Just No Good Options For P25 Phase II Simulcast Monitoring.

[CanesFan95]

So, pretty much, here's the deal. The Uniden / Whistler / GRE / Radio Shack scanner basically SUCK on simulcast P25. My local system is mostly Phase II and I've tried a BCD436HP, TRX-2, and a PSR-800. All 3 totally crap out and you're lucky to hear a clear syllable much less a few words.

Then there's software, but nothing decodes Phase II, only Phase I. The DSD+ people won't even tell us whether or not they're gonna add Phase II. Unication pagers are only Phase I and have no scan delay.

Then there's commercial radios. They cost THOUSANDS of dollars apiece and most of 'em need a system key. When you try to talk about how to hack around the system key problem, everyone gets all paranoid and queezy and won't tell you anything.

So what's the deal? Something's gotta give here. Why's it so hard to find a P25 Phase II simulcast monitoring solution. How do we get our foot in the door to actually monitor Phase 2 with decent decode and audio quality? There's gotta be a way.

 

[br0adband]

There's one option that was designed from the ground up to monitor P25 Phase I and Phase II and it excels at LSM probably as good as actual P25 Phase I and Phase II commercial hardware - ok, I'm being very gracious there but it is quite amazing with LSM - and that's OP25.

Of course it's a piece of software, it runs only on the Linux platform, and it isn't as easy as just double-clicking a setup.exe to get it up and running but it is arguably the best solution to monitor an LSM based system you're going to find short of having a physical radio that's part of the system you're trying to listen in on.

There's a thread here with some pretty detailed information about it that's been in progress for a long time now, and the original method of setup/compiling/etc has been reduced to much simpler methodology featured later on in the thread. Here's the link to the thread itself:

http://forums.radioreference.com/so...-virtualbox-project-run-op25-windows-7-a.html

and the specific up-to-date instructions that can get you up and running OP25 in under 20-30 minutes can be found in this post:

http://forums.radioreference.com/so...ject-run-op25-windows-7-a-16.html#post2654021

 

[CanesFan95]

Man, I know NOTHING about this whole Linux thing. Seems like everyone on here except me knows it inside out like it's no big deal. Geez. I wish they had like an idiot's version of the OP25 thing.

 

[CanesFan95]

See when I click that link about Running OP25 on Windows 7, it just starts talking about something called "ubuntu", and then "md5sum:

0abc200fd4b84a1e8881287d70dfb822

#Update the apt cache and system files when you first boot into ubuntu 14.04"

And I'm like, WHAAAAAT?? Just no clue where to begin and feel completely left out.

 

[fredva]

There are many others in the same boat as you, so don't feel left out.

 

[Nasby]

Yep. We all just want a scanner that will work on LSM.
There are pages and pages of suggestions and homebrew options for LSM solutions aimed at the current crop of scanners on the market.
Which ever manufacturer conquers the LSM enigma will be rewarded with record overnight scanner sales.
Much like the Tickle Me Elmo and Wii phenomena.

 

[br0adband]

You learned how to use a computer running the Windows operating system, you can learn how to use a computer running Linux just the same. If you feel like you're left out then get involved and learn, there's no other solution for that except doing it.

Of course, if you honestly believe you can't read some instructions and follow them and even ask questions when you actually do require some assistance, well, that nobody will ever be able to help with.

Nothing is ever going to be that simple in the monitoring hobby, especially as it moves forward and digital communications becomes the standard.

Considering what OP25 is capable of, and the fact that you already own a computer and probably even an RTL stick more than likely, and on top of all that Linux being free of monetary cost that makes for quite a powerful solution to monitoring P25 Phase I and Phase II comms and doing it extremely well but it's not going to be easy.

As the old saying goes, nothing really worth doing ever is.

 

[CanesFan95]

Does OP25 actually do trunk following with 2 dongles? Any screenshots of OP25 I'm seeing don't seem to have a list of the frequencies and all the active talk groups like Unitrunker or DSD+.

 

[br0adband]

OP25 only requires one RTL stick, just one, and it handles conventional systems as well as trunked ones. The configuration files you create (.tsv tab delimited files, text files that use Tab for spacing the variables) are where the talkgroup and other information is which you provide yourself.

 

[KA1RBI]

haha, this is like the one-thousanth message about simulcast LSM and scanners since they opened the
``The official "I want LSM to work properly in my scanner" thread'' right in this scanning subforum...

Thanks for the plug, Br0adband. For users not already familiar with it the primary ref page for that aspect of OP25 is

SignalScopePage

Which ever manufacturer conquers the LSM enigma...

Scanner users need to demand the manufacturers implement IF-DSP (which the amateur radio manufacturers have been doing for many years). It's not exactly an enigma - the OP25 LSM receiver implementation was developed starting in 2010 by a single volunteer (who didn't know how to spell LSM or DSP prior to 2009) and contributed in his spare time...

Interestingly, just the other day I received a mail from a retired radio engineer - I won't quote him by name as I don't have permission

...I think there is no question that the ability of OP25 is comparable to real P25 system subscriber radios and even the best of the present scanners are nowhere near in the same league. I do hear the the new Unication units do give professional equipment performance....

73

Max

 

[adcockfred]

well, I thought we all were just on the edge of our beds waiting for G-6

 

[CanesFan95]

OP25 only requires one RTL stick, just one, and it handles conventional systems as well as trunked ones. The configuration files you create (.tsv tab delimited files, text files that use Tab for spacing the variables) are where the talkgroup and other information is which you provide yourself.

My system is more than 2.4 MHz range on 700 MHz. So would I need 2 dongles?. And, I don't see where in those instructions it tells you anything about this "virtual machine" software. How do we know which one to use? And what does the part about "md5sum:

0abc200fd4b84a1e8881287d70dfb822" mean?

I also don't understand "#Update the apt cache and system files when you first boot into ubuntu 14.04".

So am I understanding this right, you can install a Linux program inside of Windows 7 64-bit with another program called a "virtual machine"?

 

[Nasby]

My system is more than 2.4 MHz range on 700 MHz. So would I need 2 dongles?. And, I don't see where in those instructions it tells you anything about this "virtual machine" software. How do we know which one to use? And what does the part about "md5sum:

0abc200fd4b84a1e8881287d70dfb822" mean?

I also don't understand "#Update the apt cache and system files when you first boot into ubuntu 14.04".

So am I understanding this right, you can install a Linux program inside of Windows 7 64-bit with another program called a "virtual machine"?

The whole process is a total PIA and really not even scanner related.

 

[Dog]

And, I don't see where in those instructions it tells you anything about this "virtual machine" software. How do we know which one to use?

It is in the title of the thread you have been reading...

VirtualBox Project - Run OP25 on Windows 7

 

[pinballwiz86]

There's a very simple solution guys. Get a "yagi" antenna and aim it straight at one of the P25 towers. Problem solved.

 

[dlwtrunked]

There's a very simple solution guys. Get a "yagi" antenna and aim it straight at one of the P25 towers. Problem solved.

Myself, I have done that with a Wilson 800 MHz yagi pointed at a tower 0.8 miles that I can actually see with my eyes. The Whistler still does not do very well copying the P25 on that tower.

 

[fredva]

There's a very simple solution guys. Get a "yagi" antenna and aim it straight at one of the P25 towers. Problem solved.

It's something to try, but not a guaranteed solution for everyone.

 

[KA1RBI]

There's a very simple solution guys. Get a "yagi" antenna and aim it straight at one of the P25 towers. Problem solved.

Has anyone EVER before heard of ANY radio service that comes in full-scale on the S meter, and yet requires a Yagi antenna to receive it, even still imperfectly?

Myself, I have done that with a Wilson 800 MHz yagi pointed at a tower 0.8 miles that I can actually see with my eyes. The Whistler still does not do very well copying the P25 on that tower.

Why is it that real system subscriber radios work fine -- with only an omni antenna -- whereas scanners don't do very well using a Yagi pointed at a tower less than one mile away??

73

Max

 

[jonwienke]

Because they have specialized demodulating circuitry that contributes significantly to their $1500-4500 per unit price tag.

 

[KA1RBI]

Because they have specialized demodulating circuitry that contributes significantly to their $1500-4500 per unit price tag.

haha, just as OP25 has special demodulating software specifically targeted at LSM -- that contributes significantly to the per unit price of OP25 ($0).

This software implements a truly shocking and unexpected, revolutionary idea -- that LSM is QPSK not C4FM, and therefore LSM needs to be demodulated as (differential) QPSK, not as FM. BTW, DQPSK is something that's taught to students in introductory DSP classes.

73

Max