Antenna problems

i was told by an old school tv engineer many years ago about signal booster amplifiers .. his way of thinking was why amplify noise along with the signal ..just get the signal better and forget amplifying the noise . he was in the business of selling tv antennas though as well as repairing televisions . he was from vhf days so pretty much same as fm . he wouldn't touch a colour set .
 
petehall347 said:
can someone please remind me which is correct when using coax
does the shield connect at the antenna end or the receiver end ?
i seem to remember its at the antenna end .
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The shield should be connected at both ends. Most antennas have two terminals, and the receiver will either have two screw terminals or else an F-Connector. If there are two screw terminals, one will normally be ground, and the shield goes to that one. If an F-connector, the shield goes to the threaded shell of the F-connector. 300-ohm antennas use a balun to match to the 75 ohm coax. The balun will also have an F connector, and there too, the shield corresponds to the threaded outer shell of the F connector.
 
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petehall347 said:
i was told by an old school tv engineer many years ago about signal booster amplifiers .. his way of thinking was why amplify noise along with the signal ..just get the signal better and forget amplifying the noise .
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That is still good wisdom today. A good antenna should come first. The amplifier is more of a last resort. It will indeed amplify noise along with the signal. A better antenna that provides a stronger signal is a better bet. Besides, if the signal is too weak, you can't amplify what isn't there!
 
In an rf system all cables should have the shield grounded at both ends, otherwise it causes impedance mismatch and reflections. This is especially important if your antenna is a whip type antenna, which requires a ground plane at the base. The shield connects to the ground plane.
 
While I fully agree with the comments about using an amplified antenna like my new indoor rabbit ears, and have so agreed for decades, until I find someone to hire to install an outdoor antenna, this amplified one has provided the best results compared with folded dipoles and other rabbit ears I have tried. Sometimes you just have to use what works, sums up my antenna experience. Thirty years ago, different house, different state, I installed a Yagi with rotator on a 16' mast myself. That was nice.
 
Rob-F said:
That is still good wisdom today. A good antenna should come first. The amplifier is more of a last resort. It will indeed amplify noise along with the signal. A better antenna that provides a stronger signal is a better bet. Besides, if the signal is too weak, you can't amplify what isn't there!
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This pretty much hits the nail on the head. Good advice.
 
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