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To: fso301

Would you offer a few tech tips?

We have a channel master antenna and a 29 dB amp, reception is iffy. It is on top of a 20’ tall pole. We have trees (maybe 50’ tall) between the antenna and the horizon, some as close as 60’ away, some a couple of hundred feet away.


11 posted on 06/23/2009 4:39:57 AM PDT by AlbertWang
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To: AlbertWang
We have a channel master antenna and a 29 dB amp, reception is iffy. It is on top of a 20’ tall pole.

My basic setup is a VHF/UHF antenna mounted in a third floor attic which is about 25' up. I have 100' of RG-6 cable from the antenna to the TV on the bottom floor. No preamp. The antenna farm the antenna points to is about 50 miles away over relatively flat terrain and the towers are about 1,000' tall. I have two story homes between my house and the antenna farm.

13 posted on 06/23/2009 4:47:34 AM PDT by fso301
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To: AlbertWang

>> We have a channel master antenna and a 29 dB amp <<

Depending on the quality of the amp, it may be doing more harm than good. Try taking it out of the line and see if reception improves. In fact, very few installations really need an amp, unless the feedline from the antenna to the TV set is more than 100’ long.

Moreover, even if your installation does call for an amp, 29 dB is really A LOT — probably way too much gain. The amp could be causing overload at your tuner. Or it could be amplifying unwanted spurs, images and/or intermod products that confuse the digital decoding circuitry in your converter box. Cheap amps like those from Radio Shack frequently have these problems. If you want a good amp, you should look first for a low noise figure, say below 3 dB. Then, 10 dB of gain should be all you’d ever need.

(And if the manufacturer doesn’t bother to specify the noise figure, you can be almost certain that you have an inferior amp.)

Also, if your feedline is either 300 ohm twinlead or old RG-59 coax, you should change over to quadshield RG-6U coax. And make sure you have a good 300-to-72 ohm balun at the antenna’s feedpoint, sealed against moisture.

Finally, check and recheck and tighten all connections from the antenna down to the set. I’ll bet that 50% of reception problems can be traced to a connection that either has worked loose, has corroded, or wasn’t properly made in the first place.


26 posted on 06/23/2009 6:53:21 PM PDT by Hawthorn
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