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Thread: XPR7550 / XPR5550 - anyone worked out how to lower squelch threshold below 2 default levels?

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    Default XPR7550 / XPR5550 - anyone worked out how to lower squelch threshold below 2 default levels?

    With my XPR7550 you only have 2 squelch (SQ) levels. However, the lowest level is still too high for weak but copyable analog signals.

    On my older Motorola analog stuff, you can use service mode to adjust the SQ level so that it will open on the weakest of signals..which is great.

    With my XPR7550, the green LED lights up when the radio is receiving a weak signal but the SQ does not open until the signal is about 3dB stronger...so weak but perfectly copyable signals are missed..unless you manually open the SQ when you see the green LED light up.

    I want the SQ on my XPR7550 to open as soon as the green LED is illuminated...not after the signal has increased by another 3dB.

    Has anybody worked out how to do this?


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    Sounds like a project for binary01.

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    There is nothing in either the codeplug structure or the tuning structure to set the values called by the squelch setting. I looked at the filter settings and there is nothing that seems to be referenced for the tight or normal setting.

    Looking at the codeplug I dont see anything obvious that can be used as the setting although it would have to be somewhere in the codeplug structure as each radio would have a different digital level. It is possible its hidden in the tuner and not visible normally.

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    This has been for me the most annoying part of my fleet of XPRs. Mobile and portable have this issue, particularly in digital mode. I can generate signals that the radios sees yet they don't unmute.
    Retarded Mongoloid on PCP...

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    The biggest issue I have seen on the XPR7550 is that there might be a analog signal present but it wont unmute because the carrier is more than 250hz from the center freq of the radio. This is a real pain. I discovered it from a customer who had mixed radios Ht750 and XPR7550s.

    Im going to have to revist this and see if it is a squelch issue and not a freq centering issue as it originally appeared. realigning the XPR units did fix the issue. But occasionally one will come in that has drifted 100hz and starts to experience the no rx fault.

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    A "weak" analog signal opens the SQ on my XPR7550 no problem on a multitude of signals which are probably greater than +/- 250Hz off freq...but the radio SQ does not open on "very weak" signals which are still copyable and which the radio has detected as the green LED light is illuminated. I can open the SQ manually and can then hear the very weak signal no problem but I want to lower the SQ threshold so that the SQ opens as soon as the green LED illuminates rather than having to wait until the very weak signal becomes approximately 3dB stronger at which level the XPR SQ opens.

    Once the SQ is open, the XPR holds the signal until the green LED goes out - so I guess there is about 3dB of hysteresis...maybe the SQ threshold is linked to the hysteresis setting?

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    Kind of on/off topic, I'd like to see the stupid green RX light, only blink when a matching squelch condition is present. Blink when PL/DPL is there, not some welfare weak signal that's below threshold. Same with digital. I don't want to see it blinking green all the time when it's receiving hash or whatever, on a digital channel. Another thing that drives the locals nutty, is the blinking green light from our IPSC beacons, or when there's voice activity present on another talkgroup or timeslot.

    Whomever is doing the firmware coding on that TRBO lineup has no analog LMR experience.