Pacific Research Solutions RI-200 User Manual
Page 19
Pacific Research Solutions
RI-200 User Manual
Page 18
3.
If you experience some problems decoding DTMF, the likely problem is that the tone levels are out of range. The DTMF
decoder has 30+ dB dynamic range and decoding DTMF should not be a problem with a reasonable discriminator input
level. The DTMF status LED lights when a tone is first decoded and remains lit until after either a function complete or
a DTMF Inter-digit time-out. We have seen problems where one row or column did not decode properly. To test this,
send one by one digit, all DTMF tone digits, letting the LED light drop off then test the next tone, confirming that all
YOUR tones are being properly decoded.
4.
If you send your password multiple times and receive an “ERROR” telemetry message, the controller may already be
unlocked. You can identify this condition because of the courtesy message will be different.
3.4.1
SETTING RECEIVER INPUT GAIN (R3)
For the squelch and internal decoders to work properly, you need to set up the receiver input audio level. The receiver input
audio level setting is a manual adjustment. Use the follow the procedure;
1.
Apply the 12 VDC power source. Confirm the green system LED is on.
2.
If the system LED is not on, see the section on troubleshooting.
3.
Transmit a carrier on the repeater’s input channel. Did the yellow COS light come on? Do not be surprised if the COS
LED did not come on or is already on, as we have two adjustments to make before the squelch circuit will work correctly.
4.
Generate a 1000 Hz tone at 1.5 or 2.5 kHz deviation on the repeater input.
5.
Adjust the receiver audio pot on the front panel for a level of 0.44 Vrms (1.5 kHzD) or 0.73 Vrms (2.5 kHzD) at U1 pin
8. You can also skip to step 7.
6.
If a service monitor is not available, you can use the number “5” button on a DTMF equipped radio. Most radios should
be setup to deviate 1.5 kHz..
7.
The RI-200 has a built in audio level meter. While you are sending your test tone, press the button on the circuit board
labeled “INIT” The system LED’s will operate as a level meter, the first red LED will indicate 1.5 kHz deviation and the
last red LED will indicate 2.5 kHz deviation.
8.
The receiver input level is adjusted by the multi turn pot R3 labeled “RCVR” located right of the radio interface
connector.
3.4.2
SETTING SQUELCH STAGE GAIN (S-COMMAND 50)
The RI-200 uses digital pots for some of its level settings. The digital pots have electrical shaft positions called steps. Each
pot has 64 steps, ranging from 0 to 63. There is an S-Command to set the pots to specific steps or allow up and down control
of the pot. Each digital pot in the RI-200 has a default setting. See Section 4 for details on each default setting. If the
squelch is open (COS LED on all the time), it will be necessary to use the “C” command terminator to get the controller to
accept any command, including the password. The following procedure will outline how to set up the digital squelch pot.
1.
Correctly enter the password.
2.
Enter the squelch pot step value with the S-Command 50 [level], where the level is a pot step value between 00 and 63.
See Section 4.5.50 for the factory default level. If the COS LED is on all the time, you need to set the pot to a higher
level. Try sending 50 45.
3.
If your squelch is too tight, you can try sending a 50 20.
4.
For best performance, set the squelch pot 2 or 3 steps above the open squelch threshold.
5.
Lock the controller, you have now completed the squelch level pot setup.
3.4.3
ADJUSTING THE REPEATER TRANSMITTER (S-COMMAND 12)
After hooking up the repeater transmitter audio and the repeater PTT keying circuit per Section 2, you will need to adjust the
repeat TX audio level. The best method is to use a service monitor to measure the transmitter deviation. If a service monitor
is not available, use any receiver that can be easily flipped back and forth between the repeater input and output channel while
listening to the levels. Ideally you will have the same transmit deviation going out of the repeater transmitter as coming in
the receiver. Transmit a 3 kHz deviation tone on the repeater input channel. As you flip back and forth between the repeater
input and output frequencies, then by listening, adjust the repeater transmitter audio level or deviation. This level is remotely
adjusted with a digital pot in the same manner as the squelch, except with S-Command 12. When you have finished this
adjustment, you have a working repeater with all audio levels correctly adjusted.