Author Topic: RTL-SDR Raspbeery Pi recommanded setup  (Read 1596 times)

Offline lbouchard

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RTL-SDR Raspbeery Pi recommanded setup
« on: March 22, 2020, 02:10:56 PM »
Many people are asking.
I think it is time to publish hardware and software recommended setup.
For single, dual and four SDRs on a raspberry pi.



Offline dave

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Re: RTL-SDR Raspbeery Pi recommanded setup
« Reply #1 on: March 22, 2020, 02:22:30 PM »
We deal with individuals on a one-on-one basis right now since they need to get connection information from us anyway. There is no "one size fits all" install and in some cases, SDR's are not even suitable, especially for on-airport installs. So for now we consult with potential feed providers to make sure they end up with the right solution for their situation.

Offline rvt

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Re: RTL-SDR Raspbeery Pi recommanded setup
« Reply #2 on: October 07, 2020, 03:00:18 PM »
can you explain I a few sentences what the issue is when using SDR?

Offline dave

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Re: RTL-SDR Raspbeery Pi recommanded setup
« Reply #3 on: October 07, 2020, 03:19:57 PM »
The issue with SDRs when used "on airport" is overload - dynamic range. In other words, strong signals (which all of them are) will cause the receiver to overload and produce very distorted (or no) audio. The "cure" is to reduce the gain (sensitivity) of the SDR - but that sometimes greatly reduces the range of signal pickup. This is typically not an issue when at least 0.5 to 1 mile form the airport.

Offline rvt

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Re: RTL-SDR Raspbeery Pi recommanded setup
« Reply #4 on: October 07, 2020, 03:58:28 PM »
Makes perfect sense, Not sure if these SDR's have some hardware AGC implemented (or even if that is possible due to the way they work).

we will keep that in consideration finalising our setup.

Offline dave

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Re: RTL-SDR Raspbeery Pi recommanded setup
« Reply #5 on: October 07, 2020, 04:22:30 PM »
That's the issue...there is no hardware AGC. There is a gain setting called "AGC," but it is not classical hardware AGC and just defaults to max gain. Not what is needed.
 This is why we recommend and use analog receivers for on-airport installs. SDRs are useful for Ground and ATIS, for example, though, as the dynamic range needed is not as great as Tower/Approach/Center.