One PC to Run (2) SDR Software Programs Simultaneously

[kingshootr]

Eventually, I will have the ability/luxury to spend a lot of time scanning (and learning more about systems, etc.) I'm curious - can a single PC:

Mine currently is: i7 4650U / 2.3GHz / 8gb RAM / 64 bit / Windows 10

Is it able to run two scan apps (SDRSharp) with 4 dongles (1 antenna) at the same time - split to 2 separate monitors?

I'll only be listening to 130 MHz -175MHz (public safety and general aviation). As far as the database is telling me, there doesn't seem to be any trunked systems in the listenable area. Navajo County, Arizona (AZ) Scanner Frequencies and Radio Frequency Reference

Mostly I'm curious if it's one PC per app, or can one PC run multiple apps. When I try right now, it will not.

Thanks.

 

[Spleen]

Eventually, I will have the ability/luxury to spend a lot of time scanning (and learning more about systems, etc.) I'm curious - can a single PC:

Mine currently is: i7 4650U / 2.3GHz / 8gb RAM / 64 bit / Windows 10

Is it able to run two scan apps (SDRSharp) with 4 dongles (1 antenna) at the same time - split to 2 separate monitors?

I'll only be listening to 130 MHz -175MHz (public safety and general aviation). As far as the database is telling me, there doesn't seem to be any trunked systems in the listenable area. Navajo County, Arizona (AZ) Scanner Frequencies and Radio Frequency Reference

Mostly I'm curious if it's one PC per app, or can one PC run multiple apps. When I try right now, it will not.

Thanks.

Be sure to change the serial numbers on the RTL-SDR dongles, that way the PC will be able to address them individually. If the serials are the same, the PC will probably only see the first one on the bus, and probably not well. If you decide to run SDRTrunk anyway, you'll need the different serials.
I do know SDR# can run multiple instances, but only if the serials have been changed.
All this is assuming the dongles are the same model/brand.

 

[morfis]

Eventually, I will have the ability/luxury to spend a lot of time scanning (and learning more about systems, etc.) I'm curious - can a single PC:

Mine currently is: i7 4650U / 2.3GHz / 8gb RAM / 64 bit / Windows 10

Is it able to run two scan apps (SDRSharp) with 4 dongles (1 antenna) at the same time - split to 2 separate monitors?

I'll only be listening to 130 MHz -175MHz (public safety and general aviation). As far as the database is telling me, there doesn't seem to be any trunked systems in the listenable area. Navajo County, Arizona (AZ) Scanner Frequencies and Radio Frequency Reference

Mostly I'm curious if it's one PC per app, or can one PC run multiple apps. When I try right now, it will not.

Thanks.

What happens when you try it now? How are you trying to run the multiple instances of SDRSharp? Which version of sdrsharp?

Should work fine now BUT because sdrsharp has to rely on the way windows has enumerated the USB devices it is not possible to say which DVB-T device is in use by each instance*....the software uses the first one available to it (so 0, 1, 2, 3 regardless of which physical device). Suppossing all four were connected to the same antenna via an active coupler and all were operating on exactly the same range this might not be a problem. However, if each was meant to be receivng a specific set of freqquencies (eg. four differnt trunked nets) you would have no way to be know which device was monitoring which as the enumeration order can change with each boot.

Individual unique serial numbers in most friendlier software will allow YOU to specify the specific device for each task regardless of the order the OS enumerates them.

May also be bearing in mind that sdrsharp is often the most processor hungry of the available simple sdr monitoring apps.
As mentioned in numerous other threads, heat is the enemy of electonics so it would be prudent to move the devices away from each other and provide reasonable air flow around them. Cheap though they are there's no opint in stressing them more than actually necessary. Powered hub(s) and short USB extension leads help. Use a couple of powered USB hubs so that the data load is spread over two USB channels if in your use scenario there is a high data throughput as well. A powered hub will also help if the actual power to the onboard USB hubs is lower than spec (many cheaper motherboards are).

* on newer versions it will show the logical ID number but that doesn't help you as it's just the number enumerated when windows detected the devices.

 

[merlin]

If the apps support multiple instances, that should not be a problem. For each instance, you will need to address each dongle by serial number.
As for dual monitors, that is up to your OS and setting each output to a given monitor.

 

[morfis]

..... For each instance, you will need to address each dongle by serial number.

No, sdrsharp doesn't need to be told which to use (I don't remember if it CAN be told which rtl device to use based on a serial number...new versions can be specified by the OS enumerated number but that is of little use).
For their own Airspy devices newer versions show the serial number so those can be selected more precisely.

 

[dave3825]

If the serials are the same, the PC will probably only see the first one on the bus, and probably not well.

If you decide to run SDRTrunk anyway, you'll need the different serials

I do know SDR# can run multiple instances, but only if the serials have been changed.

I believe the whole "you have to change serial numbers" thing is dependant on the dongles, how they are being used and with what software. I have ran up to 4 NooElec that all have the same serial numbers in SDRT. I have ran multiple instances of SDR# (older version 1742) and have also used 2 with DSDPLus without issue.

Unique numbering does have advantages (and makes life easier) and may be needed in certain situations for some people depending on exactly how they are using. To broadly say you have to or it wont work is not always so.

 

[kb5udf]

The simplest answer I can give is yes, you can run 4 dongles with one antenna on one pc. Yes you can run two windows/separate instances of SDR# at the same time (NOTE: not all other SDR programs support this). If you have one antenna for all your dongles then their ID numbers might be a moot point. If you use airspys (vastly superior IMHO to cheap dongles) you can identify them by serial number. Yes you can put your instances of SDR sharp or any other SDR program on different monitors, assuming your PC can support this.

Couple of points:
1. Your CPU benchmark is adequate for running 1 instance of SDR sharp (assuming you don’t turn up the spectrum analyzer settings too high in terms of refresh and detail). 2 instances may or may not work well on that PC; the audio will stutter if the PC is overloaded. Disabling the lower half of the display (waterfall) and reducing the refresh rate can save CPU resources.

2. IMHO while a cheap dongle may suffice for local, strong signals (such as public safety that the first responder can use with a handheld radio), something affordable like an airspy mini will do a vastly better job of “weak signals” like general aviation or receiving more distant signals in general Also the price of one airspy mini is not much more than 2 cheap dongle/sdrs but has about the same bandwidth of coverage.

3. Plan for the future: I briefly looked at your county and trunking is already here, I saw 3 sites of a P25 phase II system in your county. Also, don’t assume just because a system does not have a site in your county that you have no chance of receiving it. Check other systems and look for sites adjacent to you.

4. If you are hooking 4 dongles up to one antenna, without amplification that may work fine for, again, local strong signals. For anything weaker, you may need some type of pre-amp before the splitter.

 

[kingshootr]

I didn't think about changing the dongle serial numbers. I now remember for SDRTrunk I had to do that - I'll figure out how to do that on Sharp and try again.

When I did my first go at it, in the second window, I did get an error that a second dongle could not be found.

(Doh, Sorry - the two I'm using currently are the Nooelec Nesdr v5. I also have two RTL-SDR v3, but not being used currently.)

I put several heatsinks on each one and have them spaced well and are stable - warm but not hot.



I'm only using a splitter cable to put the one antenna to the two dongles. I've perused the multiplex forum but I'm still learning there. The preamp, could you share a bit more about units I should be looking at?

I hardly ever look at the waterfalls so turning those off is a great idea.

RE: The available signals to listen to. Yes, I (hopefully) am planning adequately for the future. I'll be using a 27ft +/- homemade antenna tower with a Sirio GP 3E antenna.

The tower will easily support another antenna for those frequencies the Sirio won't handle. Other extremely helpful RR's turned me onto the Sirio and I have one coming ($60, I couldn't pass it up.) I'm guessing a discone would be better for if there are trunked systems as well? I had looked at the WINS systems but I'm not seeing much of interest. DPS - I pick them up in Phoenix via the "regular" system (Jeez I hope someday I learn all the terminology - I'm trying - I swear!)

But all this detailed information - you all are awesome! Thank you very much for taking the time to write all this out.

 

[dave3825]

I didn't think about changing the dongle serial numbers. I now remember for SDRTrunk I had to do that - I'll figure out how to do that on Sharp and try again.

Sdr# does not change the serial numbers. If you did it already to use in sdrtrunk, then it's already done. If it was different dongles, then you would need to do it if desired.

 

[kb5udf]

A lot of folks on this board are fans of mini-circuits for preamps and filters. Which ones you need are a serious part of your system design. For example I have a Sirio 2000 disc one which is 100mhz on up feeding a stridsberg FM broadcast filter, feeding a mini-circuits preamp, feeding an 8 port SMA splitter and it works quite well. The preamp you would need would depend on gain required and the frequency ragne you desire to cover. You can also go big with a larger splitter with more ports, just terminate the unused ports (you can buy a pack of sma termination resistors easily and cheaply)