Nautel NX15, Operation And Maintenance Manual

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NX15/NX25 Operations and Maintenance Manual Operating the transmitter
Issue 6.0 2019-01-31 Page 2-53
NOTE:
Available settings on the
Analog Settings
and
Digital Settings
tabs are shown/hidden
based on the
Overall Mode
setting. Not all settings are available in all modes.
Analog Settings
( Figure 2.37 on page 2-57 )
•
AM Source
-
select the audio source for the AM signal. Options are:
– Unused
– Balanced Analog (connector J12 on A11A1)
– AES1 (connector J11 on A11A1)
– AES2 (connector J10 on A11A1)
– Audio Player/AES1: Requires installed USB sound card option. Plays audio player playlist through
single-board computer USB port; This USB port must be connected to the USB sound card, the
output of which should be connected to the AES1 input.
– Audio Player/AES2: same as above for ASE2 input.
•
Format
-
Options are:
– AM Carrier: transmits carrier only; ignores audio inputs.
– Mono L+R: adds L+R channels on AES signal.
– Mono L: transmits L channel of AES signal or Bal Analog.
– Mono R: transmits R channel of AES signal.
– Stereo C-QUAM: uses amplitude and phase modulation over AES, to transmit a stereo AM signal.
• Filter Type -
selects a filter to be applied to the input audio signal. Options are:
– None: no filter is applied (default).
– Brick Wall: applies a low pass filter with a very sharp cutoff and a 6 dB bandwidth defined by the
Filter Bandwidth setting (between 1 kHz and 10 kHz).
– Minimum Overshoot: applies a Gaussian low pass filter with a very gentle rolloff and a 3 dB
bandwidth of 5.13 kHz. Used to minimize ringing of the modulator filter with extremely high rate of
change input signals (e.g., square waves). Typically used only for testing purposes.
•
NRSC-1 Preemphasis -
applies a NRSC-1 pre-emphasis curve to the input audio signal. Default is Off.
•
Dynamic Carrier Control -
selects the DCC mode, as applicable. Options are None, AMC, EAMC, DAM
or DAM Full. Default is None. When a DCC mode is selected, a Max DCC Compression level can also be
entered. In addition, when the DCC mode is set to EAMC, the EAMC gain sets the gain applied to the
carrier power when no modulation is applied (maximum is 1.76 dB), and the Max Carrier Timeout will
cause the carrier power to drop to the setpoint after two (2) minutes with no modulation applied.
See
“Selecting the DCC mode” on page 2-61 for more information on each mode.