anyone using the P25-8600 board on 800mhz

[freqseek]

I just received my AR8600MK2 back from AOR, I had the P25 board installed, I have it running beside the PSR 500, both doing a limit search. The PSR-500 is receiving all kinds of traffic in p25 mode, but the AR8600 isn't receiving anything. I live in Michigan where the MSP have a 800mhz P25 state wide system.
looking for input before I contact AOR.

 

[DaveIN]

I think you would do better to park on a frequency rather than to use the search limit. Maybe try an active voice channel.

 

[freqseek]

I parked them both on the same frequency and just the psr-500 will decode the p25. I also did a reset and still don't receive the anything. I just put in some of the control channels which are FM and for some reason it is not receiveing them either, I can receive the control channels with my Icom Ham rigs, so Now I think it might be something else in the radio.

 

[KC1UA]

The AOR P25 decoders reportedly do not decode P25 from trunked radio systems. This is according to the specs for their ARD25 decoder. The P25 board for the AR8600 is reportedly similar in design. Have you tried it on a conventional P25 frequency?

 

[DaveIN]

It wouldn't do anything with the control channel anyway, its not a trunk tracking radio. It looks for a P25 signal. As Scott mentioned it needs a conventional frequency that you don't have, this is why I suggested parking on an active a voice channel frequency. This works with the Icom version for the R2500, not sure why it wouldn't on the AOR.

 

[freqseek]

a controll channel will tell me if the radio is receiveing a signal if you can here the the noise it puts out in FM mode and I don't pick anything up with the 8600MK2, but I will with a Icom z1a, 208h and psr-500 in conventenal mode. I can tune the psr-500 to p-25 voice frequency and listen to a complete conversation in a none trunking set up and it will receive a full signal and the 8600 acts like it deaf. I will contact AOR and see what thay have to say.
does anyone use this set up for P-25, I was not able to find any reviews, just a few topics on installation.

George

 

[freqseek]

It's on its way back to AOR and I will give an update when it returns and hopefully a positive review.

 

[kd7rto]

The $64,000 question: are you using a rooftop antenna or a telescopic whip off the back?

I have an AR5000 with an external ARD25. Even with the squelch set on it's lowest setting (the ADS command via the RS232 port on the back of the ARD25), the signal has to be fairly strong before it will start decoding. I'd estimate that it will not work with anything weaker than -90 dBm, the point where the signal to noise ratio is about 50/50, though I have not verified this with professional test equipment.

My BC796D does demodulate weaker P-25 signals that the ARD25 will not, however the AR5000/ARD25 combo is still my first choice for conventional P-25, for one very important reason: when my 796 is connected to a rooftop antenna and I try to scan 162-174 or 406-420 MHz, I get so many false squelch openings, even at max squelch, that it is effectively worthless.

Another thing you should try is to change the polarity on your AOR decoder board (APN-ON APN-OFF).

As for the claim that AOR products will not decode P-25 oin a trunked system, my AOR setup does demodulate P-25 on the nearby UHF trunked system at Hill AFB.

 

[freqseek]

I played with it for a couple days comparing it with my other radios and thought something was defiantly wrong, I never took it for a ride, but I should have for a test, I have a antenna 65 ft up with LMR400 cable and it works great in the 800 & 900Mhz with my other radios. I sold my AR5000 4yrs ago and wish I wouldn't have. that’s why I purchased the AR8600MK2. AOR USA said they tested it before sending it back to me, I told them that its not receiving when 3 other radios with the same set up did and they requested I send it in again and they would take a look at it. They never said anything about not receiving p25 on trunked systems and I couldn't find it on there web site either. All I seen was it won't follow trunked sysems. With the pro 96 and PSR 500 I could set up a search bank 866 - 869mhz lock out all the control freqs and listen in on the Mi 800mhz system and not miss any conversation, I hope this will work with the AR8600MK2, It takes a week shipping one way. I will do a follow up when it returns.
Thanks for the input.

 

[rsk]

I had the p25 board installed in my 8600mk2. It works fine as stated it will not track. I set up a bank with just MSPD voice channels (no control channels) and it works fine. One problem I found is it does a poor job on systems that use cqpsk modulation like the city if Detroit.


Bob

 

[freqseek]

rsk
thank you for the report, that is good news for me, my 8600mk2 should be back early this week.

kd7rto
a qoute from AOR - We performed a quick test on 868.450MHz and found the sensitivity is normal. (apprx. -110dBm to open squelch).
We suspect your area is using Motorola APCO trunking system. If so, the AR8600 receiver is NOT following trunking signal because the AR8600 is designed to decode conventional (not trunking) mode of P25 signal.

I believe I will need to work on a better signal to receive p25 at my home. I did try a 450 to 1450 mhz pre amp before I sent it in. I tryed the pre amp on my other radios while the 8600mk2 was at AOR and it didn't work with them either, so the pre amp must be bad.

 

[freqseek]

After receiving my 8600MK2 back from AOR, I decided to take it for a ride and I programmed the voice channels from the MPSCS in the area I was going to travel about 80 miles one way. While I was mobile I noticed I had to have at least 4 full bars of the 7 on the S-meter before the audio was intelligible, some times more. I had to set the level squelch to 45 to avoid the unintelligible annoying Audio
At home, I live in the country in a small valley, the 8600MK2 wouldn’t pick up any of the MPSCS 800mhz system from my VHF/UHF ham antenna w/lmr400 coax 65 ft up. I did a quick set up and put up a 800mhz Cellular antenna (28ft up) with a Radio shack 430 to 1450mhz uhf 20 db pre amplifier at the antenna using 2 peaces of RG 59/U coax cable coupled together. That did the trick I was picking up and decoding the p25 voice channels from the MPSCS. I had to be receiving a signal of 3 bars of the 7 while in this set up to decode at clear audio of the p25 signal. Signals under 1.5 sounded like an open FM squelch with no audio and 1.5 to 2.5 sounded garbled. When I unplugged the preamp the signals would drop totally out. Although there is lots of room for more improvement to the antenna and coax cable set up, the question is it worth it to have the p25 board installed in the AR8600MK2 to receive these signals.
The cost was aprox. $250 that includes shipping of the radio, Installation and cost of the p258600 board.
Then there is a dedicated 800mhz antenna and quality coax and pre amp needed to receive a decent signal at a decent distance that is needed to decode p25 on this receiver. The receiver of the pro96 & psr500 handhelds with the RS 800mhz rubber duck antennas have a lot better reception and they will trunk, If you live close to a tower or on a hill, then it may be worth having the p25 board installed.
With that being said, I hope that it will be helpful in anyone’s decision on a purchase of this item.
LOOKING FORWARD TO ANY COMMENTS ?