Ritron RIT17-145R 用户手册
10
DR-145/445 ALIGNMENT PROCEDURE
Only an authorized RF service technician should perform test and alignment of the DR-145/445. The unit is PC
adjusted.
adjusted.
RECOMMENDED TEST EQUIPMENT
1) 9 to 17 VDC 2 Amp current-limited power supply
3) Oscilloscope
2) RF Communications Test with:
4) RITRON PC Programming Kit
- Frequency Counter
- SINAD Measuring Device
RADIO PREPARATION
2) Connect the FM communications test set to the antenna connector.
3) Connect RITRON programming cable to radio and PC.
4) Apply 9 to 17 VDC to the red wire with the black to ground.
5) Run RITRON DTX-LS software and read the radio.
RADIO ADJUSTMENT
The programming software includes help comments. If DR needs to be changed or readjusted do the following:
2) Run RITRON DTX LS programming software.
3) On the menu bar select Edit then Tune radio.
4) If starting from scratch, set up the radio performing frequency adjustments then User Set Up. Otherwise, adjust
3) On the menu bar select Edit then Tune radio.
4) If starting from scratch, set up the radio performing frequency adjustments then User Set Up. Otherwise, adjust
what is needed.
5) Hold frequency counter probe on C455 and U103 junction. Click Frequency then Tune.
6) The frequency used in adjustment is displayed in the upper right corner. The frequency displayed is in the normal
6) The frequency used in adjustment is displayed in the upper right corner. The frequency displayed is in the normal
TX frequency band and will be used to adjust the reference oscillator.
7) Adjust frequency by clicking arrows or by click in space to right of sliding button (for up) or space left (for down).
Button can also be dragged to position.
8) Adjusted frequency reading should be less than +/-100 Hz. Click Save when done.
9) Adjust positive and negative corrections in the same way. This calibrates the reference oscillator.
10) If the reference oscillator ages and drifts in the future, only the center frequency should need trimming.
11) Click User Set Up. Here, you can adjust NOISE and RSSI squelch levels and AUX_OUT gain. If both RSSI and
9) Adjust positive and negative corrections in the same way. This calibrates the reference oscillator.
10) If the reference oscillator ages and drifts in the future, only the center frequency should need trimming.
11) Click User Set Up. Here, you can adjust NOISE and RSSI squelch levels and AUX_OUT gain. If both RSSI and
NOISE squelch are used simultaneously, the RSSI level must be set first with the NOISE squelch disabled. Disable
it by adjusting the level so high (bar to the right) that the RF level never reaches it. The NOISE and RSSI squelch
levels work as an OR function. With either level exceeded, the audio will turn on. Set the RSSI level around -106
dBm and then the NOISE level around -120 dBm** .
it by adjusting the level so high (bar to the right) that the RF level never reaches it. The NOISE and RSSI squelch
levels work as an OR function. With either level exceeded, the audio will turn on. Set the RSSI level around -106
dBm and then the NOISE level around -120 dBm** .
12) Remember to save all settings when tuning is finished.
NOTES:
NOTES:
**The DR-145/445 is capable of two squelch operating modes. Both can operate simultaneously. See the FM
Receiver Subsystem section for theory. The units can be configured as the user requires. When a low level signal
appears, the noise squelch opens when the carrier is –119 dBm or greater. When the signal appearing is –106 dBm or
greater the RSSI squelch opens the audio with an even faster attack time. The above levels are factory set levels.
Ambient noise will affect the level at which the RSSI should be set. The squelch level ideally should be set on the
desired frequency, in the actual location the radio will be used and connected to the desired antenna. The level should
be set high enough to reject most false signals. The squelch levels are the same for all channels.
appears, the noise squelch opens when the carrier is –119 dBm or greater. When the signal appearing is –106 dBm or
greater the RSSI squelch opens the audio with an even faster attack time. The above levels are factory set levels.
Ambient noise will affect the level at which the RSSI should be set. The squelch level ideally should be set on the
desired frequency, in the actual location the radio will be used and connected to the desired antenna. The level should
be set high enough to reject most false signals. The squelch levels are the same for all channels.
If a very fast receiver decay time (or squelching after signal disappears) is needed the noise squelch should be
defeated by setting it to a high level.