Dataradio Paragon, Техническое руководство

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120 20170-204a Paragon
PD
Technical Manual
36
WARNING: Do not attempt to re-tune the IF stages (i.e. L312 to L318).
These adjustments do not need to be re-adjusted after frequency re-programming.
Touching these coils will have a direct impact on the DSP modem coefficient settings
and may significantly reduce the radio performances over data.
6.2.2.4 SINAD and Linearity Check
1. Apply the following settings to the IFR:
-
Generator mode, Output T/R
-
IFR TX frequency to match the main radio RX frequency
-
Filter set to wide band (no audio filter)
-
Select Gen2 (Modulating tone fixed to 1KHz). All other Gen must be off, except for “wide-
band”.
-
Set deviation to
±
3.0KHz for full channel or
±
1.5KHz for half channel radios.
2. Lower the RF level to get a 12dB SINAD reading. Level must be better than -110dBm (including
cable loss).
3. Offset the IFR TX frequency 2KHz (full channel) or 1kHz (half channel) above the main radio
RX frequency, record the SINAD reading. It should remain within 1.5dB from the on frequency
SINAD reading.
4. Offset the IFR TX frequency 2KHz (full channel) or 1kHz (half channel) below the main radio
RX frequency, record the SINAD reading. It should remain within 1.5dB from the on-frequency
SINAD reading.
Note:
If one of the above requirements is not met, try to re-tune the front-end. If it is still “failed”,
contact your Dataradio technical support.
6.2.2.5 RSSI Adjustment
1. Apply an on-channel signal from the RF generator at a level of -110dBm modulated by a 1 kHz tone
at a deviation of ±3kHz (full channel) or ±1.5kHz (half channel).
2. Adjust RV301 (RSSI level) to give 2.0V RSSI output when measured with a multimeter at SK301
pin 2 or on the relevant backplane board at SK1 pin 5 (see Figure 28 for test point location).
3. Vary the RF level and check the RSSI output voltage (Figure 27):
1) At –120 dBm: 1.2 VDC (+0.20 –0.45VDC)
2) At –90 dBm: 4.0 VDC (+0.20 –0.20 VDC)
3) At –80dBm: 5.0 VDC (+0.20 – 0.35VDC)
If the requirement cannot be reached, contact your Dataradio technical support.