Using Squelch Setting Correctly ?

[Robert11Participant]

Hi,

A few questions on using the Squelch function, please.

a. et’s say I have a peak where the top of the peak is -80 db.
The noise floor is about -120 db

I select squelch, and want the audio to be active only
if there is actually a signal present.

I thought I would then set the slider value to -55 db (Green bar) as an experiment.
thinking I should hear nothing. But, the audio still comes thru.
Sometimes. But not all the time. Doesn’t appear consistent

Why ?
Am I using squelch correctly ? How should it be set up and used ?

b. And, any way of having a Cursor (a horiz line perhaps) to visually
show the level that has been set ?

Thanks,
Bob

[Andy2Participant]

Hi Bob

I find the squelch tricky to set. It’s ok on strong signals where there is a big difference between the signal and the noise level, but weaker ones are difficult. If I set the squelch so it opens on a noisy signal, it tends to stay open once the signal stops. If I tighten the squelch a little to mute the noise, it fails to open on the signal.

[SDRplay_TechParticipant]

There is hysteresis in the squelch function to prevent it from ‘chattering’ it does require a bit of care in setting up, but I use it to pipe signals from all three active NOAA satellites via a single VAC into Wxtoimg using three Virtual Rxs and it works well.
The squelch function does actually need bringing up to date from a GUI perspective and it is in our plans to do this. The threshold needs to be changed from dBfs to dBm (like the power meter) and a visual reference line is a great idea.

[Author]

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