Pacific Research Solutions RI-300e User Manual
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SETTING SQUELCH GAIN (S-COMMAND 50) The RI-300 uses digital pots for most of its audio level settings. The digital pots have electrical shaft positions called steps.
Each pot has 64 steps, ranging from 0 to 63. S-Command 50 is used to set the squelch potentiometer to specific steps or allow
up and down control of the potentiometer. Each digital pot in the RI-300 has a default setting. See Section 12 for details on
each default setting. If the squelch is open (COS LED on all the time), it will be necessary to let the DTMF inter-digit timer to
timeout to get the controller to accept any command, including the password. The following procedure will outline how to set
up the digital squelch potentiometer.
S-Command Description
1. 123456 Unlock the controller with your password, you are now in programming mode.
2. 50 [Level] Enter the squelch pot value where the level is a pot step value between 00 and 63. The factory default
level is 31.
3. 50 40 Try sending a larger level setting if the COS LED is still on (3 seconds after you un-key).
4. 50 20 Try sending a smaller level setting if the squelch is too tight.
5. For best performance, set the squelch level 4 to 5 steps above the closed squelch threshold.
6. 69 1 Lock the controller and save your changes.
Do not attempt to set the squelch at the squelch close threshold. The
SmartSquelch works best with a setting of 4 to 5 above the closed threshold.
You can also use the programming software to set the squelch level
potentiometer.
1. Run the programming software and open your repeater data file.
2. Pick “Repeater” then pick “Squelch Setup”.
3. Using the “Squelch Level” slide bar, decrease the squelch setting until the
COS LED on the controller is lit.
4. Then increase the slide bar until the COS LED just goes out.
5. Increase the slide bar another 4 to 5 counts.
6. Pick the “Send” button then pick the “Start” Button. This will permanently
save this setting to the controller.
7. Pick the OK and save your data file.
One of the most powerful features of the RI-300 controller is its built-in squelch circuit (COS). The RI-300 squelch circuit uses
a discriminator noise band-pass filter, an adjustable amplifier (adjustable gain), an AC to DC conversion stage, into an ADC
(Analog to Digital Converter) and then into the micro-controller. By using the micro, all the significant parameters of a squelch
circuit can be implemented in software and are remotely configurable. In the normal squelch mode, the squelch will operate
similarly to that of a standard radio. You can change the squelch level and adjust the upper and lower squelch threshold if
needed. In the SmartSquelch mode, the micro-controller performs math functions that are operated by an algorithm, resulting in
a high performance squelch system. Many parameters of the SmartSquelch are remotely adjustable. The squelch starts with a
fast 10 ms decay delay and extends this delay depending on the quality and type of the signal on the repeater’s input.
SmartSquelch also has another useful feature, the “weak signal message”. If the RI-300 detects that a user is not full quieting
on the repeater input, it will change the courtesy message to the “weak signal message”, in place of the normal courtesy
message.
A third squelch mode is provided for connecting to external squelch circuits. When using this mode, connect your external
squelch circuit to the Pi-1 digital input. This signal should be a 5 volt logic or open collector, active low.