Installation and Level Settings
34
Radio RX
Standard Alignment Procedure for a 2- or 4-wire System:
• Inject a 0dBm test tone on the RX pair (4-wire pins 12 and 24: 2-wire pins 13 and 25).
• Measure the RX level on test point TP13 for line 1 or TP1 for line 2.
• Adjust potentiometer R175 for line 1 or potentiometer R110 for line 2 until 0dBm is measured between the test
point and GND. (0dBM = 2VPP = .707VRMS).
• Detune slightly 1-2dBm to provide overhead for large transients.
• AGC (Automatic Gain Control) compression potentiometers RV5 for line 1 and RV1 for line 2 control the
aggressiveness of the AGC circuitry, if enabled. The AGC can be used to enhance the gain capabilities of the RX
circuitry. Set RV5/RV1 fully clockwise and, if required, back off 10 to 15 degrees maximum.
• Use the RX alignment tool (VU meter) accessed through the LCD display to verify the dBm level. See “General
Alignment” on page 33. The reading should be 0dBm with the AGC turned off. If the AGC is ON, it is likely the
RX alignment software always displays 0dBm, the targeted level for the AGC circuitry.
Line TX Monitor Level - Tone and Console Mode
PCB 750743 or PCB 750630 revision C and higher
The Line TX Monitor Level adjustment is used when the IP-223 is connected to consoles set in 4-wire mode. This allows for
local TX audio to be sent back on the network and played at other consoles so both sides of the radio traffic can be heard. The
alignment for TX monitor is similar to 4-wire RX alignment.
To adjust the TX monitor, do the following:
1. In the options section of the Per Line Setup window, select the TX Monitor.
NOTE: If this feature is not necessary, or the line is in 2-wire mode, the TX Monitor field in the Options section on
the Per Line Setup window should be cleared.
2. Verify the RX alignment is completed first.
To perform a standard alignment for a 4-wire system, do the following:
1. Transmit a 0dBm test tone on the TX audio pairs pins 13 and 25.
2. Measure the RX level on test point TP13 for line 1 or TP1 for line 2.
3. Adjust potentiometer R390 for line 1 or potentiometer R391 for line 2 until 0dBm is measured between the test
point and GND (0dBM = 2VPP = .707VRMS).
NOTE: Do not adjust the RX potentiometers.
4. Use the RX alignment tool (VU meter) accessed through the LCD display to verify the dBm level.
CTCSS Level
The CTCSS level is measured by connecting an oscilloscope or RMS meter to ground and Radio 1 CTCSS test point (TP7) or
Radio 2 CTCSS test point (TP10). With the radio connected to the CTCSS output, have the remote console open to receive
audio so CTCSS is present. Adjust the Radio 1 CTCSS potentiometer (R50) or Radio 2 CTCSS potentiometer (R53) until the
desired level is achieved.
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