There is a website called Antennahub.com that sells them. You may also want to check the place you brought your TV from. They will be able to tell you if you do need a high gain antenna and what will work with that TV
http://www.amazon.com/Cisco-Linksys-High-Antenna-Connectors-HGA7T/dp/B0002F3G7M is a great place to get the latest high gain antenna with great prices.
Italian Space Agency provided the High Gain Antenna for the Cassini Space Probe. The HGA was built by Alenia Aerospazio.
A high-gain antenna is an antenna which allows for precise targeting of radio signals due to it's use of a narrow radio wave beam. To use a high-gain antenna you should put attach it to a high, clear surface to allow it maximum range to receive and send radio signals. A good place would be the roof of your house.
You can buy high gain antenna's for your task at a number of online shopping sites, such as amazon.com. I would suggest going there to fulfill all of your needs.
an antenna with 0 gain. What you hear and transmit is what you get from your 2-way radio.
I am using an old Russian antenna and it does the trick pretty well. But I can not answer your from where you can buy one. Instead I can tell you that Sony make them and there are good enough.
One way to boost the signal of a wireless antenna is to upgrade to a high-gain antenna. Other methods include adding a USB adapter with an additional external antenna or even to create a parabolic dish using a soda can.
increases by 6 dB
The size of an antenna depends upon the frequecny of the RF signal and the gain.
Some advantages of the Yagi- Uda Antenna include that this is a widely used design and low cost. The construction also is simple. Some disadvantages are that the receiver of the Yagi-Uda Antenna may have problem receiving signal.
EIRP (Dbm)= Output Power(Dbm)-Losses(from cables & adapters)+Antenna Gain(Db)
It depends upon the type of antenna. For example, a Yagi antenna's gain can be increased by adding elements. A parabolic antenna's gain can be increased by increasing the diameter of the antenna. All antennas can have their gain increased by lowering the loss of the feed line. By replacing regular coaxial cable with nitrogen pressurized coax, the overall gain at the receiving end can be increased. Gain can also be increased by inserting an amplifier between the antenna and the receiver. Another method of increasing gain is to reduce the VSWR, or voltage standing wave ratio.