Having issues receiving with RTL-SDR

[BKF]

I have a uniden handheld scanner connected to an external monopole antenna that i have used for years, I get tons of local traffic from local EMS and police. I get all of the weather bands as well. I pick up some EMS from as far as 60 miles away. I recently got an RTL-SDR and with the same antenna i can get all my local FM stations as well as the weather bands. but not of the EMS stuff is picking up. Any Ideas would be appreciated.

 

[Whiskey3JMC]

Welcome to the RR forums. What app(s) are you using to drive said SDR? Are you seeing a clear waveform on screen? Gain not set too low or too high? Attaching screenshots often aide others in helping you troubleshoot. Having a looksee at the database, looks like your EMS is analog conventional. Set mode to "NFM" in whatever app you're using and a bandwidth of 12.5khz should suffice to pick up analog conventional traffic. Turn off all filtering or noise reduction if enabled

 

[BKF]

Using SDR sharp, I will take a screenshot of the waveform when i get home. Thanks for the reply

 

[RichM]

An RTL-SDR does not have the same sensitivity as a hardware scanner. The better (more expensive) SDR’s will have much improved sensitivity but still not quite as good as a hardware scanner. I use an Airspy Mini and while it is very good it does not hear everything my Pro197 does, especially the weaker analog signals using the same external antenna. My RTL-SDR V3 was much worse, similar to what you describe.

 

[BinaryMode]

The one thing that caught me off guard using an SDR for the first time was having to set the appropriate bandwidth. Make sure your bandwidth is set correctly if it isn't.

 

[Ubbe]

Try setting bandwidth to 12500 and then in the cogwheel setting use 1.024MSPS to not load the CPU too much. Then untick Offset, RTL AGC and Tuner AGC and set manual gain to 36dB. Gain can be adjusted more or less and when having too much gain you will see a lot of extra spikes turning up in the spectrum from the inter modulation issues.

If you look at the spectrum and zoom in to a singel digital signal you would adjust the Frequency correction ppm so that the signal are centered in the marked bandwidth. You can click and drag one edge of that bandwidth to just cover the signal. If your PC's CPU isn't loaded more than 50% then you can use a higher sample rate to get more bandwidth in view.

/Ubbe

 

[jwt873]

There is also an RF gain. Make sure it isn't turned down to a very low setting..

RF gain adjustments are described in the SDR# user guide.. SDRSharp Users Guide

 

[dlwtrunked]

The better (more expensive) SDR’s will have much improved sensitivity but still not quite as good as a hardware scanner."

Misleading perhaps if you use the right settings and filters which may take some time to determine. I left out pre-amplifiers as gain for those requires optimization for either type of receiver.

 

[spongella]

What RTL-SDR are you using? In my years of using both scanners and SDRs, I'd say they're pretty much equal in sensitivity if you're using established brands like RTL-SDR.com or Nooelec.