AR8200 D - Listening to P25 Digitial

[anthonykitzelmann]

When i listen into P25 digital networks (Australian Emergency Services), between transmissions the receiver emits a low audible carrier like tone. I am not sure if its a carrier tone that is part of the way P25 systems work or a configuration i need to set on the receiver. The device works perfectly but the tone is a pain in the backside as you have to turn the volume right down so that the tone is not overpowering and then you cant hear the transmission.

If anyone could give me an idea of what needs to be done or any advice i would greatly appreciate it.

Regards

Tony

 

[prcguy]

Mine works fine on most P25 transmissions but on one channel in the So Cal LAPD system there is an annoying sound like digital data between transmissions during the repeater hang time. I believe they have not implemented something right and its a flaw. I demonstrated this to AOR in person and showed them a Radio Shack PRO-96 did not have the same problem and they said they would check into it and get back to me but they never did.

I suggest you let AOR know and that its a documented problem, we don't like it and if they don't fix it we will trash the AOR digital upgrade so bad on the Internet they will never sell another one.
prcguy

 

[anthonykitzelmann]

Settings for P25 Systems for AR8200D

Thanks for your reply, i am new to digital scanning especially P25 networks, do i need to put any specific settings into my receiver apart from the frequency to listen to the frequency. I can clearly hear the transmission but not sure if their are other settings i need to set up.

Regards

Tony

 

[prcguy]

Mine may be a little different since its got the voice inversion descrambler but I hold down the CLEAR button which brings up the voice inversion menu and turning it on enables P25 decoding. Holding down the CLEAR button again will turn off P25.
prcguy

Thanks for your reply, i am new to digital scanning especially P25 networks, do i need to put any specific settings into my receiver apart from the frequency to listen to the frequency. I can clearly hear the transmission but not sure if their are other settings i need to set up.

Regards

Tony

 

[mule1075]

A bit off-topic but would one of you or anybody who has one with the upgrade be interested in posting a video of it receiving p-25.The reason i ask is i might be interested in upgrading but i am on the fence so to speak.

 

[prcguy]

I'm probably not going to post a video but I can tell you the recovered P25 audio is very good. However, the current consumption went up and the battery life diminished after the upgrade and I believe there are a lot more birdies that didn't seem to be there before the upgrade.

You might want to contact AOR USA and ask for the before and after current consumption, if there are additional birdies and if there is an explanation or fix for the burst of noise during some P25 repeater hang times.
prcguy

A bit off-topic but would one of you or anybody who has one with the upgrade be interested in posting a video of it receiving p-25.The reason i ask is i might be interested in upgrading but i am on the fence so to speak.

 

[freqseek]

I have the ar8200D from Japan and AR5001D both with P25 installed, Both receiver receive the Data sound when monitoring trunking voice channels. Both of my AOR's do the same as this link. I have not found a non trunking system to try it on, But AOR USA has no problem on the non trunking p25 system in their area, they did 3 firmware updates on my AR5001D p25 board and it was worse every update, then they sent me a new one and it still does the same as the link below.

AOR 5001D Problem - YouTube

 

[prcguy]

That's the exact same sound I get on my 8200MKIII and it happens on a voted conventional system and its very annoying. All other P25 scanners from RS, Uniden and GRE do not have this problem and they cost a lot less.

If AOR cant figure it out and fix I think a massive flood of negative reviews might get their attention.
prcguy

I have the ar8200D from Japan and AR5001D both with P25 installed, Both receiver receive the Data sound when monitoring trunking voice channels. Both of my AOR's do the same as this link. I have not found a non trunking system to try it on, But AOR USA has no problem on the non trunking p25 system in their area, they did 3 firmware updates on my AR5001D p25 board and it was worse every update, then they sent me a new one and it still does the same as the link below.

AOR 5001D Problem - YouTube

 

[Boatanchor]

Sounds to me like the AOR P25 board is not muting the TDU (Termination Data Unit) transmissions that are often sent at the end of, or in between P25 voice transmissions.

It's a pretty silly omission, if that is what is going on, and it certainly sounds to me like the radio is switching back to analogue mode immediately after the LDU (voice) packets end. That is why you are hearing that rasping TDU sound between and after voice transmissions.

And for the benefit of the OP, the NSW Police P25 network sends TDU's for the full duration of the repeater tail, which is usually 1-2 seconds after each voice transmission.

I'm no expert, but from what I can gather TDU packets are basically sent as 'fillers' on any conventional or trunking system and are often sent for the full duration of a conventional repeater tail or between voice transmissions on conventional and trunking systems. That would get pretty damned annoying VERY quickly!

If you run DSD and monitor your system, it will show all the TDU's being sent across the network when there is no valid voice (or data) activity.

I was considering the AOR with the P25 option, but not now.

Hopefully AOR fix the problem, but I'm guessing it will require a hardware (P25 decoder board) changeover since I doubt that firmware can be uploaded into it externally.

 

[Boatanchor]

Why is there no option to delete this post??

 

[SCPD]

You would think AOR would have done some extensive testing before marketing the product? How could they have missed that flaw?

 

[jslo]

Does AOR do this upgrade or is it done by a specialty firm? Etc....
I want to know more about the aor upgrade. Where can I get this info?

Thanks for all,
Jslo

 

[prcguy]

Look here:
AR8200MK3 Upgrade Procedures | Support | AOR U.S.A., INC. Authority On Radio Communications
prcguy

Does AOR do this upgrade or is it done by a specialty firm? Etc....
I want to know more about the aor upgrade. Where can I get this info?

Thanks for all,
Jslo

 

[Mileykins]

P25 on AR8200D Working Like a Dream! Ill Be Posting Some YouTube Videos Soon! Right Now Im Listening to P25 on "16 AIR/K9" Out of Los Angeles on 484.7125 mhz. Some P25 Signals Wont Decode if the Signal is too Weak. Possibably Adjust Your ATT (Attenuator) Or Switch Antennas. P25 Sounds Amazing! Very Sweet Radio!

 

[Boatanchor]

If they bring out a 8600D, I may be tempted. Otherwise, it's an expensive handheld scanner with no trunking support.

 

[KSDeputy]

I was just going to ask someone about the AOR 8200 MK 3 portable scanner. I need to monitor a new P 25
system that just went online. Now I know the answer, thanks.

 

[prcguy]

Any difference in battery life after the upgrade?
prcguy

P25 on AR8200D Working Like a Dream! Ill Be Posting Some YouTube Videos Soon! Right Now Im Listening to P25 on "16 AIR/K9" Out of Los Angeles on 484.7125 mhz. Some P25 Signals Wont Decode if the Signal is too Weak. Possibably Adjust Your ATT (Attenuator) Or Switch Antennas. P25 Sounds Amazing! Very Sweet Radio!

 

[kett]

Hi Guys, Please be gentle - this is my first post here!! Santa has been wonderful and brought me a new AR8200Digital. Among many other uses a "Ham" operator such as I may put such a toy to, I am interested in monitoring the P25 voice transmissions by our local fire fighting authority (CFA). To be honest I am still a little doubtful as to whether I am enabling the P25 mode correctly. I find the rather sparse setup guide in the "Enhanced" section of the User Manual. Anyway, assuming I do have it correct, I am hearing only a pretty much continuous sound that I guess may be a Data Stream?? (Without P25 decoding enabled it just sounds like Noise!) Does this sound correct??
I would really appreciate any guidance you guys may be able to suggest. Is there perhaps some setup tricks I have missed, etc, etc. I am a real "newbie" in this area. Please HELP!!
Cheers, kett

 

[prcguy]

For P25 reception I believe you press and hold the lower left button (maybe the clear button?) which will birng up a menu with some numbers in the lower part of the display. Then press enter and it should be set for P25.

I dont have mine nearby but thats what I remember.
prcguy

 

[Boatanchor]

Hi Guys, Please be gentle - this is my first post here!! Santa has been wonderful and brought me a new AR8200Digital. Among many other uses a "Ham" operator such as I may put such a toy to, I am interested in monitoring the P25 voice transmissions by our local fire fighting authority (CFA). To be honest I am still a little doubtful as to whether I am enabling the P25 mode correctly. I find the rather sparse setup guide in the "Enhanced" section of the User Manual. Anyway, assuming I do have it correct, I am hearing only a pretty much continuous sound that I guess may be a Data Stream?? (Without P25 decoding enabled it just sounds like Noise!) Does this sound correct??
I would really appreciate any guidance you guys may be able to suggest. Is there perhaps some setup tricks I have missed, etc, etc. I am a real "newbie" in this area. Please HELP!!
Cheers, kett

Hi Kett,

Most of the the CFA dispatch traffic occurs across on the Victorian 'RMR' P25 trunking network and the AOR 8200D does not trunk track (follow trunking systems). It is possible (likely) that you are listening to the P25 trunking control channel data stream. The 8200D will not decode this stream.