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 to 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 acceptable (see page 8).

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 19-20, 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 75 feet for 150 MHz applications or to maxi- mize 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 150 MHz transmitter, there is an average* loss of 6 dB per 100 feet of cable (A 3 dB 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.

13

Page 17
Image 17
Listen Technologies LT-800-150 manual RF Reception Maximization Strategies, Coaxial Cable

LT-800-150 specifications

Listen Technologies LT-800-150 is a robust and versatile transmitter designed primarily for assistive listening applications. It is a pivotal component of the Listen Technologies assistive listening systems, allowing users to experience clear audio in various environments, such as theaters, churches, conference rooms, and other public venues.

The LT-800-150 operates in the 72-76 MHz frequency range, which is specifically allocated for assistive listening devices, providing reliable audio transmission without interference. This wide frequency range ensures compatibility with a myriad of receivers, enabling a seamless experience for users with hearing impairments. The device offers a power output of 150 mW, ensuring a strong and clear signal that can cover a large area, making it ideal for spacious venues.

One of the standout features of the LT-800-150 is its exceptional audio quality. The transmitter is equipped with a balanced XLR microphone input, allowing users to connect a variety of audio sources, such as microphones or sound systems. This flexibility ensures that whether it's a live performance or a pre-recorded presentation, the audio remains crystal clear for the audience.

The LT-800-150 also supports multiple channels, allowing several transmitters to operate simultaneously without cross-interference. This characteristic is particularly valuable in environments where multiple events or services occur concurrently, enabling each to cater to the specific audio needs of their attendees.

User-friendly design is another hallmark of the LT-800-150. The device features a simple interface with LED indicators that provide users with real-time feedback on power, audio activity, and other essential functions. Additionally, it comes with a built-in audio compression feature, which helps to optimize sound quality and maintain consistent audio levels.

Built for durability, the LT-800-150 is constructed with high-quality materials, making it suitable for frequent use in various settings. Its compact design means it can be easily integrated into existing audio setups without taking up significant space.

In summary, the Listen Technologies LT-800-150 is a reliable and effective solution for assistive listening. With its powerful output, excellent sound quality, and user-friendly features, it stands out as an essential tool for ensuring accessible audio experiences for all individuals, particularly those with hearing challenges. Whether in a public space or at a private event, the LT-800-150 delivers superior performance that enhances communication and inclusivity.