Floyd P25 with GRE 500 very poor reception

[ram519]

After much trial I have not been successful at receiving the Floyd P25 transmissions. I get few hits compared to live feed from internet or smartphone app. The hits I do get are just a few syllables and very digital sounding. Conventional signals and older trunking types (Florida trip) work well and clear.

I have a GRE PSR500 that I bought used. I have RadioReference account and used this to load the scanner. I have loaded factory defaults and then the 2.1 update from GRE. I have used both ARC and Win500 to load the scanner. I have tried the original antenna and also bought new RS 800MHZ rubber antenna. I have read much from this and other forums as well as wiki. From this information I have adjusted many settings. Reload the defaults and reload the frequencies. I am testing with only Floyd P25 in scan list 1. All other scan lists turned off.

I live in West Rome below the Mt Alto antennas. I have not purchased any external antennas as much of what I read suggest ATT will help.

1 > Do I need an external antenna for P25 signal?
2 > It is possible for radio to be defective just with P25? Where to get repair?
3 > Should multi-site be: Roam, STAT, or OFF (WIN500 says off and ARC says Roam 95/75)?
4 > First question might should be, Will the PSR500 work with the Floyd System?

thank you,
Alan

[RomeRon]

Sent you a PM

[ram519]

Thank you,

Alan

[Cedartown1]

If the answers will help everyone please post them on the open forum. <just a suggestion>

[ram519]

RomeRon gave me some suggestions as to where his radio works such as the large Lake in Garden Lakes. Also out near Mt Funchi (? Spelling). I will try those areas with my current load. I also plan to try Cobb County P25 this weekend. I want to prove the Radio is not defective. I will report back as we are able to check off some testing. Was too wet last evening.

[ram519]

The GRE 500 worked great for Cobb Co. It was picking up as soon as I crossed into Bartow Co. and worked well into Atlanta. I added attenuation as I traveled through Cobb along I75 then turned it off as I entered Atlanta. While you knew it was a digital conversion the voices were clear. This was in the car with only the RS 800MHZ rubber antenna. On the return trip in the afternoon I had the same experience. In Cartersville I turned off the scan list for Cobb and back on for Floyd. Both were set up with RadioReference and Win500.
Nothing! All the way into the middle of Rome on a Sunday afternoon. Nothing but a few clicking noises.

What is so different about Rome / Floyd Public Safety radios? They are both listed as APCO-25 Common Air Interface Exclusive Project 25 Phase I

[ram519]

I met RomeRon. He cloned his radio to mine. We are in a parking lot where we can see the Mount Alto tower about 1.5 miles away. His radio is playing great and clear. Mine would only give a few syllables sporadically. We swapped the antennas and his played without an antenna. Mine had no change. We displayed the main control channel and they both had 5 bars. His showed the "T" light on 75% of the time and mine about 10%. This points maybe to a decode problem. RomeRon tells me there is DSP update. I had not done this,
Went home and found a DSP update. I was already at that level so I down level to 1.2. Cleared everything and then loaded the latest 1.4 DSP. I also reloaded the firmware at 2.1

I am still only getting a small percentage of traffic and it is very choppy. I don't understand why it would decode for Cobb Co and not for Floyd.

It is time to call GRE and hope for a gentile repair bill.

One more thing. My PSR500 seems to be an early build. The DSP Boot level is 1.1 and the uP Boot level is F1.1

[RomeRon]

Hello ram519
Look at the trunking tables I want to compare them to mine, I think when we cloned it it should have set the tables to what I had in mine, just want to see if they are the same.

[ram519]

Hello RomeRon,
In the trunking tables, only the first entry is set the rest are 0's.

The first list is 0, 4095, 0, 851.00000. 12.500

Alan

[dcr_inc]

Re-banded I believe..Might want to try the re-band trunk table in RR..

[ram519]

Thank you, I tried the 800MHZ rebanded and the 800MHZ splinter with everything else the same. I am using Win500 loaded from RadioReference. I can not tell much difference. I do get some hits now and then, If I look at the control channel 3 I am only seeing small percentage decoded. With custom tables getting 5 to 20 % , with default tables I can get up to 30%. I am not sure the tables made the difference or just chance.

I did open a ticket with GRE to get their opinion and price to look at it. I will let you know. I am hoping for a little coding and tuning..

Alan

[dcr_inc]

I believe that system is built around the Mastr 5 base stations which means it is using LSM (linear Simulcast Modulation) C-QPSK.. You may never hear it 100% because scanners are not made to decode this modulation scheme.. Motorola has used it in their newer systems now for about 3 years or so.. Baltimore County, Baltimore City and several other Maryland systems are LSM and are a real pain to receive.. The PSR 800 does pretty good receiving them though.. Good Luck

[ram519]

I have sent the PSR500 back to GRE to find what is wrong with the decoding of the signal. I will post again when it returns.

RAM519