A few questions about starting into SDR

[dmg1969]

I am considering the leap into SDR and will likely start with an inexpensive RTL-SDR. Before starting, I have some questions. I figured I would ask experienced users here and be able to ask follow-up questions rather than spend hours trying to find the answers online. My main area areas of interest will be public services (Police, Fire and EMS) and perhaps air.

My questions in no particular order:

1. What exactly does the dongle come with? By that, I mean does it come with a built-in tuner interface or is that another program that I will download? In the online reading I have already done, I see reference to programs such as SDR# (SDRSharp), SDRTrunk, etc. I am assume those are the tuners and where you build your listening lists.

2. Related to the last part of the question above...I assume you are able to build "favorites lists" similar to that in a digital scanner (I have the HomePatrol 1 and 2)? When doing so, are you able to simply turn lists on and off at will?

3. Does the RTL-SDR (or the related SDR applications) support P25 Phase 2 along with Phase 1?

4. Are you able to program a TDMA or FDMA system with chosen sites and then just certain talk groups? Additionally, are you able to program it to receive ANY talk groups it finds on the programmed sites?

5. Are you able to input certain frequency ranges to sweep (such as that for aircraft, mil-air, etc.)?

Lastly, is there anything to know or consider before starting. Any hints, tips or tricks that will help someone totally new to the world of SDR?

I thank you in advance.
Dave

 

[Whiskey3JMC]

1. What exactly does the dongle come with? By that, I mean does it come with a built-in tuner interface or is that another program that I will download? In the online reading I have already done, I see reference to programs such as SDR# (SDRSharp), SDRTrunk, etc. I am assume those are the tuners and where you build your listening lists.

The examples you mentioned are separate (free) downloadable software apps, they do not come with the dongle. The dongle is merely the hardware piece of the operation

2. Related to the last part of the question above...I assume you are able to build "favorites lists" similar to that in a digital scanner (I have the HomePatrol 1 and 2)? When doing so, are you able to simply turn lists on and off at will?

Yes and no. You can certainly build scan lists but they're not structured in the same way as a scanner. The scan functions (at least the ones I've tested: SDRuno, SDR#) are extremely limited in function and are quite buggy

3. Does the RTL-SDR (or the related SDR applications) support P25 Phase 2 along with Phase 1?

Focus more on the app rather than the dongle here. SDRTrunk and DSDPlus Fast Lane support trunking of both phases but if you need a bandwidth spread of more than 2.4 MHz then you'll need more than one RTL-SDR dongle or consider an SDRPlay which covers a 10MHz spread which should suffice for most trunked systems. IMHO there's a much steeper learning curve, particularly with the latter mentioned example to get trunking to work properly versus a scanner radio

4. Are you able to program a TDMA or FDMA system with chosen sites and then just certain talk groups? Additionally, are you able to program it to receive ANY talk groups it finds on the programmed sites?

Yes, this can be achieved with SDRTrunk

5. Are you able to input certain frequency ranges to sweep (such as that for aircraft, mil-air, etc.)?

Yes there are various third party plugins for SDR# that can achieve this, but they require a bit of tweaking and a lot of patience to get them to work efficiently. Again, a scanner is much better at achieving this task

Lastly, is there anything to know or consider before starting. Any hints, tips or tricks that will help someone totally new to the world of SDR?

Skim the threads of this forum or use the forum's search function to research questions that others have asked. There are plenty of folks here willing to lend you a helping hand to get you started. Always remember that the antenna connected to the dongle is just as important as the dongle itself. So make sure you get one or two tuned for the band(s) you want to bring in. Some RTL packages come with antennae but I find their performance underwhelming, especially in high-RF environments

 

[dmg1969]

The examples you mentioned are separate (free) downloadable software apps, they do not come with the dongle. The dongle is merely the hardware piece of the operation


Yes and no. You can certainly build scan lists but they're not structured in the same way as a scanner. The scan functions (at least the ones I've tested: SDRuno, SDR#) are extremely limited in function and are quite buggy


Focus more on the app rather than the dongle here. SDRTrunk and DSDPlus Fast Lane support trunking of both phases but if you need a bandwidth spread of more than 2.4 MHz then you'll need more than one RTL-SDR dongle or consider an SDRPlay which covers a 10MHz spread which should suffice for most trunked systems. IMHO there's a much steeper learning curve, particularly with the latter mentioned example to get trunking to work properly versus a scanner radio


Yes, this can be achieved with SDRTrunk


Yes there are various third party plugins for SDR# that can achieve this, but they require a bit of tweaking and a lot of patience to get them to work efficiently. Again, a scanner is much better at achieving this task


Skim the threads of this forum or use the forum's search function to research questions that others have asked. There are plenty of folks here willing to lend you a helping hand to get you started. Always remember that the antenna connected to the dongle is just as important as the dongle itself. So make sure you get one or two tuned for the band(s) you want to bring in. Some RTL packages come with antennae but I find their performance underwhelming, especially in high-RF environments

Thank you very much for the reply. That helps a lot.

 

[32dave]

If you can get a premium membership. It helps when setting up SDRtrunk or other software as you can just download the database. Welcome to the hobby !

 

[dmg1969]

Thanks! Now I have a follow-up question. After looking at SDRSharp and SDRTrunk, I think I have decided that I prefer the SDRTrunk user interface over SDRSharp. My only question is if it HAS to be a trunked system or if it can be a system like my county (Perry County, Pennsylvania (PA) Scanner Frequencies and Radio Frequency Reference), which is a mix of analog and P25 channels.

From what I have read on the SDRTrunk website, it appears that you can program the individual channels into a playlist whether they are P25 digital or analog (NBFM). There is only one P25 system that I am going to program right now because it only has one site with 5 frequencies. They range from 161.800 to 162.000, so I can use the single dongle. I don't want to get into multiple dongles until I am know what I am doing, but I think I have an OK grasp on it and printed out just about everything they had for instructions.

 

[PDXh0b0]

You'll need at least two more, perhaps three more dongles as some are in the 150 mhz and some are in 450

 

[dmg1969]

OK. This is bringing up another question. I thought the 2.4 MHz spread was for control channels on a P25 trunked site. Am I now understanding that that applies to ANY frequencies I put into a playlist to monitor? For example, my county has an analog fire/EMS dispatch on 155.1525. Digital fire ops channels are on 159.315, 158.8575 and 155.2575. So, even with non-trunked frequencies, I am limited to that 2.4 MHz spread with a single dongle?

 

[dave3825]

my county has an analog fire/EMS dispatch on 155.1525. Digital fire ops channels are on 159.315, 158.8575 and 155.2575. So, even with non-trunked frequencies, I am limited to that 2.4 MHz spread with a single dongle?

Depends what software you use. DSDPlus FastLane has a scanner feature where you can program a bunch of freqs, analog and or digital, and it will scan. No 2.4Mhz limitation. It can also do trunked systems using 1 dongle without a 2.4Mhz limitation.

 

[Jphila20]

Unitrunker works well on all P25 Phase 1. Also great for collecting data on talk groups and users. Depending on how large the system is and and how many talk groups you want to listen to I would recommend 3 or 4 SDR's. Amazon - Nooelec RTL-SDR v5 SDR - NESDR Smart HF/VHF/UHF (100kHz-1.75GHz) Software Defined Radio @ $33.95. This is the SDR only. What will cost you the most is the connectors, splitters and cable for the antenna. I run RG-6 Quad with adapters from SMA to what you are using.
If you are far from the tower you can also get a Nooelec Lana - Ultra Low-Noise Amplifier (LNA) Module for RF & Software Defined Radio (SDR) with Enclosure @ $34.95. It helps a lot with weak signals.

Enjoy!

John

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[Omega-TI]

Just my late two cents worth...
I started out with the RTL-SDR.blog unit to cut my teeth on, and while it works, I ended up upgrading to the RSP1A... right before the 1B came out. So, if I were going to give any advice to a newbie, I would first ask the following questions related to the money -vs- fuss factor.

If you are not poor or just plain cheap do you want to mess around with third party drivers and such, or would you rather have a bullet-proof install in a one shot go? Are you the type that already knows you'll stick with the hobby? If so, is it worth spending money on a low-end gadget when you could put that money towards a better unit? Also, "it works" only means it receives, but does not necessarily mean how well it receives. You only get what you pay for, and some of these low end units require additional filters, which adds additional cost and connections, which may also supply a route for signal loss or the pickup of RFI.

If I could do it all over again, I would have not have gone the inexpensive "to check it out" route, because in the end, it really required additional stuff that I no longer need with a better unit. I also think once you get into the SDR world there is a very good chance that you'll stick with it.

 

[32dave]

I have 1 rtlsdr.com V3 which I use for unitrunker , I also have 2 Airspy R2 and 2 cheap dongles. 1 Airspy and the 2 dongles on another computer running SDRTrunk which is monitoring DMR as well as NFM freqs as well as the new PSRN coming to Ontario. I picked the airspys as they give 10 mhz bandwidth and doesn't need special software. The second Airspy is on my personal computer which I use for searching using SDR#. DO NOT BUY THE ONE PICTURED BELOW NO SUPPORT