RF Reception Maximization Strategies

For proper and dependable operation, Listen receivers need to receive a strong and consistent signal from the originating transmitter. Note that on portable receivers the headset wire is the receiving antenna. The following strategies should be used maximize this signal:

1When designing and installing your system, keep in mind that the location of both the transmitting and receiving antennas is critical to maximize broadcast range.

2Eliminate or minimize obstructions between the transmitting and receiving antenna.

3Minimize the distance between the transmitting and receiving antennas.

4Move transmitting and receiving antennas away from metal or conductive objects.

5Place the transmitting antenna as high as possible.

6Orient both transmitting and receiving antennas vertically.

7Position the RF Power switch on the back of the LT-800 to full RF Power, unless lower power is necessary (see page 9).

8Keep coaxial cable from transmitter to antenna as short as possible.

CAUTION: When installing antennas, ensure the antenna is clear of power lines.

Coaxial cable, connectors, and optional antenna mounting kits are available from Listen. See page 22-23, visit www.listentech.com or ask your dealer for details.

Coaxial Cable

The antenna for the LT-800 can be mounted directly on the unit if desired. However, you may find that the unit will provide better performance when the antenna is located elsewhere. If you plan to mount the antenna in a different location other than the top of the unit, you must use cable and connectors rated at 50 ohms. Although cable used for cable TV installations looks similar to this cable, it will not work with your Listen system.

If you need to run cable over a length greater than 50 feet for 216 MHz applications or greater than 100 feet for 72 MHz applications or to maximize broadcast range, Listen recommends that you use RG-8 cable rather than RG-58. RG-8 is a lower loss cable, meaning that more of your signal will reach the antenna.

Long cable runs can result in signal degradation due to the “loss” characteristics of the cable. When using RG-58 with a 72 MHz transmitter, there is an average* loss of 4 dB per 100 feet of cable and at 216 MHz using RG-58 an average* loss of 8 dB per 100 feet of cable. (A 3dB loss means half of your power has been lost.) However, it is better to suffer coaxial power loss than to try to shoot your signal through obstacles! Obstacles, especially metal, can create drop-outs or reflections of your signal that will result in poor listening conditions.

*NOTE: There are many varieties of 50 ohm, RG-58 and RG-8 cables. You may purchase a cable that is better or worse than this value. Please check with the cable vendor or manufacturer for exact specifications.

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Listen Technologies LT- 800-072, LT-800-216 manual RF Reception Maximization Strategies, Coaxial Cable
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LT- 800-072, LT-800-216 specifications

Listen Technologies has established itself as a leading provider of assistive listening systems, and its LT-800-072 and LT-800-216 transmitters are exemplars of their commitment to quality and innovation. These devices are designed to enhance the audio experience in environments where clear sound transmission is crucial, such as theaters, lecture halls, museums, and places of worship.

The LT-800-072 is a powerful, reliable FM transmitter that operates on the 72-76 MHz frequency band. It supports both mono and stereo transmission, making it versatile for various applications. One of its standout features is its robust selectable power output, which allows users to adjust the strength of the transmission based on the specific requirements of the environment, ensuring optimal coverage without interference. This flexibility is particularly beneficial in larger spaces, where sound needs to travel further without losing clarity.

On the other hand, the LT-800-216 is designed for use within the 216 MHz frequency range, offering another layer of versatility for varying listening preferences and regulatory requirements. It boasts a compact design, making it easy to integrate into existing audio systems or set up independently. The device also features a built-in audio input that accommodates multiple audio sources, including microphones, mixers, and other devices, allowing for seamless integration and functionality.

Both transmitters utilize advanced technology to deliver exceptional audio quality. The modulation techniques employed in these devices help eliminate static and background noise, ensuring that users receive crystal clear sound. The inclusion of multiple channels allows simultaneous transmission, which is a significant advantage in settings where multiple languages or presentation options are necessary.

Durability and ease of use are also critical characteristics of the LT-800-072 and LT-800-216. They are constructed with high-quality materials that withstand the rigors of regular use, making them ideal for both permanent installations and portable applications. Additionally, user-friendly controls and clear indicators simplify operation, enabling operators to focus on delivering an excellent auditory experience rather than troubleshooting technical issues.

In summary, the Listen Technologies LT-800-072 and LT-800-216 transmitters provide advanced sound transmission solutions characterized by flexibility, excellent sound quality, and robust build quality. Their capabilities make them suitable for various applications, effectively addressing the diverse needs of listeners in a range of environments.
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