New Feed Equipment

[SurgePGH]

I am preparing to get a feed setup for my area/ county. I have an equipment related question.
Is the Raspberry Pi 400 powerful enough to handle between 1 to 4 feeds? Is the Raspberry Pi 400 a good choice for a feed?
Is an Optimal Shop USB 2.0 External Soundcard acceptable?
Are the Jabinco Ground Loop Noise Isolators acceptable?
I will be providing audio via an XTL2500. Is there any other recommended equipment to set up a good, quality feed?

 

[W3VVV]

I don't know about the Pi400 but I'm running 6 instances of OP25 on a 4 GB Pi4b with 6 RTL-SDRs providing 6 feeds. Three of the RTL-SDRs are plugged directly into the pi4b and three are plugged into a powered USB hub.

 

[Reconrider]

I don't know about the Pi400 but I'm running 6 instances of OP25 on a 4 GB Pi4b with 6 RTL-SDRs providing 6 feeds. Three of the RTL-SDRs are plugged directly into the pi4b and three are plugged into a powered USB hub.

Do you use multi rx? I can’t seem to get it to see my rtlsdr

 

[W3VVV]

No. I run 6 instances of rx.py. Multi is too resource intensive to run more than one instance on a pi4b. It's also too resource intensive to handle six sdrs.

 

[krokus]

I will be providing audio via an XTL2500. Is there any other recommended equipment to set up a good, quality feed?

Which connection are you planning on using for your audio feed? There should be a fixed level out, which would be the best for a feed. (So turning down the volume doesn't negate your feed audio.)

 

[SurgePGH]

Which connection are you planning on using for your audio feed? There should be a fixed level out, which would be the best for a feed. (So turning down the volume doesn't negate your feed audio.)

I have to get the pinout for the XTL2500 and see if there is a line level out of that radio.

 

[DC31]

I am preparing to get a feed setup for my area/ county. I have an equipment related question.
Is the Raspberry Pi 400 powerful enough to handle between 1 to 4 feeds? Is the Raspberry Pi 400 a good choice for a feed?
Is an Optimal Shop USB 2.0 External Soundcard acceptable?
Are the Jabinco Ground Loop Noise Isolators acceptable?
I will be providing audio via an XTL2500. Is there any other recommended equipment to set up a good, quality feed?

Running a standard darkice feed on a pi really requires little computer horsepower. I think that I used to run three feeds off a pi1. So to answer your first question the pi400 can definitely handle it. You will need a sound card for each audio source so you may fill the four usb ports on the pi. If you experience power supply problems you may need a powered usb hub. The cheap $5 or so usb sound cards off ebay or Amz work just fine, remember your source is a mono jack on a scanner, not Dolby surround sound. Getting a good quality feed depends on lots of things, power supplies, antennas, etc. It usually requires a bunch of trial and error. My experience has been that throwing more $$ at the equipment yields little return. Some of my best audio quality comes from a $10 Baofeng radio through a $5 sound card to a $35 raspberry pi.

Getting sidetracked here a little, but have you considered a pi with a sdr stick running rtl_airband? You might get multiple frequencies with one stick. Rtl_airband can then stream the different frequencies to different bcfy streams. This eliminates the scanners, sound cards, potential ground loops, and audio cable problems.

GitHub - szpajder/RTLSDR-Airband: Multichannel AM/NFM demodulator

Multichannel AM/NFM demodulator. Contribute to szpajder/RTLSDR-Airband development by creating an account on GitHub.

github.com

 

[n3obl]

I have to get the pinout for the XTL2500 and see if there is a line level out of that radio.

Yes there is line level on xtl mobiles.

 

[SurgePGH]

Running a standard darkice feed on a pi really requires little computer horsepower. I think that I used to run three feeds off a pi1. So to answer your first question the pi400 can definitely handle it. You will need a sound card for each audio source so you may fill the four usb ports on the pi. If you experience power supply problems you may need a powered usb hub. The cheap $5 or so usb sound cards off ebay or Amz work just fine, remember your source is a mono jack on a scanner, not Dolby surround sound. Getting a good quality feed depends on lots of things, power supplies, antennas, etc. It usually requires a bunch of trial and error. My experience has been that throwing more $$ at the equipment yields little return. Some of my best audio quality comes from a $10 Baofeng radio through a $5 sound card to a $35 raspberry pi.

Getting sidetracked here a little, but have you considered a pi with a sdr stick running rtl_airband? You might get multiple frequencies with one stick. Rtl_airband can then stream the different frequencies to different bcfy streams. This eliminates the scanners, sound cards, potential ground loops, and audio cable problems.

GitHub - szpajder/RTLSDR-Airband: Multichannel AM/NFM demodulator

Multichannel AM/NFM demodulator. Contribute to szpajder/RTLSDR-Airband development by creating an account on GitHub.

github.com

As far as the feed talkgroups they will be from a P25 simulcast, trunked system. I don’t think a USB SDR could handle this or am I mistaken? One feed I would like to do the primary dispatch talk groups for the county. Another feed I would like to do the Fire Dispatch and Fire TAC talkgroups. I am about as green as it comes when it comes to providing a feed so I’ll take any help I can get.

 

[SurgePGH]

Yes there is line level on xtl mobiles.

I believe it to be pin 21 on the accessory connector.

 

[DC31]

As far as the feed talkgroups they will be from a P25 simulcast, trunked system. I don’t think a USB SDR could handle this or am I mistaken? One feed I would like to do the primary dispatch talk groups for the county. Another feed I would like to do the Fire Dispatch and Fire TAC talkgroups. I am about as green as it comes when it comes to providing a feed so I’ll take any help I can get.

Ah, so yours is a trunked system. The pi400 is capable of running SDRTrunk as well as Trunk Recorder, both of which can stream talkgroups to BCFY. Depending on the setup of your county's system you may need more than one sdr stick. I have my county system set up on a single stick and have run SDRTrunk and Trunk Recorder on a pi4. Depending on how "green" you are, it can be challenging to set up. SDRTrunk may be the first choice.

DSheirer/sdrtrunk - GitHubhttps://github.com › DSheirer › sdrtrunk

GitHub - TrunkRecorder/trunk-recorder: Records calls from a Trunked Radio System (P25 & SmartNet)

Records calls from a Trunked Radio System (P25 & SmartNet) - TrunkRecorder/trunk-recorder

github.com

 

[wgbecks]

As far as the feed talkgroups they will be from a P25 simulcast, trunked system. I don’t think a USB SDR could handle this or am I mistaken?

OP25 works very well to decode P25 simulcast, and I believe that @louiswilen multiple instances of rx.py are all tuned to a P25 Phase-II simulcast cluster focused on different talkgroups (departments/entities) operating on that system.

I currently have a Pi-4B E/W 2GB of RAM configured for two instances of rx.py focused on different talkgroups from a 700 MHz Phase-I simulcast while a third instance is tuned to a VHF Phase-I multicast system. All receivers (instances) are working perfectly. The audio from the three instances of op25 are piped to Liquidsoap for processing and streaming to separate mountpoints on an Icecast server.