Important Things to Note Before Starting Your Installation
What is Squelch?
The LR-100 is a radio receiver that receives an RF signal from either an LT-800 or LT-700 radio transmitter. Many radio receivers, including the LR-100, include a control called “squelch” that mutes the receiver’s output signal when there is no received RF signal. Without the squelch control, a strong noise is heard at the receiver whenever it is not receiving a signal. This noise can be disturbing to listeners and if sound is turned up high enough, could damage the listen- ers’ ears.
The squelch control is a threshold adjustment, determining at what RF signal level the unit will squelch (or mute) the receiver’s output audio. When the squelch is set high, it takes more RF signal to unsquelch the receiver.
For information on setting up the LR-100’s squelch, please see page 17.
What is ListenSQTM?
We are accustomed to listening to low noise, high fidelity audio delivered to us via compact discs and other audio mediums. FM radio systems (such as used in the LR-100 are inherently noisy as compared to most sound systems. In order to reduce noise of the broadcast system, the LR-100 uses a noise reduction technology called ListenSQ™. Both the transmitter and receiver must have SQ on to achieve the desired results. You will notice on the front panel of the LR-100 (under the security plate) a switch labeled “SQ: ON/OFF”. To receive the benefits of SQ, turn this switch to the ON position. Also make sure that the transmitter also has its SQ switch turned on. If the transmitter is not capable of SQ (if you are using an older version Listen transmitter or a product from a different manufacturer), you should turn SQ OFF on the LR-100.
Coaxial Cable
The antenna for the LR-100 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 LR-100’s antenna in a different location than on the top of the unit, you must use cable and connectors rated at 50 ohms. Although cable used for cable TV installa- tions looks similar to this cable, it won’t work with your Listen system.
If you need to run cable over a greater length than 50 feet for 216 MHz applications or greater than 100 feet for 72 MHz applications, we recommend that you use RG-8 cable rather than RG-58. It is a lower loss cable, meaning that more of your signal will reach the antenna.
