AP-8275 amplifier no signal on channels

[bennor]

Trying to setup a new antenna in an apartment with no access to mounting an antenna outside. Live in an area where two channels are under 10 miles away, the rest of the channels are 25 or more miles away. Here is the TVFool report: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d67d917ead1b1a5 (zipcode 06515) I currently only receive the channels under 10 miles away. The digital tuner, a Zenith DTT900, indicates weak signal reception on several channels 25+ miles away but won't tune them (they are about 30% on the signal reception indicator). When using a newly purchased Winegard - AP-8275 amplifier on an Antennacraft U8000 antenna I am loosing the two closer channels and the distant channels are also showing zero reception instead of the previous 30%. There is power going to the power injector, and I've tried replacing the cables to the antenna/amplifier/etc, no change. Putting a 4 way splitter in line between the TV and the the power injector splitter yields just one of the two local channels being received.

I assume this means the amplifier is overdriving/overloading the signal. If so, is there anything that can be done to reduce the signal so the tuner can recieve the channels? If the amplifier has to be returned is there another amplifier that would be recommended? I'm trying to pull in the channels 25+ miles away in additon to having the antenna hooked up to six tuners (two TV's, four PC tuners).

[winegard]

Good morning bennor -

The AP-8275 with its 28dB of UHF gain is definitely overloading/overdriving your TV tuners. In your system, a six way splitter has approximately -12.0dB of loss plus whatever cable loss you have from the antenna to the splitter and then the cable loss from the splitter to farthest TV set. Try reducing your TV signal by at least 10.0dB using 10.0 dB inline attenuator or adding more splitters between the power injector and the TV tuners. You should be able to power your tuners with an Winegard AP-8700 preamplifier that has 18.0dB gain.

Preamplifiers or distribution amplifiers can no pull in signal or extend the range of a TV set. All they can do is amplify the signal the TV antenna receives and build it up to over come the signal loss from that point on. The problem is the U-8000 UHF only antenna is a directional antenna and you have signals in multiple directions and unless you can rotate the antenna you will have major difficulties receiving a strong signal or any signal on some of these channels.

[bennor]

Thanks for the reply. Looks like the 8275 will be returned to where it was purchased and an 8700 will be tried. I'm limited on the antenna type, size and placement since I cannot mount it outside at this time (an apartment building with no balcony).

I did try adding several splitters, two of which were four way splitters and it still didn't reduce the signal enough to pull in more than one VHF channel. Without boosting with the amplifier the antenna/receiver pulls in two VHF channels within 10 miles, and 3 to 4 UHF channels within 10 miles. Currently unable to pull in channels 25 to 35 miles away, the digital tuner indicates about 30% reception on those stations.

[TomV]

I know this is a late response, but it may help others in your situation.


You are in an attic that attenuates the signals. Some of the signals that you would get outdoors will not be strong enough to be seen by the preamp and amplified with a good signal to noise ratio. Anything below -80 dBm on the TV fool chart will be very challenging even for your antenna mounted outdoors. Rain on the roof adds to the misery, as do trees (water on leaves during rains and the mositure in the leaves themselves). The water attenuates the signals.

The fixed position and the preamp used for the strong signal that causes the overload can be solved by aiming the antenna away from the source a bit and thus reducing the input to the preamp.

As offered before, you have several sources of signals that essentually require an omnidirectional antenna or a directional one on a rotator. The omnis do not have the gain needed in an attic environment for the lower-level signals you are trying to reach.

You have a nice hi-gain, directional unit with your 8-bay that will be hard to top. That with your 8725 preamp and a rotator should get you some nice reception.