Listen Portable fm 863 Mhz, Руководство пользователя

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8
Design Guide
The range of a portable transmission will vary from one application to another. There are many different
obstructions that could minimize the range. In most applications, the range will be approximately as shown
below (P= Power Level - refer to page 26 for programming power levels of the LT-700).
P1 – 100 ft
P2 – 150 ft
P3 – 200 ft
Range varries depending on enviroment.
Maximizing Range
Here are some tips to maximize the transmission range:
• Eliminate or minimize obstructions between the transmitter and receivers.
• Minimize the distance between the transmitter and receivers.
• Move transmitter and receivers away from metal objects.
• Orient both transmitting and receiving antennas vertically.
Key concepts in designing a portable FM system
Use this section of the guide to choose the channel settings for the transmitter and receivers.
• The goal is to find a transmission channel(s) that is free from interference. Interference originates from
other transmitters and from other equipment (such as a computer).
• Listen products offer 17 different channels to choose from. This increases the chance you’ll find an
interference free channel.
• The best way to check for interference is to use the “SEEK” button on the receiver. Be sure all Listen
transmitters have been turned off if there is interference, the receiver will find these channels.
If the receiver finds a frequency in use, do not use this channel.
• In general, most of the channels will be free from interference.
• Interference can be overcome by maximizing the transmission power and by using the receivers close to
the transmitting antenna.
• If more than one channel is in use, space the channels further from each other. Use the Listen frequency
chart on page 61 to determine the channels frequency and space the number of channels further from
each other.
Channel Selection
Range
ExAMPLE: 2 channel system use channels 01 & 11
3 channel system use channels 01, 06 & 11