GAI-Tronics ITR1000A User And Installation Manual - page 18
Installation
ITR1000A Basic Tone Remote Desk Set
01/05
14
Line Output (Transmit) Level Adjustment
This process ensures the correct audio signal level is output to the remote control line during
transmission.
1.
Disconnect the handset from the desk set.
2.
Apply a 1000 Hz at 44 mV ac signal into the handset mic terminals (red = handset mic; black =
ground).
3.
Press the
TRANSMIT
button and adjust the line output level control (pot 4) on the main circuit board
until the desired output is obtained (e.g. -10 dBm) to the remote control line. Do not exceed the line
supplier's recommended maximum level.
4.
Remove the signal from the handset mic terminals and reconnect the handset.
Audio Level Setting Procedure
1.
Set up an RF signal generator on the receive frequency with a 1 kHz tone set to system reference
modulation applied to the station antenna.
2.
Apply sufficient RF level to ensure a fully quieted radio channel, typically 1000 microvolts. If used,
enable the correct receive CTCSS/CDCSS code.
3.
Measure and note the level of the 1 kHz tone impressed on the radio tie line. Adjust the station's tone
remote adapter to produce the desired line level, e.g. -10 dBm.
4.
With the 1 kHz tone still applied from the station receiver, monitor the remote audio with an ac
voltmeter at test point TPC1.
5.
Slowly adjust the desk set receive level potentiometer (pot 3) until the level just stops increasing
(knee of compression) at approximately -2 dBm.
6.
If multiple desk sets are used, repeat this procedure for each unit. Ensure that only the most distant
desk set from the station receiver has the RX line termination jumper in place. Refer to the Switch
Settings Table in the Description section of this manual.
7.
If an RF generator is not available, the RX level pots can be adjusted while monitoring a mobile radio
transmission. Adjust the pot as described above until the level at the test point just stops increasing at
approximately -2 dBm. This can be done during a continuous speech transmission, or during a test
conducted from the mobile radio. A setting that is too high may result in excessive background noise,
or 'pumping' of audio.