I correct this?

I tried attenuating the signal, but nothing happened. I know there are notch filters, but they can be expensive.

What about using a distribution amp and no pre-amp? Does the distribution amp help deal with co-channel/adjacent channel interference? Does it spread signals more evenly so they are less likely to interfere with each other?

And/or, what about using a lower powered amp, like the HDP-269, that supposedly can handle close proximity signals?

How should I handle this? Thank you.

[winegard]

Good morning otaer -

I would recommend changing to the HDP-269 preamplifier with the higher signal input capability to start with. A distribution amplifier will not do any thing differently for you.

Can you respond back with exactly which stations those are and where they are broadcasting from. Because you are so close to the US/Canada border we're trying to track down exactly which stations, so we can check frequency and get you a more specific answer.

Thanks!

[otaer]

CJXT (15.1) is 2.5 miles from my location, east- north-east from my location- signal strength is very strong.

WUTV (14.1) is 47 miles from my location does not come in on LG TV.
WNYO (34.1) is 47 miles from my location (same location as WUTV), and is rock solid- strong.

Both WUTV and WNYO are east from my location.

Using an 8 bay antenna and strong Pre-amp.

[winegard]

Channel 29 WUTV is broadcasting their digital signal on channel 14’s frequency and channel 49 WNYO is broadcasting their digital signal on channel 34”s frequency. Since I can not find out what frequency you channel 15.1 is broadcasting on it is hard to say if the interference is from the station frequencies or if you are creating internal harmonics in your preamplifier which can fall out on channel 14’s frequency because of the strong local channel and weaker Buffalo channels. These harmonics can fall on your channel 14’s frequency and cause all kinds of problem. Going to a lower gain preamplifier with a higher input may help such as the Winegard HDP-269.



You do not state if you are using separate antennas to receive the stations from the 2 directions and if you are how are the coupled together. You may have to use an A/B switch to isolate the 2 antenna signals instead of combining them through a splitter/coupler. Because when using a coupler you can have both sets of frequencies on each antenna and when combined cause multipathing and that will confuse the digital tuner as to which channel 14 to lock onto.



Can you borrow another TV set or a converter box the see if the problem is in the tuner of your TV set? There have been problem through out the industry where the problems have been TV set tuners and not the antenna installation.

[otaer]

Channel 15.1 (CJXT) is the real channel, it actually is not very strong, does not carry far, but I’m 2.5 miles from the transmitter.

Here is the full picture:

I have 3 antennas mounted off the same mast, off the side of my house. One 8-bay is for one TV, and two 4-bays (coupled together) are for a second TV. The 8-bay is usually pointed east to Buffalo, as is the one 4-bay which is just below, while the second 4-bay is pointed north east and is at the bottom of the mast, below the eave of the roof. I realize now that these antennas are too close to each other, even if they are not coupled together.

I have two TVs- bought this year, a Samsung and an LG.

The Samsung runs off the 8-bay antenna with a powerful pre-amp (26 gain) and a rotor. I get all the stations in my area including 29 WUTV and WNYO 49, although there are sparkles (tiny white flashes) on the WNYO 49 picture.

The LG TV runs off two 4-bay antennas that are coupled together (reverse splitter) and no pre-amp. I get all stations except 29 WUTV and WNYO 49, however, WNYO 49 does come in usually at night.

I also tested the LG TV with the 8-bay antenna and pre-amp- still no 29 WUTV; although 49 WNYO comes in rock solid.

So yes, the LG tuner might be a problem, but having the antennas close together does not help.

Soon I will be erecting a 45 foot tower that will easily clear my house and those adjacent, no major obstructions near by. Two antennas will be used, different directions, coupled together, and then split for two TVs.

Here are the proposed details:

1) Top antenna will be 8-bay pointed east to the WUTV 29 transmitter. This antenna will also have a rotor for fine-tuning the aim.

2) The second antenna, 4-bay will be 3 feet below, aimed north, and attached to the tower, it will be stationary.

3) Both antennas will have separate coax feeds that will go into the CC7870 Coupler.

WHERE SHOULD THE COAX FEEDS BE COUPLED? NEAR THE ANTENNA OR INSIDE THE HOUSE? (TO MAXIMIZE GAIN)

4) The single coax line coming out of the coupler, will then be split for two TVS using a regular splitter.

5) Now, I also have a low powered pre-amp on hand, HDP-269 (12 gain) just in case, that will be used on the 8-bay (top antenna). Should be no problem since the CC7870 has power pass. If so, I would put the power injector between the coupler and splitter.

WHAT DISTANCE SHOULD THE POWER INJECTOR BE FROM THE COUPLER AND THE SPLITTER?

How does this sound?

Thank you Winegard.

[winegard]

You can mount the CC-7870 any where between the power injector the antennas you wish. However I would suggest that you do it some where convenient to get to it if you need to work on the cables. The loss factor will be the same no matter where you mount it except the lower on the tower you will just use a little extra cable.