SDR trunk NBFM help

[Lbz7]

A little new to SDR trunk I'm trying to figure out NBFM I have the alias setup right it's like a dead channel I'm not sure if it's in the gain control or the squelch.. I had the gain setting on auto. I'm using RTL V3 dongle two of them. The frequency I was trying to monitor. Also tried Noaa weather with no results.. but can pick it up on my police scanner.. anybody have any suggestions? Thanks.

 

[dave3825]

Can you post screen shots?

 

[Lbz7]

Can you post screen shots?

No sorry..

 

[Lbz7]

Can you post screen shots?

My p25 system works excellent and my local DMR works good.. it's just that NBFM. It's like a dead channels.

 

[dave3825]

I found the auto gain to be too much and was getting poor decodes on p25. I don't normally use NBFM but just set up NOAA and this is what works for me. I have a discone and for me in my area I set gain to 327.





If your using a windows pc, type Snip in the box in the lower left. Brings up the tool to take screenshots.

 

[Lbz7]

Thank you I will try that here in a few minutes and post results. Thanks everybody for your help..

 

[kg4icg]

actually, just hit windows key and prt sc to get a screen shot on your computer

 

[Lbz7]

my local pd frequency .

 

[Lbz7]

I don't even hear no static it's like a dead channel. It's only on the conventional channels that are not working..

 

[dave3825]

Your gain is way to high and the entry you have selected in your second pic reflects Dmr and not the NBFM freq. Ditch the automatic gain and try something in the high 300's

 

[Lbz7]

I have few systems some DMR and p25 others NBFM conventional.. I have messed with the from automatic to 495 everywhere in between I cannot even get static.

 

[KC1UA]

+1 on the 327 gain setting for RTL dongles. It seems to be the best level for me. I'm running about a dozen NBFM frequencies via SDRT (on Ubuntu Linux) into Trunking Recorder. Works like a champ. Once you get it running and you're happy with the gain level be sure to check each analog channel by clicking the Channel tab in the Now Playing screen and bump your squelch down close to the noise level.

 

[dave3825]

This is your pic showing a very high noise floor due to the gain being way up. If your antenna is decent and can pick up the signal, it's getting buried in the noise. You do not want the bottom pane to be showing orange.






This is my gain set @ 327. You can see each signal rising well above the noise floor. If your lowereing you gain and not seeing signals like what's shown here then I want to ask what your using for an antenna?

 

[Lbz7]

The antenna I'm running is a diamond rh77ca.. for my local PD it's in the 155. megahertz. And when I'm monitoring p25 system I have a pair remtronics 830. Antennas. I'm pretty new to run into stuff. Just started like a week ago I usually run police scanners
I figure it's winter time give me something to do to run these SDRs. Thanks for your info.
.

 

[dave3825]

Well the 2 830's are out since there like 7/8/900mhz but the rh77 should receive 155 without much issue. Where is that antenna and if its not near a window, can you get it closer? I know you said you tried NOAA. How far are you from your local transmitter and how far is that local pd? The dongles are sma and the rh77 is bnc. I take it your using an sma to bnc @ the dongle or using a short run of coax?

 

[Lbz7]

The weather station is out of Pittsburgh PA 35 mi away from my house.. have no problem picking it up with the diamond antenna on my police scanner.. and the local PD and other agencies towers i monitor or within 15 mi from my location.. The cable came with the sdr kit I bought off of Amazon. I had a couple SMA to BNC adapters.. everything else works good except for the NBFM. I must have a sitting off or something. The NBFM channels come in good on SDR sharp.

 

[dave3825]

I must have a sitting off or something. The NBFM channels come in good on SDR sharp.

So if the pd and noaa work in sdr than that rules out crap cables/connectors. What's you ppm look like on the tuner your trying to use?

 

[Lbz7]

.

 

[dave3825]

In that box that says 1.496, make it say 0.0 and see of your signal moves to the right

 

[Lbz7]

on the tuner says 0155.614902 im trying to monitor 155.6400