Glenayre RL-903 User Manual page 18

RL-903 Receiver
DESCRIPTION
Page: 3-2
The audio_dc signal is dc-coupled all the way from the quadrature detector to J1. The
audio_ac signal is filtered to produce standard transmitter audio. This signal may be routed
through the optional tone board to produce a logic indication if a control tone is detected
and to optionally notch out the control tone to a transmitter (tone is normally not notched).
For a discussion of the tone board, refer to its manual. See Table 1-1.
An external delay device or other type of audio processor may be spliced into the audio
path, depending on jumper settings. See Table 7-7, IF Board Controls and Indicators.
The received-signal-strength indicator is a dc voltage which gives a relative indication of
the signal strength.
The R tone-controlled link receiver reserves a segment of the audio passband (normally a
narrow band centered on 2875 Hz) for control purposes. The presence of a tone at that
frequency causes the keyline to the transmitter to become active. The R receiver can be set
up to notch the control tone out of the audio passband, but the R receiver normally passes
the control tone, along with the rest of the audio passband.
Refer also to the system theory of operation of the associated transmitter for additional
discussion. Refer to the tone-control manual (see Table 1-1 for part number) for a discus-
sion of the operation of the tone board.
Some systems require more extensive control than that offered by tone keying. In such
cases, an external device uses the receiver audio and squelch status to control the associated
transmitter. Refer to the control device's manual for additional discussion.
An external 600-ohm, balanced output may be used for sending remotely monitored audio
over telephone lines. This feature may be used at the same time as the previously mentioned
features. Additional components may need to be installed on the RF board in order for this
feature to be enabled.
The received-signal-strength indicator (RSSI) is a dc voltage which gives a relative indica-
tion of the signal strength.
There are two types of squelch which may be used:
• noise squelch (NORMAL) for normal reception and
• carrier squelch (TIGHT) for reception in areas of high RF density.
The power supply uses switching techniques to provide a stable output voltage despite wide
variations in the input. The board also provides the audio amplifier for the chassis-mounted
speaker.
Copyright © 1996 Glenayre
Glenayre Document Number: 9110.00148
Issue 1, Rev. C: 12/10/96
Print Date: 12/05/96