CALAMP WIRELESS NETWORKS INC. BDD4T83-2 ユーザーズマニュアル
120 20170-302
Paragon
PD
Technical Manual
30
5.2.2.3 Front-End Alignment
1. IFR COM120B settings:
a) Connect a 3 feet long double shielded cable (N-M to BNC-M) between the IFR T/R output and the
receiver antenna connector.
b) Select the generator mode (GEN button) and set to the main receiver channel frequency
c) Select and turnon GEN2
d) Set the FM Deviation to ±3kHz (full channel) or ±1.5kHz (half channel) using 1KHz sine
e) Select SINAD meter
f) Use a X1 scope probe connected to SINAD input and monitor the Discriminator O/P on the back-
plane at SK1 pin 6 (RX-audio1). Alternately, it is also possible to monitor at the receiver I/O Pad
P207 (T885), the receiver TP314 (T855) or at the receiver IC350 pin 7 (T835).
P207 (T885), the receiver TP314 (T855) or at the receiver IC350 pin 7 (T835).
2. Adjust the helical resonators for best SINAD: #H400, #H401 and #H900 (T885); #FL410 and #FL420
(T855) or L410, L420, L460 and L470 (T835).
3. Continually decrease the RF level to reach 12dB SINAD, then re-do step 2) & 3) again. The absolute
minimum requirement level to reach is -108dBm (typical level is -109 to -110 dBm)
4. Perform the SINAD linearity tests described in paragraph 5.2.2.4. If it fails to pass the requirement,
contact your Dataradio technical support.
WARNING: Do NOT attempt to re-tune the IF stages
(I.e. L300 and L301 for T885, L310 to L390 for T855 or L330 to L360 and
CV318 for T835).
These adjustments do not need to be re-adjusted after frequency re-programming. Touch-
ing these coils will have a direct impact on the modem DSP ISI coefficient settings and may
reduce significantly the radio performances over data.
ing these coils will have a direct impact on the modem DSP ISI coefficient settings and may
reduce significantly the radio performances over data.
5.2.2.4 SINAD and Linearity Check
1. Apply the following settings to the IFR COM-120:
a) Generator mode, Output T/R, TX frequency to match the main radio RX frequency
b) Filter set to wide band (no audio filter)
c) Select Gen2 (Modulating tone fixed to 1KHz). All other Gen must be off.
d) Set deviation to
b) Filter set to wide band (no audio filter)
c) Select Gen2 (Modulating tone fixed to 1KHz). All other Gen must be off.
d) Set deviation to
±
3.0KHz for full channel or
±
1.5KHz for half channel radios.
e) Use a X1 scope probe connected to the IFR SINAD input and monitor the Discriminator O/P on the
radio backplane at SK1 pin 6 (RX-audio1). Alternately, it is also possible to monitor at the receiver
I/O Pad P207 (T885), the receiver TP314 (T855) or at the receiver IC350 pin 7 (T835).
I/O Pad P207 (T885), the receiver TP314 (T855) or at the receiver IC350 pin 7 (T835).
2. Lower the RF level to get a 12dB SINAD reading. Level should be better than -108dBm (including ca-
ble loss).
3. Offset the IFR TX frequency 2kHz (full channel) or 1kHz (half / NPSPAC channel) above the main
radio RX frequency, record the SINAD reading. It should remain within 1.5 dB from the on frequency
SINAD reading. For T885 and T855, use above values, for T835 use 1.5kHz (full channel) or 0.8kHz
(half channel).
SINAD reading. For T885 and T855, use above values, for T835 use 1.5kHz (full channel) or 0.8kHz
(half channel).
4. Offset the IFR TX frequency 2KHz (full channel) or 1kHz (half / NPSPAC channel) below the main
radio RX frequency, record the SINAD reading. It should remain within 1.5 dB from the on-frequency
SINAD reading. For T885 and T855, use above values, for T835 use 1.5kHz (full channel) or 0.8kHz
(half channel).
SINAD reading. For T885 and T855, use above values, for T835 use 1.5kHz (full channel) or 0.8kHz
(half channel).
Note: If one of the above requirements is not met, try to re-tune the front-end. If still failed, contact
your Dataradio technical support.