RELM Communications Inc SRU50ABC ユーザーズマニュアル
S Series Repeater USER MANUAL
©RELM Communications Inc. Revision 1.0
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In the Channel Info screen click on the channel you wish to setup. You can view all of the settings and calibration
data, however you will need to enter the password by clicking the "Advanced" button to proceed. This level of
protection is provided to advise that changes may allow the transmitter to potentially cause interference to vital radio
communications services. See also the QUICK FREQUENCY PROGRAMMING and FULL CALIBRATION
sections.
data, however you will need to enter the password by clicking the "Advanced" button to proceed. This level of
protection is provided to advise that changes may allow the transmitter to potentially cause interference to vital radio
communications services. See also the QUICK FREQUENCY PROGRAMMING and FULL CALIBRATION
sections.
QUICK FREQUENCY PROGRAMMING
( If a calibrate has already been performed)
In the channel information screen, click the channel number you wish to change or create. Enter into the
"Advanced" mode with the correct password. Enter the frequencies' of the channel. Inject an audio signal with
sufficient level (~0dBm) to ensure compressor operation and check the deviation is 3KHz for 25KHz channel
spacing or 1.5KHz for 12.5KHz spacing. Adjust the VCO deviation for the correct level. Most of the other settings
will not change. If in doubt see the FULL CALIBRATION section.
"Advanced" mode with the correct password. Enter the frequencies' of the channel. Inject an audio signal with
sufficient level (~0dBm) to ensure compressor operation and check the deviation is 3KHz for 25KHz channel
spacing or 1.5KHz for 12.5KHz spacing. Adjust the VCO deviation for the correct level. Most of the other settings
will not change. If in doubt see the FULL CALIBRATION section.
FULL CALIBRATION
(TX MODULATION) Suggested Method
Recommended Full Calibration Procedure with DC-FM installed. The alignment may be carried out in the SETUP
DYNAMIC for a quicker result. Calibration is performed on the center RF frequency.
DYNAMIC for a quicker result. Calibration is performed on the center RF frequency.
1. Set the Reference Level to 0 and the Reference Bias to 127.
2. On the SR35/50 Micro controller Board set Pre-emphasis, Tx HPF and the Tx VF Compressor to OFF. Turn the
Tx Compress Level RV2 fully clockwise to maximum. This will allow the hard limiter to operate.
Tx Compress Level RV2 fully clockwise to maximum. This will allow the hard limiter to operate.
3. Inject a 1KHz audio signal into the Tx VF input at a level of +10dBm. Check with an oscilloscope that the audio
signal is clipped at the Tx Limiter Test Point.
signal is clipped at the Tx Limiter Test Point.
4. Set the VCO Level to achieve 4.8KHz deviation (clipped waveform) in the case of 25KHz channel spacing and
2.3KHz deviation in the case of 12.5KHz channel spacing. If CTCSS is used then subtract further the nominal
CTCSS system deviation level.
2.3KHz deviation in the case of 12.5KHz channel spacing. If CTCSS is used then subtract further the nominal
CTCSS system deviation level.
5. Reduce the level from the audio oscillator to obtain a sinewave modulation, now vary the modulation frequency
around 50 to 500Hz and adjust the Bin Accel Factor for an approximately flat response.
Caution: Do not enter too low a value or the lock time and stability will be affected.
Return the audio level to +10dBm.
around 50 to 500Hz and adjust the Bin Accel Factor for an approximately flat response.
Caution: Do not enter too low a value or the lock time and stability will be affected.
Return the audio level to +10dBm.
6. Set the modulation frequency to about 300Hz. Observe the demodulated clipped sinewave with drooping positive
and negative deviation peaks. Now increase the "Ref Level" and the degree of drooping will reduce. Adjust so that
flat top is observed on the demodulation waveform. Check that if you vary the modulation frequency across a range
of 50Hz to 1KHz the frequency response is flat. The peak deviation should still be the same as in step 4, if not repeat
steps 4 and 6.
and negative deviation peaks. Now increase the "Ref Level" and the degree of drooping will reduce. Adjust so that
flat top is observed on the demodulation waveform. Check that if you vary the modulation frequency across a range
of 50Hz to 1KHz the frequency response is flat. The peak deviation should still be the same as in step 4, if not repeat
steps 4 and 6.