Newbie starting to get into p25 trunking and cfa victoria scanning

[ians-cfa]

Hello starting my journey into p25 scanning for listening to vic cfa transmissions.

Background retired radio tech 30yrs + , recently started reading on basic p25 info.

I am hoping to reconfigure some 10yo surplus motorola p25 vhf tranceivers for listen only in my area.
I don't have the model type at hand, should have the transceivers in the next week or so, so will be looking to try to reprogram/reconfigure them.

So my first question for help please is,
The more I poke around looking for p25 info the more confusing it gets so coulds someone please point me to a good overview of the system the cfa are using
ie frequencies, repeaters and simplex frequencies used. Then how the p25 system is configured ie talk groups control chanells to frequencies etc.
I am really hoping to get a good handle on this p25 stuff and see if I can use these tranceivers.

thanks
Ian

 

[VK3YMML]

Hi Ian

As for frequencies you might want to check out this link via Google Maps which gives the various repeaters and relevant frequencies

RMR Site Locations

In respect to the radios your trying to program can you post a photo, we can possibly identify them from this and give some advice on how and where to proceed.

However that said some systems are now moving from P25 Phase 1 to P25 Phase 2. This may affect what your able to listen to.

Some basic reading;

P25 Phase 1
Uses Frequency Division Multiple Access (FDMA) to divide frequencies and share the channel. P25 Phase 1 was designed to use the same bandwidth as a narrow band FM channel.
P25 Phase 2
Uses Time Division Multiple Access (TDMA) to divide the channel into two timeslots, allowing two independent conversations to share the same channel. P25 Phase 2 is more spectrally efficient than Phase 1, providing two effective channels per 12.5 kilohertz bandwidth.

 

[pb_lonny]

You really would be better off getting some scanners. Trying to get those radios to work on the system is not easy and you run a risk of transmitting where you should not be and getting the radios "bricked".

Save yourself the trouble and grab a UBCD436PT, much easier and safer....

 

[ians-cfa]

You really would be better off getting some scanners. Trying to get those radios to work on the system is not easy and you run a risk of transmitting where you should not be and getting the radios "bricked".

Save yourself the trouble and grab a UBCD436PT, much easier and safer....

Thanks for the reply, certainly will be Rx only. Like to see if they are useable first though.

 

[ians-cfa]

Hi Ian

As for frequencies you might want to check out this link via Google Maps which gives the various repeaters and relevant frequencies

RMR Site Locations

In respect to the radios your trying to program can you post a photo, we can possibly identify them from this and give some advice on how and where to proceed.

However that said some systems are now moving from P25 Phase 1 to P25 Phase 2. This may affect what your able to listen to.

Some basic reading;

P25 Phase 1
Uses Frequency Division Multiple Access (FDMA) to divide frequencies and share the channel. P25 Phase 1 was designed to use the same bandwidth as a narrow band FM channel.
P25 Phase 2
Uses Time Division Multiple Access (TDMA) to divide the channel into two timeslots, allowing two independent conversations to share the same channel. P25 Phase 2 is more spectrally efficient than Phase 1, providing two effective channels per 12.5 kilohertz bandwidth.

Thanks for the reply and link to repeaters. I think I got most of them from the acma site, but your map is really good as it gives the control frequencies. I will post when I have a couple of radios, havent been up to melbourne to pick them up yet.
In the mean time if anyone has some info on specific information on operation of cfa's repeater system I would appreciate it, eg voting, how its implemented etc.
Again thankyou

 

[vk2mpj]

I am not 100% familiar with the RMR, but if it is anything like the NSW PSN, then you will need to be 100% confident on how to configure Non-affiliate scanning on the Motorola. Otherwise it WILL transmit and try to affiliate as soon as you turn it on to the channel. It's not like the old PMR system where you could just put a RX frequency in and leave the TX blank or other "safe frequency"

 

[ians-cfa]

Ok thanks for the advise

 

[ians-cfa]

radio is motorola xtl 2500 model m21ksm9pw1an Appreciate if someone could advise what software I need to get to reprogram it or at least see what it was configured for when used cps seems to pop up a bit but I guess it needs a certain version? of software . Cable pinout too please if its programmed through that port. I managed to find a repair manual for that series. it has a DB connector on the rear, Im guessing for data exchange. Is it programmed using that port? Will see if I can find a user manual. I registered on the Motorola site, but when i try to find anything it comes back with credential errors, so gave up there.
Any help appreciated as I keep going down worm holes when I search for info. Seem to be so many different models/ variations. Anyhow it looks like its on the vhf band so that is good.

 

[ians-cfa]

forgot to add,
If indeed they are vhf will initially try programming for the marine band, then if successful and when familiar with the radio will try
the world of p25

 

[VK3YMML]

At the end of the day this is a "transceiver" not a scanner therefore it will lack alot of the abilities that mainstream scanners have today.

As for P25, are you looking for regional and or metropolitan. The radio only covers 136-174mhz from what I can see.

As for software it's probably going to be a commercial software package maybe check this thread - Want to know which CPS version that will read XTL2500 / 5000

 

[ians-cfa]

Thanks for the reply. All frequencies required are either marine band or CFA which are around 166mhz thanks for the link to software will take a look.

 

[astro_boy]

Honestly would be much easier to put them back on ebay and get yourself a uniden to scan all bands, rather then trying to track down software and cables and understanding the programing system, system keys (yeah, it's not easy), but it can be fun.

 

[ians-cfa]

Wouldn't learn much that way though I think

 

[VK3YMML]

Wouldn't learn much that way though I think

I think what we are trying to point out that the radio you have purchased may not give the end result you wish to achieve.

The system you have will listen to a single frequency or TGID at a time and may require to be manually changed should you wish to listen to another Channel and or TGID

I would probably suggest disconnecting the mike from the radio as this would lesson the chance of transmitting on any frequencies

 

[ians-cfa]

If unsuitable I will see if they can be reprogrammed for the vhf marine band.