sdr # issue

[docrock]

Hello,
I have version 1.0.0.1337 installed, with airspy as my sdr. when trying to listen in the public service portion of the band (around 155mhz) when on narrow fm I am able to listen to about a third of the signals visible on the waterfall, if I switch to wfm I can hear all the signals but the squelch is unavailable which means I have to listen to all the white noise in between transmissions, has anyone else had this problem? Is there something I can adjust in the settings to overcome this?

 

[moonbounce]

Hello,
I have version 1.0.0.1337 installed, with airspy as my sdr. when trying to listen in the public service portion of the band (around 155mhz) when on narrow fm I am able to listen to about a third of the signals visible on the waterfall, if I switch to wfm I can hear all the signals but the squelch is unavailable which means I have to listen to all the white noise in between transmissions, has anyone else had this problem? Is there something I can adjust in the settings to overcome this?

You could use the Mute feature on the Frequency Manager and Scanner plugin if you are using it. If so click on the wrench beside the " Seconds wait for more transmissions" or you could turn down the AGC. or raise the squelch to around 60.

 

[Voyager]

Can you define the problem? You want to listen to NFM signal in WFM mode?

WFM is for Broadcast FM (88-108 MHz). It uses a continuous carrier which is why the squelch is not required.

 

[crayon]

Have you tuned your SDR for correct ppm?

 

[docrock]

sdr# issues

The problem is that most of the signals in the public service portion of the band are narrow fm but for what ever reason I only hear them when using the wfm demodulator, I understand wfm is for the broadcast band, I just happened to try it when I couldn't hear the narrow fm signals using the narrow fm demodulator in sdr#. I am a bit of a noob so can you tell me how I tune for correct ppm?

 

[Voyager]

Tune to your local NOAA weather channel (assuming you're in the USA). Zoom into the signal until you can barely see the signal on the display. Then adjust the frequency ppm calibration until that signal is centered in the red line you are tuned to.

 

[crayon]

I am a bit of a noob so can you tell me how I tune for correct ppm?

Think of ppm as an "offset" or a way to fine tune your SDR. The SDR is not a precision device and as such its ability to select an indicated frequency drifts after it warms up.

So the cliff notes howto version is as follows:

Please give your SDR at least five minutes to stabilize then tune it to a NOAA frequency. (apologies if you are not in the US .. I didn't check) This will give you a steady signal to play around with. Next, at the top, click on the gear and at the bottom of the new window is your ppm value.

Adjust the ppm up or down (typically up) until the waterfall visual display of the audio is centered on the red line. I have 15 or 20 SDRs and when I start the calibration I usually dial in 50/55 ppm and go from there.

This procedure is well documented here and else where so you should be able to find additional information about if needed. Otherwise, check back in.

Finally, as you go up in frequency your ppm might change but the waterfall is your friend on finding the center.

HTH's

 

[wrratt]

Wild guess, Bandwidth too narrow? though the default for NFM is 12,500 it may have changed.

 

[docrock]

sdr# issue

Thank you all for your replies, I will try the ppm tuning this evening and increase bandwidth to 12500 from 8000 which it is currently set at, and see if this solves the problem