SDRTrunk and AirSpy R2 - Multiple sites

belvdr

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I live between two simulcast sites and it appears one of the sites is not streaming to BCalls. I am streaming one site successfully and it only sends one county's TGs.

Is one AirSpy R2 and SDRTrunk capable of sending both sites with potential overlapping TGs to BCalls? The sites range in frequency almost 3MHz.

Assuming it can, how do I go about streaming both sites with SDRTrunk? Is it as simple as adding in a channel config and have it set to stream to the same streaming config?
 

belvdr

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I think I figured it out and hopefully optimized my config at the same time.

I created two Alias Lists, one for each site. Each list contains the same TG config, since both sites are neighbors to each other. I had configured the original channel to have every frequency, not just controls and alternates. I deleted that and created new configs with just the controls/alts and adjusted the Frequency Rotation Delay to 650ms.

Does this pass the sniff test?

My BCFY page lists only one site, so should I request another system id to stream the other site?
 

mtindor

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I think I figured it out and hopefully optimized my config at the same time.

I created two Alias Lists, one for each site. Each list contains the same TG config, since both sites are neighbors to each other. I had configured the original channel to have every frequency, not just controls and alternates. I deleted that and created new configs with just the controls/alts and adjusted the Frequency Rotation Delay to 650ms.

Does this pass the sniff test?

My BCFY page lists only one site, so should I request another system id to stream the other site?

You will need to file another BCFY Calls request to add the additional one as a node on BCFY Calls. Once you get that, you would then use that new Node ID and API-Key in the streaming configuration of the second one.

Other than that, An Airspy or Airspy Mini (at 10 msps or 6 msps) will cover them both fine. If you have an Airspy mini, then the 3 msps sample rate might not cover all of the channels you need to have covered. But it's definitely doable with either Airspy when using correct sample rate.

M
 

belvdr

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You will need to file another BCFY Calls request to add the additional one as a node on BCFY Calls. Once you get that, you would then use that new Node ID and API-Key in the streaming configuration of the second one.

Other than that, An Airspy or Airspy Mini (at 10 msps or 6 msps) will cover them both fine. If you have an Airspy mini, then the 3 msps sample rate might not cover all of the channels you need to have covered. But it's definitely doable with either Airspy when using correct sample rate.

M
Thanks for the reply. I now have both sites going.
 

mtindor

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Thanks for the reply. I now have both sites going.

This may not ever apply to you, but you should read this:


I was sending multiple systems to BCFY Calls. I'd get chopped off audio and things like that, as SDRTrunk would keep adjusting it's center tuning. Adding the dummy channels as described made it so that SDRTrunk stopped juggling the center tuning point and kept all of the voice channels away from the edges of the dongle's receive capabilities. Thanks to @GTR8000 for the tip.
 

belvdr

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This may not ever apply to you, but you should read this:


I was sending multiple systems to BCFY Calls. I'd get chopped off audio and things like that, as SDRTrunk would keep adjusting it's center tuning. Adding the dummy channels as described made it so that SDRTrunk stopped juggling the center tuning point and kept all of the voice channels away from the edges of the dongle's receive capabilities. Thanks to @GTR8000 for the tip.
I wonder if that was due to the radio being used. I'm on an AirSpy R2 and it's using 10msps and I haven't noticed any decode issues.
 

mtindor

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I wonder if that was due to the radio being used. I'm on an AirSpy R2 and it's using 10msps and I haven't noticed any decode issues.

If it doesn't apply to you, do nothing. Just throwing it out there if you notice issues with chopped audio / poor decoding (which would likely mean that SDRTrunk would be retuning the center freq of the Airspy and causing some of the active channels to be "on the edge". Remember, any dongle, and any Airspy, do not have the full bandwidth available to them with full performance. For instance, An Airspy only has somewhere between 8-9 mhz of usable bandwidth -- not 10. And SDRTrunk can tune its center to a place where one of the active voice channels being decoded is outside that 8-9 mhz sweet spot, causing poor decoding of audio.

If that happens, gather a list of all of the freqs from both systems, note the lowest and highest, and then set up dummy channels just below the lowest and just above the highest, and then the Airspy will not shift it's center tuning.

Anyway, if you aren't experiencing decoding issues / chopped audio, then leave it alone.
 
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