Meteorcomm LLC 63020 ユーザーズマニュアル
ITCR Locomotive Radio User Guide
© 2013 Meteorcomm LLC. All Rights Reserved. Proprietary and Confidential
4/30/2013
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To adjust the master crystal reference oscillator parameters:
1. First, check the factory default setting for the crystal reference parameter by
1. First, check the factory default setting for the crystal reference parameter by
typing
cal
2. Note the value for “xo” in the cal factors table that is displayed.
3. At the XtermW command line, type:
cal,set,xo,xx
where xx is some value close to the original factory set value.
4. Use trial and error to determine the set point for the xo value to achieve the
desired carrier frequency accuracy.
To reset the XO tuning parameter to the factory setting:
Power cycle the radio.
5.4 Measure and Adjust Output Power
Caution: Avoid unnecessary adjustments. Exercise caution when setting I
and Q gain values as damage to the radio can occur if gains are set too
high.
and Q gain values as damage to the radio can occur if gains are set too
high.
The Locomotive radio is rated for 50W PEP. To achieve this power radios are pre-
calibrated at the factory. If additional tuning is required, use an appropriate method
to determine PEP for a π/4-DQPSK signal. The CCDF function on the VSA is
recommended for peak power measurement. Slowly increase/decrease I and Q gain
levels from their nominal set point, as determined by issuing the command ‘cal’.
calibrated at the factory. If additional tuning is required, use an appropriate method
to determine PEP for a π/4-DQPSK signal. The CCDF function on the VSA is
recommended for peak power measurement. Slowly increase/decrease I and Q gain
levels from their nominal set point, as determined by issuing the command ‘cal’.
A step of 100 points (for example, -250 to -150) is approximately equivalent to an
increase of 2dB in power.
increase of 2dB in power.
To measure and adjust output power:
1. At the XtermW command line, begin transmitting a π/4-DQPSK signal by
1. At the XtermW command line, begin transmitting a π/4-DQPSK signal by
typing:
dsp_mode,idle
dsp,watchdog,off