SDR for p25 systems

[iowajm780]

How about this project. A SDS 200 is way beyond my budget for new scanner for my car. The Blue Tail is nice but it also expensive. I need a P25 phase 2 scanner for my car. My car has a Panasonic Toughbook CF31 in it at all times. I travel quite often and it’s used for mapping and internet access when stopped at a job site. Being able to use Office 365 in the car saves me so much time. Would using a decent SDR with I think OP25 or DSD + work as well as P25 RX for a mobile setup?. The laptop never leaves the car and I would find a way for a powered speaker for the audio out. Since they do quite well in simulcast areas, combined by tons of storage capacity on the hard drive would make it ideal to load up areas you go in. So would I just need one dongle to trunk track a system and what software do I need to do the laptop runs Win10 Pro. This would definitely be the way until either an SDS or P25RX is in my budget.



Before the radio police steps in. The laptop is used for my home business and I am not a whacker. I am an amateur radio operator and with that license I can have a radio / scanner in my car that can receive public safety frequencies. There are no two-way antennas at all on the car. I would try and keep it that way by trying some kind of internal setup, not the greatest but I don’t want to attract undesirable attention. I don’t even have a ham radio even permanently installed in my car. The times I want to talk, I just use a portable. Not the best way but it works for me.

 

[Carter911]

Why not start simple.
An RTL-SDR receiver/USB dongle costs about $25-$35 USD.
Be sure to get one WITH a temperature compensated / controlled crystal, (perhaps $5 USD more than those without this feature).
Then run OP25 software, or one of the other options.
I run it on an RPi, so look to see what is available for the Win10.

JC

 

[kg6nlw]

I would get this and invest in DSD+ FastLane. Definitely worth the price/equipment. I have a few of them running on various laptops. https://www.amazon.com/gp/product/B0129EBDS2/ref=ppx_yo_dt_b_asin_title_o03_s02?ie=UTF8&psc=1

Regards,

-Frank C.

 

[maus92]

Either Nooelec or RTL-SDR dongles, just as long as they are TCXO. Forget the Nano Nooelecs - they will overheat and eventually fail. You will need some sort of antenna (s). For software, DSD+ Fast Lane is a good $25 investment, and *can* run off a single dongle - although screen real estate may be an issue as it has many windows. SDRTrunk is free but will likely require 2 dongles to cover all system frequencies. I find the audio produced by SDRTrunk to be superior. OP25 also uses one dongle, but is a Linux program, and your Toughbook is likely a Windows machine.

 

[merlin]

I go portable with a tablet and SDR touch. Plug a cheap RTL-SDR into the USB.
Follow all the directions for the dongle and app and it works.
With a toughbook and Windows, go with DSD+ fastlane.

 

[kcams]

Scanner in the car is legit in my state. Check the laws in your state first. It might not be. Scanner used during the commission of a crime is illegal in all states, and that's not a surprise.

For SDR mobile With a Laptop, kind of depends on what you want to do. Listen in real time, or record everything? Listening doesn't eat any hard drive space. Recording two weeks of 'mostly local metro' public safety/fire/some EMS, on a busy trunk system for later playback on my stuff, and that only burns about 15G of space. It would be an awful lot more if I included venues/public works/jails/municipal/state DOT....4000+ talkgroups using a common system here).

For cheap -- no subscription or software cost, and for listening, a single RTL-SDR dongle using boatbod/op25 seems to cover frequencies spanning about 10Mhz here as it hops around. Am I missing anything? Yeah. Works like a scanner but you can set priority channels. Maybe it doesn't really matter, you can still tell what is going on. On windows, you can install a linux virtual machine with virtualbox, the virtualbox add-on package, and then your linux virtual machine can see the USB ports and RTL-SDR dongle. Ubuntu works good for that and it's easy. There is a lot of help for configuring it available. Configure it to start on boot, and a single click lauches the virtual machine and the scanner. Did I say For Cheap? The software is free......well, maybe send boatbod a coffee and luv.

For recording, that's a different story. I can get 'almost' away with Four RTL-SDR's (~2.3 Mhz bandwidth each) to cover the frequencies the control tower is blasting out, follow, and record the conversations. I could do it with two AirSpy's. I'm using trunk-recorder and trunk-player. Maybe you don't need that many where you are and there are far less frequencies to ccover. Rdio-scanner is cool too if you want a different eye-candy interface. You need a powered USB hub for multiple dongles. Four or Five dongles will eat a lot of power.

For a speaker, you might be able to pair the laptop to the vehicle media center. Physical jack would work too. A little cheap portable bluetooth speaker also works good.

 

[WX4JCW]

Also the P25 version 2 are awesome, but construction time may vary

 

[foxtail]

Bluetooth speakers are ok for limited listening as the battery run out while in BT mode. Need usb cable plugged in for power recharge or a battery pack.

 

[jerry01]

I have been working on a mobile device for my truck, Pi4 running win10 and dsd+. This mount in between the visors on the truck.

 

[jerry01]

Also you can adapt this PIPO X9S64 with a sdr and DSD+

https://v.youku.com/v_show/id_XNDYyMjI2NTgyMA==.html

 

[kcams]

Another consideration that 'may' work for you. For my use case, I really only care about two different trunking systems and talk groups in the counties (or close counties) of those places in two states. One location is home, the other is at the cabin. Both have internet access. Both have a firewall appliance with a VPN server. Both have old laptops with wake-on-lan enabled in bios, and both setup with Trunk-Recorder and Trunk-Player to launch on boot.

Want to fire up a scanner in the truck or anywhere else with either cell or internet service? Flip on the VPN connection, send a wake-on-lan packet, bring up a web browser and you've got your scanner. Works fine using the phone/carplay or with a laptop. No electronics left behind in the truck!! (locks and windows are for honest people)....

For a VPN server, there's less packet overhead with Wireguard than with OpenVPN. Wireguard also assumes not every packet will get through, but that's not a big deal with the protocol -- so it works better with a streaming app where there may be packet loss and intermittent connectivity. When enough packets are lost with OpenVPN, the connection tears down and restarts, so that is going to mess with your stream and you may have to restart what was playing it.

Course, if your use case is hopping tower to tower mobile style over distances, that isn't for you.